JP2006295793A - Wireless communication apparatus and method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a wireless communication apparatus capable of performing transmitting-side space diversity control, independently of a receiving side without requiring receivers as many as antennas. <P>SOLUTION: While using a radio signal including a data signal and a training signal that is a known pattern; the wireless communication apparatus includes 1st to N-th antennas (N is an integer of ≥2), a delay means for delaying a signal received by a k-th antenna ((k) is an integer of ≥1 and ≤N) for a k-1 symbol length, a composition means for composing N signals received by the antennas and delayed by the delay means, a frequency converting means for converting a composed signal into a signal of an intermediate frequency band, a demodulation means for demodulating the signal of the intermediate frequency band, and a maximum likelihood sequence estimating means for specifying the data signal by performing maximum likelihood sequence estimation on the demodulated signal. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a wireless communication apparatus and method for performing communication by space diversity.

  In wireless communication, space diversity is used as one of the measures for ensuring good transmission quality. FIG. 12 is a block diagram on the receiving side of a conventional wireless communication apparatus that performs space diversity.

  According to FIG. 12, the wireless communication apparatus includes antennas 21 and 31, receivers 22 and 32, a phase shifter 23, a combiner 24, a demodulator 25, and a phase detection comparison circuit 26.

  The antennas 21 and 31 receive the same radio signal transmitted from the opposite device not having the diversity configuration, respectively, the antenna 21 outputs the received signal to the receiver 22, and the antenna 31 outputs the received signal to the receiver 32. The receivers 22 and 32 perform frequency conversion of the received signal into an intermediate frequency signal. The phase detection comparison circuit 26 detects the phase difference between the output signals of the receivers 22 and 32 and outputs a control signal to the phase shifter 23. The phase shifter 23 receives the output signal of the receiver 32 as input, and adjusts and outputs the phase of the input signal so as to be in phase with the output signal of the receiver 22 based on the control of the phase detection comparison circuit 26. The combiner 24 combines the signal from the receiver 22 and the signal from the phase shifter 23 to realize space diversity. The signal synthesized by the synthesizer 24 is demodulated by the demodulator 25 to output received data.

  FIG. 13 is a block diagram on the transmission side of a wireless communication apparatus according to the prior art for a space diversity configuration, that is, a block diagram on the transmission side of the apparatus shown in FIG.

  According to FIG. 13, the wireless communication device includes a modulator 27, a distributor 28, a phase shifter 23, transmitters 29 and 39, antennas 21 and 31, and a phase detection / comparison circuit 26. The same reference numerals are used for the same elements as in FIG.

  The modulator 27 modulates data to be transmitted, and the distributor 28 distributes the modulated signal into two systems. One output of the distributor 28 is directly input to the transmitter 29, and the other output is input to the transmitter 39 after the phase is adjusted by the phase shifter 23. As the amount of phase shift change in the phase shifter 23, the value obtained by the phase detection comparison circuit 26 through the processing on the reception side shown in FIG. 12 is used. The transmitters 29 and 39 frequency-convert the intermediate frequency input signal into a signal of a predetermined radio frequency band, and further amplify the signal to a predetermined signal level. The antenna 21 receives the signal from the transmitter 29. The antenna 31 transmits the signal from the transmitter 39 as a radio signal. The signals transmitted from the antennas 21 and 31 are received by the opposite device that does not have a diversity configuration, but by giving in advance the phase difference obtained by the processing on the reception side shown in FIG. In the opposite device, the signal from the antenna 21 and the signal from the antenna 31 are received in the same phase, and diversity on the transmission side is realized. The details of the space diversity are described in Non-Patent Document 1.

