U.S. patent number RE42,675 [Application Number 12/576,005] was granted by the patent office on 2011-09-06 for method of transferring and/or receiving data in communication system and apparatus thereof.
This patent grant is currently assigned to LG Electronics Inc.. Invention is credited to Jong Hoe An, Ki Jun Kim, Young Cho Kim, Young Jo Lee, Suk Hyon Yoon, Cheol Woo You, Young Woo Yun.
United States Patent |
RE42,675 |
You , et al. |
September 6, 2011 |
Method of transferring and/or receiving data in communication
system and apparatus thereof
Abstract
The present invention relates to Walsh Code Allocation (WCA)
field in the Packet Data Control Channel. One of the embodiments of
the WCA field is use of the WCA field as Last Walsh Code Index
(LWCI) field in the message format of the PDCCH. The LWCI field
indicates the corresponding last code index or the corresponding
number of Walsh codes in a Walsh Code Index (WCI) Table/List/Set.
In alternative embodiments, the WCA indicates a general set of
Walsh codes or a specific set of Walsh codes in the WCI table. The
WCA fields may or may not be used with one of power ranking and
sequential decoding, but is preferable used. The WCA field has
various advantages including but not limited to efficient use of
system resources.
Inventors: |
You; Cheol Woo (Seoul,
KR), Yun; Young Woo (Anyang-si, KR), An;
Jong Hoe (Anyang-si, KR), Lee; Young Jo
(Gunpo-si, KR), Kim; Ki Jun (Seoul, KR),
Kim; Young Cho (Anyang-si, KR), Yoon; Suk Hyon
(Seoul, KR) |
Assignee: |
LG Electronics Inc. (Seoul,
KR)
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Family
ID: |
36146984 |
Appl.
No.: |
12/576,005 |
Filed: |
October 8, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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10259292 |
Sep 30, 2002 |
7376076 |
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Reissue of: |
11830053 |
Jul 30, 2007 |
07471622 |
Dec 30, 2008 |
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Foreign Application Priority Data
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Sep 29, 2001 [KR] |
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10-2001-60963 |
Sep 29, 2001 [KR] |
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10-2001-60964 |
Sep 29, 2001 [KR] |
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10-2001-60962 |
Oct 13, 2001 [KR] |
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10-2001-63261 |
Oct 13, 2001 [KR] |
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10-2001-63248 |
Oct 17, 2001 [KR] |
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10-2001-64014 |
Nov 3, 2001 [KR] |
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10-2001-68403 |
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Current U.S.
Class: |
370/209; 370/335;
370/329 |
Current CPC
Class: |
H04L
1/1896 (20130101); H04J 13/18 (20130101); H04J
13/0048 (20130101); H04W 52/325 (20130101); H04W
72/14 (20130101); H04W 72/1242 (20130101) |
Current International
Class: |
H04B
7/216 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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1140004 |
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Jan 1997 |
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CN |
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1277498 |
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Dec 2000 |
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CN |
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0877512 |
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Nov 1998 |
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EP |
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10-2000-0037696 |
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Jul 2000 |
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KR |
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10-2000-0040857 |
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Jul 2000 |
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KR |
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10-2001-0045093 |
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Jun 2001 |
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KR |
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10-2001-0045618 |
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Jun 2001 |
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KR |
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10-2001-0080268 |
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Aug 2001 |
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KR |
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10-2001-0086801 |
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Sep 2001 |
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KR |
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1020010086801 |
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Sep 2001 |
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KR |
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10-2002-0074588 |
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Oct 2002 |
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KR |
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10-2003-0027606 |
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Apr 2003 |
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KR |
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99/49592 |
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Sep 1990 |
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WO |
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Other References
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in cdma2000 Forward Link"; IEEE VTC2001; vol. 2, Oct. 7-11, 2001;
pp. 747-751. cited by other .
Shi, Qinghua, et al.; "Simple Spreading Code Allocation Scheme for
Downlink MC-CDMA"; IEEE Electronic Letters; vol. 38, No. 15; Jul.
18, 2002; pp. 807-809. cited by other .
PCT Search Report dated Jan. 15, 2003. cited by other .
Korean Office Action dated Aug. 1, 2007. cited by other .
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Description"; TSG-RAN Working Group 1 @21 Meeting; TSGR1#22(01)
0787; Turin, Italy; Aug. 27-31, 2001. cited by other .
Nokia, "DL Control Channel Structures for Parameters Sent
Simultaneously with HS-DSCH TTI"; TSG-RAN Working Group 1 #20
Meeting; TSGR1#20(01) 0550; Busan Korea; May 21-25, 2001. cited by
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Ericsson, "A new code multiplexing scheme for 1xEV-DV," Vancouver,
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3GPP2-C00-20010611-010-20010611-xxx
(http://ftp.3gpp2.org/TSGC/Working/2001/TSG-C_0106/TSG-C_0601_Vancouver/W-
G5/C50-20010611-016_ERI_Code_Multiplexing.dot. cited by other .
Nokia, "HSDPA related signaling parameters in downlink, version 2,"
TSG-RAN WG2 meeting No. 21, Busan, Korea, May 21-25, 2001 (Tdoc
R2-011177) (XP-002291723). cited by other .
LG Electronics Inc., "TD/CDM for 1XEV-DV Forward Link," Nov. 5,
2001 (XP-007900608)
(ftp://ftp.3gpp2.org/TSGC/Working/2001/TSG-C_0111/TSG-C-0111-Kauai/WG5/C5-
0-2011105-011-LGE-CDMr1.pdf. cited by other .
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WG1/WG2 adhoc on HSDPA, Tdoc 12A010005, Apr. 5, 2001, XP-002290532.
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#21, Tdoc R1-01-0828, Aug. 27, 2001, XP-002478934. cited by
other.
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Primary Examiner: Jung; Min
Attorney, Agent or Firm: Lee, Hong, Degerman, Kang &
Waimey
Parent Case Text
CROSS-REFERENCE TO RELATED APPLICATIONS
This application .Iadd.is a reissue application of U.S. Pat. No.
7,471,622 B2, the entirety of which is incorporated herein by
reference, which is based on U.S. patent application Ser. No.
11/830,053 filed Jul. 30, 2007, which .Iaddend.is a Continuation
Application of prior U.S. patent application Ser. No. 10/259,292
filed Sep. 30, 2002, .Iadd.now U.S. Pat. No. 7,376,076 B2,
.Iaddend.which claims priority under 35 U.S.C. .sctn.119 to Korean
Application Nos. 60962/2001 filed Sep. 29, 2001, 60963/2001 filed
Sep. 29, 2001, 60964/2001 filed Sep. 29, 2001, 63248/2001 filed
Oct. 13, 2001, 63261/2001 filed Oct. 13, 2001, 64014/2001 filed
Oct. 17, 2001, and 68403/2001 filed Nov. 3, 2001, whose entire
disclosures therein are incorporated herein by reference.
Claims
What is claimed is:
.[.1. A method of transmitting packet data in a communication
system, comprising: transmitting a control message over a packet
data control channel, the control message having a LWCI field for
indicating that a code set used in a packet data channel includes
the 0.sub.th through the LWCI.sub.th codes on a code list; and
transmitting packet data over the packet data channel using the
0.sub.th through the LWCI.sub.th codes on the code list..].
.[.2. The method of claim 1, wherein the code allocation
information is an index (LWCI) of a last code included in the
portion of the code list..].
.[.3. The method of claim 2, wherein the portion of the code list
includes the 0.sub.th through the LWCI.sub.th code on the code
list..].
.[.4. The method of claim 1, wherein the communication system is
supporting a Time Division Multiplexing (TDM)..].
.[.5. The method of claim 1, wherein a code included in the portion
of the code list is a Walsh code..].
.[.6. The method of claim 1, wherein the packet data control
channel and the packet data channel are transmitted
simultaneously..].
.[.7. A method of receiving packet data in a communication system,
comprising: receiving a control message on a packet data control
channel, the control message having a LWCI field indicating that a
code set used in a packet data channel includes the 0.sub.th
through the LWCI.sub.th codes on a code list; and receiving packet
data over the packet data channel using the 0.sub.th through the
LWCI.sub.th codes on the code list..].
.[.8. The method of claim 7, wherein the code allocation
information is an index (LWCI) of a last code included in the
portion of the code list..].
.[.9. The method of claim 8, wherein the portion of the code list
includes the 0.sub.th through the LWCI.sub.th code on the code
list..].
.[.10. The method of claim 7, wherein a code included in the
portion of the code list is a Walsh code..].
.[.11. The method of claim 7, further comprising, detecting a
terminal identifier on the packet data control channel; and
determining whether the terminal identifier is matched with an
identifier of a mobile station or not..].
.[.12. The method of claim 11, wherein the terminal identifier is a
MAC identifier..].
.[.13. The method of claim 7, wherein the code list is stored by a
mobile station..].
.[.14. The method of claim 7, wherein there is a one-to-one mapping
between each code index and each code in the code list, and wherein
code indices in the code list have a sequential range from a first
number to a second number..].
.[.15. The method of claim 14, wherein lower code indices are
assigned to higher priority codes..].
.Iadd.16. A method of transmitting packet data at a base station in
a communication system, the method comprising: transmitting a
control message over a packet data control channel to a mobile
station, the control message comprising control information to be
used by the mobile station to receive packet data on a packet data
channel, wherein the control information comprises a start code
number and an end code number which define a range of codes
allocated to the mobile station to receive the packet data; and
transmitting the packet data over the packet data channel using the
control information to the mobile station..Iaddend.
.Iadd.17. The method according to claim 16, wherein a transmission
unit of the packet data control channel comprises a fixed time
length and a transmission unit of the packet data channel comprises
a fixed time length..Iaddend.
.Iadd.18. The method according to claim 16, wherein a transmission
unit of the packet data control channel comprises a first time
length and a transmission unit of the packet data channel comprises
a second time length, wherein the first time length and the second
time length are the same..Iaddend.
.Iadd.19. The method according to claim 16, wherein the packet data
is transmitted after delaying for a time period after the
transmitting of the control message..Iaddend.
