TW201328229A - Receiving apparatus and method for space frequency block code decoding - Google Patents

Abstract

A receiving apparatus for SFBC decoding is adapted for processing an input signal encoded by SFBC with N demodulating subcarriers and obtaining the frequencies of N first subcarriers and N second subcarriers for generating the input signal by handshaking. The receiving apparatus implements SFBC decoding with a first channel signal, a second channel and the input signal, wherein the first channel signal is obtained by analyzing the input signal and related to the first subcarriers, the second channel signal is obtained by analyzing the input signal and related to the second subcarriers, and the phase of the input signal is shifted by the subcarriers. Besides, the receiving apparatus calculates the interference from adjacent subcarriers in the SFBC decoding result in order to optimize the decoding result.

Description

Receiving device for spatial frequency block code decoding and method thereof

The present invention relates to a receiving apparatus, and more particularly to a receiving apparatus using a Space Frequency Block Code (SFBC).

SFBC is a common coding method used to increase system reliability. When applied to a Cooperative Communication system, two transmission devices with a single antenna are used together. For example, a relay is used as a transmitting device to transmit a signal to a mobile phone as a receiving device. However, there are some differences in the modulation frequency of different transmission devices, which makes it difficult for the receiving device to accurately decode from the received signal, which in turn reduces system reliability.

To this end, the industry and academia have successively proposed some decoding methods, such as: "Multiple CFOs compensation and BER analysis for co-operative communication systems" proposed by Y. Zhang in 2009, and "An SFBC-OFDM Receiver to" proposed by Sang in 2010. Combat Multiple Carrier Frequency Offsets in Cooperative Communications", but these methods can only have better decoding performance when the modulation frequency difference is not large.

Accordingly, it is an object of the present invention to provide a receiving apparatus for SFBC decoding and a method thereof that can effectively decode even if the two transmitting apparatuses perform SFBC encoding at different modulation frequencies, respectively.

Therefore, the receiving method for SFBC decoding of the present invention is applicable to processing an SFBC-coded input signal by using N demodulation subcarriers, the input signal comprising N first subcarriers respectively corresponding to demodulation subcarriers. a signal, and including another signal carrying N second subcarriers respectively corresponding to demodulation subcarriers, and corresponding first subcarriers and second subcarriers having different frequencies, N>1, the receiving method includes the following Step: (A) adjusting a phase of the input signal based on a frequency difference between the corresponding first subcarrier and the demodulation subcarrier by a frequency synchronizer to obtain a first synchronization signal, and based on the corresponding second subcarrier and the demodulation subcarrier The frequency difference adjusts the phase of the input signal to obtain a second synchronization signal; (B) by using a time-frequency converter, using the modulated subcarriers, the first synchronization signal is converted from the time domain to the frequency domain. a first frequency domain signal, and converting the second synchronization signal from the time domain to the frequency domain to obtain a second frequency domain signal; (C) analyzing the input signal by using a channel evaluator, and obtaining The a first channel signal of the signal of the first subcarrier, and a second channel signal for the signal carrying the second subcarrier; (D) the first frequency domain signal and the decoder Performing SFBC decoding on the second frequency domain signal to obtain N reduction results respectively corresponding to the demodulation subcarriers; and (E) finding, by using a discriminator, from all possible demodulation symbols for each demodulation subcarrier Which symbol is processed by SFBC and processed by the channel signals will be closest to the corresponding restoration result; wherein, in step (D), according to the component belonging to the even subcarrier in the first frequency domain signal and the second The component belonging to the odd subcarrier in the frequency domain signal is decoded to obtain a first restored signal, and is decoded according to a component belonging to the odd subcarrier in the first frequency domain signal and a component belonging to the even subcarrier in the second frequency domain signal. And a second reduction signal, and the reduction results are combined by the first reduction signal and the second reduction signal, and the decoding is based on the first channel signal and the second channel signal.

