JP2007243236A - Wireless communication system, wireless communication apparatus, and wireless communication method, and computer/program - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an excellent wireless communication system of an MB (a multi-band system wherein frequency hopping is applied between sub bands)-OFDM (Orthogonal Frequency Division Multiplexing) transmission system, wherein data subjected to spread processing on frequency and time axes are transmitted. <P>SOLUTION: When the number of deteriorated blocks is unbalanced between transmission data in a normal spread pattern due to the presence of a deteriorated channel on a frequency region assigned to a UWB (ultrawide band; a wireless communication system using a very wide frequency band, capable of attaining high speed transmission at 100Mbps or higher), the spread pattern on frequency and time axes is changed to uniformize the number of available blocks between the transmission data, thereby preventing deterioration of the PER. Furthermore, even when a transmission inhibit channel is established by the DAA (detect and avoid; an interference avoidance technology, whereby UWB transmission wave is outputted at a very weak level of a prescribed level or lower for a band wherein an existing communication system exists), the spread pattern is revised to uniformize a spread rate between the transmission data, thereby preventing the PER from deteriorating. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a radio communication system, a radio communication apparatus, a radio communication method, and a computer program that employ an OFDM modulation scheme and perform UWB communication in which a transmission signal is spread over a wide band, and in particular, on a frequency axis and a time axis. The present invention relates to an MB-OFDM wireless communication system, a wireless communication apparatus, a wireless communication method, and a computer program that perform transmission while spreading transmission data.

  In recent years, a wireless communication system called “ultra wide band (UWB) communication” that uses a very wide frequency band and enables high-speed transmission of 100 Mbps or more has attracted attention. For example, in the United States, a spectrum mask for UWB is defined by FCC (Federal Communications Commission), and UWB transmission can be performed in a band of 3.1 GHz to 10.6 GHz in an indoor environment. UWB communication is a short-distance wireless communication system because of transmission power, but high-speed wireless transmission is possible, so a PAN (Personal Area Network) with a communication distance of about 10 m is assumed, and short-distance ultra-high speed. Practical use is expected as a wireless communication system that realizes transmission.

  Further, an OFDM (Orthogonal Frequency Division Multiplexing) transmission system is expected as a technique for realizing high speed and high quality wireless transmission while avoiding deterioration of transmission quality due to fading of wireless signals. For example, in the standardization conference in IEEE802.15.3a, as a UWB transmission method, an OFDM modulation method is used together with a DSSS (Direct Sequence Spread Spectrum) -UWB method in which a spreading speed of a DS (Direct Spread) information signal is extremely increased. An OFDM_UWB system that adopts the above is defined, and trial production is performed for each system.

  Further, a frequency hopping (FH) method for flexibly changing the frequency band to be used is known. According to the FH system, communication may not be possible due to the influence of other systems, but communication is hardly interrupted by constantly changing the frequency. That is, it can coexist with other systems, has excellent fading resistance, and is easy to scale. In the IEEE802.15.3 standardization conference, in the OFDM_UWB system, the band from 3.1 GHz to 10.6 GHz defined by the FCC is divided into a plurality of subbands each having a width of 528 MHz, and frequency hopping is performed between the subbands. Multi-band systems (hereinafter referred to as “MB-OFDM systems”) are being studied.

  Currently, with regard to the MB-OFDM system, the content of the discussion in IEEE 802.15.3TG3a is almost directly the ECMA (European Computer Manufacturer Association) standard, and ECMA-368 is a standard for the PHY layer and the MAC layer in the UWB communication system. Specifications are described (for example, see Non-Patent Document 1).

  According to the above standard specifications, the MB-OFDM communication system employs a communication method that spreads transmission data on the frequency axis and the time axis. “Spreading” here means that the same data is transmitted a plurality of times using a plurality of spreading positions on the frequency axis and the time axis. By performing two-dimensional spreading in the frequency axis and time axis directions in OFDM transmission, it is possible to optimize the spreading factor according to the condition of the line and derive optimum performance (for example, see Patent Document 1). . On the receiving side, the SNR can be improved by superimposing the same data received multiple times.

  FIG. 6 illustrates a data communication mechanism using such a spreading method. On the frequency axis, three subbands (frequency channels) each having a center frequency of F1, F2, and F3 are provided, and frequency hopping is performed between the subbands for each OFDM symbol in a round robin manner. Further, when viewed on the time axis, OFDM signals are transmitted at predetermined transmission timings T1, T2, T3,.