.Iadd.20. The method according to claim 16, wherein the control
message further comprises an identifier field for identifying a
user which is to receive the packet data channel..Iaddend.
.Iadd.21. The method according to claim 16, wherein the control
message further comprises a size field for indicating an amount of
information being transmitted on the packet data
channel..Iaddend.
.Iadd.22. The method according to claim 16, wherein the control
message further comprises an automatic repeat request (ARQ) channel
identifier for identifying which channel of a plurality of packet
data channels is being retransmitted..Iaddend.
.Iadd.23. The method according to claim 16, wherein the control
message further comprises a subpacket identifier field for
identifying whether or not information of the packet data channel
is being retransmitted..Iaddend.
.Iadd.24. The method according to claim 16, wherein the start code
is one of a plurality of codes having orthogonality with each
other..Iaddend.
.Iadd.25. A method of receiving packet data at a mobile station in
a communication system, the method comprising: receiving a control
message over a packet data control channel from a base station, the
control message comprising control information to receive packet
data on a packet data channel, wherein the control information
comprises a start code number and an end code number which define a
range of codes allocated to the mobile terminal to receive the
packet data; and receiving the packet data over the packet data
channel using the control information from the base
station..Iaddend.
.Iadd.26. The method according to claim 25, wherein a transmission
unit of the packet data control channel comprises a fixed time
length and a transmission unit of the packet data channel comprises
a fixed time length..Iaddend.
.Iadd.27. The method according to claim 25, wherein a transmission
unit of the packet data control channel comprises a first time
length and a transmission unit of the packet data channel comprises
a second time length, wherein the first time length and the second
time length are the same..Iaddend.
.Iadd.28. The method according to claim 25, wherein the control
message further comprises an identifier field for identifying a
user which is to receive the packet data channel..Iaddend.
.Iadd.29. The method according to claim 25, wherein the control
message further comprises a size field for indicating an amount of
information being received on the packet data channel..Iaddend.
.Iadd.30. The method according to claim 25, wherein the control
message further comprises an automatic repeat request (ARQ) channel
identifier for identifying which channel of a plurality of packet
data channels is being retransmitted..Iaddend.
.Iadd.31. The method according to claim 25, wherein the control
message further comprises a subpacket identifier field for
identifying whether or not information of the packet data channel
is being retransmitted..Iaddend.
.Iadd.32. The method according to claim 25, wherein the start code
number is one of a plurality of codes having orthogonality with
each other..Iaddend.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a communication system, and more
particularly, to a method for transferring a packet data in a
mobile communication system.
2. Background of the Related Art
Typically, radio communication systems for transferring packet data
use physical channels, such as, Packet Data Channel (hereinafter
referred to as PDCH), Packet Data Control Channel (hereinafter
referred to as PDCCH) and so forth.
The PDCH is a channel for use of transferring packet data that
actually needs to be transferred to a relevant terminal, mobile
station or user (hereinafter being used interchangeably). Many
users prefer the PDCH based on the Time Division Multiplexing
system (hereinafter referred to as TDM system). The PDCCH contains
control information, enabling a terminal to receive the data being
transferred through the PDCH without error.
When a base station transfers packet data using TDM system, or
schedules data and later sending the data to each terminal in
sequence, the packet data, which is transmitted to every terminal,
always uses all of the available resources, e.g., Walsh codes, in
the PDCH. Even when only a part of the available resources needs to
be used, all of the resources are still used for the packet data.
As a result thereof, most of other resources are wasted at the same
time.
For example, data sent on PDCH need to be coded and decoded based
on Walsh codes. Serial bits are converted to parallel, and the
parallel bits are coded using the Walsh codes. In order to decode
the data, the information regarding the Walsh codes is sent on the
PDCCH.
In TDM system, there are plurality of time intervals 1, 2, 3, 4, 5,
6, etc, and only one of a plurality of terminals is allotted for
each time interval where a PDCH and PDCCH are sent to the terminal
during this allotted time interval. For example, if there are users
1 and 3 and time intervals 1 and 3, respectively, and if all 32-ary
Walsh codes are available for use by terminal 1, all 32-ary Walsh
codes are utilized in the PDCH during time interval 1. However, if
the available Walsh codes decrease in time interval 3, all
decreased Walsh codes are utilized for the PDCH. Even before
terminal 3 can use the changed/decreased Walsh codes in time
interval 3, it needs to know this information. In order to achieve
this, the BS broadcasts such information using a Walsh Code Space
Identification Identifier (WSI) field in the PDCCH (without PDCH)
with MAC_ID field information bit of (000000)2 before time interval
3 to all terminals within a cell.
A base station regularly or irregularly broadcasts WSI on the PDCCH
without the PDCH to all terminals under its management. In the
course of the broadcast, the base station uses every possible power
for all terminals (even including terminals in the worst
environment) to be able to receive the information such that even
the terminals in the worst environment can receive the WSI. Hence,
the broadcasting consumes much power. Moreover, when the WSI
change, the base station has to inform the changes to all terminals
every time. In those cases, the base station cannot transmit PDCH,
so the transmission efficiency of the entire system is consequently
reduced.
The above references are incorporated by reference herein where
appropriate for appropriate teachings of additional or alternative
details, features and/or technical background.
SUMMARY OF THE INVENTION
An object of the invention is to solve at least the above problems
and/or disadvantages and to provide at least the advantages
described hereinafter.
Another object of the invention is to provide a method for
transferring packet data to increase the resource usage
efficiency.
Still another object of the invention is to provide a method for
transferring packet data for use of a system based on Code Division
Multiplexing mode (CDM)/Time Division Multiplexing (TDM) mode.
The present invention can be achieved in a whole or parts by a
method comprising allowing a plurality of users to receive data;
and decoding the data based on a table of code indices indicative
of the channels, wherein a code index from the table indicate a
prescribed channel for decoding the data.
The present invention can be achieved in a whole or parts by a
method of providing information regarding the channels, comprising
sending a code index i from a plurality of code indices 0-N,
wherein code index i indicates 0 to i channels
The present invention can be achieved in a whole or parts by a
method of decoding data received through Pack Data Channel (PDCH)
using a Last Walsh Code Index (LWCI) of a Packet Data Control
Channel Message transmitted over the Packet Data Control Channel
(PDCCH) with the PDCH, comprising: decoding the LWCI; and decoding
the data using N number of Walsh codes based on the LWCI.
The present invention can be achieved in a whole or parts by a
message format of a Forward Packet Data Control Channel Message
transmitted on at least one of F-PDCCH0 physical channel and
F-PDCCH1 and having MAC_ID, WALSH_MASK, EP_SIZE, ACID, SPID, AL_SN,
EX_MSQ_TYPE AND RESERVED, wherein the improvement comprises at
least one of a first Last Walsh Code Index lwci0 of the F-PDCCH0
physical channel and a second Last Walsh Code Index lwci1, and the
lwci0indicates that Walsh code set includes 0.sup.th through
lwci0.sup.th entries in a Walsh Code Index (WCI) table. Preferably,
the WCI table may be pre-stored in a mobile station and a base
station, and respectively, the useable WCI table may be
predetermined by signaling channel with each other.
The present invention can be achieved in a whole or in parts by a
method of providing information regarding the channels, comprising
sending a code index i from a plurality of code indices 0-N,
wherein code index i indicates 0 to i channels.
The present invention can be achieved in a whole or in parts by a
method comprising: allowing a plurality of users to receive data;
decoding the data based on a table of code indices indicative of
the channels, wherein a code index from the table indicate a
prescribed channel for decoding the data.
The present invention can be achieved in a whole or in parts by a
method for decoding data in a communication network, comprising:
determining a prescribed value from a prescribed number of bits of
a received field, wherein the prescribed value corresponds to at
least one value in a table of first values; and determining a set
of second values based on the prescribed value to decode the data,
wherein there is a prescribed relationship between the first values
and the second values.
The present invention can be achieved in a whole or parts by a
method of allocating codes for corresponding data channels from a
prescribed number of codes comprising: assigning code indices to
the prescribed number of codes, such that there is a one-to-one
correspondence between each code index and each code; transmitting
a control message over the control channel, the control message
having a plurality of fields, wherein one of the fields contains
prescribed number of information bits based on at least one code
index; and transmitting the data over the PDCH, wherein control
message and data are sent concurrently.
Additional advantages, objects, and features of the invention will
be set forth in part in the description which follows and in part
will become apparent to those having ordinary skill in the art upon
examination of the following or may be learned from practice of the
invention. The objects and advantages of the invention may be
realized and attained as particularly pointed out in the appended
claims.
BRIEF DESCRIPTION OF THE DRAWINGS
The invention will be described in detail with reference to the
following drawings in which like reference numerals refer to like
elements wherein:
FIG. 1 illustrates a format of the Packet Data Control Channel
(PDCCH) Message in accordance with a preferred embodiment of the
present invention;
FIG. 2 is a diagram illustrating packet data transmission using
Time Division Multiplexing (TDM) system in accordance with a
preferred embodiment of the present invention;
FIG. 3 is a diagram illustrating packet data transmission using
CDM/TDM system in accordance with a preferred embodiment of the
present invention;
FIG. 4 illustrates WCI Table/List/Set in accordance with a
preferred embodiment of the present invention;
FIG. 5 illustrates WCI Table where Walsh Code Allocation (WCA)
field is used as Last Walsh Code Index (LWCI) field in accordance
with a preferred embodiment of the present invention;
FIG. 6A illustrates masking of the Walsh codes in accordance with a
preferred embodiment of the present invention;
FIG. 6B illustrates another embodiment of the WCA field in
accordance with a preferred embodiment of the present
invention;
FIG. 7A illustrates another embodiment of the WCA field in
accordance with a preferred embodiment of the present
invention;
FIG. 7B illustrates another embodiment of the WCA field in
accordance with a preferred embodiment of the present
invention;
FIG. 8 illustrates another embodiment of the WCA field in
accordance with a preferred embodiment of the present
invention;
FIG. 9 illustrates another embodiment of the WCA field in
accordance with a preferred embodiment of the present
invention;
FIG. 10 illustrates another embodiment of the WCA field in
accordance with a preferred embodiment of the present
invention;
FIG. 11 illustrates another embodiment of the WCA field in
accordance with a preferred embodiment of the present
invention;
FIGS. 12A and 12B illustrate a PDCH transmission chain structure in
accordance with a preferred embodiment of the present invention;
and
FIG. 13 illustrates a general PDCCH transmission chain structure in
accordance with a preferred embodiment of the present
invention.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
FIG. 1 illustrates the format of the Packet Data Control Channel
(PDCCH) Message in accordance with the preferred embodiment
(described hereinafter), over the PDCCH, e.g., forward PDCCH
(F-PDCCH). The CWSI/LWSI field of the message format preferably
prevents wasted power consumption caused by broadcasting, and
eliminates such broadcast. Even if broadcasting is used, the
additional field of CWSI/LWSI reduces the inefficiencies of a
prescribed system. This message format can be used in both a TDM
system, i.e., one PDCH physical channel and one PDCCH physical
channel within a prescribed time interval and uses the available
Walsh codes, and a Code Division Multiplex (CDM) system, i.e., a
plurality of PDCH(i) physical channels and a plurality of PDCCH(i)
physical channels, where i is an integer number that is greater
than or equal to 0, within a prescribed period of time and the
plurality of users are assigned to a plurality of physical channels
by allocation of the Walsh codes within the Walsh code space.
