JP5219528B2 - Radio receiving apparatus and radio receiving method - Google Patents

Description

  The present invention relates to a wireless reception device and a wireless reception method.

  A system in which each communication station installed in a physically different location transmits a signal only during a specific assigned time zone and performs communication is called a time division multiple access (TDMA) system. As a wireless communication system using TDMA, a satellite communication system (Dynet), (for example, refer to Non-Patent Document 1), a simplified mobile phone system PHS (for example, refer to Non-Patent Document 2), and the like are known. Further, as an independent distributed multiple access communication method that does not require allocation of a communication time zone, there is a CSMA (Carrier Sense Multiple Access / Collision Avoidance) method. A wireless LAN system compliant with IEEE802.11 (see, for example, Non-Patent Document 3) employs this CSMA / CA method.

  What is common to these TDMA systems and CSMA / CA is that radio transmission signals are multiplexed on the time axis. In order to implement time division communication, the radio transmission signal transmitted from each communication station must be intermittent. That is, it is essential to perform burst communication. In order to extract information by receiving a radio burst signal, various synchronization techniques such as symbol timing synchronization, carrier frequency synchronization, carrier phase synchronization (including propagation path fluctuation compensation), and frame synchronization are required (for example, non-patent documents). 4).

  In order to realize these various synchronizations, there is a method of multiplexing not only an information signal sequence to be transmitted to a radio burst transmission signal but also a known signal sequence (training signal) for establishing various synchronizations on a time axis. Are known.

  FIGS. 9A and 9B are conceptual diagrams showing a burst configuration of a system represented by Dynanet and PHS (hereinafter referred to as a first conventional system) according to the prior art. In Dynet, BTR (Bit Timing Recovery) symbols for symbol timing synchronization, CR (Carrier Recovery) symbols for carrier frequency synchronization, and UW (Unique Word) symbols for frame synchronization are used as training signals ( Non-patent document 1). Similarly in PHS, PR (Preamble) symbols for symbol timing synchronization and carrier frequency synchronization and UW symbols for frame synchronization are used (Non-Patent Document 2).

  Thus, in the first conventional system, as shown in FIGS. 9A and 9B, it is necessary to separate the training signal required for symbol timing synchronization and carrier frequency synchronization from the training signal for frame synchronization. There is. For this reason, the overhead due to the training signal is increased, and there is a problem that the transmission efficiency is deteriorated particularly for a burst having a short information symbol signal portion.

  FIG. 10 is a functional block diagram showing reception synchronization processing of the first conventional system. In the reception synchronization processing of the first conventional system, clock phase error estimation 10, symbol timing synchronization establishment 11, carrier frequency offset estimation 12, carrier frequency synchronization establishment 13, UW correlation detection 14, and frame synchronization establishment 15 are performed. As shown in FIG. 10, it is necessary to perform these three reception synchronization processes, that is, symbol timing synchronization establishment 11, carrier frequency synchronization establishment 13 and frame synchronization establishment 15 by separate arithmetic processing, and each block Therefore, a large load calculation such as autocorrelation calculation and Discrete Fourier Transform (DFT) is required, which increases the circuit size and power consumption of the reception processing baseband circuit.

  Furthermore, the first conventional system requires carrier phase synchronization in order to perform synchronous detection. In the first conventional system, carrier phase synchronization is established using a carrier recovery method represented by an inverse modulation method or the like. The phase uncertainty is removed using CR, which is an unmodulated signal, or information symbols are differentially encoded during modulation so that demodulation is possible even when phase uncertainty exists.

  In addition, the first conventional system is a sequential demodulation method, but in order to establish carrier frequency synchronization and perform carrier recovery, it is necessary to repeatedly refer to a plurality of burst signals and draw one burst time. It cannot be pulled in. Further, in order to perform frame synchronization, UW bit determination is required, and carrier frequency synchronization needs to be obtained with high accuracy in advance.

That is, the first conventional system has the following three problems.
(A1) Since it is necessary to prepare dedicated training signals separately for each reception synchronization process, overhead increases, and transmission efficiency deteriorates particularly when the information symbol signal portion is short.
(A2) Since each reception synchronization process is performed by different signal processing, the amount of calculation is large, and the circuit scale and power consumption of the reception apparatus increase.
(A3) Each reception synchronization cannot be established within one reception burst.

  As a burst wireless transmission system that solves the above (A3), there is IEEE802.11a (hereinafter referred to as a second conventional system) (Non-Patent Document 3). IEEE802.11a is one of IEEE802.11 compliant wireless LAN standards to which orthogonal frequency division multiplexing (Orthogonal Frequency Division Multiplexing), which is a multicarrier transmission method, is applied.

  FIG. 11 is a conceptual diagram showing a burst configuration of the second conventional system. In the second conventional system, in order to realize each reception synchronization process, a short preamble (ShortPR) for symbol timing synchronization, carrier frequency synchronization, and frame synchronization, and a long preamble (LongPR) for propagation path distortion compensation are used. Types of training signals are placed at the beginning of the burst.

  FIG. 12 is a functional block diagram showing reception synchronization processing of the second conventional system. A cross-correlation operation is performed on the short preamble signal portion by a sliding cross-correlation operation 20, a peak position of a cross-correlation value is detected by a peak detection 21, a symbol timing synchronization and a frame are detected by a frame synchronization establishment symbol timing synchronization establishment 22 The synchronization is established, the phase component of the autocorrelation value is detected by the autocorrelation calculation 23 and the phase detection 24, and the carrier frequency synchronization is established by the carrier frequency synchronization establishment 25. A long preamble signal part can also be used for carrier frequency synchronization.

  In the second conventional system, each reception synchronization is established by accumulating training signal information included in the received burst signal and performing a correlation calculation. Therefore, each reception synchronization can be established within one reception burst, and the problem (A3) of the first conventional system can be solved.

  However, in the second conventional system, since the short preamble has to be a short time period, the orthogonality of the autocorrelation is deteriorated as compared with the case where a pseudo noise (PN) sequence is used. . Therefore, there is a problem that the peak detection accuracy of the cross-correlation value is deteriorated as compared with the case where the PN sequence is used, and the symbol timing synchronization and the frame synchronization accuracy are deteriorated.

  In the second conventional system, in the case of low-speed communication in which the amount of phase rotation in the short preamble signal part cannot be ignored due to the influence of the carrier frequency offset between the transmitting and receiving apparatuses, the phase of each term is calculated in the product-sum operation of the cross-correlation values. May rotate and the correlation value may not take a peak at the desired sample position. At this time, the symbol timing and the frame synchronization system deteriorate.

