JP4737532B2 - Receiver - Google Patents

Description

The present invention relates to a communication device (transmission device, reception device, transmission / reception) using a space-time coding transmission technique (hereinafter referred to as STBC (Space Time Block Code) communication method) proposed by Alamouti (Siavash M. Alamouti). Device) and a communication system.
This method is very useful for improving the quality of communication data in mobile communication such as inter-vehicle communication.

  The space-time coding transmission technique (STBC communication system) proposed by Alamoti is described in the following Non-Patent Document 1 and the like. As a communication technique using this STBC communication system, for example, the following Patent Document 1 is described. And the like are known.

For example, consider a case where the STBC communication method is used in a 2 × 1 system with two transmission antennas and one reception antenna. At this time, the received signals on the receiving station side at successive symbol times 1 and 2 are r ₁ and r ₂ , respectively, and the channel characteristics between the first transmitting antenna and the receiving antenna are h ₁ and the second transmitting antenna. When the channel characteristic between the antenna and the receiving antenna is h ₂ and the received signal vector r, channel matrix H and symbol vector s are defined as shown in the following equation (1), the relationship of the following equation (2) is established. Here, “a ^* ” indicates the complex conjugate of a.

（２×１システムにおけるＳＴＢＣ通信方式）
ｒ ＝ Ｈｓ …（２） (Basic definition formula)

(STBC communication system in 2 × 1 system)
r = Hs (2)

This relational expression is equivalent to the case where n ₀ = n ₁ = 0 in non-patent document 1 (11). The influence of the received noises n ₀ and n ₁ can be ignored here because a certain noise margin can be provided at the time of symbol determination.
If h ₁ and h ₂ are selected so that | h ₁ | ² + | h ₂ | ² = 1 is satisfied, H becomes a unitary matrix. In this case, r is standardized. Then, the normalized symbol vector s can be easily obtained by the following equation (3).

(Derivation formula of symbol vector s)
s = H ⁻¹ r = H ^H r (3) Here, H ^H denotes an adjoint matrix of the matrix H.

In these conventional techniques, the channel characteristics of multipath (multipath) are estimated with high accuracy on the receiving side by skillfully using training signals (pilot signals), etc., in order to improve the quality of communication data. Is very important.
“A simple transmit diversity technique for wireless communications,” IEEE journal on selective areas in communications, vol.16, no.8, pp.1451-1458, Oct. 1998. JP 2004-129082 A

  However, in conventional communication devices (transmitting device, receiving device, transmitting / receiving device) conforming to the STBC communication method, the variation of the multipath environment due to station movement is not taken into consideration. That is, in the above-described conventional communication device, when the transmitting station or the receiving station moves at high speed, the rapid deterioration over time of the estimated value of the channel characteristics associated with the high-speed movement is not particularly compensated. While the transmitting station or the receiving station is moving, interference wave components may increase on the receiving side, making it impossible to decode the received signal.

For example, upon receiving a training signal (pilot signal): Any (time t ₀₎ when the estimated accuracy of the channel estimation matrix Γ to be calculated is sufficiently high, the next time of the training signal at time t ₀ + Delta] t from the time t ₀ If the transmitting station or the receiving station moves before reception, the estimation accuracy related to the channel matrix H may be rapidly deteriorated depending on the moving distance between them. That is, in the conventional apparatus, the communication quality may be rapidly deteriorated due to the dynamic distance between the transmitting and receiving stations, and this is a problem particularly in the case of mobile communication with a high moving speed.

  The present invention has been made to solve the above-described problems, and its purpose is to maintain the advantages of the STBC communication method while the transmitting station or the receiving station moves at high speed in a multipath environment. It is also to ensure high communication quality.

