WO2008083605A1 - Procédé et dispositif pour transmettre/recevoir un signal de préambule basé sur un multiplexage par répartition orthogonale de la fréquence (ofdm) - Google Patents

Procédé et dispositif pour transmettre/recevoir un signal de préambule basé sur un multiplexage par répartition orthogonale de la fréquence (ofdm) Download PDF

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Publication number
WO2008083605A1
WO2008083605A1 PCT/CN2007/071398 CN2007071398W WO2008083605A1 WO 2008083605 A1 WO2008083605 A1 WO 2008083605A1 CN 2007071398 W CN2007071398 W CN 2007071398W WO 2008083605 A1 WO2008083605 A1 WO 2008083605A1
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Prior art keywords
signal
code sequence
ofdm
signal code
information
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PCT/CN2007/071398
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English (en)
Chinese (zh)
Inventor
Bin Li
Lixia Xue
Yi Luo
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Huawei Technologies Co., Ltd.
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Application filed by Huawei Technologies Co., Ltd. filed Critical Huawei Technologies Co., Ltd.
Publication of WO2008083605A1 publication Critical patent/WO2008083605A1/fr

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    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L27/00—Modulated-carrier systems
    • H04L27/26—Systems using multi-frequency codes
    • H04L27/2601—Multicarrier modulation systems
    • H04L27/2602—Signal structure
    • H04L27/261—Details of reference signals
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L5/00—Arrangements affording multiple use of the transmission path
    • H04L5/02—Channels characterised by the type of signal
    • H04L5/023—Multiplexing of multicarrier modulation signals

Definitions

  • the present invention relates to the field of wireless communications, and more particularly to an OFDM based communication technology.
  • OFDM divides the spectrum into a number of sub-carriers, each of which is modulated with a lower data rate.
  • IDFT/DFT is implemented by Inverse Fast Fourier Transform (IFFT) and Fast Fourier Transform (FFT).
  • IFFT Inverse Fast Fourier Transform
  • FFT Fast Fourier Transform
  • PLD Programmable Logic Device
  • DSP Digital Signal Processor
  • orthogonal code sequences need to be modulated as information bits. Transmission on OFDM symbols.
  • the prefix of the superframe in the forward physical channel of the 3rd Generation Partnership Project 2 (“3GPP2") Air Interface Evolution (“AIE") needs to be based on the orthogonal code.
  • the sequence is modulated and transmitted on OFDM symbols.
  • the orthogonal code sequence includes a Walsh code sequence, a DFT code sequence, and the like.
  • the forward physical channel of the 3GPP2 AIE is composed of superframes, and each superframe has a preamble (prefix) for performing forward synchronization acquisition, identifying cells, broadcasting system parameters, and the like.
  • the Preamble is composed of 8 OFDM symbols, and the last 3 OFDM symbols are called TDM1, TDM2, and TDM3.
  • TDM1 is used to transmit synchronization acquisition and frequency offset estimation sequences.
  • TDM2, TDM3 transmits Walsh code sequence
  • TDM2 is used to transmit sector identification information
  • TDM3 is used to transmit system information
  • F-OSICH information is carried at the same time for power control.
  • the transmitting end uses 512-point DFT and 512-point IFFT
  • the transmitted signal is a time domain signal. Therefore, the receiving end needs to process all possible multipath signals in time domain. As shown in FIG. 2, the receiving end needs to All received time domain signals are subjected to multiple correlation detections, and the sequence of the transmitted Walsh codes is determined according to the maximum correlation peak thereof, thereby identifying different cells and obtaining related system parameter information.
  • the complexity of time domain processing results in very high complexity for the receiver.
  • the guard band frequency of the Walsh code sequence after DFT transformation will be intercepted, which affects the frequency domain integrity of the Walsh code, and the performance of the receiving end detection is greatly reduced.
  • Embodiments of the present invention provide a method and a device for transmitting and receiving a prefix signal based on OFDM, so that the complexity of the receiver is greatly reduced.
  • An embodiment of the present invention provides an OFDM-based prefix signal sending method, including the steps of: mapping partial prefix information in a forward physical channel into a signal code sequence, and mapping the signal code sequence as a frequency domain signal to an OFDM symbol. On the subcarrier, it is transmitted after OFDM modulation.
