U.S. patent application number 10/235918 was filed with the patent office on 2003-01-09 for cdma mobile station apparatus and cdma transmission method.
Invention is credited to Yamada, Daisuke.
Application Number | 20030007472 10/235918 |
Document ID | / |
Family ID | 16576180 |
Filed Date | 2003-01-09 |
United States Patent
Application |
20030007472 |
Kind Code |
A1 |
Yamada, Daisuke |
January 9, 2003 |
CDMA mobile station apparatus and CDMA transmission method
Abstract
Burst frame generation circuit 307 generates burst data solely
made of pilot symbols and transmission power control symbols.
Transmission interval control circuit 308 controls the transmission
interval of said burst data N times (N: a natural number) one slot
at the end of transmission and maintains synchronization while
reducing power consumption.
Inventors: |
Yamada, Daisuke;
(Yokohama-shi, JP) |
Correspondence
Address: |
James E. Ledbetter, Esq.
STEVENS, DAVIS, MILLER & MOSHER, L.L.P.
Suite 850
1615 L Street, N.W.
Washington
DC
20036
US
|
Family ID: |
16576180 |
Appl. No.: |
10/235918 |
Filed: |
September 6, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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10235918 |
Sep 6, 2002 |
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09147831 |
Mar 16, 1999 |
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6466563 |
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Current U.S.
Class: |
370/335 ;
370/342 |
Current CPC
Class: |
H04W 52/54 20130101 |
Class at
Publication: |
370/335 ;
370/342 |
International
Class: |
H04B 007/216 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 19, 1997 |
JP |
JP9-209642 |
Claims
What is claimed is:
1. A CDMA mobile station apparatus, comprising: transmission frame
generation means for generating frames by inserting pilot symbols
and transmission power control symbols into transmission data;
burst frame generation means for generating burst frames solely
made up of pilot symbols and transmission power control symbols;
transmission interval control means for controlling a transmission
interval of said burst data; and transmission means for
transmitting said transmission data and said burst data by
radio.
2. The CDMA mobile station apparatus according to claim 1,
comprising: repetition processing means for arranging pilot symbols
and transmission power control symbols in series respectively.
3. The CDMA mobile station apparatus according to claim 1, wherein
transmission interval control means transmits burst data
non-cyclically.
4. The CDMA mobile station apparatus according to claim 3, wherein
burst frame generation means generates burst frames using burst
transmission power symbols instead of transmission power control
symbols and transmission means transmits said burst data with a
same value as a transmission power value extracted from received
data.
5. A CDMA base station apparatus, which performs cellular radio
communications with the CDMA mobile station apparatus according to
claim 1.
6. A cellular radio communication system, which performs cellular
radio communications using the CDMA mobile station apparatus
according to claim 1 and the CDMA base station apparatus according
to claim 5.
7. A CDMA transmission method, which generates transmission frames
by inserting pilot symbols and transmission power control symbols
into transmission data, transmits transmission data by radio,
generates burst frames solely made up of pilot symbols and
transmission power control symbols if there are no transmission
data and transmits burst data by radio by controlling transmission
intervals.
8. The CDMA transmission method according to claim 7, which
transmits by radio burst data subjected to processing of arranging
pilot symbols and transmission power control symbols in series
respectively.
9. The CDMA transmission method according to claim 7, which
transmits burst data non-cyclically.
10. The CDMA transmission method according to claim 9, which
generates burst frames using burst transmission power symbols
instead of transmission power control symbols and sets a burst data
transmission power value same as a transmission power value
extracted from received data.
Description
TECHNICAL FIELD
[0001] The present invention relates to CDMA mobile station
apparatuses and CDMA transmission methods such as digital car
telephones and portable telephones used for cellular radio
communication systems.
BACKGROUND ART
[0002] For radio communication systems such as digital car
telephones and portable telephones, a multiple access system is
used in which multiple mobile station apparatuses perform
communications with a single base station apparatus simultaneously.