The receiving apparatus for SFBC decoding of the present invention is adapted to process an SFBC encoded input signal by using N demodulation subcarriers, the input signal comprising one of N first subcarriers respectively corresponding to demodulation subcarriers. a signal, and including another signal that carries N second subcarriers respectively corresponding to demodulation subcarriers, and corresponding first subcarriers and second subcarriers have different frequencies, N>1, and the receiving apparatus includes: a frequency synchronizer that adjusts a phase of the input signal based on a frequency difference between the corresponding first subcarrier and the demodulation subcarrier to obtain a first synchronization signal, and adjusts the input signal based on a frequency difference between the corresponding second subcarrier and the demodulation subcarrier a second synchronization signal is obtained by phase; a time-frequency converter uses the modulated subcarriers to convert the first synchronization signal from the time domain to the frequency domain to obtain a first frequency domain signal, and the second synchronization Converting the signal from the time domain to the frequency domain to obtain a second frequency domain signal; a channel evaluator analyzing the input signal to obtain a first channel for the signal carrying the first subcarriers And obtaining a second channel signal for the signal carrying the second subcarriers; a decoder for performing SFBC decoding on the first frequency domain signal and the second frequency domain signal based on the first channel signal Obtaining N reduction results r _k corresponding to the demodulation subcarriers, k=0~(N-1); a discriminator for each demodulation subcarrier f _d,k , from all possible demodulation symbols Finding which symbol is closest to the reduction result r _k after SFBC coding and processing of the channel signals; and an interference reconstructor, using the channel signals and reacting each demodulation subcarrier f _d,k respectively And a plurality of interference coefficients interfered by the first subcarrier and the second subcarriers, and a compensation signal is calculated according to the symbol of each demodulation subcarrier f _d,k ; wherein the time-frequency converter is used The compensation signal of each demodulation subcarrier f _d,k adjusts the components of the corresponding demodulation subcarriers in the frequency domain signals, and provides the adjusted frequency domain signal as the next decoding basis of the decoder.

The above and other technical contents, features and advantages of the present invention will be apparent from the following detailed description of the preferred embodiments.

Before the present invention is described in detail, it is noted that in the following description, similar elements are denoted by the same reference numerals.

Principle derivation and introduction

Referring to Figure 1, the cooperative communication system implements SFBC encoding using a first transmitting device R1 and a second transmitting device R2 each having a single antenna (not shown). Each of the transmission devices R1 and R2 uses an OFDM (orthogonal frequency division multiplexing) method to carry a plurality of to-be-transmitted symbols to the N subcarriers, and then transmit them through the antenna. The receiving device UE then restores the received signal with N corresponding demodulation subcarriers.

In order to comply with the coding characteristics of SFBC, the symbols X ₀ , X ₁ , X ₂ , X ₃ , ... to be transmitted are first paired according to the order of the symbols, so that the transmitting device R1 will assign the symbols belonging to the same pair in order. The two adjacent subcarriers are allocated to the frequency increment, and the transmitting device R2 configures the following symbols of the pairing to one subcarrier and configures the preceding symbols to the adjacent higher frequency subcarriers. Refer to Figure 2 for the symbol configuration relationship at N=8.

The N first subcarriers f _R1,k used by the transmitting device _R1, the N second subcarriers f _R2,k used by the transmitting device R2, and the N demodulation subcarriers f _d used by the receiving device UE _{, k} corresponds to each other, k=0~(N-1). However, the transmitting devices R1 R R2 and the receiving device UE are independent devices, so there are some frequency differences between the corresponding first subcarrier, the second subcarrier and the demodulating subcarrier.

As is known to those skilled in the art, the transmitting device R1 encodes the symbols into subcarriers in ascending order. And output the signal according to equation (1). On the other hand, the transmitting device R2 encodes the symbol into And output the signal according to equation (1). In the formula (1), α {R1,R2},- N _p n N -1, N _p is the number of cyclic prefix symbols.

The signals sent by the two transmitting devices R1, R2 are transmitted through the channel to form an input signal of the equation (2) at the receiving device UE, where h _α (.) is the channel impulse response of the transmitting device α to the receiving device UE. , L is the total number of taps of the channel impulse response, and z(n) represents the noise. The phase adjustment term exp( j 2 πε _α n /N) of the equation (2) is based on the subcarrier frequency difference between the transmitting device α and the receiving device UE. Preferably, ε _α is the subcarrier f _{α of the} transmitting device α . _{, k} is the ratio of the frequency difference of _k to the demodulation subcarriers f _{d , k} to the adjacent demodulation subcarriers f _{d , k} spacing.

