47results about How to "Improve anti-fading performance" patented technology

The invention discloses a short-wave multi-antenna signal enhancement receiving method. The method comprises the following steps: firstly, adding cyclical redundancy check (CRC) bits for sent information bits at a sending end, forming a data block through modulation after channel coding and interleaving processing, and adding a synchronous sequence for a receiving end to extract timing synchronous information before the data block is sent; adopting multi-antenna receiving when the receiving end receives signals, utilizing received signals to extract the synchronous information, simultaneously carrying out channel estimation, and estimating corresponding channel parameters for demodulation processing; after carrying out one-by-one antenna demodulation or one-by-one path demodulation on multi-path signals received from different antennas, and carrying out diversity combination; using parallel data after diversity combination to solve a soft bit value, after deinterlacing and decoding decision, obtaining all paths of data by sequential checking and decoding of CRC, and when checking that certain path of data is correct, stopping checking, and simultaneously outputting the path of data. By utilizing the short-wave multi-antenna signal enhancement receiving method, the receiving performance of a short-wave fixed station is improved, and the anti-fading performance of the existing short-wave communication system is enhanced.

This invention discloses a distributed mutual transfer method and a system, in which, said method includes: a mutual node set transfers radio communication data of the mutual nodes to the objective node by the MIMU technology, said objective node receives and MIMU coding radio communication data from said mutual nodes, said system includes: a mutual node set and an objective node, in which, said mutual node set is composed of at least two mutual nodes and transfers radio communication data of the nodes to the objective node used in receiving and MIMU coding radio communication data from the mutual nodes.

The invention discloses a method for distributing RBGs (resource block groups) in an LTE (long term evolution). The method comprises the following steps that: RBGs in a time slot 1 and / or time slot 2 are distributed for a terminal sending CQI (channel quality indicator) information, according to the received CQI information and recorded RBG use conditions, and the RBG distribution result is compiled in DCI (downlink control information) in a new DCI form. The invention also discloses a device for distributing RBGs in the LTE. According to the invention, RBGs are respectively distributed for two time slots of a common frame according to the signal conditions of the two time slots in the common frame, so as to improve the anti-fading property of the LTE, thereby further enhancing the performance of the whole system.

The invention discloses a coal mine under-well ultra-wide band locating method and a coal mine under-well ultra-wide band locating system. The method comprises the following steps: by adopting a RAKE receiver technology, collecting multipath components in signals, and weighing the multipath components; performing non-line-of-sight identification on the signals by utilizing the constructed identification parameters, performing data reconstruction on the non-line-of-sight signals, and performing location calculation by adopting a Taylor sequence expansion method and utilizing the reconstructed data and line-of-sight signals. The system comprises a well-surface part and an under-well part. The well-surface part comprises a ground monitor terminal, a locating server, a central switch, a dynamic host configuration protocol server, and an upper layer terminal; the under-well part comprises an intrinsically safe gateway, an intrinsically safe direct current power supply, an intrinsically safe wireless relay station, an intrinsically safe reference point terminal and an intrinsically safe locating terminal. The ultra-wide band locating method and the ultra-wide band locating system are simple in structure, accurate in positioning and strong in anti-jamming ability, can effectively inhibit multipath effect and non-line-of-sight effect, and meet use requirements of the mine.

The invention discloses an OFDM-IM modulation method for transmission diversity, and mainly solves the problem that the bit-error performance is low in the prior art. The technical scheme comprises the following steps of: (1), performing OFDM-IM frequency-domain signal design of the transmission diversity, so that a frequency-domain signal is obtained; (2), performing OFDM modulation and block interleaving of the frequency-domain signal, so that a modulated signal is obtained; (3), transmitting the modulated signal in a channel, so that a received signal is obtained; (4), performing OFDM demodulation and de-interleaving of the received signal by a receiving end, so that a demodulated signal is obtained; (5), detecting the demodulated signal by the receiving end, so that an estimated signal is obtained; and (6), inversely mapping the estimated signal into bit information, so that a signal transmission process is completed. By means of the OFDM-IM modulation method disclosed by the invention, the transmission diversity gain can be obtained; compared with the traditional OFDM-IM, the OFDM-IM modulation method has relatively high anti-fading capability and better bit-error performance, and can be used for improving the error code performance of a wireless communication system; and thus, reliable transmission is realized.