  • An embodiment of the present invention further provides an OFDM-based prefix signal receiving method, including the following steps: when receiving partial prefix information in a forward physical channel, performing OFDM demodulation on the received signal, and demodulating the received signal.
  • the signal is correlated with various possible signal code sequences, and the information corresponding to the most relevant signal code sequence is used as the information transmitted by the transmitting end.
  • An embodiment of the present invention further provides an OFDM-based prefix signal sending apparatus, including: a unit for mapping partial prefix information in a forward physical channel into a signal code sequence; and using the signal code sequence as a frequency domain The signal is mapped to a unit on a subcarrier of the OFDM symbol; a unit for performing OFDM modulation on the signal mapped to the OFDM symbol subcarrier.
  • An embodiment of the present invention further provides an OFDM-based prefix signal receiving apparatus, including: a unit for performing OFDM demodulation on the received signal when receiving partial prefix information in a forward physical channel; And a unit for performing correlation detection on the demodulated signal and various possible signal code sequences; and information for using the signal code sequence with the highest degree of correlation obtained by the correlation detection as a unit of information transmitted by the transmitting end.
  • an OFDM-based prefix signal receiving apparatus including: a unit for performing OFDM demodulation on the received signal when receiving partial prefix information in a forward physical channel; And a unit for performing correlation detection on the demodulated signal and various possible signal code sequences; and information for using the signal code sequence with the highest degree of correlation obtained by the correlation detection as a unit of information transmitted by the transmitting end.
  • the partial prefix information in the forward physical channel is mapped to a signal code sequence, and the signal code sequence is mapped as a frequency domain signal to a subcarrier of the OFDM symbol, and modulated by OFDM.
  • the receiving end When receiving the partial prefix information in the forward physical channel, the receiving end performs OFDM demodulation on the received signal, and performs correlation detection on the demodulated signal and various possible signal code sequences, and the signal code with the highest correlation degree is obtained.
  • the information corresponding to the sequence is used as information transmitted by the transmitting end. Since the demodulated frequency domain information is detected at the receiving end, it is not necessary to separately detect all possible multipath signals, so that the complexity of the receiver is greatly reduced.
  • FIG. 3 is a flowchart of a transmitting end in an OFDM-based prefix signal transmitting and receiving method according to a first embodiment of the present invention
  • FIG. 4 is a schematic diagram of a first mapping manner of a transmitting end in an OFDM-based prefix signal transmitting and receiving method according to a first embodiment of the present invention
  • FIG. 5 is a schematic diagram of a second mapping manner of a transmitting end in an OFDM-based prefix signal transmitting and receiving method according to a first embodiment of the present invention
  • FIG. 6 is a schematic diagram of a third mapping manner of a transmitting end in an OFDM-based prefix signal transmitting and receiving method according to a first embodiment of the present invention
  • FIG. 7 is a schematic diagram of a fourth mapping manner of a transmitting end in an OFDM-based prefix signal transmitting and receiving method according to a first embodiment of the present invention
  • FIG. 8 is a flowchart of a receiving end in an OFDM-based prefix signal transmitting and receiving method according to a first embodiment of the present invention
  • FIG. 9 is a flowchart of a receiving end in an OFDM-based prefix signal transmitting and receiving method according to a second embodiment of the present invention.
  • FIG. 10 is a schematic diagram of a mapping manner of a transmitting end in an OFDM-based prefix signal transmitting and receiving method according to a third embodiment of the present invention.
  • FIG. 11 is a flowchart of a transmitting end in an OFDM-based prefix signal transmitting and receiving method according to a fourth embodiment of the present invention.
  • FIG. 12 is a schematic diagram of a first mapping manner of a transmitting end in an OFDM-based prefix signal transmitting and receiving method according to a fourth embodiment of the present invention.
  • FIG. 13 is a schematic diagram of a second mapping manner of a transmitting end in an OFDM-based prefix signal transmitting and receiving method according to a fourth embodiment of the present invention.
  • FIG. 14 is a schematic diagram of a third mapping manner of a transmitting end in an OFDM-based prefix signal transmitting and receiving method according to a fourth embodiment of the present invention.
  • Figure 15 is a flowchart of a receiving end in an OFDM-based prefix signal transmitting and receiving method according to a fourth embodiment of the present invention.
  • the partial prefix information in the forward physical channel is mapped into a signal code sequence, and the signal code sequence is mapped as a frequency domain signal to a subcarrier of the OFDM symbol, and is transmitted after being modulated by OFDM.
