JP2003101504A - Transmission apparatus and method, communication system, recording medium and program - Google Patents

Transmission apparatus and method, communication system, recording medium and program

Info

Publication number
JP2003101504A
JP2003101504A JP2001289236A JP2001289236A JP2003101504A JP 2003101504 A JP2003101504 A JP 2003101504A JP 2001289236 A JP2001289236 A JP 2001289236A JP 2001289236 A JP2001289236 A JP 2001289236A JP 2003101504 A JP2003101504 A JP 2003101504A
Authority
JP
Japan
Prior art keywords
step
fading
signal
encoding
means
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
JP2001289236A
Other languages
Japanese (ja)
Inventor
Masataka Wakamatsu
正孝 若松
Original Assignee
Sony Corp
ソニー株式会社
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Sony Corp, ソニー株式会社 filed Critical Sony Corp
Priority to JP2001289236A priority Critical patent/JP2003101504A/en
Publication of JP2003101504A publication Critical patent/JP2003101504A/en
Application status is Withdrawn legal-status Critical

Links

Abstract

(57) [Summary] PROBLEM TO BE SOLVED: To easily change the assignment of subcarriers affected by fading. SOLUTION: In step S1, a transmitting side transmits a reference signal to a receiving side. In step S11, the receiving side analyzes the signal strength of each subcarrier from the received reference signal, detects fading information of the transmission path, and transmits the fading information to the transmitting side in step S12. In step S2, the transmitting side determines an appropriate mapping method based on the received fading information, and transmits the mapping method to the receiving side in step S3. In step S4, the transmission side sets parameters of the newly determined mapping method, and in step S5, preferentially maps parity bits to the subcarriers in which fading has occurred, according to the set new mapping method.