The invention discloses an Alamouti encoding method based on collaborative constellation mapping, and mainly solves the problems of high block error and worse anti-fading capability of an Alamouti space time code. The method comprises the following steps: dividing the bit stream of a transmitting end into three groups, generating a modulation constellation to map three groups of bits, constructing and combining a collaborative modulation symbol to obtain a transmission symbol, using the Alamouti space time code to transmit the symbol, receiving signals within two symbol periods by a receiving end and constructing a composite receiving signal vector, calculating a zero forcing detection solution vector according to the composite receiving signal vector, using a maximum likelihood estimator to perform first layer judgment on the zero forcing detection solution vector, calculating an European style and performing second layer judgment, and finally performing constellation inverse mapping on the judged result and combining the result to obtain the bit stream. By means of collaborative constellation mapping mode, a better error block function is obtained, the anti-fading capability of the system is enhanced, the communication confidentiality is strengthened at the same time, and the method can be applied to a two-transmit-antenna and one-receive-antenna system.

The invention relates to an encryption algorithm of encryption OFDM (Orthogonal Frequency Division Multiplexing) based on discrete Hartley transform, and belongs to the technical fields of information communication and signal processing. Compared with the conventional OFDM system, an IFFT (Inverse Fast Fourier Transform) module which is necessary in an OFDM system is omitted, and the complexity of the system is reduced. At the same time, the diversity gain of frequency selectivity of the system is increased, and the anti-fading performance and the capacity of the system are improved.

A power control method of a multi-input multi-output space multiplexing mode is suitable for a broad band wireless orthogonal frequency division multiple access (FDMA) access system and comprises the following steps: firstly, adaptively modulating a code AMC; and then, calculating the number of ranks and conditions of a channel matrix, taking the number as the judgment basis of the strength and the weakness of the channel relativity of a plurality of received parallel data streams and respectively carrying out corresponding power adjustment according to the strength and the weakness of the channel relativity. The invention controls the power according to the strength and the weakness of the channel relativity of user channels with pertinence, especially the power control method provided by aiming at the strong channel relativity of the users can effectively prevent ineffective power control under an MIMO space multiplexing mode, thereby the anti-interference property and the anti-fading property of a system are enhanced.

The invention relates to an LTE transmission and coverage system for achieving FTTH based on the digital technology. The LTE transmission and coverage system for achieving FTTH based on the digital technology is characterized by comprising near-end equipment and far-end equipment, wherein the near-end equipment comprises a near-end duplexer / time slot switch switchover unit, an LTE near-end down link, an LET near-end up link and a near-end digital signal processing unit, the far-end equipment comprises a far-end digital signal processing unit, an LTE far-end down link, an LTE far-end up link and a far-end duplexer / time slot switch switchover unit, the near-end digital signal processing unit communicates with the far-end digital signal processing unit through optical fibers, the near-end equipment is further connected with an LTE signal source, and the far-end equipment is further connected with a transmit-receive antenna. The LTE transmission and coverage system for achieving FTTH based on the digital technology is stable in performance, high in antijamming performance, high in anti-fading performance, high in safety and far in transmission distance, saving network cost and the like.

The invention provides a means of channel coding using UDI channel of PHS, it includes: coding the sound; adding the cyclic redundancy check code that is CRC code to the sound data which is after the coding; the sound coding data is convoluotinal encoding or repeat encoding [M1]; the sound data which is after the convoluotinal encoding or repeat encoding is bit slotting or filling. The invention is simple, and it increases the fading property of PHS, and increases the sound quality. Because the invention makes UDI channel possesses bearing of coding protection, so the AMR, command, VoIP can be transferred.

The invention discloses a method for receiving and transmitting signals. The method comprises the steps of distributing bit information produced by a signal source to a plurality of transmitting antennas, and encoding and modulating the bit information distributed to all transmitting antennas respectively; conducting spatial interleaving and Q-channel interleaving on all channels of encoded and modulated modulating symbols respectively; conducting pre-coding on all channels of symbols after the Q-channel interleaving, and then sending symbols through antennas respectively; receiving a plurality of channels of receiving symbols, and conducting pre-decoding on all channels of receiving symbols respectively; conducting Q-channel de-interleaving and spatial de-interleaving on all channels of symbols subjected to pre-decoding respectively; and demodulating and decoding all channels of symbols after the spatial de-interleaving. The invention also discloses a system for receiving and transmitting signals and related devices correspondingly. By the aid of the method, the system and related devices, the high transmission efficiency of the system can be achieved, the spectrum utilization efficiency can be improved, the transmission reliability can be improved through diversities, the wireless system anti-fading performance can be greatly improved, and the requirements for development of wireless transmission networks can be met.