  • the receiving end performs OFDM demodulation on the received signal, and performs correlation detection on the demodulated signal and various possible signal code sequences, and the signal code with the highest correlation degree is obtained.
  • the information corresponding to the sequence is used as information transmitted by the transmitting end. Since the receiving end detects the demodulated frequency domain information, it is not necessary to separately detect all possible multipath signals, so that the complexity of the receiver is greatly reduced.
  • a first embodiment of the present invention relates to an OFDM-based prefix signal transmission and reception method.
  • the transmitting end maps the information to be transmitted, such as TDM2 and/or TDM3 in the prefix of the forward physical channel, to a Walsh orthogonal code sequence of length 512.
  • the Walsh orthogonal code sequence obtained by the mapping is interleaved by the interleaver.
  • the Walsh code sequence is regular, and the existence of multipath fading will destroy the inherent properties of the Walsh code (such as orthogonality).
  • the protection subcarrier continuously cuts off some Walsh codes, which will destroy some important characteristics of the Walsh code (such as decreased correlation performance and reduced correlation peak), so that it cannot be correctly recognized by the receiving end.
  • the interleaved code sequence is mapped onto the subcarriers of the OFDM symbol, and the code sequence on the subcarrier and/or the zero frequency partial subcarrier serving as the guard band is set to zero.
  • the DFT transform is not performed on the code sequence, so that the demodulated frequency domain information can be directly detected at the receiving end, and it is not necessary to separately detect all possible multipath signals, thereby greatly reducing the receiver of the receiving end. the complexity.
  • step 340 the code sequence after the zero is subjected to OFDM modulation, and then transmitted through the antenna.
  • the receiving end performs OFDM demodulation on the received signal to obtain a signal on the subcarrier transmitting the information of the transmitting end.
  • step 820 in order to prevent the noise signal on the sub-carrier corresponding to the guard band and the zero-frequency portion from interfering with the subsequent detection, the signals on the sub-carrier and the zero-frequency partial sub-carrier used as the guard band are set to zero, Improve the accuracy of the test.
  • step 830 all possible 9-bit codes are generated by the sequence generator, and 512-bit Walsh code mapping is performed thereon.
  • step 840 the Walsh code sequences obtained by the mapping are interleaved. This interleaving is the same as the sender.
  • the signals after the zeroing of the interleaved Walsh code sequences are correlated. It can be divided into 4 blocks for correlation detection.
  • the received signal is not subjected to IDFT conversion, so that the demodulated frequency domain information can be directly detected at the receiving end, and it is not necessary to separately detect all possible multipath signals, thereby greatly reducing the receiver. The complexity.
  • step 860 the Walsh code sequence with the highest degree of correlation is selected, and the information corresponding to the Walsh code sequence is used as information transmitted by the transmitting end.
  • the subcarrier and the zero used as the guard band in order to prevent the noise signal on the subcarrier corresponding to the guard band and the zero frequency portion from interfering with the subsequent detection, among the received signals, the subcarrier and the zero used as the guard band.
  • the signal on the frequency partial subcarrier is set to zero; or, in each Walsh code sequence used for correlation detection, the partial code sequence corresponding to the subcarrier and/or the zero frequency partial subcarrier used as the guard band is set to Zero, correlation detection of the signal by the Walsh code sequence after zeroing.
  • the second embodiment of the present invention also relates to an OFDM-based prefix signal transmission and reception method, the transmitting end of which is the same as that of the first embodiment, and the receiving end in the present embodiment is as shown in FIG.
  • the receiving end performs OFDM demodulation on the received signal to obtain a signal on the subcarrier transmitting the information of the transmitting end.
  • step 920 the demodulated signal is deinterleaved.
  • step 930 in order to prevent the noise signal on the sub-carrier corresponding to the guard band and the zero-frequency portion from interfering with the subsequent detection, the signals on the sub-carrier and the zero-frequency partial sub-carrier used as the guard band are set to zero, Improve the accuracy of the test afterwards.
  • step 940 the signal after zeroing is correlated with various possible Walsh code sequences.
  • step 950 the Walsh code sequence with the highest degree of correlation is selected, and the information corresponding to the Walsh code sequence is used as the information transmitted by the transmitting end.