It is noted that the Walsh code, PDCH, and PDCCH are not
necessarily limited to their definitions. Rather, they generally
represent codes and channels having such prescribed functions.
Further, N.sub.max--PDCH is the maximum number of PDCHs or PDCCHs
available for a relevant system or sector, where
N.sub.max--PDCH>0. N.sub.real--PDCH is the number of PDCHs or
PDCCHs that are currently being used for a relevant system or
sector at a certain point, where
0<N.sub.real--PDCH.ltoreq.N.sub.max--PDCH.
For example, in a TDM based packet data transfer method illustrated
in FIG. 2, i.e., N.sub.max--PDCH=1 and N.sub.real--PDCH=1, a base
station schedules the data to transfer, and sends the data to each
terminal in order. In doing so, the base station uses the currently
available Walsh codes for PDCH.
In FIG. 2, a time length of a transmission unit on PDCH and PDCCH
could be fixed or varied. Further, the time length of PDCH and
PDCCH does not have to be the same. The user k means packet data or
control information for a user k. The transmission time and length
of PDCH and PDCCH for the user k are determined in conforming to a
prescribed rule. Further, the time gap between PDCH transmission
and PDCCH transmission for each user may exists or may not exist at
all, depending on the system environment. The same applies to a
dual mode system.
In a dual mode system, such as a CDM/TDM system, involves a base
station scheduling the data to be transferred to each user and
sending the data following the TDM and CDM method. Although this
system is referred to as a dual mode system, it can be appreciated
by one of ordinary skill in the art that a CDM system can be viewed
as a single mode system, since a CDM system inherently includes a
TDM mode, i.e., where only one user within a prescribed the
length.
For example, a single PDCH with a corresponding PDCCH could be
transferred at a prescribed length of the transmission unit
(interval d), or several PDCH(i) with corresponding PDCCH(i) could
be transferred together (interval a, b, c and e, etc). The PDCCH(i)
is an individual PDCCH physical channel having its own control
information. In a TDM mode, i.e., a single PDCH is transferred of
interval d, the Walsh codes need not be divided. But if a plurality
of PDCH(i) are transferred, the Walsh codes are divided or
allocated between the physical channels.
FIG. 3 illustrates a case in which a maximum 4 PDCHs could exist in
the CDM/TDM system. The empty space shown in FIG. 3 indicates when
PDCH or PDCCH is not occupied or used. For example, during the
interval a, four PDCH(i) are transferred with four corresponding
PDCCH(i). Thereafter, during interval b, three PDCH(i) are
transferred with three corresponding PDCCH(i). During interval c,
three PDCH(i) are transferred with three corresponding PDCCH(i) and
during interval d, one PDCH(i) is transferred with a corresponding
PDCCH(i). During interval e, four PDCH(i) are transferred with four
corresponding PDCCH(i).
As discussed above, the message format of PDCCH includes a
plurality of fields, e.g., 9 fields, and a prescribed number of
bits are used for each fields to form the control information bits.
Based on the binary value of the bits, each field provides a
prescribed control function for the operation of the user to use
the data/information received on the PDCH. The description of the
fields illustrated in FIG. 1 is as follows: (1.) MAC_ID: The MAC
identifier filed is a prescribed number of binary bit that is used
for identifying a user. Preferably, the prescribed number of binary
bits is 8 for the MAC_ID field. Except for `00000000` to
`00111111`, the MAC_ID field indicates which terminal the PDCCH
information is being transferred. The base station preferably sets
this field to the MAC identifier assigned to the user that is to
decode a PDCH subpacket transmission, e.g., forward PDCH (F-PDCH),
concurrent with the transmission of this message on the PDCH. If
the MAC_ID is set to `00000000`, the base station preferably
includes the WALSH_MASK field of a prescribed number of bits, e.g.,
0 or 13, and omits the remaining fields. Otherwise, the base
station preferably omits the WALSH_MASK field and includes the
remaining fields. (2.) WALSH_MASK: The Walsh Space Mask Bitmap
field is preferably set by the base station to indicate that the
mobile station, is to omit certain entries in the packet data
channel Walsh set when decoding the PDCH, e.g., F-PDCH. The base
station preferably sets each bit in this filed to `0` or `1` to
indicate that the mobile station is to include (`0`) or omit (`1`)
the corresponding indices in the Walsh index table (WCI--to be
described hereinafter). (3.) EP_SIZE: The Encoder packet size field
comprises a prescribed number of bits, e.g., 0 or 3 bits, that
indicates the number of data information bits being transferred on
the PDCH. For example, if this message field contains an extended
message, the base station preferably sets this field to the encoded
value for the encoder packet size (other than `111`) for the PDCH
subpacket transmission concurrent with transmission of this message
on the PDCH. If EP_SIZE is not set to `111`, the base station
preferably includes ACID, SPID, AI_SN and LWCI/CSWI (to be
described hereinafter). If the EP_SIZE is set to `111`, the base
station preferably includes the fields, EXT_MSG_TYPE and RESERVED,
and otherwise, the base station omits these two fields. (4.) ACID,
SPID and AI_SN: The ARQ Channel Identifier field (ACID), the
Subpacket Identifier field (SPDI) and ARQ Identifier Sequence
Number field (AI_SN), each comprising a prescribed number of bits
(preferably, 0 or 3, 0 or 2, 0 or 2, and 0 or 1, respectively), and
each is preferably set by the base station for the PDCH subpacket
transmission concurrent with the transmission of this message on
the PDCH. The ACID and SPID are used to inform a terminal whether
the information on the PDCH, which corresponds to PDCCH, is
retransmitted or not. For instance, the ACID informs a mobile
station (assuming that it can transfer a number of retransmitted
channels) which channel is being retransmitted among other
retransmitted channels, and which subpacket in the retransmitted
channel (especially for the encoded symbols from an information
stream that is being repeated and split to designated subpackets)
is being transferred. (5.) EXT_MSG_TYPE: The Extended Message Type
Identifier field has a prescribed bit length (preferably, 0 or 2)
and is preferably set by the base station to be `00` or `01`. The
base station may set this field to `00` to indicate that the mobile
station to exit a prescribed mode, e.g., PDCH Control Hold Mode.
The base station may set this field to `01` to indicate that the
mobile station is to terminate the current switching transmission
pattern prior to the maximum number of switching frames. (6.)
RESERVED: The Reserved Bits field has a prescribed bit length
(preferably 0 or 8 bits) and is preferably set by the base station
to be `00000000`. (7.) LWCI/CWSI: The Last Walsh Code Index (LWCI)
field, which can be also called a CDM Walsh Space Identification
(CWSI) field, is based on Walsh codes within a Walsh code space
and/or a code index. The label "x_i" indicates that the number of
bits x may vary depending upon the corresponding PDCCH(i) physical
channel and the code indices may or may not be based on priority.
However, for the embodiment using the LWCI field, "x_i" equals 0 or
5 bits for all PDCCH(i) physical channels and 5 bits is sufficient
for each PDCCH for allocating all the possible Walsh code
allocation patterns in the preferred embodiment.
As can be appreciated, the number of bits for this field can differ
depending on the number of all possible code allocation pattern and
the type of codes, e.g., Walsh codes, being used. Further, the
field for LWCI/CSWI serve the substantially the same
function/way/result of allocating Walsh codes for use by a
corresponding PDCCH(i), and this field can be generally called a
Walsh Code Allocation (WCA) field. Depending upon the embodiments,
the WCA field can be used to indicate the number of codes used or a
general/specific set of Walsh code belonging to the WCI table based
on the code indices.
In the preferred embodiment, the Walsh code is a common name of
codes having orthogonality to each other and is generally used for
transmission over the physical channel. As can be appreciated,
different types of codes can be used depending on the system. The
Walsh code space is a set of currently available Walsh codes when a
base station transfers packet data, and the Walsh code space can
vary depending upon time. Walsh_Max indicates a maximum number of
Walsh codes that the Walsh code space can accommodate and Walsh
(all) is a parameter indicating all Walsh codes that are usable for
PDCH on the Walsh code space. Based on the Walsh codes within the
Walsh code space, a code index from 0 to a prescribed number (num),
where num>0 are assigned with a corresponding Walsh code within
the Walsh code space. The assignment of the code indices to the
Walsh codes in the Walsh code space can also be based upon
priority.
FIG. 4 illustrates a 32-ary Walsh Code Indices (WCI) Table (or Set
or List) where Walsh_Max=28 within the Walsh code space with a code
index (e.g., num=0 to 27) assigned to each Walsh code within the
Walsh code space. FIG. 4, illustrates a 32-ary Walsh Code, but as
can be appreciated by one of ordinary skill in the art, this can be
different, e.g., 64-ary Walsh Code, based on the system
requirements. Further, Walsh_Max is illustrated herein as
exemplary, and not limited to a value of 28. Preferably, the WCI
table may be pre-stored in a mobile station and base station, and
the usable WCI table may be predetermined by signal channeling
between each other.