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmitting apparatus and a transmitting apparatus.
Methods, communication systems, recording media, and programs.
In particular, for example, OFDM (Orthogonal Frequency Divis
ion Multiplex)
Communication device and method, communication system, recording medium, and program
About the program. 2. Description of the Related Art Recently, digital broadcasting using terrestrial waves has been transmitted.
The transmission method is OFDM modulation (orthogonal frequency division multiplexing)
Expression) has attracted attention. Here, an OFDM modulation method (orthogonal frequency division multiplexing) is used.
Will be described. [0004] Generally, in OFDM modulation communication,
IEEE (Institute of Electrica)
l and Electronics Engineers) 802.11a and HiperLAN / 2
There is. FIG. 1 shows a normal state of the HiperLAN / 2 standard.
FIG. 7 is a diagram showing an example of arrangement of subcarriers of one OFDM symbol in FIG.
is there. As shown in FIG.
Wave) is 1/64 of the bandwidth of the OFDM signal,
The subcarrier actually used is the frequency band of the OFDM signal.
52 excluding both ends and the center of the area. 52 pieces
Of the subcarriers, called the pilot subcarrier
4 subcarriers and the remaining 48 subcarriers
The rear is used for data transmission. Pilot sub carry
Is the position for correctly identifying the subcarrier phase.
This is known data that serves as a phase reference and is inserted at regular intervals.
It is. Generally, IEEE802.11a and HiperLAN / 2 standards
Now, convolutional codes are used as error correction codes.
I have. In convolutional coding, coding rate R and constraint length K
It is defined by two parameters. The coding rate is R
= 1/2, 1/3 or 1/4 is used, and the constraint length is K = 3
It is selected in the range of 14 to 14, but usually the processing amount on the decoding side
, K = 7 or 9 is used. FIG. 2 shows a diagram of IEEE 802.11a and HiperLAN / 2.
Diagram showing a configuration example of a convolutional encoder adopted in the standard
It is. In FIG. 1, the coding rate is R = 1/2,
A convolutional encoder with a bundle length of K = 7 is shown. This tatami
The embedding encoder includes shift registers 1-1 to 1-6,
And adders 2-1 and 2-2.
You. As a result, the information video input to the convolutional encoder is obtained.
Bit (source signal) is equal to the constraint length K in the encoder.
That is, it is stored in the shift register 1) and the shift register
Information bit stored in 1 is added by adder 2
(Logical addition), and the addition result is used as an encoded bit.
Generated. In this case, the input 1-bit information
From the bit IN, two encoded bits X and Y are generated.
You. And output from the convolutional encoder.
Coded bit with coding rate 1/2 has high error correction capability
However, the transmission efficiency is poor. Therefore, in general, a convolutional encoder
The coded bits of the coding rate 1/2 output from
According to the rules, the puncturing process (thinning process)
And output as a punctured code. FIG. 3 illustrates the puncturing process.
FIG. FIG. 3A shows a 3-bit source signal.
FIG. 3B shows a convolutionally encoded signal.
FIG. 3C shows the punctured signal.
I do. [0011] As shown in FIG.
Signals IN1, IN2, IN3 (FIG. 3A) are convolved at a coding rate of 1/2
Only, and generate 6-bit signals X1, X2, X3, Y1, Y2, and Y3.
Generated and output (FIG. 3B). And a 6-bit signal
The signals X1, X2, X3, Y1, Y2, and Y3 are punctured at a coding rate of 3/4.
Ring processing (in this case, the 2-bit signals X3 and Y2 are
Output as 4-bit signals X1, X2, Y1, Y3
Is done. Thus, in the punctured code, the characteristic
The transmission efficiency is lower than the coding rate 1/2,
Is improved. Thus, for example, the code of a convolutional encoder
In the case of the coding rate 1/2 and the punctured coding rate 3/4, the transmission efficiency
Is improved by about 33%. For this reason, S / N (Signa
l to Noise (signal-to-noise ratio)
Rates are used properly. Also, the Shannon limit (errors in digital communications)
Error correction near the limit of the channel capacity that can be transmitted without
As a code having a positive capability, a turbo code is known.
The turbo encoder uses the source signal itself and parity.
Output two convolutional code bits. By the way, for wireless communication in a multipath environment,
And the direct wave (the signal coming directly from the transmitting station)
Launch wave (signal reflected from obstacle) or reflected wave
Specific frequency part in a relatively narrow band due to radio wave interference
Is called fading, where the signal strength of the minute deteriorates significantly
Phenomenon occurs. Thus, a number of mutually orthogonal sub-carriers
OFDM modulation that multiplexes data by phase or amplitude phase modulation
When fading occurs in communication using the
In this case, the S / N of some subcarriers will deteriorate.
You. Therefore, for example, "Adaptive Modulation"
for the HIPERLAN / 2 Air Interface ”
Methods using formulas have been proposed. FIG. 4 shows an OFDM transmission apparatus using an adaptive modulation scheme.
FIG. 3 is a diagram illustrating a configuration example of a device. The turbo encoder 11 receives the input source signal.
Error correction processing such as convolutional coding
And the source signal itself (IN) and the parity
Output convolutionally encoded bits (X, Y). Turbo mark
The convolutional coded bit output from the encoder 11 has an error.
High correction capability, but poor transmission efficiency
It is supplied to the unit 12. The punctured section 12 includes a turbo coder 11
For the convolutionally coded bits supplied from
Puncturing (thinning)
Supply Chad Code Bit to Frequency Interleaver 3
You. Frequency interleaver 3 has the same continuous data
Or assigned to a close subcarrier (carrier)
Input coded data to prevent
Thalive. Specifically, the effects of fading
For example, of the 48 subcarriers, 2 or
When the received power of three subcarriers becomes very weak
If you assign continuous data to it,
In the device, after demodulation, a continuous error
(Error corrector) and error correction cannot be performed.
There is a risk of becoming. Therefore, the frequency interleaver 3
Allows continuous input data to be assigned to each subcarrier
If you sort and assign to two or three
Even if the subcarrier becomes unavailable, the error
Is determined by the frequency deinterleaver of the receiver.
It is input to the decoder in the uncleared state, and error correction processing is easy.
Become. The control unit 15 controls the fading of the transmission path.
Information about the fading
Information to the subcarrier mapping unit 14 and the amplitude / phase change
It is supplied to the adjusting section 16 respectively. The subcarrier mapping unit 14 includes a control unit
15 based on the fading information supplied from
Assign an appropriate modulation method to the subcarrier. Sub cap
The rear mapping unit 14 determines whether the frequency interleaver 13
Frequency interleaved data sequence provided by
According to the modulation method assigned to each subcarrier.
Ping (modulation). That is, if the fading occurs,
QPSK (Quarterar), which has a relatively low required S / N
y Phase Shift Keying: 4 phase PSK and BPSK (Binary Phas)
e Shift Keying (two-phase PSK) is used.
The other subcarriers have 16QA with high transmission efficiency.
M (Quadrature Amplitude Modulation) and 64QAM
A multi-level amplitude and phase modulation scheme is used. The amplitude and phase modulator 16 is provided from the controller 15.
Based on the supplied fading information,
The data sequence mapped by the mapping unit 14 is amplitude
Phase modulated and IFFT (Inverse Fast Fourier Transform:
(Inverse fast Fourier transform processing) section 17. IFFT unit 1
7 is data subjected to amplitude and phase modulation by the amplitude and phase modulator 16
Perform inverse fast Fourier transform on the sequence. As described above, the subcarrier mapping unit 1
4 is, for example, 16QAM modulation with a coding rate of 3/4 for all subcarriers.
Where modulation should be performed in the gray scale
For the received subcarriers, a QPSK
It modulates with the key method. As a result, all services are
Subcarrier is modulated by the same modulation method.
The transmission capacity is larger and the same
Communication with lower S / N compared to the transmission capacity of
Become. [0027] However, the above-mentioned problems
In the adaptive modulation scheme, the upper layer (so-called wireless transmission / reception
The packet to be transmitted allocated from
Comparison cannot be performed because all data in
