38 results about "Diversity coding" patented technology

The present invention selects a space-time encoding mode to use when transmitting with spatial diversity based on the receive diversity associated with a receiver device and the quality of the transmission channels based on information fed back from the receiver device. The selectable space-time encoding modes are preferably space-time transmit diversity encoding and a version of BLAST-type encoding. Further, modulation modes, error encoding rates, or a combination thereof, may also be based on the quality of the transmission channels and the available diversity of the receiver device.

A transmitting device comprises a plurality of distributed transceivers, a baseband processor and a network management engine. Data streams are generated at baseband by the baseband processor. Diversity coding such as space-time coding may be performed over the generated data streams in the baseband. The transmitting device concurrently transmits each of the coded streams in a same radio frequency (RF) band to a receiving device over the entire distributed transceivers through associated antennas. When needed, the network management engine may identify one or more auxiliary devices providing available transceivers and antenna beamformers to the transmitting device for sharing. Beam patterns and antenna orientations may be determined for associated antennas of the available transceivers for the transmitting device. Each of the coded data streams in the same radio frequency band may be transmitted to the receiving device over the entire available transceivers for the transmitting device through the associated antennas.

Maximum diversity in multiple antenna distributed frequency broadband systems such as MIMO-OFDM is achievable through space-frequency (SF) and space-time-frequency (STF) coding. Full-rate full-diversity coding is achieved through a combination of maximal minimum product distance symbol set design and formation of codeword blocks. Full-diversity codes are also achieved which have reduced symbol transmission rates, such as through mapping of space-time (ST) codes to SF codes. The reduction in symbol rate may be offset by the fact that any ST code may be mapped to a full-diversity SF code.

Good transmission characteristics are achieved in the presence of fading with a transmitter that employs a trellis coder followed by a block coder. Correspondingly, the receiver comprises a Viterbi decoder followed by a block decoder. Advantageously, the block coder and decoder employ time-space diversity coding which, illustratively, employs two transmitter antennas and one receiver antenna.

A system and method of processing frequency-diversity coded signals with a low sampling rate less than the Nyquist rate for ultra-wideband devices are described. The frequency-diversity coding system comprises a frequency-diversity encoder, one or more first transformation device, a summation device, a signal filter, a sampling device, a second transformation device and a frequency-diversity decoder. The frequency-diversity encoder encodes a plurality of information blocks to output matrix elements. The first transformation devices convert the matrix elements into a plurality of OFDM symbols. The summation device superposes a plurality of frequency bands to generate a transmitted signal. The signal filter eliminates noise in the received signal. The signal filter comprises a low-pass filter for removing the noise in the received signal. The sampling device coupled to the signal filter samples the received signal by a sampling rate less than a Nyquist rate. The sampling rate is equal to the bandwidth of one subcarrier of the OFDM symbols. Additionally, the frequency-diversity decoder coupled to the second transformation device interprets the received signal to decode the information blocks.

A method and transmitter for amplifying at least first and second diversity-encoded signals, where each of the first and second diversity-encoded signals may represent information of a first signal to be transmitted using transmit diversity. Amplification of the first and second diversity-encoded signals may be shared between at least two amplifiers, and amplification for a second signal, to be amplified and transmitted without using transmit diversity, may be shared between the at least two amplifiers.

A communication system transmits and receives a plurality of spread-spectrum signals having differences in at least one diversity parameter. The signals are highly correlated when their diversity parameters are similar, and the signals are uncorrelated when at least one diversity parameter is different Any combination of a transmitter, a receiver, and a communication channel may diversity-encode the signals to effect differences in their diversity parameters. A receiver diversity-decoder compensates for differences in a diversity-parameter of at least one received signal to make the signal highly correlated with at least one other received signal. A correlator combines at least two of the received signals to recover an embedded information signal. The communication system enables the use of true-noise signals for spreading information signals, provides simplified receiver designs, and enables antenna arrays to spatially process spread-spectrum signals.