In composing the WCI table, the code index is based on priorities
of every Walsh code in the Walsh code space. For example, if there
are a total of 28 Walsh codes (Wal_Max=28) available for composing
the Walsh code space, every Walsh code corresponds to a code index.
However, since the WCI table of the preferred embodiment lists the
Walsh codes from the highest priority to the lowest, a lower code
index corresponds to a higher priority. However, when the Walsh
codes in the Walsh code space need to be allocated to the
PDCH/PDCCH, the allocation may be based on priority (priority
allocation) where the lowest code indexed Walsh codes are used
before the higher code indexed Walsh codes, or priorities do not
matter (non-priority allocation), e.g., a Walsh code with the
lowest priority may be used first before a Walsh code with the
highest priority code index.
In one of the preferred embodiments using the WCA field, especially
for the embodiment using the LWCI field, power ranking is
preferably used to determine which terminal is assigned to which
PDCCH physical channel. Unless specifically indicated in the
foregoing embodiments, power ranking may or may not be used. In
other words, the modulation symbols transmitted on PDCCH (i) should
be transmitted using at least as much energy as the modulation
symbols transmitted on PDCCH(i+1) which is transmitted
simultaneously with PDCCH(i). The power ranking generally assures
that all terminals properly receive the information sent on the
Packet Data Control Channel (PDCCH). In the preferred embodiment,
power ranking is based on the required transmission power of the
PDCCH of each scheduled user, i.e., when N PDCCH(i)/PDCH(i) are
used at some time interval, user requiring the most power is
assigned PDCCH(0) and user requiring the least power is assigned
PDCCH(N-1). Alternatively, a user with the worst environment is
assigned to PDCCH(0) and a user with the best environment is
assigned to PDCCH(N-1).
For example, the terminal furthest away from base station, i.e.,
the terminal using the largest amount of power, is assigned to
PDCH(0) and PDCCH(0), the terminal second furthest away from the
base station is assigned PDCH (1) and PDCCH(1), the terminal third
furthest away from the base station is assigned PDCH(2) and
PDCCH(2), etc, such that power ranking of the PDCCH(i) physical
channels is as follows PDCCH(0).gtoreq.PDCCH(1).gtoreq. . . .
PDCCH(i).gtoreq. . . . .gtoreq.PDCCH(N-2).gtoreq.PDCCH (N-1),
assuming that there are N number of terminals within a prescribed
time interval.
For example if terminal 1 requires 3 mW and terminal 3 requires 7
mW, e.g., terminal 3 is further away from the base station than
terminal 1 or terminal 3 is located in an environment which is
worse than the environment of terminal 1, then PDCH(0) and PDCCH(0)
is assigned or allocated to terminal 3 and PDCH(1) and PDCCH(1) is
assigned or allocated to terminal 1.
Although in this example, power ranking was based on distance, this
illustration is intending to be illustrative of power ranking, and
the present invention is not to be limited based on this example
since distance of the terminals is one of the ways for using the
power ranking and other factors can be used for power ranking with
or without distance consideration.
In 3GPP2 C.S0003-C v1.0, the 3GPP2 group has decided to use two
physical data channels, PDCH(0) and PDCH(1), with two corresponding
physical control channels, PDCCH(0) and PDCCH(1) and power ranking
is used to assign terminals to the physical channels. In other
words, the modulation symbols transmitted on the PDCCH(0) should be
transmitted using at least as much energy as the modulation symbols
transmitted on the PDCCH(1) that is being transmitted
simultaneously.
General Setup in Accordance with a Preferred Embodiment.
A base station uses an appropriate channel to inform
N.sub.max--PDCH to terminals under its management. N.sub.max--PDCH
could be a maximum PDCCH(i) a relevant system or a sector can
simultaneously use or the number of PDCH(i), and N.sub.max--PDCH
could be either fixed or variable. The base station decides
N.sub.real--PDCH(.ltoreq.N.sub.max--PDCH) according to the
scheduling result. If N.sub.real--PDCH is 1, it involves the TDM
system, and if N.sub.real--PDCH is greater than 1, it involves the
CDM system. Thereafter, the base station can use as many as
PDCH/PDCCH based on the N.sub.max--PDCH, e.g., PDCH(0)/PDCCH(0),
PDCH(1)/PDCCH(1), . . . , and PDCH
(N.sub.max--PDCH-1)/PDCCH(N.sub.max--PDCH-1) as control
channels.
A terminal preferably needs to find out which Walsh code is being
used to transmit PDCCH, and the terminal may obtain a Walsh Code
list (WCL) from the base station, in which the WCL includes the
Walsh codes PDCCH uses, and the base station provides the WCL. The
code indices wcl(0), wcl(1), . . . , and wcl(N.sub.max--PDCH-1)
preferably have a one-to-one relationship with the PDCCH(0),
PDCCH(1), . . . , and PDCCH(N.sub.max--PDCH-1), i.e., PDCCH(i) is
transmitted by using wcl(i), based upon a predetermined rules
between the base station and the terminals under its
management.
Walsh Code list (WCL) is used to differentiate the different
PDCCH(i) channels, whereas, WCA(i) is a field included in each
PDCCH(i) to indicate a number of corresponding Walsh codes or a
general/specific set of Walsh codes which is used to decode the
data received via PDCH(i). Similar to WCI, the WCL is preferably
stored in a mobile station and a base station, and the usable WCL
may be obtained by channel signaling between each other.
General Decoding in Accordance with the Preferred Embodiment
When a terminal interprets each WCA(i) received through control
channels, the interpretation of these field can be done
independently in the preferred embodiment(s). For example, if the
WCA field is indicative of a specific set (rather than a general
set or a number of corresponding Walsh codes) of Walsh codes based
on the code indices, the intended user matches the MAC_ID and
obtains the WCA(i) without reference to other WCA(j)
(i.noteq.j).
In alternative preferred embodiment(s), the WCA(i) field may be
indicative of the code index to form a set of Walsh codes or the
WCA(i) field is indicative of a general set number of Walsh codes
based on the code indices in the WCI table, the interpretation is
preferably dependent upon other WCAs, where in order to interpret
WCA(i), the terminal preferably refers to another WCA(j)(i.noteq.j)
based upon a predetermined condition for more accurate
interpretation of its own WCA(i) value.
As discussed above, WCL is preferably used to differentiate each
PDCCH(i) from one another. In this instance, the base station
transmits PDCH(i) to a corresponding terminal in accordance with
the PDCCH(i) information contain the MAC_ID of the corresponding
terminal, and the terminal matches its MAC_ID and the MAC_ID of
PDCCH(i). For example, the terminal sequentially decodes PDCCH(0),
PDCCH(1), . . . , PDCCH(N.sub.max--PDCH-1) using wcl(0), wcl(1), .
. . , wcl(N.sub.max--PDCH-1) until it finds its own MAC
identifiers. Alternatively, the terminal can decode channels in a
reverse order of PDCCH(N.sub.max--PDCH-1),
PDCCH(N.sub.max--PDCH-2), . . . , PDCCH(0) using
wcl(N.sub.max--PDCH-1), wcl(N.sub.max--PDCH-2), . . . , wcl(0)
until it finds its own MAC_ID.
The predetermined condition for the WCA(i) may be based on WCA(i-1)
being found. In this case, a terminal or a user who is assigned to
receive the WCA(i) of PDCCH(i) should be able to receive the
corresponding WCA values that are being transferred on PDCCH(0),
PDCCH(1), . . . , PDCCH(i-1) or at least a terminal assigned to
receive the WCA(i) of PDCCH(i) should be able to receive the
WCA(i-1) that is being transferred on PDCCH(i-1). Unless explicitly
indicated, this sequential decoding may or may not be used in the
forgoing embodiments.
First Preferred Embodiment of WCA Field
The following will be a discussion related to the use of the WCI
Table using the Walsh codes indices corresponding to the column
index "000" in FIG. 4 as WCA field. Further, this explanation will
be focus on two physical channels, (1) PDCH(0) and PDCCH(0) and (2)
PDCH(1) and PDCCH(1), which is exemplary of the disclosure in 3GPP2
C.S0003-C v1.0, but is not intended to limit the scope of the
claimed invention and the disclosure herein.
As discussed above, the LWCI field is based upon the use of the
code indices based on priority allocation, e.g., the PDCCH(0)
physical channel is allocated a first set of Walsh codes
corresponding to the lower code indices and the PDCCH(1) physical
channel is thereafter allocated to second set of Walsh codes
corresponding to the higher code indices after the first set of
lower code indices have been assigned. In other words, the
available Walsh codes in the Walsh code space is divided into a
plurality of sets of Walsh codes, where the lower code indices are
allocated or assigned to a lower numbered PDCCH. As can be
appreciated, this priority can be reversed, where higher code
indices are first allocated to a lower number PDCCH in an
alternative embodiment (non-priority allocation).
Power ranking is also preferably used with the LWCI field, i.e.,
the terminal requiring the most power is assigned to PDCCH(0), and
the terminal requiring the least power is assigned PDCCH(1). As can
be appreciated, power ranking is preferable especially when there
are more than two terminals. As can be further appreciated, power
ranking may or may not be needed when two physical channels for two
corresponding terminals are used, but is preferable.
For example, FIG. 5 illustrates the WCI Table, where there are 28
Walsh codes (Walsh_Max=28) in the Walsh code space, and each Walsh
code is assigned to a corresponding code index. As discussed above,
the available Walsh codes can change even though there are 28 Walsh
codes in the Wash codes space. For example, based on power ranking,
terminal 1 is assigned to PDCCH(0) and terminal 3 is assigned to
PDCCH(1). If the LWCI field (lwci0) of PDCCH(0) equals 3
(00011).sub.2 and the LWCI field (lwci1) of PDCCH(1) equals 9
(01001).sub.2, the Walsh codes are divided into two sets, where
Walsh codes corresponding to indices 0-3 would be allocated to
PDCCH(0) and Walsh codes corresponding to indices 4-9 would be
allocated to PDCCH(1). Hence, the PDCH(0) for terminal 1 is
transmitted on Walsh codes 31, 15, 23, and 7 while the PDCH(1) for
terminal 3 is transmitted on Walsh codes 27, 11, 19, 3, 30 and
14.