Recently, as one of these line switching systems using this
multiple access system, a CDMA (Code Division Multiple Access)
system is used because of its high frequency utilization
efficiency.
[0003] Data transmission timing in a conventional CDMA mobile
station apparatus is explained using a timing chart shown in FIG.
1.
[0004] FIG. 1A is a timing chart showing data transmission timing
during data transmission. Pilot symbols (hereafter referred to as
"PL") and transmission power control symbols (hereafter referred to
as "TPC") are periodically inserted into data, forming a frame.
When a portion from the start of a PL to the start of the next PL
is calculated as one slot, one frame generally consists of 16
slots, 10 ms.
[0005] FIG. 1B is a timing chart showing data transmission timing
during transmission on transmission standby. "During transmission
on transmission standby" means a time corresponding to less than K
frames after completion of data transmission or a time
corresponding to less than L frames in which a CRC detection of
received data resulted in NG (K and L are predetermined constants).
On transmission standby, the CDMA mobile station apparatus
transmits burst data in which only a PL and TPC are written and
other bits are left in blank for each slot.
[0006] Here, the CRC (Cyclic Redundancy Check) detection means
processing for detecting errors in received data by judgment by a
comparison between a received CRC bit which is given with a
coefficient of a remainder polynomial obtained by dividing an
information bit by an n-th degree generating function, and a CRC
bit generated from the received data. A complete match between the
two means that the received data have been received correctly (OK)
and mismatch of at least one element means that the received data
contain errors (NG).
[0007] FIG. 1C is a timing chart showing the data transmission
timing at the end of transmission. The end of transmission means a
state in which at least K frames are detected after data
transmission is completed and at least L frames in which a CRC
detection of the received data resulted in NG are detected.
[0008] As shown in FIG. 1C, the conventional CDMA mobile station
apparatus stops transmission of burst data in a certain time after
the end of communication in order to reduce power consumption of
batteries by a transmission amplifier.
[0009] Because of this, the conventional CDMA mobile station
apparatus above takes time to establish synchronization when
restarting communication, and it has to send a dummy signal, an
unnecessary signal, instead of data in the meantime until
synchronization is established, resulting in a problem of reducing
the transmission efficiency.
DISCLOSURE OF INVENTION
[0010] A first objective of the present invention is to provide a
CDMA mobile station apparatus and CDMA transmission method which
can maintain established synchronization with a base station
apparatus while reducing power consumption when there are no data
to be transmitted.
[0011] This objective is achieved by controlling the transmission
interval of burst data to N slots (N: a natural number) when a
certain time has elapsed after the end of data transmission.
BRIEF DESCRIPTION OF DRAWINGS
[0012] FIG. 1 is a timing chart showing the transmission timing of
data in a conventional CDMA mobile station apparatus;
[0013] FIG. 2 is a block diagram showing the configuration of a
CDMA mobile station apparatus in Embodiment 1 of the present
invention;
[0014] FIG. 3 is a timing chart showing the transmission timing of
data in the CDMA mobile station apparatus in Embodiment 1 of the
present invention;
[0015] FIG. 4 is a block diagram showing the configuration of a
CDMA mobile station apparatus in Embodiment 2 of the present
invention;
[0016] FIG. 5 is a timing chart showing the transmission timing of
data in the CDMA mobile station apparatus in Embodiment 2 of the
present invention;
[0017] FIG. 6 is a 1st block diagram showing the configuration of a
CDMA mobile station apparatus in Embodiment 3 of the present
invention;
[0018] FIG. 7 is a 1st timing chart showing the transmission timing
of data in the CDMA mobile station apparatus in Embodiment 3 of the
present invention;
[0019] FIG. 8 is a 2nd block diagram showing the configuration of
the CDMA mobile station apparatus in Embodiment 3 of the present
invention;
[0020] FIG. 9 is a 2nd timing chart showing the transmission timing
of data in the CDMA mobile station apparatus in Embodiment 3 of the
present invention.
