U.S. patent number 9,270,402 [Application Number 14/166,279] was granted by the patent office on 2016-02-23 for wireless terminal apparatus and wireless base station apparatus.
This patent grant is currently assigned to KDDI CORPORATION. The grantee listed for this patent is KDDI CORPORATION. Invention is credited to Feng Lu, Toshinori Suzuki, Toshiaki Yamamoto.
United States Patent |
9,270,402 |
Yamamoto , et al. |
February 23, 2016 |
Wireless terminal apparatus and wireless base station apparatus
Abstract
Both a wireless terminal apparatus and wireless base station
apparatus are provided that can, in an operation of encoding the
control signals of the upstream link transmitted from the multiple
terminal stations while encoding with regard to each of the
terminal stations, increase a number of the terminal stations to
which different codes are respectively assigned. A wireless
terminal apparatus includes: an encoding information receiving
portion receiving encoding information which is used at the
wireless terminal apparatus from the base station; a phase-shifting
unit which conducts a phase-shifting operation on a predetermined
first code based on the encoding information; a code selection unit
which, based on the received encoding information, selects a second
code from multiple codes orthogonally crossing each other; and a
control signal encoding portion which conducts an encoding
operation on the control signal that is going to be transmitted to
the base station by using both the first code on which the
phase-shifting operation has been conducted and the second
code.
Inventors: |
Yamamoto; Toshiaki (Fujimino,
JP), Lu; Feng (Fujimino, JP), Suzuki;
Toshinori (Fujimino, JP) |
Applicant: |
Name |
City |
State |
Country |
Type |
KDDI CORPORATION |
Tokyo |
N/A |
JP |
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Assignee: |
KDDI CORPORATION (Tokyo,
JP)
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Family
ID: |
39344271 |
Appl.
No.: |
14/166,279 |
Filed: |
January 28, 2014 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20140140307 A1 |
May 22, 2014 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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12447209 |
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8761145 |
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PCT/JP2007/071246 |
Oct 31, 2007 |
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Foreign Application Priority Data
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Oct 31, 2006 [JP] |
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2006-296910 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04J
13/0059 (20130101); H04J 13/0062 (20130101); H04W
72/042 (20130101); H04J 13/0003 (20130101); H04J
11/00 (20130101); H04J 13/18 (20130101); H04W
72/0466 (20130101); H04W 72/0413 (20130101); H04J
13/0074 (20130101); H04J 13/004 (20130101); H04L
5/0014 (20130101); H04W 88/02 (20130101); H04W
76/20 (20180201) |
Current International
Class: |
H04J
13/00 (20110101); H04J 13/18 (20110101); H04J
11/00 (20060101); H04W 72/04 (20090101); H04L
5/00 (20060101); H04W 76/04 (20090101); H04W
88/02 (20090101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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07-336323 |
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Dec 1995 |
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JP |
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8-288927 |
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Nov 1996 |
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JP |
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08-288927 |
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Nov 1996 |
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JP |
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2007-194751 |
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Aug 2007 |
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JP |
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2007-300314 |
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Nov 2007 |
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JP |
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2008/136156 |
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Jun 2008 |
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JP |
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2009-540665 |
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Nov 2009 |
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JP |
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2007/142492 |
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Dec 2007 |
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WO |
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2008/041675 |
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Apr 2008 |
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WO |
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Other References
Author Unknown, Multiplexing of L1/L2 Control Signaling when UE has
no Data to Transmit, Nokia Submission R1-062841, Third Generation
Partnership Project, Oct. 13, 2006, pp. 1-7. cited by examiner
.
Author Unknown, CDM-Based Multiplexing Method of Multiple ACK/NACK
and CQI for E-UTRA Uplink, Third Generation Partnership Project
Document R1-062742, Oct. 9, 2006, pp. 1-6. cited by examiner .
A. Dammann, S. Kaiser, Low Complex Standard Conformable Antenna
Diversity Techniques for OFDM Systems and its Application to the
DVB-T System, 4th International ITG Conference on Source and
Channel Coding, Berlin, Germany, 2002. cited by examiner .
Author Unknown, EUTRA SC-FDMA Uplink Pilot/Reference Signal Design
& TP, Third Generation Partnership Project Document R1-061176,
May 12, 2006, pp. 1-8. cited by applicant .
Author Unknown, Composition of Proposed Uplink Pilot Structures for
SC-OFDMA, Third Generation Partnership Project Document R1-060373,
Feb. 13, 2006, pp. 1-10. cited by applicant .