In order to compensate the frequency difference between the subcarriers f _{α , k and the} demodulation subcarriers f _{d , k} , the receiving device UE first multiplies the input signal by exp(− j 2 πε _R1 n /N) to obtain the first synchronization before decoding. The signal is passed , and the input signal is multiplied by exp(- j 2 πε _R2 n /N) to obtain a second synchronization signal. Then, the isochronous signal is transferred from the time domain to the frequency domain according to the demodulation subcarrier f _{d , k} to obtain the first frequency domain signal Y _R1 and the second frequency domain signal Y _R2 . The first frequency domain signal Y _R1 and the second frequency domain signal Y _R2 may be expressed as equation (3), where the interference coefficient Equation (4) is used to react to the interference of the mth first subcarrier by the kth demodulation subcarrier, and the interference coefficient Equation (4) is used to reflect that the kth demodulation subcarrier is interfered by the mth second subcarrier, m=0~(N-1). In equation (5), For a set of all interference coefficients, H _R1 is the first channel signal representing the frequency response of h _R1 (.), and H _R2 is the second channel signal representing the frequency response of h _R2 (.), , W is the frequency response of z(n), and matrix A ^H is the Hermitian conjugate matrix of matrix A.

Next, SFBC decoding is performed based on the frequency domain signals Y _R1 , Y _R2 . The detailed decoding method is as shown in equation (6), the even subcarrier components of Y _R1 are grouped into Y _R1,e , and the odd subcarrier components of Y _R2 are grouped into Y _R2,o to restore with . On the other hand, the even subcarrier components of Y _R2 are grouped into Y _R2,e , and the odd subcarrier components of Y _R1 are grouped into Y _R1,o to restore with .

Where H _R1,e is the component of the first channel signal H _R1 belonging to the even subcarrier, H _R1,o is the component of the first channel signal H _R1 belonging to the odd subcarrier, and H _R2,e is the second channel signal H The component of _R2 belonging to the even subcarrier, H _R1,o is the component of the second channel signal H _R2 belonging to the odd subcarrier. Further, G _A , G _B , G _C , and G _D are respectively obtained by G disassembly, as shown in the formula (7). And formula (8) is more listed , , with The relationship between X _e =[ X ₀ X ₂ X ₄ ... X _{N -2} ] and X _o =[ X ₁ X ₃ X ₅ ... X _{N -1} ], where W _{α , e} is the frequency domain The noise received by the even subcarrier component in the signal Y _α , W _{α , o} is the noise received by the odd subcarrier component in the frequency domain signal Y _α .

due to , , , Will decrement as | ε _R1 - ε _R2 | becomes larger, so it is intended to be discarded with And interleaved with even serial numbers Odd number The reduction results r ₀ , r ₁ , r ₂ ..., r _{N -1 are obtained} . More specifically, the reduction result is generated by: Among the components belonging to the subcarrier f _d,0 = r ₀ Among the components belonging to the subcarrier f _d,1 = r ₁ , and then Among the components belonging to the subcarrier f _{d, 2} = r ₂ The component belonging to the subcarrier f _d,3 = r ₃ ....

Finally, from the plurality of possible demodulation symbols ζ _i of each subcarrier f _d,k , it is found which demodulation symbol is closest to the restoration result r _k after being processed by SFBC coding and the channel signals. .

As is known to those skilled in the art, in OFDM modulation, each subcarrier can independently select a desired modulation mode as QAM (quadrature amplitude modulation), 16QAM or the like. For example, when QAM is selected for the modulation mode, there may be four demodulation symbols, namely ζ ₀ = "00", ζ ₁ = "01", ζ ₂ = "10", ζ ₃ = "11".

Preferably, the interference indicator is selected ∥ ∥ The smallest demodulation symbol ζ _i . here Is the kth diagonal element of (|H _R1 | ² +|H _R2 | ² ); when k is even, Refers to( (k+2)/2 diagonal elements, when k is an odd number, Refers to-( The (k+1)/2 diagonal elements of ).