Yoichi Saito, “Modulation and Demodulation of Digital Wireless Communication”, The Institute of Electronics, Information and Communication Engineers, p. 189-193

  Since the phase shifter 23 generally operates in an intermediate frequency band, when a space diversity configuration is used, a wireless communication device according to the related art requires a receiver corresponding to the number of antennas. Receivers up to the microwave band have become cheaper due to the recent spread, but radio frequencies above the quasi-millimeter wave band are expensive, which is a problem of the space diversity configuration. In addition, on the transmitting side, the phase change amount obtained by diversity control on the receiving side is used in the next transmission diversity, so the condition that transmission / reception is switched sufficiently faster than the speed of phase change in the transmission path is imposed. It is done.

  Therefore, an object of the present invention is to provide a wireless communication apparatus and a communication method that do not require a receiver corresponding to the number of antennas and enable space diversity control on the transmission side independently of the reception side.

According to the wireless communication device of the present invention,
A wireless communication apparatus that receives a wireless signal including a data signal and a training signal that is a known pattern, the first to Nth (N is an integer of 2 or more) antennas, and a kth (k is 1 or more and N or less) A delay unit that delays the signal received by the antenna of k-1 symbols, a combining unit that combines the N signals received by each antenna and delayed by the delay unit, and a combined signal. Conversion means for converting the signal into an intermediate frequency band signal, demodulation means for demodulating the intermediate frequency band signal, maximum likelihood sequence estimation for the demodulated signal, and maximum likelihood sequence estimation for identifying the data signal Means.

According to another embodiment of the wireless communication device of the present invention,
The training signal has first to Nth sections, and when receiving the training signal in the i-th section (i is an integer of 1 to N), only the signal received by the i-th antenna is received by the combining means. It is also preferable to have a timing control means that takes the signals received by all the antennas as inputs and inputs the signals to the combining means when receiving the data signal.

According to another embodiment of the wireless communication device of the present invention,
Training signal insertion means for inserting a training signal that is a known pattern into the data signal, modulation means for modulating the data signal with the training signal inserted, and frequency conversion means for converting the modulated signal into a signal in a radio frequency band , A distribution means for distributing the frequency-converted signal to first to Nth (N is an integer of 2 or more) signals, and a kth (k is an integer of 1 to N) signals, k−1 symbol length It has delay means for delaying, and first to Nth antennas for transmitting each of the first to Nth signals delayed by the delay means as radio signals.

Furthermore, according to another embodiment of the wireless communication apparatus of the present invention,
The training signal has first to Nth sections, and outputs only the i-th signal to the i-th antenna when transmitting the training signal in the i-th section (i is an integer of 1 to N). It is also preferable to have timing control means for outputting each of the first to Nth signals to the first to Nth antennas when transmitting the data signal.

Furthermore, according to another embodiment of the wireless communication apparatus of the present invention,
A radio communication apparatus that receives a radio signal transmitted by the radio communication apparatus, comprising: a maximum likelihood sequence estimation unit that performs maximum likelihood sequence estimation on a demodulated signal and identifies a data signal. .

Furthermore, according to another embodiment of the wireless communication apparatus of the present invention,
It is also preferable that the maximum likelihood sequence estimation means obtains N tap coefficients indicating impulse response characteristics of a transmission path when receiving a training signal, and performs maximum likelihood sequence estimation using the tap coefficients when receiving a data signal. .

According to the diversity wireless communication method of the present invention,
Inserting a training signal having a known pattern into a data signal; modulating a frequency of the data signal into which the training signal is inserted; and transmitting the signal as a radio signal; Is received by an antenna having an integer of 2 or more, and the output signal of the k-th antenna (k is an integer of 1 or more and N or less) is combined with a delay of k-1 symbols, and the demodulated signal is Performing maximum likelihood sequence estimation and identifying a data signal;
It is characterized by having.

According to another embodiment of the diversity wireless communication method of the present invention,
Inserting a training signal of a known pattern into the data signal; modulating the frequency of the data signal into which the training signal is inserted after modulation; and distributing the first to N-th (N is an integer of 2 or more) signals; Transmitting a k-th signal (k is an integer not less than 1 and not more than N) as a radio signal with a delay of k-1 symbols, receiving the radio signal with one antenna, and receiving the received signal The method includes a step of performing frequency conversion and demodulation, and a step of performing maximum likelihood sequence estimation on the demodulated signal and specifying a data signal.