In order to solve the above problems, the following means are effective.
That is, the first means of the present invention comprises a channel estimation means for receiving a predetermined training signal and estimating a channel matrix H representing channel characteristics of each multipath propagation path between the transmitting station and the receiving station; In a STBC communication system receiver having a channel matrix H estimated by the channel estimation means and a decoding means for performing a spatio-temporal block decoding process based on the received signal vector r, a training signal, its received signal, and To the initial channel matrix calculation means for calculating the initial channel matrix, which is the initial value of the channel matrix, and correction that is repeated at a constant calculation cycle within the period from when the training signal is received until the next training signal is received. At each timing, the current correction type is calculated using the previous channel matrix H obtained at the previous correction timing. Based on the symbol signal s after symbol determination obtained by demodulating the received signal received at the time of correction and the received signal r received at the current correction timing, the current channel matrix at the current correction timing is Assuming that only the phase is changed in common for all the components of the matrix with respect to the matrix H, the phase variation calculation means for obtaining the phase variation φ that is common to each component of the previous channel matrix H, and the phase variation φ A current channel matrix computing means for correcting the previous channel matrix H based on the current channel matrix H ′ at the current correction timing, and a previous channel used in the phase variation calculating means each time a training signal is received. The matrix H is an initial channel matrix calculated by the initial channel matrix calculation means, and the current channel matrix operation is performed at each correction timing. The current channel matrix H 'calculated by the means, the receiving apparatus characterized by and a control means for a channel matrix H before use in phase change amount calculation means in the next correction timing.

The second means of the present invention comprises a channel estimation means for receiving a predetermined training signal and estimating a channel matrix H representing channel characteristics of each propagation path of the multipath between the transmitting station and the receiving station; In a STBC communication system receiver having a channel matrix H estimated by the channel estimation means and a decoding means for performing a spatio-temporal block decoding process based on the received signal vector r, a training signal, its received signal, and To an initial channel matrix calculation means for calculating an initial channel matrix H (t ₀ ), which is an initial value of the channel matrix , and a constant calculation within a period from when the training signal is received until the next training signal is received. This time using the previous channel matrix H obtained at the previous correction timing for each correction timing repeated in a cycle. Based on the symbol signal s after symbol determination obtained by demodulating the received signal received at the correction timing and the received signal r received at the current correction timing, the current channel matrix at the current correction timing is A phase fluctuation amount calculating means for obtaining a phase fluctuation amount φ ₀ common to each component of the previous channel matrix H, assuming that only the phase is changed in common for all components of the matrix with respect to the channel matrix H, and an initial channel matrix The phase displacement Φ (k) at the current correction timing with respect to H (t ₀ ) is expressed as Φ (k) = (1−γ) Φ (k−1) + γφ ₀ (k), where 0 <γ <1, k Is a phase displacement calculation means obtained from a number representing the correction timing, a phase displacement Φ (k) obtained by the phase displacement calculation means, and an initial channel matrix H (t ₀ ) Current channel matrix calculation means for calculating the current channel matrix H 'in the ming, and the initial channel calculated by the initial channel matrix calculation means for the previous channel matrix H used in the phase fluctuation amount calculation means each time a training signal is received And a control means for setting the current channel matrix H ′ calculated by the current channel matrix calculation means for each correction timing to the previous channel matrix H used in the phase fluctuation amount calculation means at the next correction timing. It is the receiver characterized by these.
By the above means of the present invention, the above-mentioned problem can be effectively or rationally solved.

The effects obtained by the above-described means of the present invention are as follows.
That is, by the present onset bright lever, rapid deterioration over time of the estimate of the channel characteristics due to high speed movement of the receiving station or transmitting station, since it is substantially without excess or deficiency effectively compensated, the receiving station or transmitting station Even when moving at a high speed, it is possible to easily ensure higher communication quality than in the past.
In mobile communication in which at least one of the receiving station and the transmitting station moves, the fluctuation component of the channel characteristic (that is, the propagation path environment between the transmitting and receiving stations) within the transmission interval of the pilot signal is the phase component of the channel. It has been found that it can be expressed almost uniquely only by the fluctuation amount φ. That is, this phase fluctuation amount φ occurs because each multipath propagation path length changes according to the moving amount of the mobile body having the receiving station and the transmitting station, and within the pilot signal transmission interval period. It is unlikely that the channel characteristics will change suddenly due to other factors. In addition, each propagation path length between moving bodies shows a larger change as their relative speed increases, but this change often shows a monotonic or continuous fluctuation tendency with respect to time, and thus the above-described phase shift. Along with this, the fluctuation amount φ shows a substantially similar fluctuation tendency.