That is, the second conventional system has the following four problems although it solves the problem (A3).
(B1) Since dedicated training signals need to be prepared separately for each reception synchronization process, overhead increases, and transmission efficiency deteriorates particularly when the information symbol signal portion is short.
(B2) Since each reception synchronization process is performed by different signal processing, the amount of calculation is large, and the circuit scale and power consumption of the reception apparatus increase.
(B4) Since the short preamble does not become a PN sequence, symbol timing synchronization and frame synchronization accuracy are deteriorated as compared with the case where a PN sequence is used.
(B5) In low-speed communication, the phase in the short preamble rotates, and symbol timing synchronization and frame synchronization accuracy deteriorate.

  In order to solve the problems (B4) and (B5) described above, a frame synchronization method (hereinafter referred to as the first) that performs differential detection before peak detection using cross-correlation calculation using UW differential encoding for frame synchronization. 3) (see, for example, Non-Patent Document 5).

  FIG. 13 is a block diagram showing a configuration of a wireless reception apparatus using the third conventional method. FIG. 13 shows only a baseband processing unit that performs digital signal processing, and an antenna for receiving a radio signal and a radio unit are connected before.

  The analog reception burst signal S300 is converted into a digital reception burst signal S301 by the A / D converter 301. The digital reception burst signal S301 after A / D conversion is input to the reception filter 302, and the reception burst signal S302 after reception filter processing is output. The reception burst signal S302 after reception filter processing is subjected to symbol timing detection and synchronization by a symbol timing synchronization circuit 303, and a reception burst symbol sequence S303 is output.

  Reception burst symbol sequence S303 is input to carrier frequency synchronization circuit 304, and reception burst symbol sequence S304 after carrier frequency synchronization is output. Received burst symbol sequence S304 after carrier frequency synchronization is input to frame detection circuit 305, and frame position information S305 is output. Reception burst symbol sequence S304 is input to frame synchronization circuit 306, frame synchronization is established based on frame position information S305, and reception burst symbol sequence S306 is output. Received burst symbol sequence S306 after the establishment of frame synchronization is converted from an information symbol to a data bit sequence by symbol identification circuit 307 and output as received data signal S307.

  FIG. 14 is a block diagram showing a configuration of the frame detection circuit 305 in the wireless reception device shown in FIG. Received burst symbol sequence S304 after establishment of symbol timing and carrier frequency synchronization is input to training symbol extraction circuit 401, and symbol sequence S401 corresponding to the received training symbol period is output for each input symbol. The received training symbol sequence S401 is input to the one symbol delay circuit 402, and the received training symbol sequence S402 after one symbol delay is output. The received training symbol sequence S401 before one symbol delay and the received training symbol sequence S402 after one symbol delay are input to the complex conjugate multiplier circuit 403 to be differentially decoded, that is, subjected to delay detection. The received training symbol sequence S403 after delay detection is output.

  The received training symbol sequence S403 after delay detection is input to a bit determination circuit (delay detection) 404, subjected to bit determination (symbol identification), and a received frame synchronization code sequence S404 after bit determination is output. On the other hand, the synchronization code sequence generation circuit 405 generates a known frame synchronization code sequence S405. The received frame synchronization code sequence S404 and the known frame synchronization code sequence S405 are input to a cross-correlation calculation circuit (bit operation) 406, and a cross-correlation value S406 is output. The cross-correlation value S406 input for each input symbol of the received burst signal is input to the correlation peak detection circuit 407, detects a symbol position where the correlation value is maximum as a frame position, and outputs frame position information S305.

  As in the first conventional system described above, the third conventional system needs to include UW as a training signal for frame synchronization. Since a code sequence having excellent autocorrelation orthogonality such as a PN sequence can be used as the UW code sequence, the problem (B4) of the second conventional system can be solved. In addition, since the influence of the carrier frequency offset between the transmitting and receiving apparatuses can be reduced by delay detection of the UW code sequence, the problem (B5) can also be solved.

  However, since the third conventional method requires delay detection and bit determination after the symbol timing synchronization is established in order to detect the frame position, as in the first conventional system having the burst configuration shown in FIG. In addition to UW, it is necessary to provide a training symbol sequence for establishing symbol timing synchronization and carrier frequency synchronization.

Therefore, even if the third conventional method is applied after solving the problem (A3) of the first conventional system, the problems (B1) and (B2) of the second conventional system are solved. It cannot be solved.
Kiyoshi Kobayashi, Tetsu Sakata, Yoichi Matsumoto, Shuji Kubota, “Fully Digital Burst Modem for Satellite Multimedia Communication Systems” IEICE Transaction of Communications, vol.E80-B, no.1, January 1997. Yoichi Matsumoto, Shuji Kubota, Shuzo Kato, “A New Burst Coherent Demodulator for Microcellular TDMA / TDD Systems” IEICE Transaction on Communications, vol. E77-B, No. 7, July 1994. Matsue Hideaki, Morikura Masahiro, “802.11 High-Speed Wireless LAN Textbook” IDG Japan, 2003. Seiichi Sampei, “Digital Wireless Transmission Technology” Pearson Education, 2002. Hiroshi Ogura, Kaoru Serizawa, “Slot Synchronization for TDMA Digital Mobile Communications,” B-292, 1990 National Conference of the Institute of Electronics, Information and Communication Engineers

  As described above, in the first and second conventional systems and the third conventional system, transmission efficiency deteriorates due to an overhead training symbol in performing burst radio transmission, circuit scale, power consumption increases, and low speed. There has been a problem that problems such as symbol timing synchronization in communication and deterioration of frame synchronization accuracy cannot be solved.

  The present invention has been made in consideration of such circumstances, and the object thereof is to reduce transmission efficiency degradation due to overhead in wireless burst communication, and to reduce the amount of signal processing computation, thereby achieving high accuracy. It is an object of the present invention to provide a radio reception apparatus and radio reception method that can realize burst synchronization.

In order to solve the above-described problem, the present invention provides a radio receiving apparatus that receives a radio burst signal composed of a training symbol and an information symbol using a differentially-encoded synchronization code sequence as a training symbol. Frame symbol timing detection means for detecting frame symbol timing from an oversampled received burst signal sequence using a training symbol series included in a radio burst signal, and a frame detected by the frame symbol timing detection means Based on the symbol timing, a frame / symbol timing synchronization unit for extracting a received burst symbol sequence, and a received information symbol sequence is extracted from the received burst symbol sequence extracted by the frame / symbol timing synchronization unit. A symbol identifying means for performing a volume identification, wherein the frame symbol timing detecting means outputs a training symbol portion sample extracting means for outputting a received signal sample corresponding to the training symbol section for each input sample, and the training symbol portion sample. N delay means for outputting the received training symbol part signal samples output from the extraction means with a sample time delay equivalent to 1 to n (n is an integer of 1 or more) symbol time, and the training symbol part sample extracting means A complex conjugate multiplication of the output received training symbol part signal sample series and the received training symbol part signal sample series output from the n delay means is performed, and 1 to n symbol times of each of the received training symbol part sample series are obtained. Differential N complex conjugate multiplication means for performing encoding, and n for extracting the training symbol part signal sample that is differentially decoded by down-sampling the training symbol portion signal samples output from the n complex conjugate multiplication means Down-sampling means, training symbol generating means for generating a known training symbol series, and n differentials for 1-n symbol time differential decoding of the training symbol series output from the training symbol generating means A cross-correlation value between the decoding means, the differentially decoded received training symbol sequence, and the differentially decoded known training symbol sequence is calculated, and n cross-correlations output for each input sample And n cross-correlation values output from the n cross-correlation value calculation means. Zui and the cross-correlation value is a radio receiving apparatus, characterized in that it comprises a correlation peak detection means for detecting a frame symbol timing position sample position with the maximum.