  By combining the signals including the training signal, which is a known pattern, received by each of the N antennas with a time difference such that each of them differs by one symbol length, and performing maximum likelihood sequence estimation on this Thus, space diversity combining can be performed with the same effect as the path diversity of the maximum likelihood sequence estimation equalizer, and the number of receivers can be one regardless of the number of antennas.

  Similarly, by combining and transmitting signals including a training signal that is a known pattern with a time difference such that each is different by one symbol length, the radio communication apparatus that has received the signal can obtain the maximum likelihood sequence. The data sequence can be estimated by estimation, and the transmission diversity configuration can be made independent of processing in the opposite direction.

  The best mode for carrying out the present invention will be described in detail below with reference to the drawings.

  FIG. 1 is a block diagram of a wireless communication apparatus according to the first embodiment of the present invention, in which a wireless signal transmitted by the wireless communication apparatus shown in FIG. Receive.

  The wireless communication apparatus in FIG. 1A includes a training signal insertion circuit 1, a modulator 2, a transmitter 3, and an antenna 4. The training signal insertion circuit 1 inserts a training signal having a known pattern into the data signal to be transmitted and outputs it. As the training signal, for example, a PN (PseedNoise) sequence can be used. FIG. 2 shows a state in which the training signal is added before the transmission data.

  The modulator 2 modulates the output signal of the training signal insertion circuit 1, and the transmitter 3 frequency-converts the modulated signal into a signal of a predetermined radio frequency band, amplifies the signal to a predetermined level, and outputs the signal. 4 transmits the output signal of the transmitter 3 as a radio signal.

  The wireless communication device in FIG. 1B includes antennas 41 and 42, a delay circuit 5, a combiner 6, a receiver 7, a demodulator 8, and a maximum likelihood sequence estimator 9. The antennas 41 and 42 receive the radio signals transmitted by the radio communication apparatus shown in FIG. 1A, respectively, the antenna 41 outputs the received signals to the combiner 6, and the antenna 42 delays the received signals. Output to the circuit 5.

  The delay circuit 5 delays the input signal by one symbol and outputs it to the combiner 6. The synthesizer 6 synthesizes the signal from the antenna 41 and the signal from the delay circuit 5, the receiver 7 frequency-converts the signal synthesized by the synthesizer 6 into a signal in the intermediate frequency band, and the demodulator 8 Then, the received signal converted into the intermediate frequency band signal is demodulated, and the demodulated signal is input to the maximum likelihood sequence estimator 9.

  The maximum likelihood sequence estimator 9 performs maximum likelihood sequence estimation on the input signal, identifies the transmitted data signal, and outputs the identified data signal. FIG. 3 is a block diagram of the maximum likelihood sequence estimator 9. According to FIG. 3, the maximum likelihood sequence estimator includes a transmission path estimation circuit 91, a replica generation circuit 92, a branch metric generation circuit 93, and a sequence estimation circuit 94.

  The transmission path estimation circuit 91 is a 2-tap filter having a tap interval of 1 symbol length, obtains optimum values of tap coefficients c0 and c1 using a training signal included in the received radio signal, and determines the received signal In the data signal section, the obtained tap coefficients c0 and c1 are output to the replica generation circuit 92.

  FIG. 4 is a block diagram of the transmission path estimation circuit 91. According to FIG. 4, the transmission path estimation circuit 91 includes a delay circuit 910, multipliers 911 and 912, adders 913 and 914, and a tap coefficient control circuit 915.

  In FIG. 4, u (n) is a signal of the same sequence as the training signal added on the transmission side, and is generated using a fixed memory (not shown), and y (n) is the maximum likelihood sequence estimation. This is an input signal of the device 9. The transmission path estimation circuit 91 adjusts the tap coefficients c0 and c1 according to the transmission path characteristics as described below during reception of the training signal.