For this reason, if the channel characteristics are corrected as needed based on the phase fluctuation amount φ by the phase fluctuation amount calculation means and the phase correction means, it is possible to easily ensure higher communication quality than before.
Such correction can be replaced by equivalent correction processing for the received signal. It is clear from the above formulas (2) and (3) that such an operation leads to an equivalent result.

Hereinafter, the present invention will be described based on specific examples.
However, the embodiments of the present invention are not limited to the following examples.

1. Configuration and Operation of Invention Device FIG. 1 is a control block diagram of a decoding processing device 100 for STBC communication in the first embodiment. The decoding processing apparatus 100 executes decoding processing on the receiving station side of an STBC communication system (so-called 2 × 1 system) having two transmitting antennas and one receiving antenna. Therefore, the basic definition formula (formula (1)) described above will be used in the same manner below. That is, the decoding processing apparatus 100 decodes the space-time block coded (STBC) symbol s based on the received signals r ₁ and r ₂ received in order at successive symbol times.

  The decoding processing apparatus 100 mainly includes a received signal determination unit 101, a propagation path estimation unit 102, an STBC decoding unit 103, a channel matrix correction unit 104, and the like. The greatest feature of the decoding processing apparatus 100 is that the channel matrix H is sequentially corrected by feedback control of the channel matrix correction unit 104.

The received signal determination unit 101 determines whether or not the received signals r ₁ and r ₂ are pilot signals, and when these are pilot signals, the received signals r ₁ and r ₂ are sent to the propagation path estimation unit 102. Otherwise, the received signals r ₁ and r ₂ are sent to the STBC decoding unit 103. At the same time, when the received signals r ₁ and r ₂ are pilot signals, the switch sw1 is connected to the contact a, and otherwise the switch sw1 is connected to the contact b.

The propagation path estimating unit 102 estimates each propagation path characteristic of the multipath between the transmitting station and the receiving station based on the input pilot signals (received signals r ₁ and r ₂ ). That is, the channel matrix H of the above equation (1) is obtained and output to the contact a in the figure. Hereinafter, the channel matrix directly calculated from the pilot signal by the propagation path estimation unit 102 may be expressed as H (t ₀ ). Here, t ₀ represents the reception time of the pilot signal.

The STBC decoding unit 103 receives the channel matrix H from the switch sw1. If this channel matrix H is immediately after receiving the pilot signal, the switch sw1 is connected to the contact point a, and therefore matches the channel matrix H (t ₀ ).
Next, STBC decoding section 103 inputs received signals r ₁ and r ₂ to be decoded that are not pilot signals from received signal determining section 101. Then, a desired symbol signal s is obtained based on the equations (1) and (3). However, since the symbol signal s output from the STBC decoding unit 103 indicates a determination result after symbol determination, for example, when the QPSK method is employed, four symbol signals shown in the following equation (4) are used. Any one signal of s is output. Even when the 8-PSK method is adopted, the output signal (symbol signal s) from the STBC decoding unit 103 is limited to eight.
(Symbol judgment result)

The channel matrix correction unit 104 uses the received signals r ₁ and r ₂ , the channel matrix H previously used by the STBC decoding unit 103 and the determination result (symbol signal s) output by the STBC decoding unit 103. Then, the phase fluctuation amount φ of the channel is obtained by the phase fluctuation amount calculation unit 104a, and the channel matrix H is corrected by the correction calculation unit 104b based on the phase fluctuation amount φ. Hereinafter, the channel matrix after the correction is written as H ′. The phase correction matrix A is defined by the following equation (5). Here, i is an imaginary unit. Note that the signs of the phases of the diagonal components of the phase correction matrix A are opposite to each other because the second component of the received signal vector r in Equation (1) is complex conjugate.
(Definition formula of phase correction matrix A)