  One OFDM symbol is divided into two blocks at the center frequency, and the same data is transmitted in the first half and second half blocks. For example, A1 and A2 placed in the first half and the second half of the OFDM symbol transmitted on the subband of the center frequency F1 at time T1 are the same data A. The same data is transmitted using two consecutive OFDM symbols. Therefore, A3 and A4 placed in the first half and second half blocks of the OFDM symbol transmitted on the subband of center frequency F2 at time T2 are the same data A as A1. Transmitting data A twice in the first half and the second half of one OFDM symbol and transmitting data A across two consecutive OFDM symbols is equivalent to “frequency spreading”. Also, transmitting data A across two consecutive OFDM symbols is equivalent to “time spreading” because the same data is transmitted multiple times at different spreading positions on the time axis. The same applies to B1 to B4 and C1 to C4.

  By applying such spread communication, the SNR can be improved on the receiving side by superimposing the same data received multiple times. However, for example, a case where only some of the subbands are inferior frequency channels due to interference from a narrowband communication system existing in the vicinity and other channel conditions is assumed (see FIG. 7). .

  For example, as shown in FIG. 8, in a communication environment in which the first half of the symbols of the subband of the center frequency F1 and the subband of the center frequency F2 are inferior frequency channels, three of A, B, and C When data is spread and communicated on the frequency axis and the time axis, 3 blocks A1 to A3 of 4 blocks in data A, 2 blocks B3 to B4 in data B, and 1 block C1 in data C are poor. Become a channel. In the spreading method, the SNR is improved according to the number of times the same data can be received. Therefore, in the situation shown in FIG. 8, nonuniformity occurs in the improvement of the SNR for each data. As a whole, the packet error rate (PER) is deteriorated.

  Also, in UWB communication, transmission signals are spread over a wide band of frequencies, so the influence of interference on existing communication systems (for example, fixed microwaves, broadcast waves, radio astronomy, etc.) on the frequency band assigned to UWB. There is a problem. For this reason, it is indispensable to introduce interference avoidance technology that outputs UWB transmission waves below a certain level (weak level) in a band where an existing communication system exists, that is, detect and avoid (hereinafter also referred to as “DAA”). It is said that. The basic method of DAA is to check whether there is a transmission signal of another system in the UWB transmission band, and to output a UWB transmission wave below a certain level (weak level) if it exists.

  For example, as shown in FIG. 9, a case where a subband having F1 as the center frequency is set as a transmission prohibited channel is assumed by DAA. However, while channel avoidance is realized, when the transmission data spreading position as shown in FIG. 6 is applied in a fixed manner, the spreading rate becomes uneven for each transmission data. When the transmission prohibited channel is set as shown in FIG. 9, as shown in FIG. 10, two blocks A3 to A4 for data A, three blocks B1 to B2 for data B, three blocks B4, and C1 to C for data C The spreading factor is non-uniform for each transmission data, such as four blocks of C4. If the spreading factor is non-uniform, non-uniformity also occurs in the improvement of SNR, and as a result, the packet error rate (PER) is deteriorated as a whole as described above.

JP 2002-190788 A http: // www. ecma-international. org / publications / standards / Ecma-368. htm

  An object of the present invention is to provide an excellent radio communication system, radio communication apparatus, radio communication method, and computer program of the MB-OFDM method for performing data transmission while spreading on the frequency axis and the time axis.

  A further object of the present invention is to prevent the deterioration of PER as a whole system by avoiding non-uniform improvement in SNR for each transmission data even in a communication environment in which some transmission channels are deteriorated. An object of the present invention is to provide an excellent wireless communication system, wireless communication apparatus, wireless communication method, and computer program that can be prevented.

  A further object of the present invention is to avoid non-uniform spreading rates between transmitted data even when DAA is introduced to avoid interference with neighboring communication systems using narrowband signals. An object of the present invention is to provide an excellent wireless communication system, wireless communication apparatus and wireless communication method, and computer program that can prevent the deterioration of the PER of the entire system.

  The present invention has been made in consideration of the above problems, and a first aspect of the present invention is a wireless communication system that spreads transmission data on a frequency axis or a time axis. The wireless communication system is characterized in that the spread position on the frequency axis or the time axis is controlled so that the spreading factor for each transmission data is uniform. However, “system” here refers to a logical collection of a plurality of devices (or functional modules that realize specific functions), and each device or functional module is in a single housing. It does not matter whether or not (hereinafter the same).