However, only with Combine the reduction results r ₀ , r ₁ , r ₂ ..., r _{N -1} and ignore with Therefore, the demodulation symbol still has room for improvement. Therefore, the interference reconstruction is further performed, and the frequency domain signal of the equation (3) is subtracted from the reconstructed interference, and then the SFBC decoding is performed. In this way, the interference reconstruction is repeated to update the SFBC restoration result until the demodulation symbol ζ _i found for each demodulation subcarrier has been the same P times consecutively, and the receiving device UE outputs the demodulation symbols ζ _{i of} all the demodulation subcarriers, P> A specific threshold.

The following describes the interference reconstruction. It is assumed that the demodulation symbol ζ _i of the kth demodulation subcarrier used in the (t-1)th interference reconstruction is marked as ,t 1. Demodulation symbols for demodulating subcarriers f _d,0 ~f _d,(N-1) Pairwise pairing to form a first optimization vector And a second optimization vector . And, obtaining a compensation signal according to the two optimization vectors It is shown that the second vector is subjected to SFBC coding and the k-th modulated subcarriers are interfered by other subcarriers, as in equation (9). Wherein, H _{R 1, m} is a component of the first channel signal belonging to the mth first subcarrier, and H _{R 2, m} is a component of the second channel signal belonging to the mth second subcarrier.

Next, make the current frequency domain signal with Deducting the compensation signal And adjust the frequency domain signal for the next SFBC decoding with , as in formula (10). among them, Refers to the component of the kth demodulation subcarrier in the first frequency domain signal Y _R1 obtained by the time domain to frequency domain conversion. It refers to a component belonging to the kth demodulation subcarrier in the first frequency domain signal Y _R2 obtained through time domain to frequency domain conversion.

Therefore, each time the adjusted frequency domain signal excludes the interference of some other subcarriers, so that the demodulation symbols gradually converge and have higher reliability, so that there are different modulation frequency differences between different transmitting devices and receiving devices. In the case of the case, the purpose of the error floor is further improved.

Preferred embodiment

Referring to FIG. 3, based on the foregoing theory, the preferred embodiment of the receiving apparatus 100 for SFBC decoding of the present invention is suitable for wirelessly accessing a first transmitting apparatus R1 and a second each having an antenna (not shown). The transmitting device R2, the signals sent by the two transmitting devices R1, R2 can be combined to form an SFBC encoded signal, and an input signal is formed at the receiving device 100 after passing through the channel. The transmitting devices R1, R2 and the receiving device 100 may be relay stations, base stations, mobile phones, or other devices having a transmitting function.

The receiving device 100 includes a frequency synchronizer 1, a time-frequency converter 2, a decoder 3 and a discriminator 4 electrically connected in sequence, and includes an interference reconstruction spanning between the discriminator 4 and the time-frequency converter 2. Device 5. Moreover, the receiving device 100 further includes a parameter processor 6 and a channel evaluator 7 that electrically connect the aforementioned components, respectively.

In more detail, the frequency synchronizer 1 includes a first synchronization unit 11 and a second synchronization unit 12. The time-frequency converter 2 includes a first conversion unit 21, a second conversion unit 22, and an adjustment unit 23, and is decoded. The device 3 includes a first reduction unit 31, a second reduction unit 32, and a synthesis unit 33.

Referring to FIG. 4 and FIG. 5, a preferred embodiment of the receiving method for SFBC decoding of the present invention performed by the receiving apparatus 100 includes the following steps: Step 81: The channel evaluator 7 analyzes the input signal y(n) to obtain a representation A first channel signal H _{R1 of a} channel characteristic between the transmitting device R1 and the receiving device 100, and a second channel signal H _R2 indicating a channel characteristic between the second transmitting device R2 and the receiving device 100 is obtained.

Step 82: The parameter processor 6 handshaking with each of the transmitting devices R1 and R2, knows the modulation mode used by each subcarrier f _{α , k} , and knows the first subcarrier frequency and the second subcarrier. frequency.

Note that this two transport means R1, R2 use the same modulation pattern corresponding subcarrier f _{α, k,} for example: QAM, 16QAM or the like.

Step 83: The parameter processor 6 calculates a first synchronization factor ε _R1 and a second synchronization factor ε _R2 based on the frequencies of the subcarriers f _{α , k} , f _{d , k} .