More specifically, the phase fluctuation amount calculation unit 104a finds the phase fluctuation amount φ by solving the equation of the following equation (6) using the above determination result (symbol signal s).
(Equation of φ)
r = AHs or
A ⁻¹ r = Hs (6)

The equation of the phase fluctuation amount φ is configured for each component of the vector r, but it is sufficient to solve the equation only for either the first component or the second component of the vector r. Alternatively, an average value of the two solutions φ1 and φ2 may be calculated as a value of the solution φ to be finally obtained in order to increase calculation accuracy. Needless to say, if the equation to be solved is _one relating to r ₁ or r ₂ ^{*, the} amount of computation will be half or less than when the average value of the two solutions is obtained.

Next, the correction calculation unit 104b calculates a corrected channel matrix H ′ defined by the following equation (7) and outputs it to the contact b.
(Definition of corrected channel matrix H ′)
H '≡ AH (7)
As described above, the channel matrix H used in these equations is the one used by the STBC decoding unit 103 in the previous control cycle. In the next control cycle, the corrected channel matrix H ′ is used as the new channel matrix H by the STBC decoding unit 103. In other words, the correction process as described above can be periodically configured and repeatedly executed, so that the estimation accuracy of the channel matrix H can be constantly increased even in mobile communication where the moving speed of the moving object is relatively high. Can be maintained.

  According to the configuration of the decoding processing apparatus 100 as described above, changes in channel characteristics based on fluctuations in propagation path lengths in multipaths between transmitting and receiving stations can be effectively reflected in each component of the channel matrix H. As a result, the reception quality can be greatly improved as compared with the prior art.

The received signal vector r used in the above equation (6) may be mixed with noise having a magnitude larger than the assumed range. That is, noise having a magnitude exceeding the allowable range of a predetermined noise margin may be received. Alternatively, a local or temporary singular point may be formed on the spatio-temporal space that constitutes the multipath as the obstacle moves.
In such a case, the corrected channel matrix H ′ output to the contact point b receives a large disturbance. At this time, since the channel matrix H is actually obtained sequentially using a recurrence formula, according to the above configuration, until the channel matrix H (t ₀ ) based on the next pilot signal is obtained. Then, there is a risk that the subsequent series of STBC decoding processes will be inappropriate.

  In other words, when the SNR is always high, there is no problem with the method of the above-described first embodiment even if these disturbances are not particularly taken into consideration. Since a communication environment is assumed, it is desirable to take some measures to eliminate local or temporary exception values or noise related to channel characteristics.

  Therefore, in the decoding processing device 110 (FIG. 2) according to the second embodiment, the procedure for calculating the phase fluctuation amount φ with respect to the phase fluctuation amount calculation unit 104a according to the first embodiment is improved as follows. In other words, when such an environment can be assumed, an average value over several to several tens of symbols is used, or a weighted average process using a forgetting factor or the like for these many phase fluctuation amounts φ. It is good to give. Hereinafter, such improvement measures will be exemplified.

Hereinafter, in order to consider the pilot signal reception time t ₀ as a reference, H (t ₀ ) is substituted for the channel matrix H and used for the above equations (6) and (7). However, for the vectors s and r, the latest received signal vector r and its symbol determination result (example: Expression (4)) are also used in the following manner as in the first embodiment.
At this time, in the channel matrix correction unit 104 ′, first, in the phase fluctuation amount calculation unit 104a ′, the latest phase fluctuation amount φ with reference to the time t ₀ is obtained from the equation (6) and H = H (t ₀ ). ₀ (k) is obtained. Further, the phase fluctuation amount Φ (k) to be used as the phase fluctuation amount of the phase correction matrix A is calculated by the correction calculation unit 104b ′ by the following equation (8).