  First, a signal of the same series as the training signal is multiplied by a tap coefficient c0 by a multiplier 911, further delayed by 1 bit by a delay circuit 910, and then multiplied by a tap coefficient c1 by a multiplier 912. The output of the multiplier 911 and the output of the multiplier 912 are added by the adder 913. Therefore, the output of the adder 913 is c0 × u (n) + c1 × u (n−1). Since the signal y (n) is a combination of the reception signal of the antenna 41 and the signal obtained by delaying the reception signal of the antenna 42 by 1 bit, the tap is made so that the output signal of the adder 913 becomes equal to y (n). The coefficients c0 and c1 are adjusted. That is, the adder 914 subtracts the output signal of the adder 913 from y (n) to obtain an error signal e (n), and the tap coefficient control circuit 915 controls the tap coefficient so that the error becomes zero. For the control of the tap coefficient, a general LMS (Least Mean Squares) algorithm or an RLS (Recursive Last Squares) algorithm can be used.

  As described above, the transmission path estimation circuit 91 outputs the tap coefficients c0 and c1 obtained during reception of the training signal to the replica generation circuit 92 during reception of the data signal.

  The replica generation circuit 92 obtains a replica signal r (n) = c0 × s (n) + c1 × s (n−1) for each state of the transmission signal, using the tap coefficient obtained by the transmission path estimation circuit 91. Here, s (n) indicates the state of the transmission signal. For example, when QPSK (Quadrature Phase Shift Keying) modulation is used, there are four states as the state of the transmission signal as shown in FIG. However, there are a total of 16 combinations of s (n) and s (n-1). Therefore, there are 16 replica signals r (n).

The branch metric generation circuit 93 calculates a branch metric signal b (n) = | y (n) −r (n) | ² for each replica signal r (n).

The sequence estimation circuit 94 estimates and outputs the data signal sequence transmitted on the transmission side by maximum likelihood sequence estimation from the branch metric signal b (n). FIG. 6 is a diagram for explaining maximum likelihood sequence estimation. In the case of QPSK modulation, as shown in FIG. 5, there are four types of transmission symbols. Therefore, there are 4 ^M data series combinations in the M symbol data section. A near one is searched for as a data signal sequence actually transmitted by the opposite apparatus. For this reason, the branch metric b (n) corresponding to each sequence is added, the cumulative value up to M symbols is calculated for all sequences, and the smallest one is output as a data signal sequence. A Viterbi algorithm is generally used for the calculation.

  The reason for performing sequence estimation over M symbols instead of performing signal detection for each symbol is that s (n) and s (n−1) when c0 and c1 are close to each other in signal detection for each symbol. ) Cannot be distinguished from each other and the detection accuracy is deteriorated. In the sequence estimation, since the accumulated values of detection errors over a plurality of symbols are compared, the discrimination between s (n) and s (n-1) is improved. Because it does.

  Performing maximum likelihood sequence estimation means performing signal detection using the signal power of two symbols, and has the effect of combining the signal powers of both symbols at the maximum ratio. The impulse response characteristic of the combiner 6 output is as shown in FIG. 7, and the artificially generated delay wave and main wave are combined by maximum likelihood sequence estimation. When there is no correlation between the received powers of the two antennas, an effective space diversity gain can be obtained.

  A feature of the present invention is that, as described above, a maximum likelihood sequence estimation equalizer is obtained by combining the received signals of two antennas in a state where there is a time difference of one symbol length and performing maximum likelihood sequence estimation on this. Space diversity synthesis is performed with the same effect as the path diversity.

  In this embodiment, space diversity combining using two antennas has been described. However, space diversity combining using three antennas can be developed. In this case, a delay circuit for a length of 2 symbols is inserted into the third antenna, the transmission path estimation circuit is also 3 taps, and the replica signal r (n) is also 3 symbols s (n), s ( The total number of combinations of n-1) and s (n-2) is 64. 4 or more antennas can be extended in the same way.