BEST MODES FOR CARRYING OUT THE INVENTION
[0021] With reference now to the attached drawings, the best modes
for carrying out the present invention are explained in detail.
[0022] Embodiment 1
[0023] FIG. 2 is a block diagram showing the configuration of a
CDMA mobile station apparatus in Embodiment 1 of the present
invention.
[0024] The CDMA mobile station apparatus shown in FIG. 2 mainly
comprises data detection circuit 1 that carries out data
transmission/reception with a data terminal, data reception section
2 that processes a received radio signal, data transmission section
3 that processes data to be transmitted by radio, and timing
control circuit 4 that controls whole timing and sequence of signal
processing.
[0025] Data reception section 2 comprises reception antenna 201
that receives a radio signal, reception circuit 202 that converts
the frequency of the received signal to a baseband signal,
despreading circuit 203 that performs the correlation detection on
the baseband signal and extracts data directed to the own station,
demodulation circuit 204 that demodulates the data directed to the
own station, and received data conversion circuit 205 that
separates the demodulated data into a control signal and voice data
or data terminal data and performs a CRC detection.
[0026] Data transmission section 3 comprises transmission data
conversion circuit 301 that inserts PLs and TPCs into data to be
transmitted by radio forming a frame and carries out CRC coding,
modulation circuit 302 that modulates the data combined into frames
according to various modulation methods, spreading circuit 303 that
spreads the modulated data, conversion/transmission circuit 304
that converts the spread signal to a signal with a desired carrier
frequency, transmission antenna 305 that transmits the
frequency-converted signal by radio, and transmission power control
circuit 306 that determines transmission power and TPC according to
the received signal and reception level, etc.
[0027] Furthermore, data transmission section 3 comprises burst
frame generation circuit 307 that generates burst frames consisting
solely of PLs and TPCs, transmission interval control circuit 308
that controls transmission intervals of burst data, and switch 309
that switches connections based on the control signal of data
detection circuit 1.
[0028] FIG. 3 is a timing chart showing the transmission timing of
data in the CDMA mobile station apparatus in Embodiment 1. In the
following timing charts, the time is plotted on the horizontal axis
and transmission power is plotted on the vertical axis.
[0029] FIG. 3A is a timing chart showing the transmission timing of
data during data transmission. As shown in FIG. 3A, PLs and TPCs
are periodically inserted into the data output from data detection
circuit 1 in transmission data conversion circuit 301, combined
into a frame. Data combined into a frame are output to modulation
circuit 302 via changeover switch 309.
[0030] Data detection circuit 1 controls switch 309 during data
transmission so that transmission data conversion circuit 301 and
modulation circuit 302 are connected. The data input to modulation
circuit 302 are modulated according to various modulation methods,
spread by spreading circuit 303, converted to a signal with a
desired carrier frequency by transmission circuit 304 with
transmission power controlled and transmitted by radio from
transmission antenna 305.
[0031] On the other hand, data detection circuit 1 controls switch
309 so that transmission interval control circuit 308 and
modulation circuit 302 are connected when there are no data to be
transmitted.
[0032] Burst frame generation circuit 307 generates burst data in
which only PLs and TPCs are written and other bits are left in
blank when there are no data to be transmitted.
[0033] Transmission interval control circuit 308 controls the burst
data transmission interval to one slot on transmission standby.
"Transmission standby" means a time corresponding to less than K
frames after completion of data transmission or a time
corresponding to less than L frames in which a CRC detection of
received data resulted in NG (K and L are predetermined constants).
FIG. 3B is a timing chart showing the transmission timing of data
on transmission standby.
[0034] Transmitting burst data when there are no data to be
transmitted allows synchronization with the base station apparatus
to be maintained, making it possible to restart communication
immediately.
[0035] However, continuing transmission of burst data for a long
time after the end of data transmission results in an increase of
power consumption of batteries by a transmission amplifier.