  In the wireless communication system according to the present invention, a wireless communication apparatus that performs data transmission determines a channel condition on the frequency axis or time axis, and based on the result, a spreading factor of each transmission data on the frequency axis or time axis The diffusion position on the frequency axis or the time axis is controlled so as to be uniform.

  UWB communication using a very wide frequency band is expected as a wireless communication system realizing near field ultra high speed transmission, and standardization work is being performed. For example, an OFDM_UWB communication system employs a spread data communication system in which the same data is transmitted a plurality of times using a plurality of positions on the frequency axis and time axis. According to such a data transmission method, the SNR can be improved on the receiving side by superimposing the same data received multiple times.

  However, in UWB communication in which a transmission signal is spread over a wideband frequency, it is likely to be affected by interference from neighboring communication systems, and only some of the subbands may be poor frequency channels. In order to avoid the influence of interference on an existing communication system on the frequency band assigned to UWB, a transmission prohibited channel may be set by the DAA mechanism.

  In these cases, when the same spreading position is used in a space consisting of a frequency axis and a time axis, the ratio of occurrence of bad blocks for each transmission data becomes uneven, or between transmission data A situation in which the spreading factor becomes non-uniform occurs, and the improvement in SNR for each transmission data becomes non-uniform, which may result in the deterioration of the PER of the entire system.

  Therefore, in the wireless communication apparatus according to the present invention, if the normal spreading position is used as it is due to the presence of a poor channel in the frequency domain assigned to UWB, the number of bad blocks between transmission data becomes uneven. In such a case, by appropriately changing the transmission data spreading position on the frequency axis or time axis, the number of inferior blocks between the transmission data is made uniform to prevent the deterioration of the PER.

  In addition, since the wireless communication apparatus according to the present invention sets a transmission prohibition channel in order to avoid the influence of interference on the existing communication system, the spreading factor becomes uneven between transmission data at a normal spreading position. In some cases, by appropriately changing the transmission data spreading position on the frequency axis or time axis, the spreading factor between the transmission data is made uniform to prevent the deterioration of the PER.

The second aspect of the present invention is a computer program described in a computer-readable format so that processing for spreading transmission data on a frequency axis or a time axis and performing transmission is executed on a computer. For the computer,
A channel status determination procedure for determining the channel status in the frequency axis or the time axis;
A communication operation control procedure for controlling the spread position so that the spread rate of each transmission data is made uniform on the frequency axis or the time axis based on the channel condition;
Is a computer program characterized in that

  The computer program according to the second aspect of the present invention defines a computer program described in a computer-readable format so as to realize predetermined processing on the computer. In other words, by installing the computer program according to the second aspect of the present invention in the computer, a cooperative action is exhibited on the computer, and the same as the wireless communication apparatus according to the first aspect of the present invention. An effect can be obtained.

  According to the present invention, it is possible to provide an excellent wireless communication system, wireless communication apparatus, wireless communication method, and computer program of the MB-OFDM method for performing data transmission while spreading on the frequency axis and the time axis.

  According to the wireless communication device of the present invention, when data transmission is performed with a fixed spread position fixed in a communication environment in which some transmission channels are inferior, the number of inferior channel blocks between transmission data is reduced. In the case of non-uniformity, by appropriately changing the spread position of the transmission data on the frequency axis and time axis, avoiding non-uniform improvement in SNR for each transmission data, the PER as the entire system Can be prevented.

  According to the wireless communication device of the present invention, even if a DAA mechanism is introduced and a transmission prohibited channel is set to avoid interference with a neighboring communication system using a narrowband signal, By equalizing the spreading factor between the data, it is possible to prevent the deterioration of the PER of the entire system.

  Other objects, features, and advantages of the present invention will become apparent from more detailed description based on embodiments of the present invention described later and the accompanying drawings.

  The present invention relates to a wireless communication apparatus that performs UWB communication adopting an OFDM modulation scheme, and specifically, a plurality of bands each having a bandwidth of 3.1 GHz to 10.6 GHz defined by the FCC and each having a width of 528 MHz. It is an MB-OFDM communication device that divides into subbands and performs frequency hopping (FH) between the subbands. In addition, the wireless communication apparatus according to the present invention introduces a DAA mechanism for mitigating the level of interference with other systems caused by UWB transmission waves, and whether there is a transmission signal of another system within the UWB transmission band. The data transmission is started while avoiding interference. Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 shows the configuration of an MB-OFDM transceiver according to an embodiment of the present invention. The upper side in the figure corresponds to a receiver, and the lower side corresponds to a transmitter, and a single antenna 1 is shared via an antenna switch (ANT SW) 3.