  FIG. 8 is a block diagram of the wireless communication apparatus according to the second embodiment of the present invention. The wireless communication apparatus shown in (b) receives a signal transmitted by the wireless communication apparatus having the space diversity configuration shown in (a). I do. In addition, the same code | symbol is used for the same component and detailed description is abbreviate | omitted.

  The wireless communication apparatus in FIG. 8A includes a training signal insertion circuit 1, a modulator 2, a transmitter 3, a distributor 10, a delay circuit 5, and antennas 41 and 42. The training signal insertion circuit 1 inserts a training signal having a known pattern into a data signal to be transmitted. The distributor 10 distributes the signal modulated by the modulator 2 and converted into a signal of a predetermined radio frequency band by the transmitter 3 into two systems, outputs one signal to the antenna 41, and outputs the other signal. Output to the delay circuit 5.

  The delay circuit 5 delays the input signal by one symbol and outputs the delayed signal to the antenna 43. The antennas 42 and 43 each transmit the input signal as a radio signal.

  The wireless communication apparatus in FIG. 8B includes an antenna 4, a receiver 7, a demodulator 8, and a maximum likelihood sequence estimator 9. The antenna 4 receives both radio signals transmitted by the antennas 41 and 42 of the radio communication apparatus shown in FIG. 8A and outputs the received signals to the receiver 7. After that, as in the first embodiment, the receiver 7 frequency-converts the input signal into an intermediate frequency band signal, and the demodulator 8 demodulates the received signal converted into the intermediate frequency band signal. The likelihood sequence estimator 9 estimates and outputs a data signal sequence by maximum likelihood sequence estimation. Also in the second embodiment, the impulse response characteristic of the output of the antenna 4 has a main wave and a delayed wave as in FIG. 7, and a space diversity configuration is realized by combining two waves by performing maximum likelihood sequence estimation. it can.

  In a wireless system in which a wireless base station communicates with a plurality of wireless terminals, the receiving side of the wireless base station is configured as shown in FIG. 1B, the transmitting side of the wireless base station is configured as shown in FIG. The reception side of the terminal is configured as shown in FIG. 8B, and the transmission side of the wireless terminal is configured as shown in FIG. 1A, so that the same number of receivers as the number of antennas are required on the wireless base station side. However, on the wireless terminal side, the antenna configuration is small, that is, space diversity can be configured by one antenna. Also, in this configuration, unlike the prior art, diversity from the radio base station to the radio terminal, that is, transmission diversity does not depend on processing from the radio terminal to the radio base station, ie, reception diversity.

  The second embodiment can be expanded to three or more antenna configurations as in the first embodiment.

  FIG. 9 is a block diagram of a wireless communication apparatus according to the third embodiment of the present invention. According to FIG. 9, the wireless communication device includes antennas 41 and 42, delay circuit 5, switches 10 and 11, synthesizer 6, receiver 7, demodulator 8, maximum likelihood sequence estimator 9, And a timing control circuit 12.

  FIG. 10 shows training signals used in the present embodiment. According to FIG. 10, the training signal is composed of a first training signal and a second training signal, each of which is a known sequence.

  The antennas 41 and 42 receive the radio signals shown in FIG. 10 transmitted by the radio communication apparatus shown in FIG. 1A, respectively. The antenna 41 outputs the received signals to the switch 10, and the antenna 42 The received signal is output to the delay circuit 5, and the delay circuit 5 delays the input signal by one symbol and outputs it to the switch 11.

  The switches 10 and 11 turn the switch ON or OFF based on the control of the timing control circuit 12, and output an input signal to the combiner 6 while the switch is ON, and do not output while it is OFF.