The present invention, in the above invention, the frame symbol timing detection means, before Symbol of n to n-number of cross-correlation values output from the correlation value calculation means, the phase corresponding to each symbol delay time Phase compensation means for performing compensation, and summing means for calculating the sum of the n phase-compensated cross-correlation values output from the phase compensation means , wherein the correlation peak detecting means comprises the summing means. the cross-correlation value is characterized and Turkey be detected as a frame symbol timing position sample position with the maximum of.

According to the present invention, in the above invention, the frame / symbol timing detection unit further estimates a carrier frequency, the frame / symbol timing synchronization unit further performs carrier frequency synchronization, and the correlation peak detection unit further includes A carrier frequency is estimated from a phase component of a cross-correlation value of the frame / symbol timing position, and the frame / symbol timing synchronization means further performs carrier frequency synchronization.

According to the present invention, in the above invention, the frame / symbol timing detection unit further estimates a carrier frequency, the frame / symbol timing synchronization unit further performs carrier frequency synchronization, and the correlation peak detection unit further includes The carrier frequency is estimated from the phase component using a part or all of the cross-correlation values before summation of the frame symbol timing position, and the frame symbol timing synchronization means It is characterized by performing frequency synchronization.

Further, in order to solve the above-described problem, the present invention provides a radio reception method for receiving a radio burst signal composed of a training symbol and an information symbol using a differentially-encoded synchronization code sequence as a training symbol. A frame symbol timing detection step for detecting frame symbol timing from an oversampled received burst signal sequence using a known training symbol sequence included in the radio burst signal, and detection by the frame symbol timing detection step A frame / symbol timing synchronization step for extracting a received burst symbol sequence based on the received frame / symbol timing, and a reception burst symbol sequence extracted in the frame / symbol timing synchronization step. A symbol identification step of extracting a reporting symbol sequence and performing symbol identification, and in the frame symbol timing detection step, a training symbol portion sample extraction for outputting a received signal sample corresponding to the training symbol interval for each input sample And n delay steps for outputting the received training symbol portion signal samples output in the training symbol portion sample extraction step with a sample time delay equivalent to 1 to n (n is an integer of 1 or more) symbol time, and Complex conjugate multiplication of the received training symbol part signal sample sequence output in the training symbol part sample extraction step and the received training symbol part signal sample sequence output in the n delay steps. N complex conjugate multiplication steps for performing 1 to n symbol time differential decoding of each of the received training symbol portion sample sequences, and downsampling of the training symbol portion signal samples output in the n complex conjugate multiplication steps N times of downsampling steps for extracting a received training symbol sequence subjected to differential decoding, a training symbol generation step for generating a known training symbol sequence, and a training symbol sequence output in the training extraction step Cross-correlation between n differential decoding steps for 1-n symbol time differential decoding, the differentially decoded received training symbol sequence, and the differentially decoded known training symbol sequence Calculate the value and input sample And the sample position where the cross-correlation value is maximized based on the n cross-correlation values output step and the n cross-correlation values output in the n cross-correlation value calculation steps. And a correlation peak detection step of detecting as a timing position.

The present invention, in the radio receiving method, in the frame symbol timing detection step, for n-number of cross-correlation values output before Symbol n times of the cross-correlation value calculation step, corresponding to each symbol delay time A phase compensation step for performing phase compensation, and a summation step for calculating a sum of n phase-compensated cross-correlation values output in the phase compensation step , wherein in the correlation peak detection step, the cross-correlation value at summing step and said and Turkey be detected as a frame symbol timing position sample position with the maximum.

According to the present invention, in the radio reception method described above, a carrier frequency is further estimated in the frame / symbol timing detection step, a carrier frequency synchronization is further performed in the frame / symbol timing synchronization step, and the correlation peak detection is performed. In the means step, the carrier frequency is further estimated from the phase component of the cross-correlation value of the frame / symbol timing position, and in the frame / symbol timing synchronization means step, carrier frequency synchronization is further performed.

According to the present invention, in the radio reception method described above, a carrier frequency is further estimated in the frame / symbol timing detection step, a carrier frequency synchronization is further performed in the frame / symbol timing synchronization step, and the correlation peak detection is performed. In the means step, a carrier frequency is estimated from the phase component by using a part or all of the cross-correlation value before summation of the frame symbol timing position, and in the frame symbol timing synchronization means step, In addition to frame / symbol timing, carrier frequency synchronization is performed.

  According to the present invention, a training symbol sequence necessary for frame synchronization and symbol timing synchronization necessary for radio burst communication is provided as a common training symbol sequence, and therefore it is necessary to provide an individual training symbol sequence for each reception synchronization process. The overhead can be reduced and the transmission efficiency of the system can be improved.

  Also, any synchronization code sequence can be used as the training symbol sequence. However, by using a sequence excellent in autocorrelation orthogonality, such as an M sequence, as the synchronization code sequence, the frame synchronization and symbol timing synchronization accuracy in the receiving apparatus can be further improved.

  Further, since the synchronization code sequence is differentially encoded and transmitted, differential decoding (delay detection) of the synchronization training symbol sequence can be performed at the time of reception. Since the carrier frequency offset before the carrier frequency synchronization can be canceled at the time of differential decoding, it is possible to reduce the deterioration of the cross-correlation peak detection accuracy due to the influence of the local oscillator error between the transmitting and receiving apparatuses.

In addition, when multiple training symbol sequences are inserted at different positions in a burst, high-accuracy frame synchronization and symbol timing synchronization are possible even when signal power fluctuates within the burst due to propagation path fluctuations such as fading. Become.

In addition, since frame synchronization and symbol timing synchronization can be established at the same time in the frame / symbol timing detection means, the symbol timing synchronization means required in the first conventional system becomes unnecessary, and the circuit scale of the receiving apparatus is reduced. It becomes possible.

  Further, by performing a sliding cross-correlation operation on the oversampled received burst signal, it is possible to simultaneously detect the frame position and the symbol timing position as a common peak position.

  Further, by performing complex conjugate calculation (differential decoding) at a sample interval corresponding to a symbol adjacent to a training symbol, a synchronization code sequence before differential encoding can be extracted from the received signal. The cross-correlation calculating means performs a sliding cross-correlation operation between the detected synchronous code sequence after differential decoding and the synchronous code sequence of a known training symbol, so that the frame position and symbol timing position are set to a common position. Can be detected at the same time.