[0036] On the other hand, if transmission of burst data is
completely stopped, it takes time to establish synchronization with
the base station apparatus when restarting transmission.
[0037] Therefore, transmission interval control circuit 308
controls the transmission interval of burst data to N times one
slot (N: a natural number) at the end of transmission. The end of
transmission means at least K frames after data transmission is
completed and the time at which at least L frames are detected in
each of which a CRC detection of received data resulted in NG. FIG.
3C is a timing chart showing the transmission timing of data at the
end of transmission.
[0038] Burst data are output to modulation circuit 302 via
changeover switch 309. The data input to modulation circuit 302 are
modulated according to various modulation methods, spread by
spreading circuit 303, converted to a signal with a desired carrier
frequency by transmission circuit 304 with transmission power
controlled and transmitted by radio from transmission antenna
305.
[0039] As described above, controlling the transmission interval of
burst data to N times one slot makes it possible to reduce power
consumption of batteries by a transmission amplifier, shorten the
time until synchronization is established when restarting
transmission, reduce transmission of a dummy signal, an unnecessary
signal, thus improving the transmission efficiency. Furthermore,
transmitting burst data in a slot with a free space makes it
possible to reduce interference with other stations.
[0040] Here, the transmission interval of burst data may be
non-cyclic. Using a non-cyclic transmission interval of burst data
makes it possible to avoid hearing aid problems, eliminating the
danger of affecting through resonance heart pacemakers.
[0041] Embodiment 2
[0042] Then, Embodiment 2 is explained using FIG. 4 and FIG. 5.
[0043] Embodiment 2 is an embodiment which performs repetition
processing on burst data at the end of transmission.
[0044] FIG. 4 is a block diagram showing the configuration of a
CDMA mobile station apparatus in Embodiment 2. In the CDMA mobile
station apparatus shown in FIG.4, the same components as those in
FIG. 2 are assigned the same numbers and their explanations are
omitted.
[0045] FIG. 5 is a timing chart showing the transmission timing of
data of the CDMA mobile station apparatus in Embodiment 2. FIG. 5A
is a timing chart showing the transmission timing of data during
data transmission and FIG. 5B is a timing chart showing the
transmission timing of data on transmission standby. Since the
transmission timing of data during data transmission and on
transmission standby is the same as in FIG. 3, its explanation is
omitted.
[0046] In comparison with FIG. 2, the CDMA mobile station apparatus
shown in FIG. 4 is provided with repetition processing circuit 310
added to data transmission section 3.
[0047] Repetition processing circuit 310 performs repetition
processing on PLs and TPCs of burst data input from burst frame
generation circuit 307 at the end of transmission and outputs them
to transmission interval control circuit 308. The repetition
processing means processing of arranging the same information n
times (n: a natural number) in series for PLs and TPCs.
[0048] Transmission interval control circuit 308 sets the
transmission interval of burst data subjected to repetition
processing N times (N: a natural number) one slot. FIG. 5C shows
the transmission timing of data at the end of transmission.
[0049] Burst data are output to modulation circuit 302 via
changeover switch 309. The data input to modulation circuit 302 are
modulated according to various modulation methods, spread by
spreading circuit 303 and output to transmission circuit 304.
[0050] Transmission circuit 304 controls the transmission power of
burst data to 1/n of that prior to the repetition processing,
converts the burst data to a signal with a desired carrier
frequency and transmits it by radio from transmission antenna
305.
[0051] Repeating the same information n times (n: a natural number)
and arranging them in series at the end of transmission can
maintain synchronization even if the transmission power is reduced
to 1/n of that prior to the repetition processing by transmission
circuit 304, reducing interference with other stations. The
transmission interval of burst data at the end of transmission may
be non-cyclic.
[0052] Embodiment 3
[0053] Then, Embodiment 3 is explained using FIG. 6 and FIG. 7.
[0054] Embodiment 3 is an embodiment which transmits burst data
with a transmission power value extracted from the received data
when the base station apparatus cannot transmit TPCs during
non-cyclic transmission.