(Phase Φ (k) (k ≧ 1) used for the phase correction matrix A)
Φ (k) = (1−γ) Φ (k−1) + γφ ₀ (k) (0 <γ <1) (8)
However, the argument k is a serial number given in ascending order to each calculation cycle, and the serial number k of the control cycle next to t ₀ is 1. The value of the first term Φ (0) is 0. Here, the matrix A (Φ (k)) is a phase correction matrix obtained by substituting φ = Φ (k) into the phase correction matrix A of the equation (5).

In this case, the corrected channel matrix H ′ is output to the STBC decoding unit 103 by the multiplier 105 of FIG.
(Improvement formula for H 'after improvement)
H ′ = A (Φ (k)) H (t ₀ ) (9)

  That is, in this case, the switching control for the switch sw1 by the received signal determination unit 101 in FIG. 1 is abolished, and instead of the switch sw1 in FIG. 1, a multiplier 105 that executes this equation (9) is always used. If the output information of the correction calculation unit 104b ′ for the multiplier 105 is A (Φ (k)) instead of H ′ in FIG. 1, the desired channel matrix H corrected in the form of equation (9) is used. 'Can be output to the STBC decoding unit 103 each time. The specific value of γ is preferably about 0.02 to 0.2, for example, about 0.04. The value of γ can be optimally set according to the moving speed of the moving object, the symbol signal decoding processing cycle, and the like.

According to the setting of the phase Φ (k) using such a recurrence formula, each phase variation amount φ (j) (continuously obtained in the past, included in the phase variation amount Φ (k−1). Although the influence of j <k) gradually decreases exponentially with respect to time (ie, forgotten), the influence remains for a while, so the most recently obtained phase fluctuation amount It is also possible to prevent φ (k) from acting too strongly and dominantly on the current system.
Of course, these averaging techniques regarding the phase fluctuation amount φ may be arbitrary, and a plurality of methods may be combined.

  According to the configuration of the decoding processing apparatus 110 as described above, even when the SNR is relatively small, the channel matrix H can be effectively changed in channel characteristics based on fluctuations in propagation path lengths in multipaths between transmitting and receiving stations. Therefore, the reception quality can be greatly improved as compared with the prior art.

In addition, when there are other receiving antennas, the device is reconfigured so that the average value can be adopted over each phase fluctuation amount φ that can be obtained for each of the receiving antennas. May be. That is, for example, a so-called 2 × 2 system can obtain the same operation and effect based on the same configuration as described in the verification simulation described later, so that the weighted average of the phase variation amounts φ between a plurality of receiving antennas can be obtained. A value or the like may be used.
The reason why such averaging is effective is that the phase fluctuation amount φ is caused by a change in the propagation path length between the transmitting and receiving stations. For each individual antenna, other individual fluctuations related to the phase fluctuation amount φ are obtained. This is because it is difficult to think that there is a fluctuation factor, and as long as the receiving antennas are arranged on the same moving body, each value of the phase fluctuation amount φ based on the change of each propagation path length is basically the same. This is because there is a high possibility that

When γ = 1 in the above equation (8), Φ (k) = φ ₀ (k). In this case, since the channel matrix H ′ having a very strong forgetting tendency is always generated, this method of γ = 1 is advantageous in that the latest channel matrix H ′ is always maintained during a period in which the pilot signal is not received. It can be said that this is disadvantageous in that an unstable decoding processing unit that is very weak against temporary and exceptional system disturbances due to noise or the like is configured.

The above processing is repeatedly executed at a predetermined calculation cycle. Here, in the calculation period of the phase fluctuation amount φ, φ ₀ , or Φ by the phase fluctuation amount calculation means, the absolute value of the phase fluctuation amount φ is smaller than the amplitude of the allowable range of noise margin in the demodulation method. Set it to an expected time interval or less. As a result, even during the period from when the training signal is received until the next training signal is received, high communication quality can be ensured while maintaining the advantages of the STBC communication method.