PCT Search Report, PCT/JP2007/071246. cited by applicant .
NTT DoCoMo, Ericsson, Fujitsu, Mitsubishi Electric, Sharp, Toshiba
Corp., 3GPP TSG RAN WG1 Meeting #46bis, R1-062742, "CDM-based
Multiplexing Method of Multiple ACK/NACK and CQ1 for E-UTRA
Uplink," Oct. 2006; pp. 1-6. cited by applicant .
Kiddi, NTT DoComo, "L1/L2 Control Channel Structure with CDM Based
Multiplexing in Downlink," 3GPP TSG RAN WG1 Meeting #46bis;
R1-062805; Oct. 2006; pp. 1-4. cited by applicant .
Kiddi, NTT DoComo, "Scrambling Code for L1/L2 Control Channel with
CDM Based Multiplexing in E-UTRA Downlink," 3GPP TSG RAN WG1
Meeting #46bis; R1-062945; Oct. 2006; pp. 1-4. cited by applicant
.
Office Action dated Aug. 1, 2014, issued by the U.S. Patent and
Trademark Office in U.S. Appl. No. 14/166,237. cited by applicant
.
Notice of Allowance issued on May 18, 2015, issued by the U.S.
Patent & Trademark Office in U.S. Appl. No. 14/166,300. cited
by applicant .
Popovic, "Generalized Chirp-Like Polyphase Sequence with Optimum
Correlation Properties," IEEE Transactions on Information Theory,
vol. 38, No. 4, Jul. 1992, pp. 1406-1409. cited by
applicant.
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Primary Examiner: Crutchfield; Christopher
Attorney, Agent or Firm: Morgan, Lewis & Bockius LLP
Parent Case Text
TECHNICAL FIELD
The present invention relates to a wireless terminal apparatus and
a wireless base station apparatus.
This application is a divisional of U.S. patent application Ser.
No. 12/447,209, filed on Apr. 24, 2009, which claims the benefit of
the Japanese Patent Application No. 2006-296910, filed on Oct. 31,
2006, the entire disclosure of each of which is incorporated herein
by reference.
Claims
The invention claimed is:
1. A method of wireless terminal apparatus which encodes and
transmits a control signal to a wireless base station apparatus,
comprising: by a receiver, receiving encoding information which is
used at the wireless terminal apparatus and which is transmitted
from the wireless base station apparatus; by an encoder, inputting
the encoding information comprising a first code, a second code,
and a phase shift amount from the receiver, and conducting an
encoding and multiplexing operation on the control signal using a
first multiplier and a second multiplier, wherein the first
multiplier conducts a multiplication operating using the first code
on which a phase-shift operation is conducted by a phase shift
portion using the phase-shift amount, and where the second
multiplier conducts a multiplication operating using the second
code; and by a transmitter, transmitting the encoded control
signal, wherein the second code is an orthogonal code of a three
dimension which is generated from complex numbers and which has a
code length of 3.
Description
BACKGROUND ART
In recent years, a standardization project "3GPP: 3rd Generation
Partnership Project" has been discussing a standard regulation of a
third generation (3G) mobile communication system. One of topics
which has been discussed is a control signal transmission method of
an upstream link (link in a direction from a terminal station to a
base station).
For example, Non-Patent Document 1 proposes a method of encoding
both ACK/NACK signals transmitted from multiple terminal stations
and CQI (Channel Quality Indicator) signals at the upstream link
with regard to each of the terminal stations. ACK/NACK signals are
response signals of 1 bit for confirmation of transmission, ACK
signal has a bit "1" used when responding positively, and NACK
signal is a bit "0" used when responding negatively. CQI signal is
a signal of 5 bits that reports a receiving level.
In a technique of Non-Patent Document 1, ACK/NACK signals and CQI
signals are encoded by using "CAZAC (Constant Amplitude Zero Auto
Correlation)" code. In this conventional technique, the phase shift
amount of CAZAC code used for encoding is varied with regard to
each of the terminals. It should be noted that the CAZAC code is a
code that has constant amplitude and no autocorrelation.
However, the above-described conventional technique assigns CAZAC
code of the different phase shift amount to each of the terminals,
but has a problem in which a number of the terminal stations to
which the code can be assigned is small.