Subcarrier modulation method with good S / N ratio
It is necessary to adjust the balance by changing the key
Therefore, there is a problem that complicated processing is required. The present invention has been made in view of such a situation.
Sub-carrier that is affected by fading
Make it easy to change the assignment
Things. Means for Solving the Problems First transmitting apparatus of the present invention
Is the encoding means for encoding the signal and the
Obtaining means for obtaining the switching information and obtaining by the obtaining means
Based on the received fading information,
Setting means for setting an allocation pattern;
Based on the set allocation pattern.
Encoding means for subcarriers where coding has occurred.
Priority is given to the parity part of the encoded data
Allocating means for dynamically allocating
You. An encoding method in the first transmitting apparatus of the present invention
The stages shall consist of turbo coder
Can be. The allocation pattern set by the setting means
Notification means for notifying the receiving device of the
can do. The first transmission method of the present invention encodes a signal
Encoding step and the transmission path fading information
Acquisition control step for controlling acquisition and acquisition control step
Based on the fading information whose acquisition was controlled by the
To set the subcarrier allocation pattern
The set step and the setting
Fading has occurred based on the
Code for the subcarriers
Parity part of encoded data is given priority
And allocating.
You. The information is recorded on the first recording medium of the present invention.
The program comprises an encoding step for encoding the signal and a transmission step.
An acquisition control switch that controls the acquisition of fading information
The acquisition is controlled by the step and the acquisition control step.
Subcarrier allocation based on the fading information
Setting step for setting the
Based on the allocation pattern set by the
Therefore, for subcarriers where fading has occurred,
Encoded data encoded by the encoding step processing
Of the parity part of the
And a tip. The first program of the present invention encodes a signal
Encoding step and transmission path fading information
An acquisition control step for controlling acquisition of
To the fading information whose acquisition is controlled by the
Set subcarrier allocation pattern based on
Setting step and setting step processing
Fading occurs based on the allocation pattern
For the subcarriers that are
Priority is given to the parity part of the encoded data
And assigning steps to the computer
It is characterized by making it. A first transmitting apparatus and method according to the present invention,
In the program, the signal is encoded and transmitted
Fading information is acquired and the acquired fading
Subcarrier allocation pattern based on
Is set, and based on the set allocation pattern,
For the subcarriers where fading occurs,
Parity part of the encoded data
Assigned. The second transmitting apparatus of the present invention encodes a signal
Encoding means and subcarrier allocation patterns
Acquisition means to acquire and allocation acquired by the acquisition means
Based on the pattern,
Code encoded by the encoding means for the carrier
That assigns the parity part of the
Contact means. An encoding method in the second transmitting apparatus of the present invention
The stages shall consist of turbo coder
Can be. In the second transmission method of the present invention, a signal is encoded.
Coding steps to be performed and subcarrier allocation patterns
An acquisition control step for controlling acquisition of the
To an allocation pattern whose acquisition is controlled by the
Based on the subcarriers where fading occurs
On the other hand, the encoding encoded by the processing of the encoding step
Assignment to assign priority to the parity part of data
And a step. The information is recorded on the second recording medium of the present invention.
The program includes an encoding step for encoding the signal,
Acquisition system that controls acquisition of carrier assignment patterns
The acquisition is controlled by the control step and the acquisition control step.
Fading based on controlled allocation patterns
Processing of the encoding step
Parity part of encoded data encoded by
And an assignment step for preferentially assigning
Features. According to a second program of the present invention, a signal is encoded.
Coding steps to be converted and subcarrier allocation patterns
An acquisition control step for controlling the acquisition of the
Allocation pattern whose acquisition is controlled by the processing of TEP
Based on the subcarrier with fading
For the code encoded by the encoding step
That assigns the parity part of the
And causing the computer to execute the guessing step.
And The second transmitting apparatus and method of the present invention,
In the program, the signal is encoded and
Rear allocation pattern is obtained and the obtained allocation
Based on the pattern,
Carrier, the encoded data of the encoded
The parity part is assigned preferentially. A first transmission system according to the present invention comprises a transmitting device
Is an encoding means for encoding the signal, and a notification from the receiving apparatus
Acquisition means for acquiring fading information of a transmission line to be used
Based on the fading information acquired by the acquisition means.
To set the subcarrier allocation pattern
Assignment means and the assignment pattern set by the setting means
Notification means for notifying the receiving device of the
Based on the set allocation pattern.
Encoding means for subcarriers where coding has occurred.
Priority is given to the parity part of the encoded data
And a allocating means for allocating the data to the receiving device.
Detecting means for detecting the fading information of the transmission path;
Sending the fading information detected by the means to the transmitting device
And a second notifying unit for notifying. In the first transmission system of the present invention,
In the transmitting device, the signal is encoded and notified by the receiving device.
Based on the transmission path fading information
Assignment pattern is set, and the set assignment
The pattern is notified to the receiver, and the assigned
Based on the turn, the subkey with fading
To the carrier, the paris of the encoded data
Is assigned with priority and the receiving device
Fading information is detected and the detected fading
The transmitting information is notified to the transmitting device. According to a second transmission system of the present invention, a transmitting device
Is an encoding means for encoding the signal, and a notification from the receiving apparatus
Get the subcarrier allocation pattern to be obtained
Means and the assignment pattern obtained by the obtaining means
Based on the subcarriers where fading occurs
On the other hand, the data of the encoded data
Means for assigning the parity part preferentially.
The receiver detects the fading information of the transmission path
Detecting means, and the phady detected by the detecting means.
Subcarrier allocation pattern based on
Setting means for setting the
Notification means for notifying the transmission device of the hit pattern
It is characterized by the following. In the second transmission system of the present invention,
In the transmitting device, the signal is encoded and notified by the receiving device.
Based on the subcarrier allocation pattern
Encoded subcarriers
Parity part of encoded data
And the receiver detects the fading information of the transmission path.
And based on the detected fading information,
The carrier allocation pattern is set, and the set allocation
The allocation pattern is notified to the transmitting device. Referring to the drawings, an embodiment of the present invention will be described below.
An embodiment will be described. FIG. 5 shows an OFDM communication system to which the present invention is applied.
Is a diagram showing a configuration example of a transmission system according to the present invention. Transmission device 3
1 is a predetermined code for the input digital data.
Performs convolutional coding at the conversion rate and performs convolutional coding.
The coded bits are transmitted along with the source signal through the transmission medium 32.
And sends it to the receiving device 33. The receiving device 33 is a transmission medium.
Convolutionally encoded transmitted over field 32
Receives data and decrypts it. FIG. 6 shows an example of the configuration of the transmitting device 31 of FIG.