The detailed calculation method is: comparing the first subcarrier f _{R 1, k} frequency and the corresponding demodulation subcarrier f _{d , k} frequency to obtain a first frequency difference, and dividing the first frequency difference by the adjacent demodulation subcarrier f _{d , k} The first synchronization factor ε _{R1 is} obtained by the spacing. The second synchronization factor ε _R2 can be found in a similar manner and will not be explained any more.

Step 84: The parameter processor 6 calculates an interference coefficient of the kth first subcarrier interference by the kth demodulation subcarrier based on the equation (4). And calculating the interference coefficient of the kth demodulation subcarrier interfered by the mth second subcarrier .

Step 85: The first synchronization unit 11 uses the first synchronization factor ε _R1 to adjust the phase of the input signal y(n) to obtain a first synchronization signal; the second synchronization unit 12 uses the second synchronization factor ε _R2 to adjust the input signal y. A phase of (n) results in a second synchronization signal.

This is adjusted by multiplying the input signal y(n) by the corresponding exp(- j 2 πε _α n /N).

Step 86: The first conversion unit 21 performs Fourier transform on the demodulation subcarriers f _{d , k} , and converts the first synchronization signal from the time domain to the frequency domain to obtain the first frequency domain signal Y _R1 ; the second conversion unit 22 utilizes The demodulation subcarriers f _{d , k} are Fourier transformed, and the second synchronization signal is converted from the time domain to the frequency domain to obtain a second frequency domain signal Y _R2 .

Step 87: The first restoration unit 31 receives the components belonging to the even subcarriers in the first frequency domain signal Y _R1 , and receives the components belonging to the odd subcarriers in the second frequency domain signal Y _R2 , and performs SFBC decoding based on the equation (11). Obtaining the first reduction signal .

On the other hand, the second restoration unit 32 receives the components belonging to the odd subcarriers in the first frequency domain signal Y _R1 and receives the components belonging to the even subcarriers in the second frequency domain signal Y _R2 , and performs SFBC based on the equation (12). Decoding to obtain the second restored signal .

Step 88: The synthesizing unit 33 merges the first restored signals in an interleaved manner And second reduction signal To produce reduction results r ₀ , r ₁ , r ₂ ..., r _{N -1} .

Step 89: The discriminator 4 finds _, for each demodulation subcarrier f _{d, k} , which symbol ζ _i from all possible demodulation symbols can cause the interference indicator ∥ ∥minimum, k=0~(N-1).

Step 90: The discriminator 4 checks whether the demodulated symbols ζ _i found for each demodulation subcarrier f _{d, k} have been consecutive P times the same. If so, the symbols ζ _{i of} all demodulation subcarriers f _d,k are sent to the subsequent stage circuit 600; if not, proceed to step 91.

Step 91: The interference reconstructor 5 makes the N symbols Pairwise pairing to form a first optimization vector And a second optimization vector And using the two vectors to find a compensation signal based on equation (9) .

Step 92: The adjusting unit 23 makes the current frequency domain signal based on the formula (10). with Deduction compensation signal And adjusting the first frequency domain signal And second frequency domain signal . Then, the process returns to step 87 to perform SFBC decoding with the adjusted frequency domain signal.

Simulation result

Figure 6 shows the bit error rate simulation using this example and the method proposed by Sang in 2010. It can be observed that when ε _R1 = 0.3 and ε _R2 = -0.3, the bit error rate of this example is significantly better than the Sang method. Also, as | ε _R1 - ε _R2 | increases, the bit error rate of the Sang method rises sharply, and the increase in this case is moderate.

It should be noted that although this example illustrates that the transmitting devices R1, R2 each have a single antenna, those skilled in the art can easily generalize to the case where the transmitting devices R1, R2 each have multiple antennas by the foregoing description.

In summary, in the foregoing preferred embodiment, the receiving apparatus 100 performs more accurate SFBC decoding based on the equation (6) by the decoder 3, and optimizes the frequency domain signal by the interference reconstructor 5, and may be at | ε _R1 - ε _R2 | There is still a good bit error rate performance when the difference is quite large, so the purpose of the present invention can be achieved.

The above is only the preferred embodiment of the present invention, and the scope of the invention is not limited thereto, that is, the simple equivalent changes and modifications made by the scope of the invention and the description of the invention are All remain within the scope of the invention patent.