[Non-Patent Document 1] 3GPP, R1-062742, NTT DoCoMo et al.,
"CDM-based Multiplexing Method of Multiple ACKJNACK and CQI for
E-UTRA Uplink", Oct. 9-13, 2006
DISCLOSURE OF INVENTION
The present invention was conceived in order to solve the
above-described problem and has an object to provide both a
wireless terminal apparatus and wireless base station apparatus
that can, in an operation of encoding the control signals of the
upstream link transmitted from the multiple terminal stations while
encoding with regard to each of the terminal stations, increase a
number of the terminal stations to which different codes are
respectively assigned.
In order to solve the above-described problems, the present
invention provides, for example, following aspects.
A first aspect is a wireless terminal apparatus which encodes and
transmits a control signal to a wireless base station, including:
an encoding information receiving unit receiving encoding
information which is used at the wireless terminal apparatus from
the base station; a first phase-shifting unit which conducts a
phase-shifting operation on a predetermined first code based on the
encoding information; a code selection unit which, based on the
encoding information, selects a second code from multiple codes
orthogonally crossing each other; an encoding unit which conducts
an encoding operation on the control signal by using both the first
code on which the phase-shifting operation has been conducted and
the second code; and a transmission unit which transmits the
encoded control signal.
A second aspect is a wireless base station apparatus which
communicates with the above-described wireless terminal apparatus,
including: an encoding information transmission unit transmitting
the encoding information which is respectively different with
regard to the wireless terminal apparatus; a receiving unit the
encoded control signal from the wireless terminal apparatus; a
second phase-shifting unit which conducts a phase-shifting
operation on the first code based on the encoding information
corresponding to the wireless terminal apparatus; a second code
selection unit which, based on the encoding information
corresponding to the wireless terminal apparatus, selects the
second code from multiple codes orthogonally crossing each other;
and a decoding unit which decodes the encoded control signal by
using both the first code on which the phase-shifting operation has
been conducted and the second code.
A third aspect is the above-described wireless terminal apparatus,
wherein the first code has both a constant amplitude and a zero
autocorrelation.
A fourth aspect is a control signal transmission method of a
wireless terminal apparatus including steps of: based on
predetermined encoding information, conducting a phase-shifting
operation on a first code which has both a constant amplitude and a
zero autocorrelation; based on the encoding information, selecting
a second code from multiple codes orthogonally crossing each other;
conducting an encoding operation on the control signal by using
both the first code on which the phase-shifting operation has been
conducted and the second code; and transmitting the encoded control
signal.
In accordance with the above-described first, second and fourth
aspects, in an operation of encoding the control signals of the
upstream link transmitted from the multiple terminal stations while
encoding with regard to each of the terminal stations, it is
possible to increase a number of the terminal stations to which
different codes are respectively assigned. In addition, in
accordance with the above-described third aspect, it is possible to
use CAZAC that is generally known.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram showing a constitution of a terminal
station (wireless terminal apparatus) 1 of one embodiment of the
present invention.
FIG. 2 is a block diagram showing a constitution of a control
signal encoding portion 14 shown in FIG. 1.
FIG. 3 is a block diagram showing a constitution of a base station
(wireless base station apparatus) 40 of one embodiment of the
present invention.
FIG. 4 is a drawing for explaining Example 1 in which a first code
and a second code of the present invention are used.
FIG. 5 is a drawing for explaining Example 2 in which a first code
and a second code of the present invention are used.
FIG. 6 is a drawing for explaining Example 3 in which a first code
and a second code of the present invention are used.
DESCRIPTION OF THE REFERENCE SYMBOLS
1 . . . terminal station (wireless terminal apparatus) 11, 41 . . .
antenna 12, 42 . . . wireless communication portion 13, 43 . . .
control portion 14 . . . control signal encoding portion 15 . . .
encoding information receiving portion 21 . . . phase shift portion
22 . . . code generation portion 23, 24 . . . multiplier 40 base
station (wireless base station) 44 . . . control signal decoding
portion 45 . . . encoding information transmission portion
BEST MODE FOR CARRYING OUT THE INVENTION
Hereinafter, in reference to the drawings, a preferable embodiment
of the present invention as an example is explained. It should be
noted that the following embodiments are not limitations on the
present invention, and for example, it is possible to add, remove
or replace the constitutional elements, and in addition, it is
possible to combine the constitutional elements.
In reference to the drawings, one embodiment of the present
invention is explained below.