2. 2. Verification of action and effect by simulation 2.1 Intersection model FIG. 3 illustrates a spatial structure of an intersection model configured to verify each embodiment of the present invention. The intersection model to be evaluated is shown. In this intersection model, an office building area of 300 m square is assumed, the road width is assumed to be 10 m, and a concrete block having a height of 10 m that simulates a building is arranged around the intersection as shown in the figure. The initial positions of the antennas of the transmitting station Tx and the receiving station Rx are both 40 m away from the road intersection. That is, an average stoppable distance (about 40 m) of an automobile moving at a speed of 60 km per hour was considered as one guide.

  In this intersection model, two standard dipole elements are used as transmitting and receiving antennas, the element interval between the two antennas on the vehicle is 1.5 m, the antenna height is 0.8 m, and the antenna axis is the ground. It was perpendicular to. The distance from the wall of the concrete block is 1. It was 5 m. The transmission power from each transmission antenna was set to 10 mW.

In this simulation, the image method of the ray tracing method, which is a geometric optical method, was adopted. In this method, the reflection, transmission, and diffraction are calculated from the combination of the transmission point, reception point, and all other reflection surfaces. At this time, the Fresnel coefficient is used as the reflection coefficient and transmission coefficient, and the diffraction coefficient is calculated. Used UTD (Uniform Geometric Theory of Diffraction). In these simulations, the number of reflections was changed to 1 to 3, the number of transmissions was fixed to 0, the number of diffractions was changed to 1 to 2, and ground reflection was also considered. The electrical characteristics of the concrete block and the ground were set to the values shown in Table 1 below.

2.2 Verification Results FIG. 4 illustrates the effect of the first embodiment. In this simulation, the BER under the QPSK method when applying thermal noise to each receiving antenna based on the above intersection model was examined. In this simulation, the moving speeds of the receiving station Rx and the transmitting station Tx are Both were 60 km / h. For this reason, the movement amount Δx of the receiving station Rx in the x-axis direction and the movement amount Δy of the transmission station Tx in the y-axis direction are always equal to each other (Δx = Δy). In addition, the frequency f of the electromagnetic wave used for communication is set to three types of 6 GHz, 5 GHz, and 2 GHz. In any case, when the parameter Δx / λ using each wavelength λ is used, the simulation results are shown in FIG. As shown in FIG. 4, since they coincide, no distinction regarding the frequency f is shown on the graph. The transmission period of one symbol is 1 μsec, and the value of γ in the above equation (8) is about 0.03.

The graph described as conventional in the figure is the simulation result according to the conventional STBC communication method in which the correction processing of the present invention is omitted, and the graph of the simulation result according to the first embodiment is described as proposed. Indicated.
From this simulation result, in the prior art, the reception quality (BER) rapidly deteriorates due to the movement of the moving body, whereas according to the method based on the first embodiment, the reception quality (BER) associated with the movement is reduced. It can be seen that there is almost no deterioration.

FIG. 5 shows the same simulation results as those in FIG. 4 from another aspect, with the SNR as the horizontal axis. Also from this graph, it can be confirmed that the effectiveness of the present invention is very remarkable.
The same verification simulation was performed assuming that the first floor of the building at the corner of the intersection between the transmitting and receiving stations in FIG. 3 is composed of a glass-walled showroom, etc. Carried out. In these cases, the effectiveness of the present invention could be verified in substantially the same manner as described above.

[Other variations]
The embodiment of the present invention is not limited to the above-described embodiment, and other modifications as exemplified below may be made. Even with such modifications and applications, the effects of the present invention can be obtained based on the functions of the present invention.
(Modification 1)
For example, in the above-described configuration examples of the decoding processing device 100 in FIG. 1 and the decoding processing device 110 in FIG. 2, a configuration example of a so-called 2 × 1 system is illustrated, but the above-described example also in a 2 × m system (m> 1) The same actions and effects can be obtained.