  Further, the differential decoding process in the training symbol portion corresponds to the autocorrelation calculation of the synchronization code sequence. Therefore, the phase component of the cross-correlation value output from the cross-correlation calculating means that performs differential decoding of n symbols in the previous stage includes a carrier frequency offset between the transmitting and receiving apparatuses per n symbols, and each cross-correlation calculation The phases of the cross-correlation values output from the means are not aligned. Therefore, by performing the summation process after aligning the phases of the cross-correlation values in the phase compensation means, it is possible to reduce the degradation of the correlation peak due to the carrier frequency offset.

  For example, for each cross-correlation value obtained by n-symbol differential decoding, the phase compensation means detects the phase component θn, and then has a phase of − {(n−1) / n} × θn. This can be done by applying rotation. By applying the phase rotation in the previous period, the phase component of each cross-correlation value can be adjusted to 1 / n, that is, the phase rotation amount per symbol.

  In addition, since the phase component of the cross-correlation calculation result in the frame / symbol timing detection process becomes a carrier frequency offset between transmitting and receiving apparatuses per symbol, the carrier frequency offset can be estimated by detecting the phase component. It becomes.

  In addition to performing complex conjugate calculation (differential decoding) at a sample interval corresponding to an adjacent symbol of the training symbol, complex conjugate calculation (differential decoding) also at a sample interval corresponding to a plurality of symbols, An effect equivalent to that obtained when the training symbol sequence length is increased and the correlation calculation is performed can be obtained.

  That is, frame synchronization and symbol timing synchronization accuracy are improved even with the same training symbol length, so that it is possible to improve anti-noise synchronization characteristics without deteriorating transmission efficiency. Alternatively, the training symbol length can be shortened while maintaining anti-noise synchronization characteristics, and transmission efficiency can be improved.

  Further, since the phase component of the cross-correlation calculation result in the frame / symbol timing detection process becomes a carrier frequency offset between the transmitting and receiving apparatuses per 1 to K symbols, each phase component is detected, and some or all of these are detected Can be used to estimate the carrier frequency offset. If the differential decoding symbol interval is small, the acquisition range is wide but the frequency estimation accuracy is low. Conversely, if the differential decoding interval is large, the acquisition range is narrow but the frequency estimation accuracy is high. It is also possible to perform carrier frequency synchronization with a wide pull-in range and excellent frequency estimation accuracy by appropriately combining these, such as estimating the frequency.

  In addition, since the cross-correlation value calculation processing has already been completed in the frame / symbol timing detection processing, additional signal processing for carrier frequency offset estimation is unnecessary, and reception signal processing for carrier frequency offset estimation is unnecessary. It is possible to reduce the calculation amount or the circuit scale.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

A. First Embodiment FIG. 1 is a block diagram showing a configuration of a wireless transmission device according to a first embodiment of the present invention. FIG. 1 shows only a baseband processing unit that performs digital signal processing, and a radio unit and an antenna for transmitting radio signals are connected to the subsequent stage. In the figure, a symbol generation circuit 101 generates a transmission information symbol sequence S101 from a transmission data bit sequence S100. The training symbol generation circuit 102 includes a synchronous code sequence generation circuit 201 and a differential encoding circuit 202. The synchronization code sequence generation circuit 201 generates a synchronization code sequence S201. The differential encoding circuit 202 generates a training symbol sequence S102 from the synchronous code sequence S201. Multiplexing circuit 103 time-multiplexes transmission information symbol sequence S101 and training symbol sequence S102 to generate transmission burst symbol sequence S103. Transmission filter means 104 limits the band of transmission burst symbol sequence S103 and outputs transmission burst signal S104. The D / A conversion means 105 converts the transmission burst signal S104 after the transmission filter processing into an analog transmission burst signal S105.

  In the configuration described above, the transmission data bit sequence S100 is input to the symbol generation circuit 101, and the transmission information symbol sequence S101 is generated. In the training symbol generation unit 102, the synchronization code sequence S 201 is generated by the synchronization code sequence generation unit 201. The synchronization code sequence S201 is input to the differential encoding means 202, and a training symbol sequence S102 is generated. Transmission information symbol sequence S101 and training symbol sequence S102 are time-multiplexed by symbol multiplexing means 103 to generate transmission burst symbol sequence S103.

  Transmission burst symbol sequence S103 is input to transmission filter means 104 for band limitation, and transmission burst signal S104 after transmission filter processing is output. The transmission burst signal S104 after the transmission filter process is converted into an analog transmission burst signal S105 by the D / A conversion means 105. The analog transmission burst signal S104 is finally input to the wireless unit, converted into a carrier frequency, and wirelessly transmitted.

  FIG. 2 is a conceptual diagram showing a burst configuration generated when the first embodiment is used. As shown in FIG. 2, in the first embodiment, the individual training pattern for each reception synchronization processing found in the first conventional system is not necessary, and frame synchronization and symbols are performed using a common training symbol sequence. Timing synchronization and carrier frequency synchronization can be established.

  According to the first embodiment described above, since the training symbol sequence necessary for frame synchronization and symbol timing synchronization necessary for radio burst communication is provided as a common training symbol sequence, individual training is performed for each reception synchronization process. There is no need to provide a symbol sequence, overhead can be reduced, and the transmission efficiency of the system can be improved.

  Further, according to the first embodiment, an arbitrary synchronization code sequence can be used as the training symbol sequence. However, the accuracy of frame synchronization and symbol timing synchronization in the receiving apparatus can be further improved by using a sequence excellent in autocorrelation orthogonality, such as an M sequence, as the synchronization code sequence.

  Also, according to the first embodiment, since the synchronization code sequence is differentially encoded and transmitted, differential decoding (delay detection) of the synchronization training symbol sequence can be performed at the time of reception. . Since the carrier frequency offset before the carrier frequency synchronization can be canceled at the time of differential decoding, it is possible to reduce the deterioration of the cross-correlation peak detection accuracy due to the influence of the local oscillator error between the transmitting and receiving apparatuses.

  Furthermore, according to the first embodiment, when a plurality of training symbol sequences are inserted at different positions in the burst, even if the signal power fluctuates in the burst due to propagation path fluctuations such as fading, high accuracy is achieved. Frame synchronization and symbol timing synchronization are possible.

  In the first embodiment, it is not necessary for the wireless transmission apparatus to include the training symbol generation circuit 102 capable of generating the sequential training symbol sequence, and storage means for storing the generated training symbol sequence is provided instead. May be.

B. Second Embodiment Next, a second embodiment of the present invention will be described.
FIG. 3 is a block diagram illustrating a configuration of the wireless reception device according to the second embodiment. In the figure, an A / D converter 301 oversamples and A / D-converts a received burst signal S300 and outputs a received burst signal S301. The reception filter 302 limits the band of the reception burst signal S301 and outputs the reception burst signal S302. The frame / symbol timing detection circuit 503 outputs frame / symbol timing position information S503-1 and carrier frequency information S503-2 from the band-limited reception burst signal S302.