FIG. Note that the parts corresponding to the
The same reference numerals are given, and the description thereof will be omitted as appropriate. The turbo encoder 11 receives the input source signal.
Error correction processing such as convolutional coding
And the source signal itself (IN) and the parity
Output convolutionally encoded bits (X, Y). FIG. 7 shows an example of the configuration of the turbo encoder 11.
It is a block diagram. The source signal (IN) is transmitted through a delay 51
Output as is. The source signal is also
Mizume (RSC: Recursive Systematic Convolutional)
While being supplied to the encoder 53-1, the random
To the source signal, where the source signal is randomized.
Recursive systematic convolutional encoder after interleaving
53-2. The recursive systematic convolutional encoder 53 is shown in FIG.
As shown, recursive (circular) parts and non-recursive
It has a configuration in which the parts are combined. That is, the adder
Reference numeral 61 denotes an output of the delay unit 62 and a delay
The output of the delay unit 63 is input, and the adder 64
1 and the outputs of the delay units 62 and 63 are input.
It is empowered. The recursive systematic convolutional encoder shown in FIG.
The configuration is called IIR (Infinite Impulse Response) format
It is. Thus, the recursive systematic convolutional encoder 5
3 both the current input information i and the past input information p
Is more complex and obtained by systematically encoding
Output convolutional encoded bits (parity bits)
It is. Returning to the description of FIG. Recursive organization convolution
Coded bit (X) generated by encoder 53-1
Is output through a delay unit 54, and the recursive tissue convolution
Convolutionally encoded bit generated by encoder 53-2
(Y) is output as it is. As described above, from the turbo encoder 11,
Source signal (IN) encoded at a coding rate of 1/3
And two convolutional encoded bits (X, Y), for a total of 3
The encoded bits of the bits are output. Returning to the description of FIG. Punctured part 12
Is the convolutional encoded video supplied from the turbo encoder 11.
Puncturing process for puncturing
And supplies the encoded code bits to the subcarrier mapping unit 14.
You. FIG. 9 illustrates the puncturing process.
FIG. FIG. 9A shows a 3-bit source signal.
FIG. 9B shows the convolutionally coded signal.
FIG. 9C shows the punctured signal.
I do. As shown in the figure, a 6-bit source
Signals IN1, IN2, IN3, IN4, IN5, and IN6 (FIG. 9A) are 符号 signs
12-bit signals X1, X2, X
3, X4, X5, X6, Y1, Y2, Y3, Y4, Y5, Y6 are generated and output
(FIG. 9B). Then, the 12-bit signals X1, X2, X3, X4, X
5, X6, Y1, Y2, Y3, Y4, Y5, Y6 are punctured with a coding rate of 3/4
Charging process (in this case, 10-bit signal X
1, X2, X4, X5, X6, Y1, Y2, Y3, Y4, Y5 are thinned out)
Are output as signals X3 and Y6. Thus, the characteristic
The source signal IN with large deterioration is not thinned out and the parity bit
Only those that are decimated. The control unit 15 controls the fading of the transmission path.
Information is acquired in advance from the receiving device 33,
Appropriate mapping settings based on fading information
Method, and according to the determined mapping setting method,
Just like mapping subcarriers,
The parameters of the tapping unit 14 are set. Control unit 15
Notifies the receiving device 33 of the determined mapping setting method.
I do. The sub-carrier mapping unit 14 includes a control unit
15 according to the appropriate mapping method set by
Therefore, for subcarriers where fading has occurred,
The parity bit supplied from the punctured unit 12 is
Map ahead. The amplitude and phase modulation section 16
The data sequence mapped by the ping unit 14
The signal is modulated and supplied to the IFFT unit 17. IFFT unit 17
Inverse high-speed data series subjected to amplitude and phase modulation by phase modulator 16
Perform Fourier transform processing. FIG. 10 shows an example of the configuration of the receiving device 33 shown in FIG.
It is a block diagram shown. The FFT unit 81 transmits the transmission medium
32, the encoded data transmitted through
After the conversion, the signal is supplied to the amplitude / phase demodulation unit 82. Amplitude position
The phase demodulation unit 82 encodes the encoded data subjected to the fast Fourier transform.
The data is subjected to amplitude / phase demodulation,
Supply 3 The subcarrier demapping unit 83 transmits
The mapping setting method is obtained in advance from the device 31,
Amplitude and phase demodulation is performed based on the mapping setting method.
The demodulated data is demapped (demodulated). Fady
Detecting section 84 is a subcarrier demapping section 83
From the demodulated data of the reference signal supplied from
Each time, it detects information about the fading of the transmission line,
Notify the transmitting device 31 of the detection result (fading information)
I do. Punctured decoding section 85 has a subcarrier
Of the parity part demapped by the demapping unit 83
Punctured decoding processing (interpolation processing)
) And outputs the result to the turbo encoder 86. The turbo encoder 86 performs, for example, Viterbi decoding.
Subcarrier demapping unit
83 and a punctured decoding unit
Decodes coded bits that are parity supplied from 85
And outputs the decoded data. Next, referring to the flowchart of FIG.
Next, the data transmission process will be described. Here,
Indicates that the transmitting device 31 is a base station and the receiving device 33 is a mobile station.
It will be described as what is. In step S1, the transmitting device 31
The reference signal for setting (deciding) the mapping method is
The data is transmitted to the receiving device 33 via the transmission medium 32. In step S11, the receiving device 33
Is transmitted from the transmission device 31 via the transmission medium 32.
Received by the FFT unit 81,
D conversion processing, and the amplitude / phase demodulation unit 82
The subcarrier demapping unit 83
Demapping for each carrier, and a fading detection unit 84
To supply. The fading detecting section 84 is a sub-carrier.
Demodulation of the reference signal supplied from the adder mapping unit 83
From the data, analyze the signal strength of each subcarrier, and
To detect the fading information. In step S12
Then, the fading detection unit 84 determines in step S11
The fading information detected in the processing is transmitted to the transmitting device 31.
Send (notify). In step S2, the control of the transmitting device 31
The control unit 15 receives the fading
Receiving the fading information, and based on the fading information,
Determine an appropriate mapping method. In step S3
Therefore, the control unit 15 determines whether or not the
The ping method is transmitted (notified) to the receiving device 33. Stay
In step S4, the control unit 15 executes the processing in step S2.
Each sub-carrier according to the new mapping method determined in
Subcarrier mapping, like mapping the rear
The parameters of the unit 14 are set. In step S13, the receiving device 33
The subcarrier demapping section 83
Receives the notified mapping method, and
Set. As described above, steps S1 to S4
In addition, by the processing of steps S11 to S13,
Appropriate mapping between transmitting device 31 and receiving device 33
A method is negotiated. In step S5, the transmission device 31
The encoder 11 is a convolutional code for the signal to be transmitted.
Error correction processing such as encoding, and the source signal itself and 2
Output two convolutional encoded bits. Punctured
12 is a puncturing scheme for the convolutionally coded bits.
To the subcarrier mapping unit 14
You. The subcarrier mapping unit 14 is controlled by the control unit 15
According to the new mapping method configured
Puncturing for subcarriers with
Parity bit supplied from the
Ping. The amplitude and phase modulator 16 is a subcarrier manager.
The data sequence mapped by the
The phase is modulated and supplied to the IFFT unit 17. IFFT unit 17
Performs inverse fast Fourier transform on a phase-modulated data sequence.
You. Thereafter, the encoded data is received via the transmission medium 32.
It is transmitted to the device 33. In step S6, the transmitting device 31
After a predetermined time (for example, several tens ms or several tens μs)
It is determined whether or not it has passed, and if the predetermined time has not elapsed
If it is determined, the process returns to step S5 to repeat the above-described processing.
Execute again. In step S6, the predetermined time
If it is determined that the time has elapsed, the process proceeds to step S7, and the transmission is performed.