The invention discloses a weighted fractional Fourier transform time domain two-component signal interleaving transmission method, and belongs to the technical field of wireless communication. According to the invention, the problem of poor channel fading resistance of the existing single carrier communication method is solved. The invention designs a signal transmission method of an extended transform domain for an existing single carrier communication system, and an energy averaged signal form is formed for communication transmission by interleaving two component signals of a time domain. Because the energy of a single symbol and other multiple symbols are mixed and expanded in the process, an effect of relatively more uniformly distributing the signal energy in a time-frequency plane isachieved, the energy loss caused by channel fading is averaged to multiple symbols, the probability of distortion of a high-power signal is greatly reduced, the bit error rate under a fading channelis effectively reduced, and the reliability of the system is improved. The present invention can be applied to the technical field of wireless communications.

This invention relates to a hybrid recursive lattice empty time coding method used in serial cascade empty time coding system based on different modulation modes such as phase shift key control modulation, 8 phase shift key control modulation, 16 carry orthogonal amplitude modulation and other 2n one stage. The coding includes selection of component code and determination of image mode that is to determine the modulation mode according to the required transmission rate and state number of coding to further determine the state number code rate and coding mode of the component code appling 1 / 2 rate two state system recursive convolutional codes which number equals to the required transmission rate value, the coding mode is a first class system code, the image mode includes image of different transmitted symbols and different positions, that is to image the information bit output by every component code and check bit to different positions of different symbols.

The invention discloses a decoding method based on iterative layer space-time group codes, which comprises the following steps: firstly, grouping channel matrixes and receiving vectors according to the grouping number of an antenna; secondly, performing the group interference suppression to each group of receiving vectors, and performing the STBC decoding to the obtained modified receiving vectors to obtain each group of non-iterative decoding result; thirdly, feedbacking the result to a receiving terminal for performing the STBC decoding again to obtain each group of new decoding matrix used for eliminating the interference of the receiving terminal to decode a certain of group of receiving vectors; fourthly, performing the STBC decoding to the receiving vectors after being eliminated with the interference again, and feedbacking each group of obtained iterative decoding result to the receiving terminal; fifthly, repeating the step 3 and the step 4 for n-1 time(s) according to the set iterative time n, and performing the parallel-to-serial conversion to each group of decoding result iterated by n times to obtain the final decoding result. The invention has high antifading property relative to the prior LSBC decoding method, and can be used for the space-time coding in an MIMO system.

The invention discloses a transmitting method for a constant envelope frame synchronization signal, comprising the following steps of: respectively modulating a segment of constant envelope sampling point sequence (FORMULA referred) with a sampling rate as FS at a frequency F and a frequency F+deltaF, and respectively obtaining modulated sequence (FORMULA referred) and sequence (FORMULA referred),wherein the sampling point sequence includes M constant envelope sampling points, the transmission time corresponding to the first point of the sequence(FORMULA referred) is (FORMULA referred), the transmission timing corresponding to the first point of the sequence (FORMULA referred) is (FORMULA referred), and the sequences (FORMULAE referred) are combined to obtain the constant envelope frame synchronization signal (FORMULA referred). The synchronization signal provided by the invention has a multi-segment structure, and the number of segments can be controlled and distributed over different frequencies. By using the frequency diversity, the time overhead can be reduced with the same false synchronization or miss synchronization probability compared to other synchronization signals.

The invention discloses an OFDM-IM modulation method for transmission diversity, and mainly solves the problem that the bit-error performance is low in the prior art. The technical scheme comprises the following steps of: (1), performing OFDM-IM frequency-domain signal design of the transmission diversity, so that a frequency-domain signal is obtained; (2), performing OFDM modulation and block interleaving of the frequency-domain signal, so that a modulated signal is obtained; (3), transmitting the modulated signal in a channel, so that a received signal is obtained; (4), performing OFDM demodulation and de-interleaving of the received signal by a receiving end, so that a demodulated signal is obtained; (5), detecting the demodulated signal by the receiving end, so that an estimated signal is obtained; and (6), inversely mapping the estimated signal into bit information, so that a signal transmission process is completed. By means of the OFDM-IM modulation method disclosed by the invention, the transmission diversity gain can be obtained; compared with the traditional OFDM-IM, the OFDM-IM modulation method has relatively high anti-fading capability and better bit-error performance, and can be used for improving the error code performance of a wireless communication system; and thus, reliable transmission is realized.