  In the receiver, after the analog reception signal is amplified by the low noise amplifier (LNA) 4, a complex local signal corresponding to the frequency hopping pattern is supplied from a frequency generation unit (not shown), and the reception signal is subjected to frequency synthesis processing by the mixer 5. Downconvert to analog baseband signal.

  After the frequency conversion, unnecessary components other than the desired signal are removed using a bandpass filter (BPF) 6 and converted into a digital signal by the AD converter 8. A variable gain amplifier (VGA) 7 is disposed after the downconverter output so that the received signal always has an optimum dynamic range (that is, keeps the target level) in the AD converter 8 following the next stage. In addition, the gain of the VGA is controlled from the baseband signal processing unit side. Specifically, the digital signal after AD conversion is input to the automatic gain control unit (AGC) 13, and the adjusted gain information is fed back to the VGA 7 via the DA converter 14.

  In the Phy baseband processing unit 10, the digital baseband signal after AD conversion is Fourier-transformed by a fast Fourier transformer (FFT) 11 to convert it into a frequency domain signal. In addition to demodulating the phase and amplitude, the signal point on the phase space is decoded into the original signal sequence, and then passed to the upper layer 30.

  At the time of data transmission, in the Phy baseband processing unit 10, transmission data requested from the upper layer 30 is encoded by the transmission data generation unit 15, and subsequently assigned to a plurality of subcarriers to be phase and amplitude for each subcarrier. Apply modulation. Then, a fast inverse Fourier transformer (IFFT) 16 performs inverse Fourier transform on the plurality of subcarriers, and converts the subcarriers into signals on the time axis while maintaining the orthogonality of each subcarrier.

  Subsequently, the OFDM-modulated signal is DA-converted by the DA converter 17, and only the signal component in the desired band is extracted by the low-pass filter (LPF) 18, and then multiplied by the complex local signal in the mixer 19. Up-convert baseband signals to radio signals.

  The radio signal is further amplified to a desired transmission power level by a power amplifier (PA) 20 and emitted from the antenna 1 to the transmission path via the antenna switch 3 and the RF band-pass filter 2. By providing an RF bandpass filter that limits the band in front of the antenna 1 end, it is possible to prevent spurious signals from being generated outside the desired band.

  The communication operation control unit 40 controls the transmission data spreading process on the frequency axis and the time axis in the transmission system. "Spreading" here means that the same data is transmitted a plurality of times using a plurality of positions on the frequency axis and time axis. For example, data transmission is performed according to the spreading position as shown in FIG. Is done.

  In addition, the communication operation control unit 40 uses the frequency detection function of the FFT 11 to detect a frequency channel with poor communication quality or to detect the presence of a narrowband signal transmitted from a nearby communication system. Then, based on these detection results, the transmission data spread position is controlled to be switched on the frequency axis and the time axis. According to the FFT frequency detection function, channel quality and interference signals can be detected in units of subcarriers, but transmission data is spread in units of blocks corresponding to half of OFDM symbols. The detection process may be performed in block length units.

  For example, when the number of bad blocks becomes uneven between transmission data at a normal spreading position due to the presence of a bad channel in the frequency domain assigned to UWB, the communication operation control unit 40 determines whether the frequency axis or time By appropriately changing the diffusion position on the axis, the number of blocks that become inferior between transmission data is made uniform, and the deterioration of PER is prevented.

  Further, when a signal from an existing communication system is detected, a transmission prohibited channel is set in order to avoid the influence of DAA, that is, interference. At this time, if the spreading rate is nonuniform between transmission data at the normal spreading position, the communication operation control unit 40 changes the spreading position on the frequency axis or the time axis as appropriate, thereby spreading between the transmission data. The rate is made uniform to prevent the deterioration of PER.

  FIG. 2 shows, in the form of a flowchart, an operation procedure for changing the spread position of transmission data in order to eliminate the influence of a poor channel existing on the frequency domain assigned to UWB.

  First, channel estimation is performed (step S1), and transmission is started (step S2). Then, based on the channel estimation value, the number of inferior blocks is counted for each transmission data (step S3).