FIG. 1 is a block diagram showing a constitution of a terminal
station (wireless terminal apparatus) 1 of this embodiment of the
present invention. The terminal station 1 is a terminal station of
a mobile communication system and conducts a wireless communication
with a base station explained below. In FIG. 1, the terminal
station 1 includes an antenna 11, a wireless communication portion
12, a control portion 13, a control signal encoding portion 14 and
an encoding information receiving portion 15.
The wireless communication portion 12 receives wireless signals
from the base station via the antenna 11. In addition, the wireless
communication portion 12 transmits wireless signals to the base
station via the antenna 11. The control portion 13
transmits/receives control signals to/from the base station via the
wireless communication portion 12. The control signal encoding
portion 14 receives a control signal of an upstream link which is
used for a transmission to the base station and conducts an
encoding operation on the received control signal. The control
signal encoding portion 14 outputs the control signal after
encoding (encoded control signal) to the wireless communication
portion 12. The wireless communication portion 12 inputs the
encoded control signal and transmits the encoded control signal to
the base station via the antenna 11.
The encoding information receiving portion 15 receive encoding
information from the base station via the wireless communication
portion 12. The encoding information receiving portion 15 outputs
the received encoding information to the control signal encoding
portion 14. Based on the encoding information received from the
encoding information receiving portion 15, the control signal
encoding portion 14 obtains a code used for encoding the control
signal.
FIG. 2 is a block diagram showing a constitution of the control
signal encoding portion 14 shown in FIG. 1. In FIG. 2, the control
signal encoding portion 14 includes a phase shift portion 21, a
code generation portion 22, and multipliers 23 and 24.
Based on the encoding information received from the encoding
information receiving portion 15, the phase shift portion 21
conducts a phase shift operation on a first code. The phase shift
portion 21 outputs the first code to the multiplier 23 after the
phase shift operation. The encoding information output from the
encoding information receiving portion 15 includes information that
indicates amount of a phase shift with regard to the first code.
The first code has a constant amplitude and a zero autocorrelation.
It is possible to use, for example, CAZAC code as the first
code.
The code generation portion 22 generates a second code based on the
encoding information input from the encoding information input from
the encoding information receiving portion 15. The second code is
generated after selecting one of multiple codes that are
orthogonally crossing each other. The encoding information received
from the encoding information receiving portion 15 includes
information for determining the second code. It is possible to use,
for example, Walsh codes as the orthogonally crossing codes.
It should be noted that it is possible to directly include the
second code in the encoding information received from the encoding
information receiving portion 15. In other words, the code
generation portion 22 can be a code selection unit that provides a
function of selecting the second code from the codes which
orthogonally cross each other, based on the encoding information
input from the encoding information receiving portion 15.
In the control signal encoding portion 14 shown in FIG. 2, the
multiplier 23 which is firstly provided conducts a multiplication
operation between the control signal input from the control portion
13 and the code (the first code after phase shift operation) output
from the phase shift portion 21. In a following step, the
multiplier 24 which is secondary provided conducts a multiplication
operation between a signal output from the multiplier 23 and the
code (second code) output from the code generation portion 22. In
accordance with such an operation, the control signal output from
the control portion 13 is converted to the encoded control signal
which is encoded by using both the first code after phase-shifting
and the second code. The multiplier 24 outputs the encoded control
signal to the wireless communication portion 12.
FIG. 3 is a block diagram showing a constitution of a base station
(wireless base station apparatus) 40 of one embodiment of the
present invention. The base station 40 shown in FIG. 3 is a base
station of the mobile communication system and conducts a wireless
communication to the terminal station 1 shown in FIG. 1. In FIG. 3,
the base station 40 includes an antenna 41, a wireless
communication portion 42, a control portion 43, a control signal
decoding portion 44 and an encoding information transmission
portion 45.
The wireless communication portion 42 receives wireless signals
from the terminal station 1 via the antenna 41. In addition, the
wireless portion 42 transmits wireless signals to the terminal
station via the antenna 41. The control portion 43
transmits/receives control signals to/from the terminal station 1
via the wireless communication portion 42. The control signal
decoding portion 44 receives the encoded control signal transmitted
from the terminal station 1 via the wireless communication portion
42 and decodes the encoded control signal after receiving. The
control signal decoding portion 44 outputs the decoded control
signal to the control portion 43.