100. . . Receiving device

600. . . Rear stage circuit

1. . . Frequency synchronizer

11. . . First synchronization unit

12. . . Second synchronization unit

2. . . Time-frequency converter

twenty one. . . First conversion unit

twenty two. . . Second conversion unit

twenty three. . . Adjustment unit

3. . . decoder

31. . . First reduction unit

32. . . Second reduction unit

33. . . Synthetic unit

4. . . Discriminator

5. . . Interference reconstructor

6. . . Parameter processor

7. . . Channel evaluator

R1. . . First conveyor

R2. . . Second conveyor

UE. . . Receiving device

81~92. . . step

Figure 1 is a block diagram illustrating a cooperative communication system;

Figure 2 is a schematic diagram showing the symbol configuration of the transmitting device;

Figure 3 is a block diagram showing a preferred embodiment of the receiving device;

4 to 5 are flowcharts illustrating a preferred embodiment of a receiving method; and

Fig. 6 is a simulation diagram showing the bit error rate of this example and the Sang method.

100. . . Receiving device

600. . . Rear stage circuit

1. . . Frequency synchronizer

11. . . First synchronization unit

12. . . Second synchronization unit

2. . . Time-frequency converter

twenty one. . . First conversion unit

twenty two. . . Second conversion unit

twenty three. . . Adjustment unit

3. . . decoder

31. . . First reduction unit

32. . . Second reduction unit

33. . . Synthetic unit

4. . . Discriminator

5. . . Interference reconstructor

6. . . Parameter processor

7. . . Channel evaluator

R1. . . First conveyor

R2. . . Second conveyor

Claims (10)