  The frame / symbol timing synchronization circuit 504 performs a frame synchronization process and a downsampling process based on the symbol timing on the received burst signal S302 based on the frame / symbol timing position signal S503-1, and the carrier wave carrier information S503- 2, carrier frequency synchronization is performed, and a received burst symbol sequence S504 is output. Information symbol identification circuit 505 outputs received data bit sequence S505 from received burst symbol sequence S504.

  In the configuration described above, the received burst signal S300 input from the receiver radio unit is oversampled and A / D converted by the A / D converter 301, and the A / D converted received burst signal S301 is output. The reception burst signal S301 after A / D conversion is input to the reception filter 302, and the band-limited reception burst signal S302 is output. The band-limited reception burst signal S302 is input to the frame / symbol timing detection circuit 503, which outputs frame / symbol timing position information S503-1 and carrier frequency information S503-2.

  The frame / symbol timing position signal S503-1 and the carrier wave carrier information S503-2 are input to the frame / symbol timing synchronization unit 504, and based on the frame synchronization processing and the symbol timing based on the frame / symbol timing position signal S503-1. Downsampling is performed, carrier frequency synchronization is performed based on the carrier wave carrier information S503-2, and a frame / symbol timing synchronization reception burst symbol sequence S504 is output. Received burst symbol sequence S504 after frame / symbol timing synchronization is input to information symbol identifying section 505, and received data bit sequence S505 is output.

  According to the second embodiment described above, since frame synchronization and symbol timing synchronization can be established at the same time in the frame / symbol timing detection circuit, symbol timing synchronization means, which has been necessary in the past, is no longer necessary. The circuit scale can be reduced.

C. Third Embodiment Next, a third embodiment of the present invention will be described.
The third embodiment realizes frame synchronization and symbol timing synchronization in the above-described radio reception apparatus of the second embodiment, and extracts a training symbol sequence component from an oversampled received burst signal and performs sliding mutual processing. A correlation calculation is performed to detect a peak position, and the peak position is identified as a frame position and a symbol timing position. This differs from the third conventional method described above in that signal processing is performed for each sample.

  FIG. 4 is a block diagram showing a configuration of the frame / symbol timing detection circuit 503 of FIG. 3 according to the third embodiment. In the figure, a training symbol portion sample extraction circuit 601 outputs, for each input sample, a sample series S601 corresponding to a training symbol section from the oversampled received burst signal S302 output from the reception filter 302. The Ns sample (one symbol time) delay circuit 602 outputs the sample sequence S602 of the received training symbol part after the sample delay corresponding to one symbol time from the sample sequence S601.

  The complex conjugate multiplication circuit 603 performs differential decoding by performing complex conjugate multiplication of the sample sequence S601 of the reception training symbol part before one symbol time delay and the sample series S602 of the reception training symbol part after one symbol time delay. . The 1 / Ns downsampling circuit 604 outputs, from the sample sequence S603 of the received training symbol part after 1 symbol time differential decoding, the sample sequence S604 of the received training symbol part after 1 symbol differential decoding for each input sample. To do.

  The training symbol generation circuit 605 generates a known training symbol series S605. The 1-symbol differential decoding circuit 606 performs 1-symbol differential decoding on the known training symbol sequence S605 and outputs a training symbol sequence S606. The cross-correlation calculation circuit 607 calculates the cross-correlation value S607 of the received training symbol sequence S604 after 1-symbol differential decoding and the known training symbol sequence S606 after 1-symbol differential decoding by multi-value complex operation.

  Correlation peak detection circuit 608 detects the sample position at which cross-correlation value S607 output for each input sample of the received burst signal is maximum as a frame symbol position, and outputs it as frame symbol timing position information S503-1. At the same time, the carrier frequency offset is estimated using the phase component of the correlation peak value corresponding to the frame / symbol timing position S503-1, and is output as the carrier frequency information S503-2. This is because in the frame / symbol timing detection process, the differential decoding process in the training symbol portion corresponds to the autocorrelation calculation of the synchronization code sequence. As a result, the phase component of the cross-correlation calculation result at the frame / symbol timing detection position The fact that a frequency offset component is included is used.

  In the configuration described above, the oversampled reception burst signal S302 output from the reception filter 302 is input to the training symbol portion sample extraction circuit 601, and a sample series S601 corresponding to the training symbol period is output for each input sample. . The received training symbol part sample series S601 is input to the Ns sample delay circuit 602, and the received training symbol part sample series S602 after the sample delay corresponding to one symbol time is output.

  The received training symbol part sample series S 601 before one symbol time delay and the received training symbol part sample series S 602 after one symbol time delay are differentially decoded by being input to the complex conjugate multiplier circuit 603. The received training symbol part sample series S603 after differential decoding is input to the downsampling circuit 604, and the received training symbol series S604 after 1-symbol differential decoding is output for each input sample.

  On the other hand, the training symbol generation circuit 605 generates the same known training symbol sequence S605 as that generated by the wireless transmission device. The known training symbol sequence S605 is input to the 1-symbol differential decoding circuit 606, and the known training symbol sequence S606 after the 1-symbol differential decoding is output. The received training symbol sequence S604 after 1-symbol differential decoding and the known training symbol sequence S606 after 1-symbol differential decoding are input to the cross-correlation calculation circuit 607, and the cross-correlation value S607 of both is calculated as a multivalued complex operation. Is calculated by

  The cross-correlation value S607 output for each input sample of the received burst signal is input to the correlation peak detection circuit 608, the sample position where the correlation value is maximum is detected as the frame symbol position, and the frame symbol timing position information S503. −1, the carrier frequency offset is estimated using the phase component of the correlation peak value corresponding to the frame symbol timing position S503-1, and the carrier frequency information S503-2 is also output.

  According to the third embodiment described above, the frame position and the symbol timing position can be simultaneously detected as a common peak position by performing a sliding cross-correlation operation on the oversampled received burst signal.

  In addition, according to the third embodiment, a complex code operation (differential decoding) is performed at a sample interval corresponding to an adjacent symbol of a training symbol, so that a synchronization code sequence before differential encoding is performed from the received signal. Can be extracted. In addition, by performing a sliding cross-correlation operation between the detected synchronization code sequence after differential decoding and the synchronization code sequence of a known training symbol, the frame position and symbol timing position are simultaneously detected as a common position. be able to.

  In addition, according to the third embodiment, the carrier frequency offset before the carrier frequency synchronization can be canceled by performing differential decoding (delay detection) of the synchronization training symbol sequence. It is possible to reduce the deterioration of the cross-correlation peak detection accuracy due to the influence of the local oscillator error.