Judge whether or not the transmission has been completed.
If set, the process returns to step S1 and repeats the above-described processing.
Return and execute. That is, the processing in step S6 is performed
Since the device 33 is a mobile station, the condition of the transmission path may change.
Therefore, the reference signal is transmitted every predetermined time,
Rows to allow setting new mapping methods
Be done. In step S14, the receiving device 33
The FFT unit 81 performs the encoding transmitted from the transmitting device 31.
The data is subjected to fast Fourier transform processing, and the amplitude / phase demodulation unit 82
To supply. The amplitude and phase demodulation unit 82 performs a fast Fourier transform
Amplitude / phase demodulation of the processed encoded data
It is supplied to the adder mapping unit 83. Subcarrier Demap
The ping unit 83 outputs the password set in the process of step S13.
The demodulated data is decoded according to the parameters (mapping method).
Map. In step S7, it is determined that the transmission has been completed.
If determined, the transmission process ends. As described above, the transmitting device 31 and the receiving device 33
Sending and receiving signals according to the mapping method agreed between
Communication, so any one of the 48 subcarriers
If one of them is affected by fading,
Priority for subcarriers with
Efficient transmission by assigning
can do. In the above, the detection is performed by the receiving device 33.
Notifying the transmitting device 31 of the issued fading information,
The transmitting device 31 may determine an appropriate mapping method.
However, the receiving apparatus 33 determines the mapping method.
You may do so. FIG. 12 shows another configuration of the receiving device 33 of FIG.
It is a block diagram showing an example. In addition, the part corresponding to FIG.
The same reference numerals are given to the minutes, and the description thereof will be appropriately omitted.
You. In the case of the example of FIG. 12, the receiving device 33 shown in FIG.
The configuration further includes a mapping setting section 91.
You. The mapping setting section 91 performs fading.
Based on the fading information supplied from the detector 84
To determine an appropriate mapping setting method, and
Sub-mapping according to the ping setting method
The parameters of the carrier demapping unit 83 are set.
The mapping setting unit 85 determines the determined (set) mapping.
The setting method is notified to the transmission device 31. Next, referring to the flowchart of FIG.
Next, the data transmission process will be described. Steps S31 and S41
The process is the same as that described with reference to the flowchart of FIG.
Step S1 and step S11, respectively.
Therefore, the description is omitted. In step S42, the receiving device 33
The mapping setting unit 91 detects in the process of step S41
Based on the fading information
Decide on the logging method. In step S43, the mapping
The setting unit 91 determines whether the mask determined in the process of step S42 is correct.
The transmission method is transmitted (notified) to the transmission device 31. In step S32, the transmission device 31
The control unit 15 performs the mapping notified from the receiving device 33.
Receive the method and confirm it. In step S33
Then, the control unit 15 receives the confirmation that the mapping method has been confirmed.
The information is transmitted (notified) to the device 33. In step S34
Then, the control unit 15 sends the new
Map each subcarrier according to the mapping method
As shown in FIG.
Set. In step S44, the receiving device 33
The mapping setting unit 91 receives a confirmation notification from the transmission device 31.
Receiving the new map determined in the process of step S42.
Sub-mapping according to the ping setting method
The parameters of the carrier demapping unit 83 are set. As described above, steps S31 to S3
4 and the processing of steps S41 to S44,
In advance, an appropriate mapping between the transmitting device 31 and the receiving device 33 is performed.
The ping method is negotiated. Steps S35 to S37 and step
The process of step S45 will be described with reference to the flowchart of FIG.
Steps S5 to S7 and step S14
Since the processing is the same as the above, the description is omitted. As described above, when fading occurs
Are output from the turbo encoder 11
Convolutional code that is the parity part of the encoded data
Bit is mapped preferentially,
Sources that dominate the error correction process
The signal is transmitted on subcarriers with little degradation. Soshi
The parity part, which has a small effect even if there is an error
The convolutional coded bit, which is the
Transmitted on carrier. Therefore, data transmission from the transmitting device 31
Indicates that the thinning out of the parity part is slightly larger
It has almost the same characteristics as transmission, with no fading at all.
Fading
Source signals to subcarriers without considering
The transmission characteristics are greatly improved compared to the case where Next, the transmission method using the adaptive modulation method and
The transmission method according to the method to which the present invention is applied will be described in comparison.
You. FIG. 14 shows one OFDM symbol in each modulation scheme.
Number of transmission data per bol and per subcarrier
FIG. 4 is a diagram showing the number of transmission data items. As shown in the figure, the BPS with a coding rate of 1/2
In the case of the K modulation scheme, 24-bit data per OFDM symbol is used.
Data can be transmitted, and 0.5 per subcarrier.
Bit data can be transmitted. B at coding rate 3/4
In the case of PSK modulation, 36 bits per OFDM symbol
Data can be transmitted and 0 per subcarrier.
75-bit data can be transmitted. Coding rate 1 /
2 QPSK modulation scheme, 48 bits per OFDM symbol
Can transmit the data of one subcarrier
1.0 bit data can be transmitted. Coding
In the case of a QPSK modulation scheme with a rate of 3/4, 72 per 1 OFDM symbol
Bit data can be transmitted and one subcarrier
1.5 bits of data can be transmitted. Also, in the case of a 16QAM modulation system with a coding rate of 9/16,
In this case, 108 bits of data are transmitted per OFDM symbol.
2.25 bits of data per subcarrier
Data can be transmitted. 16QAM modulation method with coding rate 3/4
In the case of the formula, 144 bits of data per OFDM symbol
Can be transmitted, 3.0 bits per subcarrier
Can be transmitted. 64QAM with coding rate 3/4
In the case of the modulation scheme, 216 bits of data per OFDM symbol are used.
Data can be transmitted and 4.5 per subcarrier.
Bit data can be transmitted. For example, in the case of a BPSK modulation scheme with a coding rate of 3/4,
In this case, 4 subcarriers are equivalent to 3 bits (= 0.75 × 4)
Data can be transmitted, code rate 3/4 QPSK modulation
In the case of the method, 3 bits (= 1.5 ×
2) Can send minute data. Here, data is decoded by the QPSK modulation method with a coding rate of 3/4.
The case of transmitting data will be described. Usually on the transmission line
If there is no fading in the
The coded bits output from the device 11 are
The 3: 1 ratio of the
There is a parity sub-carry. This parity sub
Assuming that carriers are allocated equally, for example, FIG.
It becomes as shown in. Subcarrier allocation as shown in FIG.
Out of the 48 subcarriers, 7 subcarriers
Carrier is affected by fading and the amplitude decreases
Assuming that there is a conventional adaptive modulation scheme,
As shown in FIG. 16, the modulation scheme of each subcarrier varies.
Will be updated. Specifically, first, the effect of fading
BPSK with a coding rate of 1/2
Assume that a modulation scheme is assigned. However, the coding rate
In the 1/2 BPSK modulation method, subcarriers are divided into two subcarriers.
Because of the need to
8 subcarriers including the subcarriers
Change (replace) BPSK modulation method with rate 1/2. With this change, the number of transmission data becomes 8 bits.
(= (1.5−0.5) × 8), the coding rate is 3/4
Encoding with higher data transmission efficiency than the QPSK modulation method
To compensate for the shortage with the 16QAM modulation method with a rate of 3/4, one sub
The number of transmission data per carrier is 1.5 (= 3−1.5)
Increase. Therefore, the coding rate of the six subcarriers is
By changing to the 3/4 16QAM modulation method, the number of transmission data becomes 9
The bit (= 1.5 × 6) increases, and conversely, one bit is left. Further
In order to eliminate the remainder of one bit, two subkeys
Carrier to QPSK modulation method with coding rate 1/2
Therefore, the number of transmission data is 1 bit (= (1.5−1.0) ×