  • the third embodiment of the present invention also relates to an OFDM-based prefix signal transmission and reception method, which is substantially the same as the first and second embodiments, except that in the first second embodiment, the code sequences corresponding to TDM2 and TDM3 are mapped together.
  • the code sequences corresponding to TDM2 and TDM3 are respectively mapped on 512 subcarriers of one OFDM symbol, and the code sequence corresponding to TDM2 is mapped to the second OFDM.
  • the code sequence corresponding to TDM3 is mapped on 512 subcarriers of the 8th OFDM symbol, as shown in FIG. 10, which has good compatibility with the prior art.
  • the fourth embodiment of the present invention also relates to an OFDM-based prefix signal transmission and reception method, as shown in Fig. 11 at the transmitting end.
  • step 1110 for the 9-bit information (TDM2 or TDM3, the primary transmission system parameter) to be transmitted, it is divided into the first half and the second half, the first half being n bits and the second half being m bits.
  • the scrambling mode is selected according to m bits, and there are 2 m scrambling modes in total.
  • step 1140 the mapped Walsh code sequence is subjected to force interference by the m-bit selected force perturbation mode.
  • the scrambled code sequence is interleaved.
  • the Walsh code sequence is regular. Due to the existence of multipath fading, the inherent characteristics of the Walsh code (such as orthogonality) will be destroyed. At the same time, the protection subcarrier continuously intercepts part of the Walsh code, which will destroy some important characteristics of the Walsh code (such as related performance degradation, correlation peak reduction), and thus cannot be correctly recognized by the receiving end. Interleaving the code sequence to be transmitted makes the effects of multipath fading and guard subcarriers uniform, so that even if the frequency domain signal of the guard band or the zero frequency part is lost, it is only equivalent to introducing some noise, which does not cause the receiver to completely fail. Identify and improve the performance of signal code detection.
  • the interleaved code sequence is mapped onto the subcarriers of the OFDM symbol, and the code sequence on the subcarrier and/or the zero frequency partial subcarrier serving as the guard band is set to zero.
  • step 1170 the code sequence after the zero is subjected to OFDM modulation, and then transmitted through the antenna.
  • the DFT transform is not performed on the code sequence, so that the demodulated frequency domain information can be directly detected at the receiving end, and it is not necessary to separately detect all possible multipath signals, thereby greatly reducing the receiver of the receiving end. the complexity.
  • the transmitting end divides the 9-bit information to be transmitted into the first 8 bits and the last 1 bit, performs 256-bit Walsh code mapping on the 8-bit information, selects the scrambling mode according to the last 1 bit, and selects the scrambling mode according to the 1 bit.
  • the orthogonal sequence obtained by mapping the 8-bit information is scrambled, and the scrambled code sequence is interleaved, and then mapped to subcarriers of two OFDM symbols. For 256 code sequences obtained by interleaving TDM2 or TDM3 information, there are many ways to map.
  • the code sequences corresponding to TDM2 and TDM3 are respectively mapped on 128 subcarriers of 2 OFDM symbols, and are repeatedly placed twice at corresponding time-frequency resource locations, and the code sequences corresponding to TDM2 and TDM3 can be interleaved and repeatedly mapped to 512 sub-carriers.
  • the code sequence corresponding to TDM2 may be repeatedly mapped on the middle 256 subcarriers to reduce the influence of the guard band, and the code sequence mapping corresponding to TDM3 is repeatedly mapped on the externally measured 256 subcarriers.
  • the 256 symbols obtained by interleaving TDM2 or TDM3 may also be repeatedly mapped to 512 subcarriers of one corresponding OFDM symbol, as shown in FIG.
  • An embodiment is the same.
  • the invention includes, but is not limited to, these mapping methods. Then, the code sequence on the protection subcarrier and the subcarrier corresponding to the zero frequency is zeroed, because the code sequence obtained by the mapping is repeatedly transmitted, thereby weakening the influence of the guard band on it. After the zeroed code sequence is OFDM modulated, it is sent through the antenna Go out.
  • step 1510 the received signal is subjected to OFDM demodulation to obtain a signal on the subcarrier transmitting the information of the transmitting end.
  • step 1520 in order to prevent the noise signal on the sub-carrier corresponding to the guard band and the zero-frequency portion from interfering with the subsequent detection, the signals on the sub-carrier and the zero-frequency partial sub-carrier used as the guard band are set to zero, Improve the accuracy of the test afterwards.