Via the wireless communication portion 42, the encoding information
transmission portion 45 transmits the encoding information which is
different with regard to each of the terminal stations. In
addition, the encoding information transmission portion 45 outputs
the encoding information corresponding to each of the terminal
stations to the control signal decoding portion 44. Based on the
encoding information input from the encoding information
transmission portion 45, the control signal decoding portion 44
obtains the code which is used to decode the encoded control
signal.
The control signal decoding portion 44 conducts a decoding
operation which corresponds to the encoding operation by the
control signal encoding portion 14 shown in FIG. 2. The control
signal decoding portion 44 provides a phase shifting portion which
conducts a phase shifting operation on the first code based on the
encoding information which is provided in correspondence with each
of the terminal stations. The phase shifting operation on the first
code in correspondence with each of the terminal stations is
conducted. The encoding information corresponding to each of the
terminal stations includes information of amount of phase-shift of
the corresponding terminal station. The first code is a code which
has both a constant amplitude and a zero autocorrelation, and the
first code is common between the terminal stations.
In addition, based on the encoding information corresponding to
each of the terminal stations, the control signal decoding portion
44 provides a code selection portion which selects the second code
from the codes which orthogonally cross each other. With regard to
each of the terminal stations, as the second code, one code is
selected between the codes which orthogonally cross each other. The
codes which orthogonally cross each other and form which the second
code is selected are common among the terminal stations. The
encoding information corresponding to each of the terminal stations
includes information which specifies the second code of the
corresponding terminal station.
In addition, the control signal decoding portion 44 provides a
decoding portion which decodes the encoded control signal by using
both the first code after phase-shifting and the second code.
Therefore, the encoded control signal transmitted from each of the
terminal stations is decoded. The control signal after decoding is
output to the control portion 43.
In a following explanation, examples of the first code and second
code of this embodiment are shown and explained. Here, CAZAC code
is used as the first code, and Walsh codes are used as "the codes
which orthogonally cross each other" from which the second code is
selected.
EXAMPLE 1
FIG. 4 is a drawing for explaining Example 1 in which the first
code and the second code of this example are used. In the Example
1, a pair of Walsh codes of two dimensions "(1,1) and (1,-1)" are
used. In FIG. 4, a control signal area has a 12 bit length, and the
encoding operation is conducted on data stored in this 12 bit area.
In an example shown in FIG. 4, each of four terminal stations 1
("UE1", "UE2", "UE3" and "UE4") transmits a control signal of an
uplink to the base station 40 which is a single base station.
As shown in FIG. 4, both "UE1" and "UE2" conducts an encoding
operation on the control information by using CAZAC codes obtained
by a phase-shifting of amount of .DELTA.1. In addition, "UE1"
conducts the encoding operation on the control information by using
Walsh code of (1, 1), and "UE2" conducts the encoding operation on
the control information by using Walsh code of (1, -1). In
accordance with such a manner, even when both of CAZAC codes have
the same amount of phase-shifting, it is possible to conduct
encoding operations on the control information of uplink so as to
be orthogonal with regard to each of "UE1" and "UE2" because
different Walsh codes are used. Therefore, it is possible to assign
a pair of terminal stations to a single phase-shifting amount of
.DELTA.1.
In a similar manner, both "UE3" and "UE4" conducts an encoding
operation on the control information by using CAZAC codes obtained
by a phase-shifting of amount of .DELTA.2, but different Walsh
codes are used. "UE3" uses Walsh code of (1, 1), and "UE4" uses
Walsh code of (1, -1). Therefore, it is possible to assign a pair
of terminal stations to a single phase-shifting amount of
.DELTA.2.
In accordance with the Example 1, it is possible to assign a pair
of terminal stations to a single phase-shifting amount applied to
the CAZAC code. Therefore, compared to a prior art in which CAZAC
code with an unique phase-shifting amount is assigned to each of
terminal stations, it is possible to increase a number of terminal
stations to be double while different codes are respectively
assigned to the terminal stations.
EXAMPLE 2
FIG. 5 is a drawing for explaining Example 2 in which a first code
and a second code are used. In the Example 2, Walsh codes of four
dimensions "(1, 1, 1, 1), (1, -1, 1, -1), (1, 1, -1, -1), (1, -1,
-1, 1)" are used. In an example shown in FIG. 5, in the similar
manner as shown in FIG. 4, an encoding operation is conducted on a
control signal area of 12 bits. In the similar manner as shown in
FIG. 4, each of four terminal stations 1 ("UE1", "UE2", "UE3" and
"UE4") transmits a control signal of an uplink to the base station
40 which is a single base station.