  Channel estimation is performed based on the power level of each subcarrier obtained by FFT. Specifically, for each block (that is, the first half and the second half of the OFDM symbol), if the number (or ratio) of subcarriers whose power level falls below a predetermined threshold exceeds a certain value, the block is regarded as bad. In the example shown in FIG. 7, it is determined that the blocks on both sides of the OFDM symbol whose center frequency is F1 and the first half of the OFDM symbol whose center frequency is F2 are inferior.

  In the spreading pattern shown in FIG. 6, one data is transmitted four times using four blocks provided on the frequency-time space. In the case where the channel quality is shown in FIG. 7, as shown in FIG. 8, 3 blocks A1 to A3 of 4 blocks in data A, 2 blocks B3 to B4 in data B, 1 of C1 in data C Only blocks are poor channels. Thus, when the number of inferior blocks differs for each transmission data, nonuniformity occurs in the improvement of SNR among the transmission data, and the data A becomes a bottleneck and the PER deteriorates.

  Therefore, it is checked whether or not the number of inferior blocks for each data is equal (step S4), and if it is equal, the normal transmission position is used for data transmission (step S5). Then, the process of changing the spread position on the frequency axis and the time axis is performed so that the number of blocks between transmission data is inferior (step S6).

  When the number of spreads for each transmission data at the normal spreading position is N, the total number of blocks prepared on the frequency axis is Cmax, and the number of usable blocks without bad channel quality is Ca, the spreading number of each transmission data is The spread position of the transmission data on the frequency axis and the time axis is changed so as to be equal to N × Ca / Cmax.

  FIG. 3 shows an example of changing the spread position in which the number of inferior blocks is made uniform among transmission data. As shown in the figure, the number of blocks used in the transmission data A to C is equalized to 2.

  Also, in FIG. 4, when a transmission prohibited channel is set to avoid the influence of interference, the transmission data spreading position on the frequency axis and the time axis is changed so that the spreading factor is uniform between the transmission data. The operation procedure for this is shown in the form of a flowchart.

  First, the communication path is investigated (step S11), and transmission is started (step S12). Then, based on the investigation result of the communication path, a transmission prohibited channel is set, and the number of transmission prohibited blocks for each transmission data at that time is counted (step S13).

  For example, as shown in FIG. 9, a subband having F1 as the center frequency is set as a transmission-prohibited channel by DAA. In this case, interference with other adjacent narrowband systems can be avoided, but as shown in FIG. 10, two blocks A3 to A4 for data A, three blocks B1 to B2 and B4 for data B, In data C, the spreading factor is nonuniform for each transmission data, such as four blocks C1 to C4. And transmission data with a low spreading factor becomes a bottleneck and causes deterioration of PER.

  Therefore, it is checked whether or not a transmission-prohibited channel is set (step S14). If the transmission-prohibited channel is not set, data transmission is performed using a normal spreading position as it is (step S15). If it is set, it is further checked whether the spreading factor is uniform for each data (step S16).

  Here, if the spreading factor is equal, data transmission is performed using the normal spreading position as it is (step S17), but if it is not equal, the frequency axis and the time axis are set so that the number of blocks is poor between transmission data. A process for changing the spread position of the transmission data is performed (step S18).

  When the number of spreading for each transmission data at the normal spreading position is N, the total number of blocks prepared on the frequency axis is Cmax, and the number of blocks usable after setting the transmission prohibited channel is Ca, the number of spreading of each transmission data Is changed so that N × Ca / Cmax is equal to N × Ca / Cmax.

  FIG. 5 shows an example of changing the spreading position where the spreading factor is made uniform between transmission data. As shown in the figure, the transmission data A has a spreading factor of 2, and B to C have a spreading factor of 3, which is uniform compared to the case shown in FIG.

  The present invention has been described in detail above with reference to specific embodiments. However, it is obvious that those skilled in the art can make modifications and substitutions of the embodiment without departing from the gist of the present invention.

  In the present specification, the embodiment in which the present invention is applied to the MB-OFDM communication system that performs OFDM_UWB communication has been mainly described, but the gist of the present invention is not limited to this. Even in a communication system that performs spreading processing only on either the frequency axis or the time axis, or a communication system that performs data spreading processing on other axes, the present invention can be applied to achieve a spreading factor between transmission data. Can be made uniform to prevent the deterioration of PER.