[0055] FIG. 6 is a block diagram showing the configuration of a
CDMA mobile station apparatus in Embodiment 3 of the present
invention. In the CDMA mobile station apparatus shown in FIG. 6,
the same components as those in FIG. 2 are assigned the same
numbers as in FIG. 2 and their explanations are omitted.
[0056] FIG. 7 is a timing chart showing the transmission timing of
data of the CDMA mobile station apparatus in Embodiment 3. FIG. 7A
is a timing chart showing the transmission timing of data during
data transmission. FIG. 7B is a timing chart showing the
transmission timing of data on transmission standby. Since the
transmission timing of data during data transmission and on
transmission standby is the same as in FIG. 3, its explanation is
omitted.
[0057] In comparison with FIG. 2, the CDMA mobile station apparatus
shown in FIG. 6 is provided with burst transmission power control
circuit 311 that controls the transmission power value of burst
data using the transmission power value extracted from the received
data instead of TPCs and switch 312 that switches connections based
on the control signal of data detection circuit 1 added to data
transmission section 3.
[0058] Data detection circuit 1 controls switch 309 at the end of
transmission so that transmission interval control circuit 308 and
modulation circuit 302 are connected. It also controls switch 312
so that transmission circuit 304 and burst transmission power
control circuit 311 are connected.
[0059] Burst frame generation circuit 307 generates burst frames
only from PLs and burst transmission power control symbols
(hereafter referred to as "BTPC") at the end of transmission and
outputs the burst data to transmission interval control circuit
308. Information indicating the transmission power value is written
to the BTPC and the base station transmits the signal with the
transmission power value written to the BTPC.
[0060] Transmission interval control circuit 308 sets the burst
data transmission interval to N times (N: a natural number) one
slot at the end of transmission and sets it non-cyclic. Setting the
burst data transmission interval non-cyclic can avoid hearing aid
problems, eliminating the danger of affecting through resonance
heart pacemakers.
[0061] Burst data are output to modulation circuit 302 via
changeover switch 309. The data input to modulation circuit 302 are
modulated according to various modulation methods, spread by
spreading circuit 303 and output to transmission circuit 304.
[0062] Transmission circuit 304 inputs the transmission power value
extracted from the received data from burst transmission power
control circuit 311 at the end of transmission, controls the
transmission power of the burst data to the same value as the
transmission power value extracted from the received data, converts
it to a signal with a desired carrier frequency and transmits it by
radio from transmission antenna 305.
[0063] FIG. 7C is a timing chart showing the transmission timing of
data at the end of transmission and transmission power value BdB at
the end of transmission is the same as the transmission power value
extracted from the received data.
[0064] Thus, during non-cyclic transmission when the base station
apparatus cannot transmit TPCs, transmission circuit 304 sets the
data transmission power to the same value as the transmission power
value extracted from the received data, preventing it from
interfering other stations by transmitting too high a power value
and preventing it from failing to maintain synchronization by
transmitting too low a power value.
[0065] It is also possible to perform repetition processing on
burst data by adding repetition processing circuit 310 to
Embodiment 3. FIG. 8 is a block diagram showing a 2nd configuration
of the CDMA mobile station apparatus in Embodiment 3 and repetition
processing circuit 310 is added to FIG. 6. FIG. 9 is a 2nd timing
chart showing the data transmission timing of the CDMA mobile
station apparatus in Embodiment 3 which performs repetition
processing on FIG. 7 at the end of transmission.
[0066] Carrying out repetition processing allows synchronization to
be maintained even if the transmission power value is reduced by
transmission circuit 304, making it possible to reduce interference
with other stations.
[0067] As explained above, according to the CDMA transmission
apparatus and CDMA transmission method of the present invention,
the burst data transmission interval can be controlled when there
are no data to be transmitted, making it possible to maintain
synchronization while reducing power consumption.
* * * * *