  The timing control circuit 12 receives the output of the demodulator 8, detects the reception timing of the first training signal and the second training signal, turns on the switch 10 while receiving the first training signal, The switch 11 is turned off, the switch 10 is turned off while the second training signal is being received, the switch 11 is turned on, and the switches 10 and 11 are turned on while the data signal is being received.

  Under the control of the timing control circuit 12, the transmission path estimation circuit 91 of the maximum likelihood sequence estimator 9 receives only the antenna 41 and controls only the tap coefficient c0 corresponding to the main wave while receiving the first training signal. To do. Similarly, while receiving the second training signal, the transmission path estimation circuit 91 of the maximum likelihood sequence estimator 9 receives the antenna 42 and controls only the tap coefficient c1 corresponding to the delayed wave.

  With the above configuration, the transmission path estimation circuit 91 of the maximum likelihood sequence estimator 9 can execute tap coefficient control using only the received signal from the corresponding antenna, and can improve the accuracy of tap coefficient control.

  FIG. 11 is a block diagram of a wireless communication apparatus according to the fourth embodiment of the present invention. According to FIG. 11, the radio communication device includes a training signal insertion circuit 1, a modulator 2, a transmitter 3, a distributor 10, switches 10 and 11, a delay circuit 5, antennas 41 and 42, timings, and the like. And a control circuit 12. The training signal insertion circuit 1 adds a first training signal and a second training signal, which are known patterns, shown in FIG. 10 to the transmission data. The distributor 10 distributes the signal modulated by the modulator 2 and converted into a signal of a predetermined radio frequency band by the transmitter 3 into two systems, outputs one signal to the switch 10, and outputs the other signal. Output to the switch 11.

  The timing control circuit 12 receives the output of the training signal insertion circuit 1 as input, detects the transmission timing of the first training signal and the second training signal, and turns on the switch 10 while transmitting the first training signal. The switch 11 is turned off, the switch 10 is turned off while the second training signal is being transmitted, the switch 11 is turned on, and the switches 10 and 11 are turned on while the data signal is being transmitted. .

  Based on the control of the timing control circuit 12, the switch 10 outputs an input signal to the antenna 41 while the switch is ON, the antenna 41 transmits the input signal as a radio signal, and the switch 11 is the timing control circuit 12. As long as the switch is ON, the input signal is output to the delay circuit 5. The delay circuit 5 delays the input signal by 1 bit and then outputs it to the antenna 42. The antenna 42 receives the input signal. Transmit as a radio signal.

  The block diagram on the reception side is the same as FIG. 8B, but the transmission path estimation circuit 91 of the maximum likelihood sequence estimator 9 adjusts the tap coefficient c0 using the first training signal transmitted by the antenna 41. The tap coefficient c1 is adjusted using the second training signal transmitted by the antenna 42. Therefore, the accuracy of the tap coefficient can be improved as in the third embodiment.

  The third and fourth embodiments can be expanded to three or more antenna configurations as in the first embodiment.

It is a block diagram of the radio | wireless communication apparatus in 1st Embodiment of this invention. It is a figure which shows the state which added the training signal before the transmission data. It is a block diagram of a maximum likelihood sequence estimator. It is a block diagram of a transmission path estimation circuit. It is a figure which shows the transmission symbol of QPSK. It is a figure explaining maximum likelihood sequence estimation. It is a figure which shows the impulse response characteristic of a combiner | synthesizer. It is a block diagram of the radio | wireless communication apparatus in 2nd Embodiment of this invention. It is a block diagram of the radio | wireless communication apparatus in 3rd Embodiment of this invention. It is a figure which shows the training signal used in 3rd and 4th embodiment. It is a block diagram of the radio | wireless communication apparatus in 4th Embodiment of this invention. It is a block diagram by the side of reception of the radio | wireless communication apparatus by a prior art. It is a block diagram by the side of transmission of the radio | wireless communication apparatus by a prior art.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Training signal insertion circuit 2, 27 Modulator 3, 29, 39 Transmitter 4, 21, 31, 41, 42 Antenna 5, 910 Delay circuit 6, 24 Synthesizer 7, 22, 32 Receiver 8, 25 Demodulator 9 Maximum likelihood sequence estimator 10, 11 Switch 12 Timing control circuit 23 Phase shifter 26 Phase detection comparison circuit 28 Divider 91 Transmission path estimation circuit 92 Replica generation circuit 93 Branch metric generation circuit 94 Sequence estimation circuit 911, 912 Multiplier 913, 914 Adder 915 Tap coefficient control circuit