  In the third embodiment, the frame / symbol timing detection circuit 503 shown in FIG. 4 uses the same configuration as the training symbol generation circuit 102 shown in FIG. 1 as the training symbol generation circuit 605. The training symbol generation circuit 605 performs differential encoding of the original synchronization code sequence, and the differential decoding circuit 606 performs differential decoding, both of which are signal processing for known synchronization code sequences. In practice, the differential encoding and encoding processing pair may be omitted.

  In the third embodiment, the frame / symbol timing detection circuit 503 does not include the training symbol generation circuit 602 that can generate sequential training symbol sequences, but instead includes storage means for storing the training symbol sequences. May be.

D. Fourth Embodiment Next, a fourth embodiment of the present invention will be described.
As in the third embodiment described above, the fourth embodiment realizes frame synchronization and symbol timing synchronization in the wireless reception device of the second embodiment. From the oversampled received burst signal, A training symbol sequence component is extracted, a sliding cross-correlation operation is performed, a peak position is detected, and it is identified as a frame position and a symbol timing position. This differs from the third conventional method in that signal processing is performed for each sample.

  FIG. 5 is a block diagram showing another configuration example of the frame / symbol timing detection circuit 503 shown in FIG. 3 according to the fourth embodiment. In the figure, a training symbol part sample extraction circuit 701 outputs the oversampled reception burst signal S302 output from the reception filter 302 for each input sample as a sample series S701 corresponding to a training symbol period. The 1 × Ns sample delay circuit 702-1 to K × Ns sample delay circuit 702-K receives the received training symbol part sample series S702 after the sample delay corresponding to 1 to K symbol times from the received training symbol part sample series S701. 1 to K are output.

  Complex conjugate multiplication circuits 703-1 to 703-K differentially receive received training symbol part sample series S701 before time delay processing and received training symbol part sample series S702-1 to S702-K after time delay of 1 to K symbols. Decrypt. The 1 / Ns downsampling circuits 704-1 to 704-K differ from the received training symbol part sample series S703-1 to S703-K after 1-K symbol time differential decoding by 1-K symbol differences for each input sample. Received training symbol sequences S704-1 to S704-K after the dynamic decoding are output.

  The training symbol generation circuit 705 generates a known training symbol sequence S705. The 1-K symbol differential decoding circuits 706-1 to 706-K output the known training symbol sequences S706-1 to S706-K after the 1-K symbol differential decoding from the known training symbol sequence S705. To do. The cross-correlation calculation circuits 707-1 to 707 -K are received training symbol sequences S 704-1 to S 704 -K after 1-K symbol differential decoding and known training symbol sequences after 1-K symbol differential decoding. From S706-1 to S706-K, the cross-correlation values S707-1 to S707-K of both are calculated by multivalued complex arithmetic.

  The phase compensation circuit 708 compensates for the difference in influence of the carrier frequency offset that differs depending on the delay time difference during differential encoding from the cross-correlation values S707-1 to S707-K, and cross-correlation values S708-1 to S708-1 after phase compensation Output as S708-K. The summation circuit 709 sums the cross-correlation values S708-1 to S708-K after phase compensation and outputs the result as a cross-correlation value S709. Correlation peak detection circuit 710 detects, from the cross-correlation value S709 after summation, the sample position where the correlation value is maximum for each input sample of the received burst signal as the frame symbol position, and the frame symbol timing position information S503. Output as -1. The carrier frequency estimation circuit 711 estimates the carrier frequency offset using the phase components of the cross-correlation values S707-1 to S707-1 corresponding to the frame / symbol timing position S503-1, and outputs it as carrier frequency information S503-2. As in the third embodiment described above, in the frame / symbol timing detection process, the differential decoding process in the training symbol portion corresponds to the autocorrelation calculation of the synchronization code sequence, resulting in the detection of the frame / symbol timing. This utilizes the fact that a carrier frequency offset component is included in the phase component of the cross-correlation calculation result at the position.

  In the configuration described above, the oversampled reception burst signal S302 output from the reception filter 302 is input to the training symbol portion sample extraction circuit 701, and a sample series S701 corresponding to the training symbol period is output for each input sample. . The received training symbol part sample series S701 is input to the 1 × Ns sample delay circuit 702-1 to K × Ns sample delay circuit 702-K, and the received training symbol part sample series after the sample delay corresponding to 1 to K symbol time. S702-1 to S702-K are output. Reception training symbol part sample series S701 before time delay processing and reception training symbol part sample series S702-1 to S702-K after time delay of 1 to K symbols are input to complex conjugate multiplication circuits 703-1 to 703-K. Differential decoding. Received training symbol part sample sequences S703-1 to S703-K after differential decoding of 1 to K symbol times are input to downsampling circuits 704-1 to 704-1K, and 1 to K symbol differentials are input for each input sample. Received training symbol sequences S704-1 to S704-K after decoding are output.

  On the other hand, the training symbol generation circuit 705 generates a known training symbol sequence S705. The known training symbol sequence S705 is input to 1-K symbol differential decoding means 706-1 to 706-K, and known training symbol sequence S706-1 to S706-K after 1-K symbol differential decoding. Is output. The received training symbol sequences S704-1 to S704-K after 1-K symbol differential decoding and the known training symbol sequences S706-1 to S706-K after 1-K symbol differential decoding are cross-correlation calculation circuits. 707-1 to K, and the cross-correlation values S707-1 to S707-K of both are calculated by a multi-value complex operation.

  The cross-correlation values S707-1 to S707-K are input to the phase compensation circuit 708, and the difference in the influence of different carrier frequency offsets is compensated by the delay time difference during differential encoding, and the cross-correlation value S708- after phase compensation is compensated. 1 to S708-K are output. The cross-correlation values S708-1 to S708-K after the phase compensation are input to the summation circuit 709, and the cross-correlation value S709 after the summation is output. The cross-correlation value S709 after summation is input to the correlation peak detection circuit 710 for each input sample of the received burst signal, and the sample position where the correlation value is maximized is detected as the frame symbol position, and frame symbol timing position information It is output as S503-1. Further, the carrier frequency estimation circuit 711 estimates the carrier frequency offset using the phase components of the cross-correlation values S707-1 to S707-K corresponding to the frame / symbol timing position S503-1, and generates carrier frequency information S503-2. It can also be output.

  According to the fourth embodiment described above, it is possible to simultaneously detect the frame position and the symbol timing position as a common peak position by performing a sliding cross-correlation operation on the oversampled received burst signal. is there.

  Also, according to the fourth embodiment, the carrier frequency offset before the carrier frequency synchronization can be canceled by performing differential decoding (delay detection) of the synchronization training symbol sequence. It is possible to reduce the deterioration of the cross-correlation peak detection accuracy due to the influence of the local oscillator error.