As shown in FIG. 5, by using the CZAC codes obtained by
phase-shifting with a phase-shifting amount of .DELTA.1, all of
"UE1", "UE2", "UE3" and "UE4" conducts an encryption operation on
the control information. It should be noted that each of these
terminal stations, by using respectively different Walsh code,
conducts the encryption operation on the control information. "UE1"
uses Walsh code of (1, 1, 1, 1), "UE2" uses Walsh code of (1, -1,
1, -1), "UE3" uses Walsh code of (1, 1, -1, -1), and "UE4" uses
Walsh code of (1, -1, -1, 1). Therefore, it is possible to assign
four terminal stations even though the amount of phase-shifting is
a single value, .DELTA.1.
In accordance with Example 2, it is possible to assign four
terminal stations to a single phase-shifting amount applied to the
CAZAC code. Therefore, compared to a prior art in which CAZAC code
with an unique phase-shifting amount is assigned to each of
terminal stations, it is possible to increase a number of terminal
stations to be four times while different codes are respectively
assigned to the terminal stations.
EXAMPLE 3
FIG. 6 is a drawing for explaining Example 3 in which a first code
and a second code are used. In the Example 3, in a similar manner
as explained in Example 1, a pair of Walsh codes of two dimensions
"(1,1) and (1,-1)" are used. In addition, in a similar manner as
explained in Example 1, the encoding operation is conducted on data
stored in a control signal area which has a 12 bit length. It
should be noted that the encoding operation on Walsh codes is
conducted only on a predetermined bit position included in the
control signal area of 12 bits. In other words, the encoding
operation on Walsh codes is not necessary that is conducted on all
bit positions included in the control signal area. In accordance
with Example 3, similarly as described in Example 1, it is possible
to assign a pair of terminal stations to a single phase-shifting
amount applied to the CAZAC code. Therefore, compared to a prior
art in which CAZAC code with an unique phase-shifting amount is
assigned to each of terminal stations, it is possible to increase a
number of terminal stations to be double while different codes are
respectively assigned to the terminal stations.
As described above, in accordance with this embodiment, compared to
a prior art in which CAZAC code with a unique phase-shifting amount
is assigned to each of terminal stations, it is possible to
increase a number of terminal stations while different codes are
respectively assigned to the terminal stations. As a result, it is
possible to provide an advantage in which it is possible to
increase a number of terminal stations that are covered by a single
base station.
It should be noted that, in the above-described Examples 1-3, Walsh
codes are used as "the codes which orthogonally cross each other"
from which the second code is selected. However, Walsh codes are
not a limitation for "the codes which orthogonally cross each
other".
For example, it is possible to use orthogonal codes generated from
complex numbers as "the codes which orthogonally cross each other".
Following example shows orthogonal codes of a three dimension
generated from complex numbers.
(1,1,1)(1,e.sup.j2.pi./3,e.sup.-j2.pi./3)(1,e.sup.j4.pi./3,e.sup.-j4.pi./-
3)
In addition, it is possible to use orthogonal codes on a rotating
coordinate system as "the codes which orthogonally cross each
other". Following example is orthogonal codes on a rotating
coordinate system of two dimensions. (cos .theta., sin
.theta.)(-sin .theta., cos .theta.) It should be noted that .theta.
is a rotation angle.
When orthogonal codes on a rotating coordinate system are used, by
adjusting the rotation angle .theta., it is possible to adjust or
lower detection errors due to differences between reception levels
of symbols.
In reference to the drawings, embodiments of the present invention
are explained above. It should be noted that a concrete
constitution is not limited by the above-described embodiments, and
it is possible to include modifications of the constitution if the
modifications is not out of a scope of the present invention.
For example, it is possible to conduct a modulation operation on
the control signal. For example, it is possible to apply a
modulation of QPSK (Quadrature Phase Shift Keying, Quadri-Phase
Shift Keying) to CQI signal of 5 bits. In such a case, 2 bits can
be transmitted per one symbol, and hence, it is possible to
increase amount of information of a control storage area, and it is
possible to achieve a higher communication quality of control
signals.
INDUSTRIAL APPLICABILITY
In accordance with the above-described examples, in an operation of
encoding the control signals of the upstream link transmitted from
the multiple terminal stations while encoding with regard to each
of the terminal stations, it is possible to increase a number of
the terminal stations to which different codes are respectively
assigned.
* * * * *