  • step 1530 the signal after the zero is deinterleaved.
  • the deinterleaved signal is descrambled according to all possible scrambling modes of the transmitting end.
  • step 1550 correlation detection is performed on the descrambled signals in various possible Walsh code sequences. Since the IDFT transform is not required at the receiving end to directly detect the frequency domain information, it is not necessary to separately detect all possible multipath signals, so that the complexity of the receiver is greatly reduced.
  • step 1560 selecting the Walsh code sequence with the highest degree of correlation, and using the information corresponding to the Walsh code sequence as the information transmitted by the transmitting end portion (ie, the first n bits of information), according to the corresponding Walsh code sequence with the highest degree of correlation.
  • the method of scrambling obtains the information transmitted by the remaining part of the transmitting end (ie, the last m bits of information). In this way, more information can be transmitted through the same resource, and resource utilization is greatly improved without degrading system performance.
  • the receiving end After receiving the OFDM signal, the receiving end obtains the signal of the subcarrier transmitting the information of the transmitting end. Because the guard band and the subcarrier corresponding to the zero frequency have interference, in order to improve the accuracy of the detection, the corresponding position is set to zero. Then, the signal after zeroing is deinterleaved, and the deinterleaved signal is descrambled according to all possible scrambling modes (2 types in total), and the descrambled sequences are respectively associated with all possible Walsh codes.
  • Correlation is performed, and the 8-bit information transmitted by the transmitting end is obtained according to the Walsh code with the highest degree of correlation, and the information of the remaining 1 bit of the channel is obtained according to the scrambling code method corresponding to the Walsh code sequence with the highest degree of correlation.
  • the interpolating method is directly selected by the m-bit at the transmitting end, and the Walsh code sequence mapped by the n-bit information is interleaved by the selected interleaving method, and the interleaved code sequence is mapped onto the sub-carriers of the OFDM symbol.
  • the zeroed signal is opposite.
  • the number is deinterleaved, and all signals after deinterleaving are correlatedly detected, and the partially transmitted information (first n bits) of the transmitting end is obtained according to the Walsh code sequence with the highest degree of correlation, according to the Walsh code sequence with the highest degree of correlation.
  • the interleaving method obtains the information (the last m bits) transmitted by the rest of the transmitting side.
  • the receiving end may also interleave or scramble various possible Walsh code sequences according to all possible interleaving or scrambling modes of the transmitting end, and perform interleaving or scrambling of each Walsh code sequence pair.
  • the demodulated signal is correlated, and the partially transmitted information of the transmitting end is obtained according to the Walsh code sequence with the highest degree of correlation, and the remaining part of the transmitting end is obtained according to the interleaving or scrambling method corresponding to the Walsh code sequence with the highest degree of correlation.
  • Information is also interleave or scramble various possible Walsh code sequences according to all possible interleaving or scrambling modes of the transmitting end, and perform interleaving or scrambling of each Walsh code sequence pair.
  • a fifth embodiment of the present invention relates to an OFDM-based prefix signal transmitting apparatus, including: a unit that maps partial prefix information into a signal code sequence; and maps the signal code sequence as a frequency domain signal to a unit on a subcarrier of an OFDM symbol A unit that transmits OFDM after subcarriers of OFDM symbols.
  • the signal code sequence therein may be an orthogonal code sequence, such as a Walsh code sequence.
  • the partial prefix information is TDM2 and/or TDM3 in the prefix of the forward physical channel.
  • the received signal is not required to be DFT-transformed, so that the demodulated frequency domain information can be directly detected at the receiving end, and it is not necessary to separately detect all possible multipath signals, thereby greatly reducing the receiver.
  • the complexity is not required to be DFT-transformed, so that the demodulated frequency domain information can be directly detected at the receiving end, and it is not necessary to separately detect all possible multipath signals, thereby greatly reducing the receiver. The complexity.
  • the signal transmitting apparatus further includes: a unit that interleaves the sequence of signal codes to be transmitted; a unit that maps the interleaved signal code sequence to subcarriers of the OFDM symbol; a subcarrier and/or a zero frequency portion that will be used as a guard band A unit in which the signal code sequence on the subcarrier is set to zero.
  • the sequence of signal codes is regular, and due to the presence of multipath fading, the inherent characteristics of the signal code (such as orthogonality) will be destroyed.