  Further, according to the fourth embodiment, not only complex conjugate calculation (differential decoding) is performed at a sample interval corresponding to an adjacent symbol of the training symbol, but also complex conjugate calculation is performed at a sample interval corresponding to a plurality of symbols. By performing (differential decoding), an effect equivalent to increasing the training symbol sequence length can be obtained. That is, frame synchronization and symbol timing synchronization accuracy are improved even with the same training symbol length, so that it is possible to improve anti-noise synchronization characteristics without deteriorating transmission efficiency. Alternatively, the training symbol length can be shortened while maintaining anti-noise synchronization characteristics, and transmission efficiency can be improved.

  Further, according to the fourth embodiment, the differential decoding process in the training symbol part corresponds to the autocorrelation calculation of the synchronization code sequence. Therefore, the phase component of the cross-correlation value output from the cross-correlation calculation circuit that performs differential decoding of n symbols in the previous stage includes the carrier frequency offset between the transmitting and receiving apparatuses per n symbols, and each cross-correlation calculation circuit The phases of the cross-correlation values output from are not aligned. Therefore, by performing summation processing after aligning the phases of the cross-correlation values in the phase compensation circuit, it is possible to reduce the degradation of the correlation peak due to the carrier frequency offset.

  Further, according to the fourth embodiment, for example, for each cross-correlation value obtained by n-symbol differential decoding, the phase compensation circuit detects the phase component θn, and then − {( It can be implemented by giving a phase rotation of (n-1) / n} × θn. By applying phase rotation, the phase component of each cross-correlation value can be adjusted to 1 / n, that is, the phase rotation amount per symbol.

In the fourth embodiment, assuming that the training symbol sequence length is _NTR , the upper limit value of the maximum delay time K [symbol] of differential decoding in the previous stage for performing cross-correlation calculation is given by _NTR- 1. . However, if θn of the phase compensation circuit exceeds ± π, the correlation peak characteristic deteriorates beyond the compensable pull-in phase range, so the maximum n where θn does not exceed ± π is the upper limit of K. The value of K that is actually mounted on the receiving apparatus is further determined by the trade-off between the circuit scale of the receiving apparatus, processing delay, frame and symbol timing synchronization accuracy, and the like.

E. Examples of the third embodiment and the fourth embodiment Next, examples of the third embodiment and the fourth embodiment described above will be described. However, the third embodiment described above is the same as the case where K = 1 in the fourth embodiment. The frame error detection rate is evaluated for the first and second embodiments in which the training symbol sequence length is changed.

  FIG. 6 is a table showing computer simulation conditions of the first and second embodiments. BPSK is assumed as the training symbol modulation method, and BPSK or QPSK is assumed as the information symbol modulation method. Also, in order to obtain good radio transmission characteristics in the low CNR region, error correction using convolutional coding and Viterbi decoding was assumed. As a propagation path model, an additive white Gaussian noise (AWGN) was assumed.

  FIGS. 7A and 7B are conceptual diagrams showing burst configurations used in the first and second embodiments. In the first embodiment, training symbol sequences of 8 symbols are added before and after the information symbol sequence of 32 symbols, and in the first embodiment, 16 symbol symbols are added similarly. Note that, as a synchronization code sequence, an M sequence having a code length of 7 and a code length of 15 was used, respectively, and a differentially encoded sequence was used as a training symbol sequence.

  FIG. 8 is a diagram showing required CNR characteristics satisfying the frame misdetection rate = 1% in the first and second embodiments. When synchronous detection is used under the parameter conditions shown in FIG. 6, the required CNR characteristic that satisfies the information symbol packet error rate = 1% is about 3 dB in QPSK and about 0 dB in BPSK. In the case of K = 1 using the third embodiment described above, when QPSK and BPSK are applied to the first and second examples, respectively, the frame error detection rate and the packet error rate are Therefore, the required CNR characteristics of the same level are obtained, and the training symbol length is slightly insufficient as a design of the radio burst communication system. Here, by applying the above-described fourth embodiment and setting K ≧ 2, it is possible to secure a required CNR margin of 1 dB or more, and to increase the frame error detection rate without increasing the training symbol length. It becomes possible to make it sufficiently smaller than the packet error rate.

  Further, comparing the first and second embodiments, it can be seen that when the value of K is the same, the difference in training symbol length is about 2.5 dB in terms of frame synchronization characteristics. Here, since K = 3 in the first embodiment and K = 1 in the second embodiment have substantially the same synchronization characteristics, the fourth embodiment does not deteriorate the frame synchronization characteristics. It can be seen that the transmission efficiency is improved.

  According to the first to fourth embodiments described above, it is possible to reduce transmission efficiency deterioration due to overhead in wireless burst communication. In addition, frame and symbol timing synchronization can be established while reducing the amount of signal processing computation in the wireless reception device. Also in low-speed wireless communication, frame and symbol timing synchronization that achieves highly accurate synchronization characteristics can be established. Also, frame and symbol timing synchronization with high noise tolerance can be established with a shorter training symbol length. Also, carrier frequency synchronization can be established at the same time as frame and symbol timing synchronization is established.

It is a block diagram which shows the structure of the radio | wireless transmitter by the 1st Embodiment of this invention. It is a conceptual diagram which shows the burst structure produced | generated when this 1st Embodiment is used. It is a block diagram which shows the structure of the radio | wireless receiving apparatus by the 2nd Embodiment. FIG. 10 is a block diagram showing a configuration of a frame / symbol timing detection circuit 503 according to the third embodiment. It is a block diagram which shows the other structural example of the frame symbol timing detection circuit 503 by the 4th Embodiment. It is a table | surface figure which shows the computer simulation conditions of the 1st Example and the 2nd Example. It is a conceptual diagram which shows the burst structure used in the 1st Example and the 2nd Example. It is a figure which shows the required CNR characteristic which satisfy | fills frame misdetection rate = 1% in this 1st Example and 2nd Example. It is a conceptual diagram which shows the burst structure of the system represented by Dynanet and PHS by a prior art. It is a functional block diagram which shows the reception synchronous process of a 1st conventional system. It is a conceptual diagram which shows the burst structure of a 2nd conventional system. It is a functional block diagram which shows the reception synchronous process of a 2nd conventional system. It is a block diagram which shows the structure of the radio | wireless receiver using a 3rd conventional system. It is a block diagram which shows the structure of the frame detection circuit 305 in the radio | wireless receiver using a 3rd conventional system.