2) Reduce and match the total number of transmitted bits
Can be. As described above, the conventional adaptive modulation method uses 48
To 8 subcarriers out of 8 subcarriers
Assign BPSK modulation method of rate 1/2
The number of transmission bits is 8 bits), code on 6 subcarriers
16QAM modulation scheme with 3/4
(The number of transmission bits is 6 bits.)
QPSK modulation scheme with a coding rate of 1/2 (assigned to this modulation scheme
The number of transmission bits is 2 bits), and the remaining 32 subkeys
Carrier is assigned a QPSK modulation scheme with a coding rate of 3/4 (this
The number of transmission bits by the modulation method is 48), the transmission data
The process of matching the number of tabs is performed. On the other hand, when the present invention is applied, FIG.
As shown in Figure 17, under the influence of fading
For a subcarrier that is
Priority data. this
The amount of transmitted data as in the case of the adaptive modulation method.
Normal transmission without complicated processing
It can be transmitted at exactly the same transmission rate as. A series of processing described above (for example, transmission system
Transmission process of the transmission device 31 and the reception device 33)
Can be implemented by hardware, but
It can also be executed by software. A series of processing
Is executed by software,
The programs that make up the hardware are converted to dedicated hardware
Embedded computer or various programs
Perform various functions by installing the RAM
Capable of, for example, general-purpose personal computers
The program is installed from the program storage medium. FIG. 18 shows the internal structure of a general-purpose computer.
It is a figure showing an example. Computer CPU (Central Pro
cessing Unit) 101 is a ROM (Read Only Memory) 1
02 or the storage unit 108
From the RAM (Random Access Memory) 103
Various processes are executed according to the program. RAM10
In addition, the CPU 101 executes various processes by the CPU 101.
Necessary data is also stored as appropriate. CPU 101, ROM 102, and RAM 103
Are connected to each other via a bus 104. This ba
The input / output interface 105 is also connected to the
Has been continued. The input / output interface 105 has a button
Components, switches, keyboard or mouse.
Input unit 106, CRT (Cathode Ray Tub)
e) and displays such as LCD (Liquid Crystal Display)
And an output unit 107 including a speaker and the like.
Storage unit 108 including a hard disk and the like.
Communication unit 10 composed of dem, terminal adapter, etc.
9 is connected. The communication unit 109 is the Internet
The communication processing is performed via a network including. The input / output interface 105 also has
The drive 110 is connected if necessary and the magnetic disk
121, an optical disk 122, a magneto-optical disk 123,
Or a semiconductor memory 124 or the like is appropriately mounted,
The computer program read from the storage unit 10
8 installed. Installed on the computer,
Stores programs that can be executed by the computer.
The program storage medium to be stored is as shown in FIG.
The magnetic disk 121 (including a flexible disk)
), Optical disk 122 (CD-ROM (Compact Disc-Read)
Only Memory), DVD (Digital Versatile Disc)
), Magneto-optical disk 123 (MD (Mini-Disc)
), Or the semiconductor memory 124 or the like
Not only consist of package media
To the user in a state pre-installed in the computer.
Provided, the program is temporarily or permanently recorded
ROM 102, storage unit 108, and the like.
The storage of the program on the program storage medium is
Via the communication unit 109 such as a router or a modem.
Network, local area network, internet
Wired or wireless communications such as digital satellite broadcasting
This is performed using a medium. In this specification, the program storage
The steps for writing the program stored on the medium are as follows:
The processing performed in chronological order according to the order listed
It is parallel, even if it is not necessarily processed in chronological order
Or individually executed processing. In the present specification, the system is
It represents the entire device composed of multiple devices.
You. The first transmitting apparatus and method according to the present invention, as well as
According to each program, the signal is encoded and the transmission path
Obtain fading information and obtain fading
Based on the information, set the subcarrier allocation pattern.
Based on the set allocation pattern.
Encoded subcarriers
Priority is assigned to the parity part of the encoded data
Sub-channels affected by fading
Easily change carrier assignments and improve efficiency
Data can be transmitted well. [0110] The second transmission apparatus and method according to the present invention,
According to the program, the signal is encoded and the subcarrier
Gets the allocation pattern of the
Based on the
To the rear, the parity of the encoded data
The priority is assigned to the
Allocation of subcarriers affected by
Data can be transmitted efficiently.
Wear. According to the first transmission system of the present invention, transmission
The transmitting device encodes the signal and transmits the signal notified by the receiving device.
Based on the transmission fading information,
Set the allocation pattern and set the allocation pattern
Notification to the receiving device, and
Based on the subcarriers where fading occurs
On the other hand, the parity part of the encoded data
Assigned preferentially, and the receiving device
Detecting fading information and transmitting the detected fading information
Since the device is notified, the effect of fading
Data can be transmitted efficiently even when
You. According to the second transmission system of the present invention, transmission
The receiving device encodes the signal and notifies the receiving device
Based on the carrier's allocation pattern.
Encoded sub-carriers
The parity part of the encoded data is assigned with priority and received.
The transmission equipment detects the fading information of the transmission line and detects it.
Based on the received fading information,
Set the allocation pattern and set the allocation pattern
Notification to the transmitting device,
Data can be transmitted efficiently even when
Can be.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a diagram illustrating an example of arrangement of subcarriers of one OFDM symbol in a normal state. FIG. 2 is a diagram illustrating a configuration example of a convolutional encoder. FIG. 3 is a diagram illustrating a puncturing process. FIG. 4 is a diagram illustrating a configuration example of an OFDM transmission device using an adaptive modulation scheme. FIG. 5 is a diagram showing a configuration of a transmission system of an OFDM communication system to which the present invention is applied. FIG. 6 is a block diagram illustrating a configuration example of a transmission device of FIG. 5; FIG. 7 is a block diagram illustrating a configuration example of a turbo encoder in FIG. 6; 8 is a diagram illustrating a configuration example of a recursive systematic convolutional encoder in FIG. 7; FIG. 9 is a diagram illustrating a puncturing process. FIG. 10 is a block diagram illustrating a configuration example of a receiving device in FIG. 5; FIG. 11 is a flowchart illustrating a data transmission process. FIG. 12 is a block diagram illustrating another configuration example of the receiving device in FIG. 5; FIG. 13 is a flowchart illustrating a data transmission process. FIG. 14 is a diagram showing the number of transmission data per OFDM symbol and the number of transmission data per subcarrier in each modulation scheme. FIG. 15 is a diagram illustrating subcarrier allocation in a QPSK modulation scheme with a coding rate of 3/4. FIG. 16 is a diagram illustrating a change in the modulation scheme of a subcarrier affected by fading when an adaptive modulation scheme is used. FIG. 17 is a diagram illustrating allocation of subcarriers affected by fading when the present invention is applied. FIG. 18 is a diagram illustrating an example of the internal configuration of a general-purpose computer. [Description of Code] 11 Turbo encoder, 12 Punctured part, 14
Subcarrier mapping unit, 15 control unit, 16
Amplitude and phase modulator, 17 IFFT, 31 transmitter,
32 transmission medium, 33 receiving device, 53-1, 5
3-2 Recursive systematic convolutional encoder, 81 FFT unit,
82 amplitude / phase demodulation unit, 83 subcarrier demapping unit, 84 fading detection unit, 85 punctured decoding unit, 86 turbo encoder, 91 mapping setting unit, 121 magnetic disk, 122
Optical disk, 123 magneto-optical disk, 124 semiconductor memory