  • the protection subcarrier continuously cuts off part of the transmitted signal code, which will destroy some important characteristics of the transmitted signal code (such as related performance degradation, correlation peak reduction), and thus cannot be correctly recognized by the receiving end.
  • the interleaving of the signal codes to be transmitted makes the effects of multipath fading and guard subcarriers uniform, so that even if the frequency domain signal of the guard band or the zero frequency portion is lost, it is only equivalent to introducing some noise, which does not cause the receiving end to completely fail. Identify and improve the performance of signal code detection.
  • the method may further include: dividing the partial prefix information to be transmitted into two units of n and m bits; mapping the n-bit portion into a unit of the signal code sequence; and selecting, in the manner of interleaving or scrambling, the unit of the m-bit portion; Interleaving or scrambling the signal code sequence by interleaving or scrambling Unit; mapping the interleaved or scrambled signal code sequence to a unit on a subcarrier of the OFDM symbol.
  • a sixth embodiment of the present invention relates to an OFDM-based prefix signal receiving apparatus, including: a unit for performing OFDM demodulation on a received signal when receiving partial prefix information in a forward physical channel; and demodulating the signal
  • a unit for performing correlation detection with various possible signal code sequences and information corresponding to the signal code sequence having the highest degree of correlation obtained by correlation detection is used as a unit of information transmitted by the transmitting end.
  • the signal code sequence is an orthogonal code sequence, such as a Walsh code sequence.
  • the partial prefix information is TDM2 and TDM3 in the prefix of the forward physical channel.
  • the signal receiving apparatus further includes: means for deinterleaving the demodulated signal; means for performing correlation detection on the deinterleaved signal; or comprising: means for interleaving various possible signal code sequences; The subsequent units of the signal code sequence perform correlation detection.
  • the signal receiving apparatus may further include: a unit that sets a partial signal corresponding to a subcarrier used as a guard band and/or a subcarrier of a zero frequency portion to zero in the received OFDM signal; correlating the signal after the zero is set a unit of detection; or comprising: a unit that sets a partial code sequence corresponding to a subcarrier used as a guard band and/or a subcarrier of a zero frequency portion to zero among various possible signal code sequences; A unit of signal code sequence for correlation detection.
  • the signal receiving apparatus may further include: a unit that deinterleaves or descrambles the demodulated signal according to all possible interleaving or scrambling modes of the transmitting end; and a unit that performs correlation detection on all signals after deinterleaving or descrambling Or, a unit that interleaves or scrambles various possible signal code sequences according to all possible interleaving or scrambling methods at the transmitting end; correlates the demodulated signals by interleaving or scrambled signal code sequences a unit for detecting; and comprising: a unit for obtaining information of a partial transmission of the transmitting end according to a signal code sequence with the highest degree of correlation after the correlation; and obtaining an excess of the transmitting end according to an interleaving or scrambling method corresponding to the signal code sequence having the highest correlation degree A unit of partially transmitted information. This enables more information to be transmitted through the same resources, greatly improving resource utilization without degrading system performance.
  • part of the prefix information in the forward physical channel is mapped into a signal code sequence, and the signal code sequence is mapped as a frequency domain signal to subcarriers of the OFDM symbol. , transmitted after OFDM modulation.
  • the receiving end performs OFDM demodulation on the received signal, and the demodulated signal and various possibilities
  • the signal code sequence performs correlation detection, and the information corresponding to the signal code sequence with the highest degree of correlation is used as the information transmitted by the transmitting end. Since the demodulated frequency domain information is detected at the receiving end, it is not necessary to separately detect all possible multipath signals, so that the complexity of the receiver is greatly reduced.
  • the signal code sequence to be transmitted is interleaved, and the interleaved signal code sequence is mapped onto the subcarriers of the OFDM symbol; the signal code sequence on the subcarrier and/or the zero frequency partial subcarrier used as the guard band is set to zero.
  • the signal code is usually regular, and due to the presence of multipath fading, it will destroy the inherent characteristics of the signal (such as orthogonality).
  • the protection subcarrier continuously cuts off part of the transmitted signal, which will destroy some important characteristics of the transmitted signal (such as the related performance degradation, the correlation peak is reduced), so that it cannot be correctly recognized by the receiving end.