A receiving method for spatial frequency block code (SFBC) decoding, which is suitable for processing an input signal based on SFBC coding with N demodulation subcarriers, the input signal including N corresponding correspondences, etc. Demodulating a signal of the first subcarrier of the subcarrier, and including another signal carrying N second subcarriers respectively corresponding to the demodulated subcarriers, and corresponding first subcarriers and second subcarriers have different frequencies, N>1, the receiving method includes the following steps: (A) adjusting a phase of the input signal based on a frequency difference between the corresponding first subcarrier and the demodulation subcarrier by a frequency synchronizer to obtain a first synchronization signal, and based on Adjusting a phase of the input signal by adjusting a frequency difference between the corresponding second subcarrier and the demodulation subcarrier to obtain a second synchronization signal; (B) using the modulated subcarrier, the first synchronization signal by using a time-frequency converter Converting from the time domain to the frequency domain to obtain a first frequency domain signal, and converting the second synchronization signal from the time domain to the frequency domain to obtain a second frequency domain signal; (C) analyzing by using a channel evaluator The loss Entering a signal to obtain a first channel signal for signals carrying the first subcarriers, and obtaining a second channel signal for signals carrying the second subcarriers; (D) by decoding Performing SFBC decoding on the first frequency domain signal and the second frequency domain signal to obtain N reduction results respectively corresponding to the demodulation subcarriers; and (E) using a discriminator for each demodulation subcarrier Finding which symbol from all possible demodulation symbols is closest to the corresponding restoration result after SFBC coding and processing of the channel signals; wherein, in step (D), according to the first frequency domain signal The component belonging to the even subcarrier and the component belonging to the odd subcarrier in the second frequency domain signal are decoded to obtain a first restored signal, and according to the component belonging to the odd subcarrier and the second frequency domain signal in the first frequency domain signal The component belonging to the even subcarrier is decoded to obtain a second restoration signal, and the reduction result is combined by the first reduction signal and the second reduction signal, and the decoding is established in the first channel signal and the second Channel signal based The receiving method for SFBC decoding according to claim 1, wherein the decoding of the step (D) is based on the following formula: And the second reduction signal , Y _{R 1 , e is} a component belonging to the even subcarrier in the first frequency domain signal, Y _{R 1 , o is} a component belonging to the odd subcarrier in the first frequency domain signal, and Y _{R 2 , e is} the first a component belonging to the even subcarrier in the two-frequency domain signal, Y _{R 2 , o is} a component belonging to the odd subcarrier in the second frequency domain signal; and H _{R 1 , e} is a subcarrier carrier in the first channel signal The component, H _{R 1 , o is a component of} the first channel signal belonging to the odd subcarrier, and H _{R 2 , e is} a component of the second channel signal belonging to the even subcarrier, and H _{R 2 , o is} the second channel The components of the signal that belong to the odd subcarrier. The receiving method for SFBC decoding according to claim 1, wherein in step (A), the frequency difference between the corresponding first subcarrier and the demodulation subcarrier is proportional to the spacing of adjacent demodulation subcarriers. Making a first synchronization factor ε _R1 , taking the ratio of the frequency difference between the corresponding second subcarrier and the demodulation subcarrier to the adjacent demodulation subcarrier spacing as a second synchronization factor ε _R2 ; and multiplying the input signal by exp (- j 2 πε _R1 n /N) to obtain the first synchronization signal, and multiply the input signal by exp(- j 2 πε _R2 n /N) to obtain the second synchronization signal. The receiving method for SFBC decoding according to claim 1, wherein each demodulating subcarrier corresponds to a modulation mode having a plurality of possible demodulation symbols, and the receiving method further comprises the following steps: And calculating, by a parameter processor, an interference coefficient that interferes with the modulated subcarrier f _d,k by the first subcarrier f _R1,m , and calculates a response to the modulated subcarrier f _d,k by the first The interference coefficient of the two subcarriers f _R2,m interference, m=0~(N-1), k=0~(N-1); (G) by using an interference reconstructor, using the channel signals and each Demodulating the interference coefficients of the subcarriers f _d,k , and calculating a compensation signal according to the symbols of each demodulation subcarrier f _d,k ; and (H) by using the time-frequency converter, based on each demodulation And a compensation signal of the carrier, adjusting a component of the corresponding demodulation subcarrier in the first frequency domain signal, and adjusting a component of the corresponding demodulation subcarrier in the second frequency domain signal. A receiving method for SFBC decoding according to item 4 of the patent application scope, wherein in step (E), the symbol ζ _i found for each demodulated subcarrier f _d,k with The sum of the closest is closest to the reduction result r _k ; Is the kth diagonal element of (|H _R1 | ² +|H _R2 | ² ); when k is even, Refers to( The k/2th diagonal element of the ), when k is an odd number, Refers to-( (k-1)/2 diagonal elements; and H _R1,e is a component of the first channel signal H _R1 belonging to the even subcarrier, and H _R1,o is the first channel signal H _R1 is odd The component of the subcarrier, H _{R2, e} is a component of the second channel signal H _R2 belonging to the even subcarrier, and H _R1,o is a component of the second channel signal H _R2 belonging to the odd subcarrier; Representing the interference coefficient of the kth demodulation subcarrier interfered by the mth first subcarrier, Representing the interference coefficient of the kth demodulation subcarrier interfered by the mth second subcarrier, α {R1, R 2}, The receiving method for SFBC decoding according to item 4 of the patent application scope further includes a step of repeating steps (D), (E), (G), (H) with the frequency domain signal adjusted in step (H). ), until the symbol ζ _i found for each