The invention discloses a weighted fractional Fourier transform extended hybrid carrier transmission method, and belongs to the technical field of wireless communication. According to the invention, the problems of poor channel fading resistance and low transmission reliability of the existing single carrier communication method are solved. The invention designs an extended hybrid carrier signal transmission method for improving the bit error rate performance of a single carrier communication system, an extended hybrid carrier modulation is carried out on a signal after constellation mapping to form an anti-fading signal form with equalized time domain energy for communication transmission, and the equalization processing of channel time selective fading is realized, so the energy loss of a single symbol is shared by a plurality of symbols participating in the transformation process, the probability of misjudgment of the single symbol due to overlarge distortion is greatly reduced, the bit error rate under a fading channel is effectively reduced, and the performance of resisting channel fading of a single carrier system is improved. Meanwhile, the method has good compatibility with an existing single-carrier system. The present invention can be applied to the technical field of wireless communications.

A power control method of a multi-input multi-output space multiplexing mode is suitable for a broad band wireless orthogonal frequency division multiple access (FDMA) access system and comprises the following steps: firstly, adaptively modulating a code AMC; and then, calculating the number of ranks and conditions of a channel matrix, taking the number as the judgment basis of the strength and the weakness of the channel relativity of a plurality of received parallel data streams and respectively carrying out corresponding power adjustment according to the strength and the weakness of the channel relativity. The invention controls the power according to the strength and the weakness of the channel relativity of user channels with pertinence, especially the power control method provided byaiming at the strong channel relativity of the users can effectively prevent ineffective power control under an MIMO space multiplexing mode, thereby the anti-interference property and the anti-fading property of a system are enhanced.

A time-frequency fully averaged orthogonal multiple access transmission method based on extended weighted fractional Fourier transform belongs to the technical field of wireless communication. The invention solves the problems of poor time-frequency deep fading performance and low transmission reliability of existing multiple access systems. The present invention proposes a new orthogonal multiple access transmission method. By performing symbol mapping and extended weighted fractional Fourier transform on each user data, a signal form with time-frequency energy averaging characteristics is formed, while retaining The quadrature advantage of the original signal. In the solution proposed by the present invention, each user can occupy all the time-frequency resources available to the system without causing mutual interference. At the same time, since the proposed multiple access system achieves a uniform distribution of signals in the time-frequency plane, it has better anti-time-frequency deep fading performance, effectively improves the bit error performance under harsh channel conditions, and enhances the transmission of the multiple access system. reliability. The present invention can be applied to the technical field of wireless communication.

The invention relates to an LTE transmission and coverage system for achieving FTTH based on the digital technology. The LTE transmission and coverage system for achieving FTTH based on the digital technology is characterized by comprising near-end equipment and far-end equipment, wherein the near-end equipment comprises a near-end duplexer / time slot switch switchover unit, an LTE near-end down link, an LET near-end up link and a near-end digital signal processing unit, the far-end equipment comprises a far-end digital signal processing unit, an LTE far-end down link, an LTE far-end up link and a far-end duplexer / time slot switch switchover unit, the near-end digital signal processing unit communicates with the far-end digital signal processing unit through optical fibers, the near-end equipment is further connected with an LTE signal source, and the far-end equipment is further connected with a transmit-receive antenna. The LTE transmission and coverage system for achieving FTTH based on the digital technology is stable in performance, high in antijamming performance, high in anti-fading performance, high in safety and far in transmission distance, saving network cost and the like.

A signal time-frequency energy complete average transmission method based on extended weighted fractional Fourier transform belongs to the technical field of wireless communication. The invention solves the problem of poor capability of dispersing and compensating channel fading in existing methods. The invention realizes the design of the extended mixed carrier signal having both time-domain energy averaging characteristics and frequency-domain energy averaging characteristics through the extended weighted fractional Fourier transform. In a fading channel, the energy loss of each symbol is shared by other symbols, and its energy is well preserved. The receiving end only needs to perform the corresponding inverse transformation to achieve signal recovery with high probability. The solution proposed by the invention greatly improves the dispersion and compensation capabilities for channel fading, effectively reduces the bit error rate under fading channels, and improves the reliability of the communication system. At the same time, the method has good compatibility with the existing communication system. The present invention can be applied to the technical field of wireless communication.