Control block diagram of decoding processing apparatus 100 for STBC communication according to the first embodiment Control block diagram of a decoding processing device 110 which is a modification of the decoding processing device 100 Plan view illustrating the spatial configuration of the intersection model The graph which illustrates the effect of Example 1 (BER at the time of thermal noise grant) The graph which illustrates the effect of Example 1 (BER at the time of thermal noise grant)

DESCRIPTION OF SYMBOLS 100: Decoding processing apparatus 101: Received signal determination part 102: Propagation path estimation part 103: STBC decoding part 104: Channel matrix correction | amendment part 104a: Phase fluctuation amount calculation part 104b: Correction calculation part

Claims (2)

Receiving a predetermined training signal, the multipath channel estimation means for estimating the channel matrix H representing the channel characteristics of each propagation path, the channel estimated by the channel estimation means between the transmitting station and the receiving station In a STBC communication system receiver having a matrix H and decoding means for performing space-time block decoding processing based on a received signal vector r received,
An initial channel matrix computing means for computing an initial channel matrix, which is an initial value of a channel matrix, from the training signal and the received signal;
This time using the previous channel matrix H obtained at the previous correction timing for each correction timing repeated at a constant calculation cycle within the period from the reception of the training signal to the reception of the next training signal . Based on the symbol signal s after symbol determination obtained by demodulating the received signal received at the correction timing and the received signal r received at the current correction timing, the current channel matrix at the current correction timing is Phase fluctuation amount calculating means for obtaining a phase fluctuation amount φ common to each component of the previous channel matrix H, assuming that only the phase is changed in common for all components of the matrix with respect to the channel matrix H;
Current channel matrix calculation means for correcting the previous channel matrix H based on the phase fluctuation amount φ and calculating the current channel matrix H ′ at the current correction timing;
Each time the training signal is received, the previous channel matrix H used in the phase fluctuation amount calculating means is the initial channel matrix calculated by the initial channel matrix calculating means, and the current channel matrix is calculated at each correction timing. Control means for setting the current channel matrix H ′ calculated by the calculation means to the previous channel matrix H used in the phase fluctuation amount calculation means at the next correction timing;
Receiving apparatus characterized by having a. Channel estimation means for receiving a predetermined training signal and estimating a channel matrix H representing channel characteristics of each multipath propagation path between the transmission station and the reception station; and the channel estimated by the channel estimation means In a STBC communication system receiver having a matrix H and decoding means for performing space-time block decoding processing based on a received signal vector r received,
From the training signal and the received signal, an initial channel matrix H (t ₀ ) For calculating an initial channel matrix;
This time using the previous channel matrix H obtained at the previous correction timing for each correction timing repeated at a constant calculation cycle within the period from the reception of the training signal to the reception of the next training signal. Based on the symbol signal s after symbol determination obtained by demodulating the received signal received at the correction timing and the received signal r received at the current correction timing, the current channel matrix at the current correction timing is Assuming that only the phase is changed in common for all the components of the matrix with respect to the channel matrix H, the phase fluctuation amount φ common to each component of the previous channel matrix H ₀ A phase fluctuation amount calculating means for obtaining
Initial channel matrix H (t ₀ ), The phase displacement Φ (k) at the current correction timing is expressed as Φ (k) = (1−γ) Φ (k−1) + γφ. ₀ (K), where 0 <γ <1, k is a number representing the correction timing,
The phase displacement Φ (k) obtained by the phase displacement calculating means and the initial channel matrix H (t ₀ ) To calculate the current channel matrix H ′ at the current correction timing,
Each time the training signal is received, the previous channel matrix H used in the phase fluctuation amount calculating means is the initial channel matrix calculated by the initial channel matrix calculating means, and the current channel matrix is calculated at each correction timing. Control means for setting the current channel matrix H ′ calculated by the calculation means to the previous channel matrix H used in the phase fluctuation amount calculation means at the next correction timing;
A receiving apparatus comprising:

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