  • the interleaving of the signal codes to be transmitted makes the effects of multipath fading and guard subcarriers uniform, so that even if the frequency domain signal of the guard band or the zero frequency portion is lost, it is only equivalent to introducing some noise, which does not cause the receiving end to completely fail. Identify and improve the performance of signal code detection.
  • the partial prefix information to be transmitted is divided into two parts of n and m bits, the n-bit part is mapped into a signal code sequence, and the interleaving or scrambling mode is selected according to the m-bit part; according to the selected interleaving or adding
  • the scrambling method interleaves or scrambles the signal code sequence, and maps the interleaved or scrambled signal code sequence to the subcarriers of the OFDM symbol.
  • the number sequence obtains the partial transmission information of the transmitting end, and the information transmitted by the remaining part of the transmitting end is obtained according to the interleaving or scrambling method corresponding to the most relevant signal code sequence. This enables more information to be transmitted through the same resources, greatly improving resource utilization without degrading system performance.
  • the signal code sequence mapped by the partial prefix information in the forward physical channel is directly mapped to the subcarrier of the OFDM symbol as the frequency domain signal, and then received.
  • the terminal can perform correlation detection on the demodulated frequency domain information, and does not need to detect all possible multipath signals separately, thus greatly reducing the complexity of the receiver.
  • the influence of the protection subcarrier is overcome, and the characteristics of the OFDM system are utilized to enhance the transmission performance under the multipath channel.
  • the signal code sequence to be transmitted is interleaved, and the interleaved signal code sequence is mapped to subcarriers of the OFDM symbol; the signal code sequence on the subcarrier and/or the zero frequency partial subcarrier used as the guard band is set to zero.
  • the signal code is usually regular, due to the existence of multipath fading, Destroy the inherent characteristics of the signal (such as orthogonality).
  • the protection subcarrier continuously cuts off part of the transmitted signal, which will destroy some important characteristics of the transmitted signal (such as related performance degradation, correlation peak reduction), so that it cannot be correctly recognized by the receiving end.
  • the interleaving of the signal codes to be transmitted makes the effects of multipath fading and guard subcarriers uniform, so that even if the frequency domain signal of the guard band or the zero frequency portion is lost, it is only equivalent to introducing some noise, which does not cause the receiving end to completely fail. Identify and improve the performance of signal code detection.
  • the partial prefix information to be transmitted is divided into two parts of n and m bits, the n-bit part is mapped into a signal code sequence, and the interleaving or scrambling mode is selected according to the m-bit part; according to the selected interlacing Or scrambling the signal code sequence to interleave or scramble, and map the interleaved or scrambled signal code sequence to the subcarriers of the OFDM symbol.
  • the number sequence obtains the information of the partial transmission of the transmitting end, and obtains the information transmitted by the remaining part of the transmitting end according to the interleaving or scrambling manner corresponding to the signal code sequence with the highest degree of correlation. This enables more information to be transmitted through the same resources, greatly improving resource utilization without degrading system performance.

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Abstract

L'invention concerne un procédé et un dispositif pour transmettre/recevoir un signal de préambule sur la base d'un système de communication par multiplexage par répartition orthogonale de la fréquence (OFDM). Le procédé comprend les opérations consistant à : du côté transmission, mapper une partie des informations de préambule dans FPCH (canal physique aller) à la séquence de code de signal, mapper la séquence de code de signal sous forme de signal de domaine fréquentiel sur une sous-porteuse d'un symbole OFDM, et la transmettre après modulation OFDM. Du côté réception, lors de la réception des informations de préambule dans le FPCH, démoduler par OFDM le signal reçu, effectuer la détection de corrélation entre le signal démodulé et les diverses séquences de code de signal possibles, les informations correspondant à la séquence de code de signal ayant le plus de corrélation étant les informations transmises par le côté transmission.
PCT/CN2007/071398 2006-12-31 2007-12-29 Procédé et dispositif pour transmettre/recevoir un signal de préambule basé sur un multiplexage par répartition orthogonale de la fréquence (ofdm) WO2008083605A1 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
CN200610063879.X 2006-12-31
CN200610063879XA CN101212437B (zh) 2006-12-31 2006-12-31 基于ofdm的前缀信号收发方法及设备

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WO2008083605A1 true WO2008083605A1 (fr) 2008-07-17

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CN106878221B (zh) * 2015-12-14 2021-08-06 中兴通讯股份有限公司 一种多载波信号的生成方法和装置
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