In other words, the terminal assigned to PDCCH(0) transmission of
the PDCH(0) occurs on Walsh codes with index 0 to index i in the
WCI table, where i=the binary bits indicated in the LWCI field
(lwci0) of the PDCCH(0). The terminal assigned to PDCCH(1)
transmission of the PDCH(1) occurs on Walsh codes with index (i+1)
to the j-th Walsh code, where j=the binary bits indicated in the
LWCI field (lwci1) of the PDCCH(1).
As shown in FIG. 5, the present invention does not use all the
Walsh codes in the WCI Table, and Walsh codes from code index 10 to
code index 27 can be used for other purposes. Further, the WCI
Table is divided into two sets and allocated for PDCCH(0) and
PDCCH(1) transmission of PDCH(0) and PDCCH(1), respectively.
Moreover, this allocation of the WCI Table can be readily
applicable to situations where more than two physical channel
assignments are required. With such CDM scheduling, the base
station is no longer required to broadcast within an entire cell
the available codes.
Similar to CDM scheduling, the LWCI field (lwci0) of PDCCH(0) is
used to indicate the available Walsh code space in TDM scheduling.
Only PDCCH(0) is used and PDCCH(1) is suspended. Further, if there
are more than two physical channels, PDCCH(1) to
PDCCH(N.sub.max--PDCH-1) are suspended. Likewise, not all available
Walsh codes need to be used, and broadcasting is not required in
this preferred embodiment.
In terms of the mobile station or terminal, a sequential decoding
of the PDCCH is performed by all mobile station. Starting from
PDCCH(0), the mobile station keeps on decoding the PDCCH until its
corresponding MAC_ID is found. Once detecting the corresponding
MAC_ID on the PDCCH(i), the mobile station assigned to PDCCH(i)
collects the LWCI fields (lwci(i-1)) of PDCCH(i-1) and the LWCI
field (lwci(i)) of PDCCH(i).
For example, when PDCCH(0) has been assigned to terminal 1 for
transmission of PDCH(0), terminal 1 decodes the PDCCH(0) to
determine lwci0. Since the code indices are based on priority
allocation, terminal 1 can determine that PDCH(0) has been
transmitted based on Walsh codes from index 0 to index lwci0 of the
WCI table. However, for terminal 3 assigned to PDCCH(1) for
transmission of PDCH(1), terminal 3 needs to collect the lwci0 in
order to determine the Walsh codes from index lwci0+1 to index
lwci1. Although terminal 3 can readily collect the lwci1 based on
the MAC_ID of the PDCCH(1), terminal 3 still needs to obtain lwci0
from PDCCH(0). Due to power ranking, terminal 3 can ascertain that
PDCCH(0) is transmitted with a higher power than itself or at least
a equal power. Based on power, terminal 3 can obtain the lwci0 from
PDCCH(0) to decode the PDCH(1) using the Walsh codes corresponding
to index lwci0+1 to index lwci1.
In certain instances, the Walsh codes in the WCI table may be
masked, and the terminal needs to receive the information regarding
the masked Walsh codes to properly determine lwci(i), e.g., lwci0
and lwci1. FIG. 6A illustrates the masking of Walsh codes
corresponding to indices 1-3 (lightly shaded with italic text and
underling). It is noted that Walsh codes from indices 13-27 (darkly
shaded with bold text and underling) are used for other
purposes.
In such a situation, the base station notifies all the terminals by
sending on PDCCH(0) with a MAC_ID field of `00000000` and the
WALSH_MASK field indicating which corresponding indices in the WCI
table need to be omitted or deleted during a first prescribed time
interval. Further, lwci0 is equal to -1 (negative 1). Thereafter,
during the PDCCH(1) transmission of PDCH(1) within the first
prescribed time interval, the corresponding terminal deletes the
Walsh codes corresponding to the indices indicated to be omitted
from PDCCH(0). Based upon such deletion, the decoding of PDCH(1) is
based upon the WCI table illustrated in FIG. 6A. For example, if
lwci1 on PDCCH(1) is equal to 12 and since -1 (lwci0)+1 equals 0,
the PDCH(1) is decoded using Walsh codes 31, 27, 11, 19, 3, 30, 14,
22, 6 and 26 (Walsh codes corresponding to indices 0-12). Hence,
the WALSH_MASK is applied to walsh codes determined by lwci0 and
lwci1.
During the second prescribed time interval after the first
prescribed time interval, a terminal is assigned to the PDCCH(0)
transmission of the PDCH(0) includes a message format having a
lwci0 field of 4 and another terminal is assigned to the PDCCH(1)
transmission of the PDCH(1) includes a message format having a
lwci1 field of 12. When the terminal assigned to PDCCH(0) obtains
the lwci0 of 4, the masked Walsh codes are deleted as shown in FIG.
6A, and Walsh codes used for decoding PDCH(0) are 31 and 27. After
the terminal assigned to PDCCH(1) obtains both the lwci0+1 and
lwci1, the masked Walsh codes are deleted, as shown in FIG. 6A, and
the Walsh codes used for decoding PDCH(1) are 11, 19, 3, 30, 14,
22, 6 and 26.
Based on the above description, the following applies when LWCI is
used as a field for the PDCCH. The base station preferably sets
this field to the last Walsh code index for the PDCH subpacket
transmission concurrent with the transmission of this message on
the PDCCH. If this message is being transmitted on the PDCCH(0)
physical channel, the base station preferably sets this field to
indicate that the Walsh code set includes the 0th through LWCIth
entries in the WCI table. Otherwise, if this message is being
transmitted on the PDCCH(1) physical channel, the base station
preferably sets this field to indicate that the Walsh code set
includes the (lwci0+1)th through LWCIth entries in the WCI table.
If the MAC_ID in the PDCCH(0) message transmitted at the same time
as this message is greater than or equal to `01000000`, then lwci
is the last Walsh code index in the PDCCH(0) message. If the MAC_ID
in the PDCCH(0) message is less than `01000000`, lwci0 is -1.
Second Preferred Embodiment of WCA Field
FIG. 6B is a diagram illustrating one of WCA interpretation method
using 5-bit WCA in accordance with another embodiment of the
present invention. Referring to FIG. 6B, which illustrates the
Walsh codes corresponding to column "001" of FIG. 4, the Walsh
codes disposed between a position corresponding to WCA(m-1) value
and WCA(m) value are the ones used for the transmission of PDCH(m).
As can be appreciated by one of ordinary skill in the art, there is
no substantive difference between the first preferred embodiment
and this second preferred embodiment other than the location of the
code index within the WCI table. Hence, the code index number and
location within the WCI table can be arbitrary decided. Further, N
or M both refer to Walsh code users for transferring the PDCH, and
are just arbitrary labels. Moreover, the label (i) for PDCH(i) or
PDCCH(i), WCA(i) and WCL(i), where i=0 to a prescribed number, are
also arbitrary, e.g., i can be 1 to a prescribed number.
When there are a plurality of physical channels, N.sub.max--PDCH
greater than 1, i of FIG. 1 has a range from 0, 1, . . . , to
(N.sub.max--PDCH-1). The WCA(i) of PDCCH(i) is the information
about those codes that are used for transferring PDCH(i). Usually,
the number of bits x_i of the WCA field does not have to be a fixed
number of bits, but can vary depending upon the whether this field
indicates the number of Walsh codes based on the code index, and/or
this field indicates a specific set of the codes belong to the
Walsh code space of the WCI table. In this preferred embodiment,
every message format of the PDCCH(i) has an identical
configuration, i.e., the number of information control bits x_i is
5 for every PDCCH(i).
The WCA(0) on the PDCCH(0) indicates that the same number of Walsh
codes with the WCA(0) value is used from the WCI table, starting
from the code index indicative of higher priority Walsh codes. If i
is greater than zero, the CWSI on the PDCCH(i) means a specific set
of the codes taken from the Walsh code space of the Code priority
table, following a specific rule. Specifically, the WCA(i)
(i>0), of the PDCCH(i) indicates that the data is being
transferred on the PDCH(i) using the Walsh codes from a relevant
set based on the code index.
In addition, when i is greater than zero, the WCA(i) on the
PDCCH(i) indicates that the WCA(i) value corresponds to the code
index in the WCI table such that the number of Walsh codes
indicated by the code index in the WCI table (except for the Walsh
codes used by PDCH(0), PDCH(1), PDCH(2), . . . , and PDCH(i-1)) is
used based on priority allocation for transferring PDCH(i). The
base station performs scheduling to make the transmission power of
PDCCH(i) equal to or stronger than that of PDCCH(i+1) based on the
assumption that the terminal for transmission of PDCCH(i) is
located in a better or similar communication environment than the
terminal for transmission of PDCCH(i+1), i.e., power ranking.
Further, when a terminal interprets a WCA(i) value of PDCCH(i), it
preferably uses the WCA(j) information of other PDCCH(j) other than
PDCCH(i), i.e., sequential decoding.
For example, suppose that the CDM/TDM system is used, and
N.sub.max--PDCH is 2, and broadcasting is not used. Hence, two of
each PDCH(0), PDCCH(0), PDCH(1), and PDCCH(1) are used. If the
WCA(0) field of the PDCCH(0) corresponds to the index code 4 of the
WCI table, the same number (1-4) of Walsh codes, e.g., 31 (code
index=1), 15 (code index=2), 23 (code index=3) and 7 (code index=4)
in FIG. 6B, corresponding to the index code 4 are used for the
transmission of PDCH(0).
Further, if the WCA(1) field of PDCCH(1) corresponds to the code
index 10 of the WCI table, the WCA(1) value indicates that the
corresponding number of Walsh codes, except for the Walsh codes
used by the PDCH(0), are taken from the WCI table for the
transmission of PDCH(1), starting from the higher priority code
indexed Walsh codes to the lower priority code indexed Walsh codes,
e.g., 27 (code index=5), 11 (code index 6), 19 (code index=7), 3
(code index=8), 29 (code index=9) and 13 (code index=10) of FIG.