demodulation subcarrier has been the same P consecutive times, the truncated symbol is used as the demodulation output, P>a specific threshold; wherein, in step (G), The symbol found by the (t-1)th time of the N demodulation subcarriers Pairwise pairing to form a first optimization vector And a second optimization vector , t>1; and using the component H _{R 1, m} belonging to the mth first subcarrier in the first channel signal _, and using the component H _{R 2} belonging to the mth second subcarrier in the second channel signal _{, m} , using the interference coefficient of the demodulation subcarrier f _d,k interfered by the first subcarrier f _R1,m Interfering with the interference coefficient of the second subcarrier f _R2,m by using the demodulation subcarrier f _d,k And using these optimization vectors with And the compensation signal is obtained according to the following formula: A receiving apparatus for spatial frequency block code (SFBC) decoding, which is adapted to process an SFBC-encoded input signal by using N demodulation subcarriers, the input signal comprising N corresponding pairs, etc. Demodulating a signal of the first subcarrier of the subcarrier, and including another signal carrying N second subcarriers respectively corresponding to the demodulated subcarriers, and corresponding first subcarriers and second subcarriers have different frequencies, N>1, the receiving device includes: a frequency synchronizer, adjusting a phase of the input signal based on a frequency difference between the corresponding first subcarrier and the demodulation subcarrier to obtain a first synchronization signal, and based on the corresponding second subcarrier and solution Adjusting the phase of the input signal to adjust a phase of the input signal to obtain a second synchronization signal; a time-frequency converter, using the modulated subcarriers, converting the first synchronization signal from a time domain to a frequency domain to obtain a first a frequency domain signal, and converting the second synchronization signal from the time domain to the frequency domain to obtain a second frequency domain signal; a channel evaluator analyzing the input signal to obtain information about the carrier a first channel signal of the signal of the first subcarrier, and a second channel signal for the signal carrying the second subcarrier; a decoder for the first frequency domain based on the first channel signal Performing SFBC decoding on the signal and the second frequency domain signal to obtain N reduction results r _k corresponding to the demodulation subcarriers, k=0~(N-1); a discriminator for each demodulation subcarrier f _{d , k} , find out from all possible demodulation symbols which symbol is SFBC encoded and processed by the channel signals to be closest to the reduction result r _k ; and an interference reconstructor that utilizes the channel signals and responses A demodulation subcarrier f _{d,k is} respectively interfered with by the first subcarrier and the second subcarrier, and a compensation is calculated according to the symbol of each demodulation subcarrier f _d,k a signal; wherein the time-frequency converter uses a compensation signal of each demodulation subcarrier f _{d, k} to adjust a component of a corresponding demodulation subcarrier in the frequency domain signal, and provides an adjusted frequency domain signal as the decoding The next decoding basis. The receiving apparatus for SFBC decoding according to item 7 of the patent application scope, wherein the discriminator _i finds the symbol ζ _i for each demodulation subcarrier f _d,k with The sum of the closest is closest to the reduction result r _k ; Is the kth diagonal element of (|H _R1 | ² +|H _R2 | ² ); when k is even, Refers to( The k/2th diagonal element of the ), when k is an odd number, Refers to-( (k-1)/2 diagonal elements; and H _R1,e is a component of the first channel signal H _R1 belonging to the even subcarrier, and H _R1,o is the first channel signal H _R1 is odd The component of the subcarrier, H _R2,e is the component of the second channel signal H _R2 belonging to the even subcarrier, and H _R1,o is the component of the second channel signal H _R2 belonging to the odd subcarrier; Representing the interference coefficient of the kth demodulation subcarrier interfered by the mth first subcarrier, Representing the interference coefficient of the kth demodulation subcarrier interfered by the mth second subcarrier, α {R1, R 2}, m=0~(N-1), The receiving apparatus for SFBC decoding according to claim 7, wherein: the interference reconstructor finds the symbols of the N demodulation subcarriers Pairwise pairing to form a first optimization vector And a second optimization vector , t>1; and the interference reconstructor calculates a corresponding compensation signal for each demodulation subcarrier f _d,k The component H _{R 1, m} belonging to the mth first subcarrier in the first channel signal is used according to the following formula _, and the component H _{R 2, m} belonging to the mth second subcarrier in the second channel signal is utilized _. Interfering with the interference coefficient of the first subcarrier f _R1,m by using the demodulation subcarrier f _d,k Interfering with the interference coefficient of the second subcarrier f _R2,m by using the demodulation subcarrier f _d,k And using these optimization vectors with And get: The receiving device for SFBC decoding according to claim 9 further includes: a parameter processor, configured to generate a first synchronization factor and a second synchronization factor, and obtain the first synchronization factor according to the first synchronization factor Responding to an interference coefficient of the kth demodulation subcarrier interfered by the mth first subcarrier, and determining, according to the second synchronization factor, that the kth demodulation subcarrier is interfered by the mth second subcarrier Interference coefficient; wherein the parameter processor is configured to use the ratio of the frequency difference of the corresponding first subcarrier and the demodulation subcarrier to the adjacent demodulation subcarrier spacing as the first synchronization factor ε _R1 to the corresponding second subcarrier And the ratio of the frequency difference of the demodulation subcarrier to the adjacent demodulation subcarrier spacing is regarded as the second synchronization factor ε _R2 ; and the parameter processor is determined according to the following equation: the kth demodulation subcarrier is subjected to the mth Interference coefficient of the first subcarrier interference And determining an interference coefficient that the kth demodulation subcarrier is interfered by the mth second subcarrier ,