Claims (1)

1. A transmitting apparatus for transmitting a signal by the OFDM method, comprising: an encoding unit that encodes the signal; an acquiring unit that acquires fading information of a transmission path; Setting means for setting an allocation pattern of subcarriers based on the obtained fading information; and, based on the allocation pattern set by the setting means, for the subcarrier in which fading occurs, the code And a allocating means for preferentially allocating a parity part of the encoded data encoded by the converting means. 2. The transmitting apparatus according to claim 1, wherein said encoding means is constituted by a turbo encoder. 3. The transmitting device according to claim 1, further comprising a notifying unit that notifies the receiving device of the allocation pattern set by the setting unit. 4. A transmission method of a transmission apparatus for transmitting a signal according to the OFDM method, comprising: an encoding step of encoding the signal; an acquisition control step of controlling acquisition of fading information of a transmission path; and the acquisition control step. A setting step of setting an allocation pattern of subcarriers based on the fading information whose acquisition is controlled by the processing of; and fading has occurred based on the allocation pattern set by the processing of the setting step. An allocation step of preferentially allocating a parity part of the encoded data encoded by the processing of the encoding step to a subcarrier. 5. A program for controlling a transmission device for transmitting a signal in an OFDM system, comprising: an encoding step of encoding the signal; an acquisition control step of controlling acquisition of fading information of a transmission path; A setting step of setting an allocation pattern of subcarriers based on the fading information whose acquisition is controlled by the processing of the acquisition control step; and, based on the allocation pattern set by the processing of the setting step, fading. Allocating a parity part of encoded data encoded by the encoding step with priority to the generated subcarriers. Recording media. 6. A computer that controls a transmitting device that transmits a signal by the OFDM system, an encoding step of encoding the signal, an acquisition control step of controlling acquisition of fading information of a transmission line, and the acquisition control. A setting step of setting an allocation pattern of subcarriers based on the fading information whose acquisition is controlled by the processing of the step, and occurrence of fading based on the allocation pattern set by the processing of the setting step. And assigning a parity part of the encoded data encoded by the processing of the encoding step preferentially to the subcarriers. 7. A transmitting apparatus for transmitting a signal according to the OFDM method, comprising: an encoding unit that encodes the signal; an acquisition unit that acquires a subcarrier assignment pattern; and an acquisition unit that acquires the assignment pattern acquired by the acquisition unit. And a allocating means for preferentially allocating a parity part of the coded data coded by the coding means to a subcarrier on which fading has occurred. 8. The transmitting apparatus according to claim 7, wherein said encoding means is constituted by a turbo encoder. 9. A transmission method of a transmission apparatus for transmitting a signal according to the OFDM method, comprising: an encoding step of encoding the signal; an acquisition control step of controlling acquisition of a subcarrier allocation pattern; Assignment for preferentially assigning a parity part of the encoded data encoded by the processing of the encoding step to a subcarrier in which fading has occurred, based on the allocation pattern whose acquisition is controlled by the processing. And a transmitting method. 10. A program for controlling a transmission device for transmitting a signal in the OFDM system, comprising: an encoding step of encoding the signal; an acquisition control step of controlling acquisition of a subcarrier allocation pattern; On the basis of the allocation pattern controlled to be obtained by the control step, priority is given to the parity part of the coded data coded by the coding step, for the subcarrier in which fading has occurred. And a allocating step of allocating the program to a computer-readable recording medium. 11. A computer that controls a transmitting apparatus that transmits a signal by the OFDM method, comprising: an encoding step of encoding the signal; an acquisition control step of controlling acquisition of a subcarrier allocation pattern; and the acquisition control step. The parity part of the coded data coded by the processing of the coding step is preferentially allocated to the subcarrier in which fading has occurred, based on the allocation pattern whose acquisition is controlled by the processing of A program for executing the assignment step. 12. A communication system comprising: a transmitting device that transmits a signal by the OFDM method; and a receiving device that receives the coded signal transmitted from the transmitting device, wherein the transmitting device encodes the signal. Encoding means, acquisition means for acquiring fading information of a transmission path notified from the receiving apparatus, and setting for setting a subcarrier allocation pattern based on the fading information acquired by the acquiring means. Means, first notifying means for notifying the receiving device of the allocation pattern set by the setting means, based on the allocation pattern set by the setting means, to a subcarrier in which fading has occurred On the other hand, the parity part of the encoded data encoded by the encoding means is preferentially assigned. A receiving unit, wherein the receiving device includes: a detecting unit that detects fading information of the transmission line; and a second notifying unit that notifies the transmitting device of the fading information detected by the detecting unit. A communication system comprising: 13. A communication system comprising: a transmitting device that transmits a signal according to the OFDM method; and a receiving device that receives the coded signal transmitted from the transmitting device, wherein the transmitting device encodes the signal. Encoding means, and acquisition means for acquiring an allocation pattern of subcarriers notified from the receiving device, based on the allocation pattern acquired by the acquisition means, for the subcarriers where fading has occurred, Allocating means for preferentially allocating a parity part of the coded data coded by the coding means, wherein the receiving device comprises: detecting means for detecting fading information of a transmission path; and Setting means for setting an allocation pattern of the subcarriers based on the detected fading information; Communication system, comprising a notification means for notifying the allocation pattern set by the setting means to the transmission device.
JP2001289236A 2001-09-21 2001-09-21 Transmission apparatus and method, communication system, recording medium and program Withdrawn JP2003101504A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2001289236A JP2003101504A (en) 2001-09-21 2001-09-21 Transmission apparatus and method, communication system, recording medium and program