6B.
As can be appreciated for all the embodiments, the composition of
the WCI table allows many flexibilities. In this embodiment and the
previous embodiment, the last code index has been used, but the
code index can also be used as beginning Walsh Code index (BWCI).
For example, if WCA (0)=4, PDCCH(0) will indicate Walsh codes 31,
15, 23 and if WCA(1)=10, PDCCH(1) will indicate Walsh codes 7, 27,
11, 19, 3, and 29. Based on the disclosure of the embodiments, the
implementation will be apparent to one of ordinary skill in the
art.
Third Preferred Embodiment of WCA Field
FIG. 7A illustrates another preferred embodiment of the present
invention, where the code indices for WCA are used as start code
numbers (SCN) and end code numbers (ECN). As shown in FIG. 7, which
is one of the exemplary methods of using the SCN/ECN, the message
format of FIG. 1 will include SCN and/or ECN (SCN/ECN) field for
PDCCH(i) having either 0 or x_i number of bits rather than
LWCI/CWSI field. The SCN/ECN indicates a specific set of Walsh
codes in the WCI Table based on the code indices.
For example, if there are N number of users and Walsh codes
corresponding to code indices 0 to 16 from the WCI table are
available, where the other Walsh codes are used for other purposes,
the SCN/ECN field for the 1st user (terminal or mobile station) of
PDCCH(i) for transmission of PDCH(i), where i=0 to N-1 and i
between different users are not the same, will include a SCN(0) of
0 and a ECN(0) of 3, the SCN/ECN field for the 2nd user of PDCCH(i)
will include a SCN(1) of 4 (ENC(0)+1) and a ECN(1) of 9, . . . ,
and the SCN/ECN field for the Nth user of PDCCH(i) will include a
SCN(N-1) of 13 (ECN(N-2)+1) and ECN(N-1) of 16 within a prescribed
time interval for CDM scheduling.
In other words, the PDCH(i) for the 1st user is transmitted on
Walsh codes 31, 15, 23, and 7, the PDCH(i) for the 2nd user is
transmitted on Walsh codes 27, 11, 19, 3, 29 and 13, . . . , and
the PDCH(i) for the Nth user is transmitted on Walsh codes 9, 30,
14 and 22. In terms of decoding, the 1st user searches for the
corresponding MAC_ID field to obtain or collect the SCN and the ECN
information bits, the 2nd user searches for the corresponding
MAC_ID field to obtain or collect the SCN and the ECN information
bits, . . . , and the Nth user searches for the corresponding
MAC_ID field to obtain or collect the SCN and the ECN information
bits in control message of the PDCCH(i).
In this embodiment, the priority, power ranking and/or sequential
decoding may or may not be used due to the flexibility of this
Walsh code allocation. For example, if none of the above is used,
the SCN and ECN fields would comprise, for example, 10 bits, where
5 bits is would be representative of the SCN information bits and
the other 5 bits would be representative of the ECN information
bits. In such a case, the different users search for the
corresponding MAC_ID field in corresponding PDCCH transmission of
the PDCH, and use the Walsh codes corresponding to the SCN and the
ECN in the WCI table.
If priority of the code indices is used, the PDCCH(0) will be
allocated with the lowest code indices or the highest code indices,
depending upon the order of priority. In such an instance, there is
no need for the SCN(0) for the PDCCH(0) since this will be equal to
0 or the highest code index in the WCI table. Hence, the SCN/ECN
field of PDCCH(0) may be, for example, 5 bits representative of the
ECN information bits corresponding to a set of lower code indices
within the WCI table whereas the SCN/ECN fields of the remaining
PDCCH(i), where i=0 to N-1, will include both SCN(i) and ECN(i)
information bits.
If both priority of the code indices and power ranking is use, the
same as above applies to the PDCCH(0) physical channel. However,
the SCN/ECN field of the last PDCCH(N-1) physical channel does not
need to contain one of SCN(N-1) and ECN(N-1) information bits. For
example, if the SCN/ECN field includes, for example, 5 information
bits representative of SCN(N-1) of the code indices, the Nth user
can readily utilize the Walsh codes corresponding to the set of
code indices starting from SCN(N-1) to the last code index within
the WCI table. Alternative, if the SCN/ECN field includes, for
example, 5 information bits representative of ECN(N-1) of the code
indices, the Nth user can readily utilize the Walsh codes
corresponding to the set of code indices starting from the ECN(N-1)
to the ECN(n-2)+1.
In another modification which uses priority, power ranking and
sequential decoding, SCN/ECN field become the same as the LWCI
field. In this instance, the SCN/ECN would preferable contain ECN
information bits, which would be the same as LWCI field. Hence, the
description above regarding the LWCI field is readily applicable to
this preferred embodiment. Further, the discussion regarding
masking is also readily applicable to this preferred embodiment
whether or not priority or priority allocation, power ranking
and/or sequential decoding is applied.
For TDM scheduling or mode, the PDCCH(0) is preferably used to
provide ECN(0) of 5 bits, and the other physical channels PDCCH(1)
to PDCCH(N-1) are suspending similar to the embodiment of LWCI.
This embodiment has various advantages. For example, in both CDM
and TDM scheduling or mode, broadcasting is not required since the
PDCCH is transmitted with the corresponding MAC_ID information.
Further, Walsh code allocation (CDM) and available Walsh space
indication (TDM) can be performed in a common manner. Also, the
Walsh code allocation can be done in a fully flexible manner such
that there is flexibility in system operation.
Fourth Preferred Embodiment of the WCA Field
FIG. 7B illustrates another embodiment of WCA interpretation in
accordance with the present invention. This embodiment is similar
to the embodiment of FIG. 7A. In other words, there is no
substantive difference between the two embodiments other than the
numbering of the code indices and what location or point in the WCI
table the code indices corresponds to the Walsh codes. As can be
appreciated, the index numbering and location on the WCI table to
reference the Walsh codes can be arbitrary decided. For
transmission of PDCH(m) for m>=0, the WCA(m) field of the
PDCCH(m) will contain a value which would indicate that Walsh codes
disposed between a starting position calculated by Equation 1 and
an ending position calculated by Equation 2 are used. .times.
.times..function..times. .times..times. .times..function..times.
.times. ##EQU00001##
For example, the Walsh codes used for transferring PDCH(m)
corresponds to Walsh codes from the code index starting point
14[=WCA(0)+WCA(1)+ . . . +WCA(m-1)=14] and the code index ending
point 19[=WCA(0)+WCA(1)+ . . . +WCA(m)]. In this preferred
embodiment, the code index starting point of PDCH(0) is zero based
on priority allocation. That is, the Walsh codes used for
transferring PDCH(0) are the ones between the cod index starting
point 0 and the code index ending point 4[=WCA(0)].
The WCA(m) can be interpreted by a terminal independently and once
WCA(m) of PDCCH(m) including a terminal's MAC identifier is
interpreted, any arbitrary terminal can get the information about
the Walsh codes that are used by PDCH(m) where its packet data is
being transferred.
The independent interpretation on WCA(m) by a terminal is largely
divided into two cases. In the first case, all WCA(m) values have
the same meaning. In the second case, one of the WCA value among
all other WCA values has a different meaning.
In the first case, a plurality of control channels PDCCH (i)
includes information regarding the Walsh codes that are positioned
in the WCI table based on the first and the last code index. When
PDCH(m) is transferred by using codes placed between a certain code
index (Start_Walsh_Code; hereinafter referred to as SWC) in the WCI
table and another specific code index (End_Walsh_Code; hereinafter
referred to as EWC) in the Code priority table, the WCA(m) value
comprises the value of the SWC and EWC.
For example, suppose that the WCA information bit on PDCCH(i) is 10
bits (x_i=10), then WCA(1)=(00100 01010).sub.2, as illustrated in
FIG. 7B. The starting point Walsh code is based on a SWC index
whose position on the WCI table is 00100.sub.2=4.sub.10, and the
ending Walsh code is based on a EWC index whose position on the WCI
table is 01010.sub.2=10.sub.10. In this first case, every WCA(m)
field of PDCCH(m) can use the same message format, e.g.,
x_i=10.
In the second case, at least one WCA(m) is based on a single code
index number indicative of the number of Walsh codes used for the
data transmission channel in accordance with the priority
allocation, and the other WCA(m) include both the SWC index and the
EWC index according to the priority allocation. In such a case,
PDCCH(i), except for PDCCH(0), can use the same configuration with
each other such that x.sub.--0=5, and x_i=10(i>0). In general,
if i is larger than 0, x_i is twice x.sub.--0. In this example
based on the illustration of FIG. 7B, the x_i equals 5 for WCA(0)
and WCA(0)=(00100)=code index 4, which indicates that the number of
Walsh codes equals the corresponding Walsh codes based on the code
index 4 on the WCI table in accordance with priority allocation,
i.e., Walsh codes 31, 15, 23 and 7.
However, for WCA(m), where m>0, the WCA(m) field includes both
the SWC index and the EWC index in the WCI table. In this example
based on the illustration of FIG. 7B, the number of bits of
WCA(m)=x_i=10, where m>0 such that WCA(1)=(00100 01010), where
SWC=4 and EWC=10, . . . , WCA(m)=(01110 10011), where SWC=14 and
EWC=19, . . . , and WCA(M-1)=(10111 11010), where SWC=23 and
EWC=26.
Fifth Embodiment of the WCA Field
Walsh(i) is a set of Walsh codes the PDCH(i) uses at a particular
time of transmission. It is composed of the components of the Walsh
code space. Although the Walsh code space does not change, the
Walsh codes included in the Walsh(i) changes based on time. In
other words, a previous Walsh(i) and a current Walsh(i) have
different components and the total number of their components. The
Walsh code unit for the Walsh(i) is x, and the number of components
of each Walsh(i) is a multiple of x., i.e., 1x, 2x, 3x and so
forth. Here, the number of components of Walsh(i) is independent of
the number of Walsh(all).