Claims (8)

A wireless communication device that receives a wireless signal including a data signal and a training signal that is a known pattern,
First to Nth antennas (N is an integer of 2 or more);
Delay means for delaying a signal received by a k-th antenna (k is an integer of 1 to N) by a length of k-1 symbols;
Combining means for combining the N signals received by each antenna and delayed by the delay means;
A frequency converting means for converting the synthesized signal into an intermediate frequency band signal;
Demodulation means for demodulating the intermediate frequency band signal;
Maximum likelihood sequence estimation means for performing maximum likelihood sequence estimation on the demodulated signal and identifying a data signal;
A wireless communication apparatus comprising: The training signal has first to Nth sections,
When receiving the i-th section of the training signal (i is an integer between 1 and N), only the signal received by the i-th antenna is input to the combining means, and when receiving the data signal, the signals received by all antennas are received. The wireless communication apparatus according to claim 1, further comprising a timing control unit that inputs the combining unit. Training signal insertion means for inserting a training signal that is a known pattern into the data signal;
Modulation means for modulating the data signal with the training signal inserted;
A frequency conversion means for converting the modulated signal into a radio frequency band signal;
Distributing means for distributing the frequency-converted signal into first to Nth (N is an integer of 2 or more) signals;
Delay means for delaying a k-th (k is an integer from 1 to N) signal by a length of k-1 symbols;
First to Nth antennas for transmitting each of the first to Nth signals delayed by the delay means as a radio signal;
A wireless communication apparatus comprising: The training signal has first to Nth sections,
When transmitting the training signal in the i-th section (i is an integer between 1 and N), only the i-th signal is output to the i-th antenna, and when transmitting the data signal, each of the first to N-th signals is output. 4. The wireless communication apparatus according to claim 3, further comprising timing control means for outputting to the first to Nth antennas. A wireless communication device that receives a wireless signal transmitted by the wireless communication device according to claim 3 or 4,
A radio communication apparatus comprising a maximum likelihood sequence estimation means for performing maximum likelihood sequence estimation on a demodulated signal and identifying a data signal. The maximum likelihood sequence estimation means includes:
When receiving the training signal, N tap coefficients indicating the impulse response characteristics of the transmission path are obtained,
6. The wireless communication apparatus according to claim 1, wherein maximum likelihood sequence estimation is performed using the tap coefficient when receiving a data signal. A wireless communication method using diversity,
Inserting a training signal of a known pattern into the data signal;
The data signal into which the training signal is inserted is modulated and frequency-converted and transmitted as a radio signal;
The radio signal is received by first to Nth antennas (N is an integer of 2 or more), and an output signal of the kth antenna (k is an integer of 1 to N) is delayed by k−1 symbols. Synthesizing step;
Performing maximum likelihood sequence estimation on the demodulated signal and identifying the data signal;
A wireless communication method comprising: A wireless communication method using diversity,
Inserting a training signal of a known pattern into the data signal;
A step of modulating the frequency of the data signal into which the training signal is inserted after modulation and distributing the data signal to first to Nth (N is an integer of 2 or more) signals;
Transmitting a k-th (k is an integer from 1 to N) signal as a radio signal with a delay of k-1 symbols, and
Receiving the wireless signal by one antenna;
Demodulating the received signal by frequency conversion;
Performing maximum likelihood sequence estimation on the demodulated signal and identifying the data signal;
A wireless communication method comprising:

Images