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2001289236A JP2003101504A (en) 2001-09-21 2001-09-21 Transmission apparatus and method, communication system, recording medium and program

Publications (1)

Publication Number Publication Date
JP2003101504A true JP2003101504A (en) 2003-04-04

Family

ID=19111758

Family Applications (1)

Application Number Title Priority Date Filing Date
JP2001289236A Withdrawn JP2003101504A (en) 2001-09-21 2001-09-21 Transmission apparatus and method, communication system, recording medium and program

Country Status (1)

Country Link
JP (1) JP2003101504A (en)

Cited By (10)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2006077933A1 (en) * 2005-01-21 2006-07-27 Matsushita Electric Industrial Co., Ltd. Wireless communication apparatus and wireless communication method
JP2007506359A (en) * 2003-09-17 2007-03-15 アシロス コミュニケイションズ インコーポレイテッド Iterative coding for wireless systems
JP2007067567A (en) * 2005-08-29 2007-03-15 Mitsubishi Electric Corp Communication apparatus, transmitter and receiver
WO2007119403A1 (en) * 2006-03-16 2007-10-25 Matsushita Electric Industrial Co., Ltd. Terminal
JP2007312060A (en) * 2006-05-18 2007-11-29 Kddi Corp Radio apparatus adaptively changing pilot signal disposition, program, and communication method
WO2008023643A1 (en) * 2006-08-22 2008-02-28 Ntt Docomo, Inc. Radio communication apparatus and radio communication method
JP2008211489A (en) * 2007-02-26 2008-09-11 Mitsubishi Electric Corp Mapping method, decoding method, and communicating system
JP2009514323A (en) * 2005-10-31 2009-04-02 サムスン エレクトロニクス カンパニー リミテッド Apparatus and method for transmitting and receiving data in a multi-antenna communication system
JP2009544257A (en) * 2006-07-14 2009-12-10 クゥアルコム・インコーポレイテッドQualcomm Incorporated Encoding and decoding method and apparatus for use in a wireless communication system
US8531937B2 (en) 2004-08-11 2013-09-10 Interdigital Technology Corporation Channel sounding for improved system performance

Cited By (23)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP2007506359A (en) * 2003-09-17 2007-03-15 アシロス コミュニケイションズ インコーポレイテッド Iterative coding for wireless systems
US9197374B2 (en) 2003-09-17 2015-11-24 Qualcomm Incorporated Repetition coding for a wireless system
US8923421B2 (en) 2003-09-17 2014-12-30 Qualcomm Incorporated Repetition coding for a wireless system
KR101178818B1 (en) * 2003-09-17 2012-09-03 콸콤 아테로스, 인코포레이티드 Repetition coding for a wireless system
US9444531B2 (en) 2004-08-11 2016-09-13 Interdigital Technology Corporation Channel sounding for improved system performance
US9258040B2 (en) 2004-08-11 2016-02-09 Interdigital Technology Corporation Channel sounding for improved system performance
US8917583B2 (en) 2004-08-11 2014-12-23 Interdigital Technology Corporation Channel sounding for improved system performance
US8531937B2 (en) 2004-08-11 2013-09-10 Interdigital Technology Corporation Channel sounding for improved system performance
JP4841440B2 (en) * 2005-01-21 2011-12-21 パナソニック株式会社 Wireless communication apparatus and wireless communication method
US7738592B2 (en) 2005-01-21 2010-06-15 Panasonic Corporation Wireless communication apparatus and wireless communication method
WO2006077933A1 (en) * 2005-01-21 2006-07-27 Matsushita Electric Industrial Co., Ltd. Wireless communication apparatus and wireless communication method
JP2007067567A (en) * 2005-08-29 2007-03-15 Mitsubishi Electric Corp Communication apparatus, transmitter and receiver
JP2009514323A (en) * 2005-10-31 2009-04-02 サムスン エレクトロニクス カンパニー リミテッド Apparatus and method for transmitting and receiving data in a multi-antenna communication system
US7978698B2 (en) 2006-03-16 2011-07-12 Panasonic Corporation Terminal for performing multiple access transmission suitable to a transmission path having varied characteristics
WO2007119403A1 (en) * 2006-03-16 2007-10-25 Matsushita Electric Industrial Co., Ltd. Terminal
JP2007312060A (en) * 2006-05-18 2007-11-29 Kddi Corp Radio apparatus adaptively changing pilot signal disposition, program, and communication method
JP2009544257A (en) * 2006-07-14 2009-12-10 クゥアルコム・インコーポレイテッドQualcomm Incorporated Encoding and decoding method and apparatus for use in a wireless communication system
JP2008053862A (en) * 2006-08-22 2008-03-06 Ntt Docomo Inc Wireless communication device and wireless communication method
WO2008023643A1 (en) * 2006-08-22 2008-02-28 Ntt Docomo, Inc. Radio communication apparatus and radio communication method
US7987406B2 (en) 2006-08-22 2011-07-26 Ntt Docomo, Inc. Wireless communications apparatus and method
EP2056507A1 (en) * 2006-08-22 2009-05-06 NTT DoCoMo, Inc. Radio communication apparatus and radio communication method
EP2056507A4 (en) * 2006-08-22 2013-08-07 Ntt Docomo Inc Radio communication apparatus and radio communication method
JP2008211489A (en) * 2007-02-26 2008-09-11 Mitsubishi Electric Corp Mapping method, decoding method, and communicating system

Similar Documents

Publication Publication Date Title
Kim et al. On the use of linear programming for dynamic subchannel and bit allocation in multiuser OFDM
US7486735B2 (en) Sub-carrier allocation for OFDM
CA2560462C (en) Method and apparatus for transmitting uplink acknowledgement information in an ofdma communication system
US8665855B2 (en) Method and apparatus for transmitting/receiving uplink signaling information in a single carrier FDMA system
CA2592616C (en) Communicating non-coherent detectable signal in broadband wireless access system
KR100946923B1 (en) Method and apparatus for transmitting/receiving channel quality information in a communication system using orthogonal frequency division multiplexing scheme, and system thereof
CN101808290B (en) Communication resource allocation systems and method
US7340006B2 (en) Apparatus and method for reducing PAPR in OFDM communication system
EP2398203B1 (en) Shared signaling channel
RU2433535C2 (en) Multiplexing control information and data with varying power offsets in single-carrier frequency-division multiple access (sc-fdma) system
JP4754200B2 (en) Method for subcarrier allocation and subcarrier modulation scheme selection in a wireless multi-carrier transmission system
CN1585394B (en) Orthogonal frequency division multiplexing system apparatus and method for allocating subcarriers
US8718036B2 (en) Configurable pilots in a wireless communication system
US7586836B2 (en) Apparatus and method for transmitting/receiving pilot signals in a communication system using an orthogonal frequency division multiplexing scheme
KR101023311B1 (en) Digital audio broadcasting method and apparatus using complementary pattern-mapped convolutional codes
JP4991730B2 (en) Method and apparatus for pilot communication in a multi-antenna wireless communication system
JP5318922B2 (en) Forward link variable rate coding
US8804609B2 (en) Systems and methods for use with orthogonal frequency division multiplexing
US7069489B2 (en) Transmission apparatus, reception apparatus, transmission method, and reception method
AU2005260313B2 (en) System and method for transmitting uplink control information in an OFDMA communication system
EP1867125B1 (en) Transmission methods and apparatus combining pulse position modulation and hierarchical modulation
US7613244B2 (en) System for communicating channel quality information
US8842514B2 (en) Systems and methods for OFDM channelization
EP2137841B1 (en) Method and apparatus for resource allocation within a multi-carrier communication system
KR100991797B1 (en) A method of implementing superposition coding for a forward link in a wireless communication system

Legal Events

Date Code Title Description
A300 Withdrawal of application because of no request for examination

Free format text: JAPANESE INTERMEDIATE CODE: A300

Effective date: 20081202