For example, if Walsh_max is 28, the Walsh code usage unit is 3,
and the bit number of the WCA field is 6 based on WCA field
indicates the number of Walsh codes (vs. WCA field containing the
information about the set, in which case the number of bits of the
WCA field can be as many as necessary.), the 11 points (e.g.,
P.sub.--0, P.sub.--1, . . . , P.sub.--10, as shown in FIG. 8) can
be designated in the WCI table and a total of 55 sets can be
created from this 11-point set although a total of `2.sup.6=64`
sets can be used based on the number of bits of the WCA field.
Hence, there is a one to one (1:1) correspondence of the 11-point
set WCA value but the remaining WCA values, `64 -55=9`, may be used
for different purposes
Sixth Embodiment of WCA Field
FIG. 9 illustrates another preferred embodiment, where the WCA is
used as Walsh code index set values (WCISV), in which case the
message format of FIG. 1 will include CISV field for PDCCH(i)
having either 0 or x_i number of bits rather than LWCI/CWSI field.
In this preferred embodiment, the code indices divided into sets
based on the value indicated in the WCISV field of the PDCCH(i).
The WCISV field is indicative of a general set of Walsh codes of
the WCI table based on the code indices. Preferably, priority,
power ranking and sequential decoding is used.
In the example shown in FIG. 9, the WCISV(0) field of PDCCH(0)
would equal 4 for the 1st user, which would indicate that the Walsh
codes corresponding to the 1st four code indices of the WCI table
is preferably used to for transmission of the PDCH(0). Similarly,
the WCISV(1) field would equal 6 for the 2nd user, which would
indicate that the Walsh codes corresponding to code indices from
WCISV (0)+1 to WCISV(0)+WCISV(1) is preferably used for
transmission of the PDCH(1). The WCISV(n) field would equal 4 for
the nth user, which would indicate that Walsh codes corresponding
to code indices from WCISV(0)+WCISV(1)+ . . . +WCISV(n-1) to
WCISV(0)+WCISV(1)+ . . . +WCISV(n-1)+WCISV(n) is preferably used
for transmission of the PDCH(n). Due to sequential decoding, the
user can collect the WCISV fields from PDCCH(0) to PDCCH(n). The
number of information bits for this field is preferably be 5, but
can be different depending upon the number of possible variations
of the Walsh code allocation.
In TDM mode, the PDCCH(0) physical channel can be used to transmit
the available Walsh codes with the WCISV(0) field. Again, no
broadcasting is required and the various advantages described above
can be readily applicable to this embodiment.
Seventh Embodiment of the WCA Field
When a terminal interprets WCA(i) with reference to other WCA(j)
that are receives through a control channel, if a PDCCH(i)
satisfies a specific condition, the WCA(i) bit number, x_i, of the
PDCCH(i) can be set to zero. In other words, given that the WCA is
not broadcasted, and if the transmission power of a previously
transmitted control channel among a plurality of control channels
is the same or greater than the transmission power of a control
channel that is to be transmitted, the number of bits of WCA of the
control channel that is to be transmitted is 0. Hence, a terminal,
which received WCA of 0 bits in the control channel implicitly
interpreted such 0 bits of the WCA as indicative of using Walsh
codes except the ones presently used for other control channels
among the Walsh codes used for the plural control channels
previously.
FIG. 10 illustrates control channels in terms of time when the
number of bits of WCA(M,t2) is set to 0 bit in accordance with this
preferred embodiment of the present invention. In this embodiment,
it is that assumes PDCCH(i) transferred during a prescribed time
interval t is PDCCH(i, t), and WCA on the PDCCH(i, t) is WCA(i, t),
and the PDCH corresponding to the PDCCH(i, t) is PDCH(i, t).
Further, the control channels that a base station transfers during
a specific time interval t1 are PDCCH(1, t1), PDCCH(2, t1), . . . ,
PDCCH(L, t1), and the control channels during the next time
interval t2 are PDCCH(1, t2), PDCCH(2, t2), . . . , PDCCH(M, t2),
where L and M are arbitrary natural numbers.
If the following conditions are satisfied, the number of bits for
WCA(M,t2) of PDCCH(M, t2) could be 0. The transmission power of
PDCCH(L, t1) is equal or greater than the transmission power of
PDCCH(1, t2). In a such case, the Walsh codes for transferring
PDCH(M,t2) are the remaining codes except for the Walsh codes that
are used for transferring PDCCH(1, t2), PDCCH(2, t2), . . . , and
PDCCH(M-1, t2)} among the Walsh codes used for transferring
PDCCH(1, t1), PDCCH(2, t1), . . . , and PDCCH(L, t1).
Eighth Embodiment of the WCA Field
In the above-described embodiments, there is a possibility there
are more than one PDCCH(i) having the same MAC identifier among a
the plurality of PDCCHs being simultaneously transferred. In other
words, among {PDCCH(0), PDCCH(1), . . .,
PDCCH(N.sub.real--PDCH-1)}, the MAC identifier for PDCCH(i) and for
PDCCH(j)(i.noteq.j) could be identical with each other.
In this instance, the terminal may collectively regard part or all
of the PDCHs corresponding to the PDCCHs having the same MAC
identifier as one PDCH, and the terminal may undertake the
reception procedure thereof (e.g., performing decoding, or error
correction code check) and performs signal processing thereon. The
terminal determines, with reference to the other information bits
besides the MAC_ID, whether it should collectively regard certain
PDCHs among the plurality of PDCHs corresponding to PDCCHs with the
same MAC identifier as one PDCH/PDCCH.
If the MAC_ID of two PDCCH are the same (two is intended to be
exemplary), but EP_SIZE, ACID, AI_SN, and SPID are different, the
terminal regards the two PDCHs and two corresponding PDCCHs as
different, and the terminal undertakes the reception procedure for
each PDCH separately. However, if the MAC_ID, EP_SIZE, ACID, AI_SN,
and SPID are the same, the terminal collectively regards the two
PDCHs and PDCCHs as one PDCH and PDCCH, and the terminal initiates
the reception procedure for one PDCH/PDCCH. Further, the Walsh
codes that are used for transferring PDCH at this time are the ones
that are used by the relevant PDCHs for relevant PDCCHs.
For example, if PDCCH(2) and PDCCH(5) have the same MAC_ID,
EP_SIZE, ACID, AI_SN, and SPID, the PDCH(2) and the PDCH(5) being
transferred are actually as one PDCH. Hence, if the WCA(2) and
WCA(5) fields of PDCCH(2) and PDCCH(5) indicates Walsh codes 31,
15, 23 and Walsh codes 22, 6, 26, 10, and 18, respectively, based
on a code index indicative of a number of Walsh codes in the WCI
table, or based on a general set of Walsh codes corresponding to
code index or based on a specific set of Walsh codes corresponding
to the code index, the terminal can readily determine that Walsh
codes 31, 15, 23, 22, 6, 26, 10, 18 is to be used for decoding.
Ninth Embodiment of the WCA Field
In addition to the above embodiments illustrating the use of the
additional field which is broadly labeled as the WCA field, a Code
Division Multiple Indicator field (hereinafter referred to as CDMI)
may be further added to the information bits of PDCCH(i) in order
to increase the overall system efficiency, as illustrated in FIG.
11(). The CDMI allows the terminals to know the number of control
channels that are currently being transferred through the CDM
system. FIG. 11 also illustrates the number of information bits in
the message format of PDCCH(i) (excluding EXT_MSG_TYPE and
RESERVED). The CDMI is used to inform the terminal as to whether
there are additional PDCCH to be received, and if so, the terminal
can estimate the number of control channels that are being
transferred through the CDM system.
According to a predetermined rule between the terminal and the base
station, the CDMI(i) will indicate to the terminal that it is
suppose to receive another PDCCH(k). For example, if
CDMI(i)=(0).sub.2, this will indicate to the terminal that it will
not receive PDCCH(k) since there is no PDCCH(k), and if
CDMI(i)=(1).sub.2, this will indicate to the terminal that it
should attempt to receive PDCCH(k), if necessary, since there is a
PDCCH(k). As can be appreciated, the value of 0 or 1 or vice versa
can be use to indicate whether there is another control channel,
and further, other values of CDMI may be used. To implement this
embodiment, the terminal preferably includes an additional device
for detecting different bit number of the CDMI. One example of the
additional devices is generating error detection bits in accordance
with the bit number of y_i when PDCCH is generated.
Tenth Embodiment of the WCA Field
For the purpose of improving the applicability of Walsh codes, the
Walsh codes that are reserved for the transmission of PDCCH(i)
(i.e., codes in the Walsh Code Space) can be used for the
transmission of PDCHs if a corresponding PDCCH(i) is not currently
using the Walsh codes. In such case, the base station preferably
informs the terminals which PDCHs are using the Walsh codes in the
WCI table. In such a case, the CDMI of the previous embodiment can
be used for such a task.
The base station allows the terminals to know which Walsh codes in
the WCI table are being used for which PDCH based on the code
indices. The terminals, discovering in which PDCCH(i) a specific
value of CDMI is found, concludes which Walsh codes in WCI table
are used for which PDCH. In complying to the predetermined rule(s)
between the base station and the terminals, a terminal is supposed
to receive PDCCH(i) and thereafter PDCCH(k). If the value of the
CDMI(i) equals 0, there is no PDCCH(k).
For example, let assume that N.sub.max--PDCH is 4, and WCL=wcl(0),
wcl(1), wcl(2), and wcl(3). When CDMI(i) value on a certain
PDCCH(i) is 0, the Walsh codes for use of the transmission of
PDCH(i) corresponding to PDCCH(i) includes the Walsh codes that are
allocated for transferring PDCH(i) in the WCI table, and the Walsh
codes that are not yet used by PDCCH(0), PDCCH(1), . . . , PDCCH(i)
in the WCI table. For instance, suppose that PDCCH(1) indicates a
PDCCH whose CDMI value is 0. Then, among wcl(2) and wcl(3), the
codes, which satisfy the predetermined requirements between the
terminal and the base station, are used additionally for
transferring PDCH(1).