The invention discloses a cooperative transmission method for extended hybrid carrier modulation and data interleaving, and belongs to the technical field of wireless communication. According to the invention, the problem of poor channel fading resistance of the existing communication method is solved. The invention designs an interleaving transmission method of an extended mixed carrier signal, which forms an anti-fading signal form with dispersed burst error energy and dispersed burst error position capability by performing inter-block bit interleaving on the extended mixed carrier signal. Under a channel condition with a long burst error, the burst error can be converted into a statistical independent error due to replacement of signal sorting by interleaving, and meanwhile, energy dispersion and compensation are performed on a symbol influenced by the burst error by extended hybrid carrier modulation, so that the probability of deep attenuation loss is greatly reduced, a receiving end can recover an original signal, and the communication reliability of the wireless communication system under a complex channel condition is effectively improved. The method can be applied to the technical field of wireless communication.

The invention discloses an Alamouti encoding method based on collaborative constellation mapping, and mainly solves the problems of high block error and worse anti-fading capability of an Alamouti space time code. The method comprises the following steps: dividing the bit stream of a transmitting end into three groups, generating a modulation constellation to map three groups of bits, constructing and combining a collaborative modulation symbol to obtain a transmission symbol, using the Alamouti space time code to transmit the symbol, receiving signals within two symbol periods by a receiving end and constructing a composite receiving signal vector, calculating a zero forcing detection solution vector according to the composite receiving signal vector, using a maximum likelihood estimator to perform first layer judgment on the zero forcing detection solution vector, calculating an European style and performing second layer judgment, and finally performing constellation inverse mapping on the judged result and combining the result to obtain the bit stream. By means of collaborative constellation mapping mode, a better error block function is obtained, the anti-fading capability of the system is enhanced, the communication confidentiality is strengthened at the same time, and the method can be applied to a two-transmit-antenna and one-receive-antenna system.

The invention discloses a decoding method based on iterative layer space-time group codes, which comprises the following steps: firstly, grouping channel matrixes and receiving vectors according to the grouping number of an antenna; secondly, performing the group interference suppression to each group of receiving vectors, and performing the STBC decoding to the obtained modified receiving vectors to obtain each group of non-iterative decoding result; thirdly, feedbacking the result to a receiving terminal for performing the STBC decoding again to obtain each group of new decoding matrix usedfor eliminating the interference of the receiving terminal to decode a certain of group of receiving vectors; fourthly, performing the STBC decoding to the receiving vectors after being eliminated with the interference again, and feedbacking each group of obtained iterative decoding result to the receiving terminal; fifthly, repeating the step 3 and the step 4 for n-1 time(s) according to the setiterative time n, and performing the parallel-to-serial conversion to each group of decoding result iterated by n times to obtain the final decoding result. The invention has high antifading propertyrelative to the prior LSBC decoding method, and can be used for the space-time coding in an MIMO system.

The invention discloses an OFDM signal transmission method for expanding hybrid carrier precoding, and belongs to the technical field of wireless communication. According to the invention, the problem that the existing multi-carrier communication method is poor in channel fading resistance under the condition of time-frequency double fading channels is solved. The invention designs a signal transmission method of an extended transform domain for an existing multicarrier communication system, and by performing extended hybrid carrier precoding on a modulated signal in front of an IDFT module, an extended hybrid carrier precoded OFDM signal with an energy averaging characteristic can be obtained. Under the channel condition with time dispersion, due to equalization processing on channel fading, the probability of complete loss of signal energy due to deep attenuation is greatly reduced, so that a receiving end can recover an original signal, a system has better error code performance, and the communication reliability of a multi-carrier system is effectively improved. Meanwhile, the method has good compatibility with other existing multi-carrier communication methods. The present invention can be applied to the technical field of wireless communications.

The invention discloses an energy averaging precoding OFDM (Orthogonal Frequency Division Multiplexing) transmission method, and belongs to the technical field of wireless communication. According to the invention, the problem of poor bit error rate performance of the existing OFDM system under the condition of the time-frequency double-fading channel is solved. A novel pre-coding scheme is designed for an OFDM system, and at a sending end, the construction of a pre-coding OFDM signal with both a time domain energy averaging characteristic and a frequency domain energy averaging characteristic is realized by designing a pre-coding matrix. Under a double-selection channel, due to complete average distribution of symbol energy on a time-frequency plane, the scheme has good channel fading compensation capability, a receiving end can realize signal reconstruction with a higher probability through data processing, the bit error rate is effectively reduced, the anti-fading performance of an OFDM system is improved, and the communication reliability is guaranteed. The method can be applied to the technical field of wireless communication.