  In short, the present invention has been disclosed in the form of exemplification, and the description of the present specification should not be interpreted in a limited manner. In order to determine the gist of the present invention, the claims should be taken into consideration.

FIG. 1 is a diagram illustrating a configuration of an MB-OFDM transceiver according to an embodiment of the present invention. FIG. 2 is a flowchart showing an operation procedure for changing the spread position of transmission data in order to eliminate the influence of an inferior channel existing on the frequency domain assigned to UWB. FIG. 3 is a diagram showing an example of changing the spreading position in which the number of inferior blocks is made uniform among transmission data. FIG. 4 is a flowchart showing an operation procedure for changing the spread position of transmission data so that the spreading factor is uniform between transmission data when a transmission prohibition channel is set to avoid the influence of interference. is there. FIG. 5 is a diagram showing an example of changing the spreading position where the spreading factor is uniformized between transmission data. FIG. 6 is a diagram showing a state in which transmission data is arranged two-dimensionally in the frequency axis direction and the time axis direction by the spreading method. FIG. 7 is a diagram showing a state in which only some of the subbands are inferior frequency channels. FIG. 8 is a diagram illustrating a state in which transmission data is two-dimensionally spread in the frequency direction and the time axis direction in a communication environment in which a part of the channel is an inferior frequency channel. FIG. 9 is a diagram illustrating a state in which a subband having a center frequency of F1 is set as a transmission prohibited channel. FIG. 10 is a diagram illustrating a state in which transmission data is two-dimensionally spread in the frequency direction and the time axis direction in a communication environment in which a transmission prohibition channel is set.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Antenna 2 ... RF band pass filter 3 ... Antenna switch 4 ... Low noise amplifier (LNA)
5 ... Mixer 6 ... Bandpass filter 7 ... Variable gain amplifier (VGA)
8 ... AD converter 10 ... Phy baseband processor 11 ... Fast Fourier transform (FFT)
12 ... Received data reproduction unit 13 ... Automatic gain control unit (AGC)
14 ... DA converter 15 ... Transmission data generator 16 ... Fast inverse Fourier transformer (IFFT)
17 ... DA converter 18 ... Low-pass filter (LPF)
19 ... Mixer 20 ... Power amplifier (PA)
30 ... Upper layer 40 ... Communication operation control unit

Claims (7)

  A wireless communication system that spreads transmission data on the frequency axis or time axis, and spreads on the frequency axis or time axis so that the spreading factor for each transmission data is uniform based on the channel condition on the frequency axis or time axis A wireless communication system characterized by controlling a position. A wireless communication device that performs transmission by spreading transmission data on a frequency axis or a time axis,
A channel status determination unit for determining the channel status on the frequency axis or the time axis;
A communication operation control unit that controls the spread position on the frequency axis or the time axis so that the spreading rate of each transmission data is made uniform on the frequency axis or the time axis based on the channel condition;
A wireless communication apparatus comprising: Perform UWB communication using broadband,
The wireless communication apparatus according to claim 2. The communication operation control unit counts the number of inferior blocks among the blocks on the frequency axis or time axis used when transmitting each data based on the channel status, and the number of inferior blocks is equal among the transmission data. Change the spread position on the frequency axis or time axis so that
The wireless communication apparatus according to claim 2. The channel status determination unit detects the presence of a nearby narrowband communication system based on the channel status,
The communication operation control unit sets a transmission prohibited channel for avoiding interference with the narrowband communication system on a frequency axis or a time axis, and a spreading factor between transmission data in a region other than the transmission prohibited channel. Change the spread position on the frequency axis or time axis to be equal,
The wireless communication apparatus according to claim 2. A wireless communication method for performing transmission by spreading transmission data on a frequency axis or a time axis,
A channel status determination step for determining the channel status in the frequency axis or the time axis;
A communication operation control step for controlling the spread position on the frequency axis or time axis so that the spreading rate of each transmission data is made uniform on the frequency axis or time axis based on the channel condition;
A wireless communication method comprising: A computer program written in a computer-readable format so as to execute on a computer a process for spreading transmission data on a frequency axis or a time axis, and for the computer,
A channel status determination procedure for determining the channel status in the frequency axis or the time axis;
A communication operation control procedure for controlling the spreading position on the frequency axis or time axis so that the spreading rate of each transmission data is made uniform on the frequency axis or time axis based on the channel condition;
A computer program for executing

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