Eleventh Embodiment of the WCA Field
As previously described in some of the embodiment, the WCA can be
used for the TDM system or TDM scheduling. However, all the
previous embodiments are readily applicable to TDM system or TDM
scheduling. In TDM system, N.sub.max--PDCH is equal to 1, and
hence, TDM system uses only one PDCH(i) and one PDCCH(i), and the
other PDCHs and PDCCHs are suspended. In such an instance, the WCA
can be used as WSI, but without the need to broadcast regularly or
intermittently. Further, the WCA serving as the WSI can allocate
the resources such that not all available Walsh codes are used for
transmission of the PDCH(i) and PDCCH(i).
In this instance, the 5-bit WCA, 2-bit ACID, and the 3-bit EP_SIZE
are preferably used. Further, the value of the WCA represents the
code index on the WCI table, and represent the number of codes from
the highest priority code indexed Walsh code to the lower priority
code index Walsh code of the WCI table, e.g., LWCI. For example, if
the value of WCA is `00011.sub.2(3.sub.10)`, 3 Walsh codes from
code index 0 to code index 3 of FIG. 5 are used for transmission of
the PDCH and thereafter, the WCA can be used to decode the data on
the PDCH by the terminal. Further, since the PDCCH(i) includes the
MAC_ID, broadcasting is not needed and such that the WCA need not
be transferred to all terminals, but only to a particular relevant
terminal requiring the WCA.
Twelfth Embodiment of the WCA Field
In the above 11 embodiments, WCA was not broadcasted to all the
terminals, but was transferred only to specific terminals. However,
the unique feature of the WCA allows flexibility such that WCA may
be used via broadcasting using a prescribed control channel. This
control channel may be one of the existing control channels or a
new broadcasting channel labeled as Walsh Code Allocation
Channel.
For example, when N.sub.max--PDCH is 2, two PDCH(i) and two
PDCCH(i) are used, wherein i=0 and 1. Assuming that the PDCCH(0) is
used for broadcasting, the information bits on the PDCCH(0) are set
up in a particular way, e.g., MAC_ID equals `00000000`, and SPID is
set up as `11` and the 2-bit ACID is added with the x.sub.--0 bits,
e.g., 5 bits, of the WCA. This can be broadcasted to all the
terminals to notify the available Walsh codes. The 5 bit WCA can
indicate the number of Walsh codes in the WCI table, e.g., LWCI, a
general set of Walsh codes in the WCI table or a specific set of
Walsh codes in the WCI table. Alternatively, the PDCCH(1) physical
channel can be used for such broadcasting.
Transmission Chain for Packet Data Channel Structure
The Packet Data Channel preferably transmits a prescribed number of
information bits, e.g., 386, 770, 1538, 2306, 3074, or 3842 bits.
Sixteen packet frame quality indicator bits and six turbo encoder
tail allowance bits are added to the information bits to form
encoder packets. The encoder packets are encoded with a rate-1/5
turbo encoder, interleaved, and scrambled. Thereafter, symbols from
the scrambled sequence are selected for transmission as a
subpacket. The selected symbols may not include all of the
scrambled output symbols or they may include all of the scrambled
output symbols with some symbols repeated one or more times. The
selected subpacket symbols are modulated into QPSK, 8-PSK, or
16-QAM symbols and demultiplexed into one to 28 32-chip Walsh
channels used for that Forward Packet Data Channel. Each of these
Walsh channels is spread with a different 32-chip Walsh function.
Then, the spread symbols on the Walsh channels are summed to obtain
a single sequence of I/Q-symbols.
FIGS. 12A and 12B illustrate such a transmission chain for the
PDCH. The prescribed number of information bits of the PDCH is
inputted to a CRC generator 10 to add 16 frame quality indicator
bits and thereafter to a tail allowance generator 11 to add 6 turbo
encoder tail allowance bits. A Cyclic Redundancy Code (CRC) is a
class of linear error detecting codes, which generate parity check
bits by finding the remainder of a polynomial division. The encoder
tail bits a fixed sequence of bits added to the end of a block of
data to reset the turbo encoder to a known state.
A turbo encoder 12 discards the turbo encoder tail allowance bits
and adds turbo encoder output tail bits such that the number of
bits out of the rate-1/5 turbo encoder is five times the number of
bits in an encoder packet. The encoder packets are turbo encoded
with a code rate of 1/5.
During encoding, an encoder output tail sequence is added, and the
turbo encoder generates Nturbo/R encoded data output symbols
followed by 6/R tail output symbols, where R is the code rate of
1/2, 1/3, 1/4, or 1/5, where Nturbo is the total number of
information bits and frame quality indicator bits. The turbo
encoder 12 employs two systematic, recursive, convolutional
encoders connected in parallel, with an interleaver, the turbo
interleaver, preceding the second recursive convolutional encoder.
The two recursive convolutional codes are called the constituent
codes of the turbo code. The outputs of the constituent encoders
are punctured and repeated to achieve the (Nturbo+6)/R output
symbols.
The turbo encoder output sequence is interleaved by a channel
interleaver 13. The interleaving comprises symbol separation,
subblock interleaving, and symbol grouping of the turbo encoder
output sequence. Every interleaver output symbol are exclusive-OR'd
with the corresponding bit of the scrambling sequence generated by
a scrambler 13 based on a public long code mask or a private long
code mask to yield a scrambled output bit.
Subpacket symbols are selected from the scrambler output sequence
by a selector 15. Encoder packets are transmitted as one or more
subpackets. Initially, the first subpacket is transmitted. Then,
subsequent subpackets are transmitted if requested by the mobile
station. The symbols in a subpacket are formed by selecting
specific sequences of symbols from the interleaved and scrambled
turbo encoder output sequence. The resulting subpacket sequence is
a binary sequence of symbols for a modulator 16.
The symbols from the subpacket symbol selection process are
modulated. The modulator 16 maps the symbols from the subpacket
symbol selection process into a sequence of QPSK, 8-PSK, or 16-QAM
modulation symbols. The type of modulation depends on the encoder
packet size, number of Walsh channels, and number of slots.
The modulated symbols are demultiplexed into Walsh channels, each
Walsh channel is Walsh spread, and the spread symbols from the
Walsh channels are summed. A demultiplexer 17 demultiplexes the
in-phase stream at the output of QPSK/8-PSK/16-QAM modulator into N
parallel streams, I1, I2, . . . , IN, where N is the total number
of 32-chip Walsh codes that are indicated in WCI_SET (i.e., WCI
table). Similarly, the quadrature stream at the output of the
QPSK/8-PSK/16-QAM modulator are demultiplexed into N parallel
streams, Q1, Q2, . . . , QN. For each k=1, 2, . . . , N, the
demultiplexed streams with labels Ik and Qk are assigned to the
in-phase and quadrature phases, respectively, of the kth Walsh code
that appears in the WCI_SET. Following the Walsh channel spreading,
the spread subpacket modulation symbols from the Walsh channels are
summed by a summer 18 to form a single sequence of (I, Q)
symbols.
After performing a orthogonal spreading and channel gain, each code
channel is spread in quadrature by a spreader. The spreading
sequence is preferably a quadrature sequence of a prescribed
length, e.g., 215 (i.e., 32768 PN chips in length). This sequence
is called the pilot PN sequence. Following the spreading operation,
the I and Q impulses are applied to the inputs of the I and Q
baseband filters 20a and 20b. Thereafter, the outputs of the
filters 20a and 20b are mixed, summed and transmitted over the
PDCH.
On the terminal side, the decoding is substantially the reverse of
this encoding process.
Transmission Chain for Packet Data Control Channel Structure
FIG. 13 illustrates a general configuration of PDCCH transmission
chain in accordance with one preferred embodiment of the present
invention. The input sequence of PDCCH includes 2-bit ARQ channel
identifier, 3-bit encoder packet size, 1-bit AI_SN, x_i-bit WCI,
and 2-bit subpacket identifier with or without the 8-bit MAC,
An error detection code like CRC (cyclic redundancy check) code in
an error detection code adding block 101 to the input sequence.
This added bit is provided with tail bits for sending a final state
of the encoder from a tail bit adding blocks 102 trellis
termination. The bits with tail bit are encoded to convolutional
code at the encoder 103.
The encoded bits are repeated to a prescribed repetition factor at
the symbol repetitive block 104. Such repeated bits goes through
puncturing process at the symbol puncturing block 105. Those
puncturing processed bits are interleaved at the block interleaver
106, and are modulated at the modulator 107, in conforming to QPSK
method. The modulated signals are divided into I channels and Q
channels, by using part of the Walsh codes indicated by WCL.
For a given base station, the I and Q pilot PN sequences for the
Forward Packet Data Control Channel preferably use the same pilot
PN sequence offset as for the Forward Pilot Channel. The modulation
symbols transmitted on the first Forward Packet Data Control
Channel (PDCCH_ID=`0`) should preferably be transmitted using at
least as much energy as the modulation symbols transmitted on the
second Forward Packet Data Control Channel (PDCCH_ID=`1`) that is
being transmitted simultaneously, N.sub.max--PDCH is 2.
The tail bit generator generates the last eight bits of each
Forward Packet Data Control Channel frame are called the Encoder
Tail Bits. Preferably, each of the eight bits is set to `0`. The
encoder convolutionally encodes as the PDCCH frame. Preferably, the
encoder is initialized to the all-zero state at the end of each
frame. The encoded PDCCH frame undergoes code symbol repetition and
the code symbols resulting from the symbol repetition are
punctured. The modulation symbols on the PDCCH are then
interleaved, and the interleaver block is align with the PDCCH
frame. The modulation signal is provided to the signal point
mapping block (e.g., modulator) for transmission
The foregoing embodiments and advantages are merely exemplary and
are not to be construed as limiting the present invention. The
present teaching can be readily applied to other types of
apparatuses. The description of the present invention is intended
to be illustrative, and not to limit the scope of the claims. Many
alternatives, modifications, and variations will be apparent to
those skilled in the art. In the claims, means-plus-function
clauses are intended to cover the structures described herein as
performing the recited function and not only structural equivalents
but also equivalent structures.
* * * * *
References