Explanation of symbols

Reference Signs List 101 symbol generation circuit 102 training symbol generation circuit 103 multiplexing circuit 104 transmission filter 105 D / A conversion circuit 201 synchronous code sequence generation circuit 202 differential encoding circuit 301 A / D converter 302 reception filter 503 frame symbol timing detection circuit 504 Frame symbol timing synchronization circuit 505 Information symbol identification circuit 601 Training symbol part sample extraction circuit 602 Ns sample delay circuit 603 Complex conjugate multiplication circuit 604 1 / Ns downsampling circuit 605 Training symbol generation circuit 606 1 symbol differential decoding circuit 607 Cross correlation calculation circuit 608 Correlation peak detection circuit 701 Training symbol part sample extraction circuit 702-1 to 702-K 1 to K × Ns sample delay circuit 70 3-1 to 703-K Complex conjugate multiplication circuit 704-1 to 704-K 1 / Ns downsampling circuit 705 Training symbol generation circuit 706-1 to 706-K 1 to K symbol differential decoding circuit 707-1 to 707 -K Cross correlation calculation circuit 708 Phase compensation circuit 709 Summation circuit 710 Correlation peak detection circuit 711 Carrier frequency estimation circuit

Claims (8)

In a radio receiver that receives a radio burst signal composed of a training symbol and an information symbol, using a differentially encoded synchronous code sequence as a training symbol,
Frame symbol timing detection means for detecting frame symbol timing from an oversampled received burst signal sequence using a training symbol sequence included in the radio burst signal;
Frame symbol timing synchronization means for extracting a received burst symbol sequence based on the frame symbol timing detected by the frame symbol timing detection means;
Symbol identifying means for extracting a received information symbol sequence from the received burst symbol sequence extracted by the frame / symbol timing synchronizing means and performing symbol identification;
The frame symbol timing detection means includes:
Training symbol part sample extracting means for outputting a received signal sample corresponding to the training symbol section for each input sample;
N delay means for outputting the received training symbol part signal samples output from the training symbol part sample extracting means with a sample time delay equivalent to 1 to n (n is an integer of 1 or more) symbol time;
A received training symbol part sample is obtained by performing complex conjugate multiplication of the received training symbol part signal sample series output from the training symbol part sample extracting means and the received training symbol part signal sample series output from the n delay means. N complex conjugate multiplier means for performing 1-n symbol time differential decoding of each of the sequences;
N down-sampling means for down-sampling the training symbol portion signal samples output from the n complex conjugate multiplication means and extracting a differentially decoded received training symbol sequence;
Training symbol generation means for generating a known training symbol sequence;
N differential decoding means for performing 1 to n symbol time differential decoding of the training symbol series output from the training symbol generating means;
N cross-correlation value calculating means for calculating a cross-correlation value between the differentially decoded received training symbol sequence and the differentially-decoded known training symbol sequence, and outputting each input sample;
Correlation peak detection means for detecting, as a frame symbol timing position, a sample position at which the cross correlation value is maximum based on n cross correlation values output from the n cross correlation value calculation means. A wireless receiver characterized by the above. The frame symbol timing detection means includes :
Over the previous SL n number of cross-correlation values of n of the cross-correlation values output from the calculation means, and phase compensating means for performing phase compensation corresponding to each symbol delay time,
A summing means for calculating a sum of n phase-compensated cross-correlation values output from the phase compensation means ;
The correlation peak detection means, radio receiving apparatus according to claim 1, wherein the cross-correlation value from said summing means and wherein the benzalkonium detecting the sample position with the maximum as the frame symbol timing position. The frame symbol timing detection means includes:
In addition, the carrier frequency is estimated,
The frame symbol timing synchronization means includes:
In addition, carrier frequency synchronization
The correlation peak detecting means includes
Further, the carrier frequency is estimated from the phase component of the cross-correlation value of the frame symbol timing position,
The frame symbol timing synchronization means includes:
Radio receiving apparatus according to claim 1 further characterized by performing the carrier frequency synchronization. The frame symbol timing detection means includes:
In addition, the carrier frequency is estimated,
The frame symbol timing synchronization means includes:
In addition, carrier frequency synchronization
The correlation peak detecting means includes
Further, by using a part or all of the cross-correlation value before summation of the frame symbol timing position, the carrier frequency is estimated from the phase component,
The frame symbol timing synchronization means includes:
3. The radio receiving apparatus according to claim 2 , wherein not only frame symbol timing but also carrier frequency synchronization is performed. In a radio receiving method for receiving a radio burst signal composed of a training symbol and an information symbol, using a differentially encoded synchronous code sequence as a training symbol,
A frame symbol timing detection step for detecting a frame symbol timing from an oversampled received burst signal sequence using a known training symbol sequence included in the radio burst signal;
A frame symbol timing synchronization step for extracting a received burst symbol sequence based on the frame symbol timing detected in the frame symbol timing detection step;
A symbol identifying step of extracting a received information symbol sequence from the received burst symbol sequence extracted in the frame symbol timing synchronization step and performing symbol identification;
In the frame symbol timing detection step,
A training symbol portion sample extraction step for outputting a received signal sample corresponding to the training symbol section for each input sample;
N delay steps for outputting the received training symbol portion signal samples output in the training symbol portion sample extraction step with a sample time delay equivalent to 1 to n (n is an integer of 1 or more) symbol time;
A received training symbol part sample is obtained by performing complex conjugate multiplication of the received training symbol part signal sample sequence output in the training symbol part sample extraction step and the received training symbol part signal sample sequence output in the n delay steps. N complex conjugate multiplication steps for 1-n symbol time differential decoding of each of the sequences;
Down-sampling steps of down-sampling the training symbol part signal samples output in the n-time complex conjugate multiplication steps to extract a differentially decoded received training symbol sequence;
A training symbol generation step for generating a known training symbol sequence;
N differential decoding steps for performing 1-n symbol time differential decoding of the training symbol sequence output in the training extraction step;
N cross-correlation value calculating steps for calculating a cross-correlation value between the differentially decoded received training symbol sequence and the differentially-decoded known training symbol sequence, and outputting each input sample;
A correlation peak detection step of detecting, as a frame symbol timing position, a sample position where the cross-correlation value is maximum based on the n cross-correlation values output in the n-time cross-correlation value calculation step. A wireless reception method characterized by the above. In the frame symbol timing detection step ,
For n-number of cross-correlation values output before Symbol n times of the cross-correlation value calculation step, the phase compensation step of performing phase compensation corresponding to each symbol delay time,
A summation step of calculating a sum of the n phase-compensated cross-correlation values output in the phase compensation step ,
Wherein in the correlation peak detection step, the radio receiving method according to claim 5, wherein said cross-correlation value in said summing step and said and Turkey detecting the sample position with the maximum as the frame symbol timing position. In the frame symbol timing detection step,
In addition, the carrier frequency is estimated,
In the frame symbol timing synchronization step,
In addition, carrier frequency synchronization
In the correlation peak detecting means step,
Further, the carrier frequency is estimated from the phase component of the cross-correlation value of the frame symbol timing position,
In the frame symbol timing synchronization means step,
6. The radio reception method according to claim 5, further comprising performing carrier frequency synchronization. In the frame symbol timing detection step,
In addition, the carrier frequency is estimated,
In the frame symbol timing synchronization step,
In addition, carrier frequency synchronization
In the correlation peak detecting means step,
Further, by using a part or all of the cross-correlation value before summation of the frame symbol timing position, the carrier frequency is estimated from the phase component,
In the frame symbol timing synchronization means step,
7. The radio reception method according to claim 6 , wherein not only frame symbol timing but also carrier frequency synchronization is performed.

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