In one aspect, a method to enhance coverage in a heterogeneous wireless network wireless communication is disclosed. The method includes generating a reference signal indicating a plurality of transmit antenna ports and generating modulation symbols. Modulation symbols are assigned to each of the plurality of transmit antenna ports, in accordance with a spatial diversity coding scheme for the plurality of transmit antenna ports. At least one of the modulation symbols assigned to at least one of the plurality of transmit antenna ports is muted prior to transmission in accordance with the spatial diversity coding scheme. The non-muted modulation symbols and the reference signal are transmitted on the other of the plurality of transmit antenna ports.

Transmit diversity coding of symbols employing four antennas is disclosed. An example embodiment of the invention comprises providing blocks of symbols to four transmit antennas, the blocks of symbols being determined by transforming input blocks and extending the blocks by adding zeroes in groups before or after groups of elements in the blocks.

Disclosed is a four-antenna diversity transmitting device based on a GMC system, a transmitting method and a receiving device and a receiving method. In the transmitting device, a shaping filter pack module divides the whole channel bandwidth intp a plurality of orthogonal sub-channels, and each sub-channel is corresponding to a subfilter, then each pixel symbol in the column vector of the signal is respectively mapped onto the corresponding sub-channel, and then a multi-antenna diversity coding module converts the parallel symbol data sequence into the similar Alamouti structure and the signal pack with the diversity degree 4, finally four antennas are adopted to transmit the signal pack in eight block time, while in the receiving device, the minimum mean-squared error is adopted to balance the received signal, then the signal sequence is processed with the sub-belt matching filter, to generate the symbol data sequence of outputting a plurality of sub-belts in parallel, thereby obtaining the full diversity gain and effectively ensuring the communication quality of the chain, also realizing the peak-to-average power ratio and the reduction of the carrier frequency deviation error suseptibility.

A wireless communication network is configured to provide distributed diversity transmissions, wherein different diversity-coded versions of the same information signal are transmitted from each of two or more network sectors. The diversity-coded versions of the information signal are based on space-time or space-frequency codes, and the information signal may comprise a dedicated channel signal targeted to an individual user or a broadcast signal targeted to one or more users. Thus, spaced-apart network transmitters, which may be located at the same cell site, or at different cell sites, are configured to transmit diversity-coded versions of a given information signal and, in this manner, the advantages of space-time and / or space frequency transmission coding may be applied across multiple sectors of a communication network. Such transmissions may be used to improve soft and softer handoff reception of dedicated channel signals, and to improve reception of Broadcast-Multicast Services (BCMCS) signals, or the like.

The invention discloses a coding method based on a frequency diversity coding orthogonal frequency division multiplexing superwide band system, the method comprises: modulating input data and space-time block coding the modulated data, then mapping the coded data, mapping coded data corresponding to each subband to corresponding subcarriers in different orthogonal frequency division multiplexing symbols, or mapping coded data corresponding to each subband to corresponding subcarriers in one orthogonal frequency division multiplexing symbol. According to the coding method, the invention also provides a coding device, a coding method and a decoding device. The invention can make the system transmit data with a higher speed, also can guarantee the system obtain higher diversity gain. Moreover, the decoding complexity of the invention is lower, while the decoding accuracy is higher, thereby performance of the system is improved.

The invention discloses a method increasing the diversity effect of a wireless communication system. After a binary sequence is modulated, a symbol sequence to be transmitted is transformed to cause all or one part of each symbol in the symbol sequence to be transmitted to exist in each space resources unit, each frequency resource unit and each time resource unit which are occupied by diversity coding blocks. The invention is the diversity enhancement technique which can be jointed with any one diversity method for using. The invention causes every one transmission symbol adopting the diversity method to obtain the diversity gain on the space-time frequency occupied by the whole diversity coding blocks, thereby wholly improving the quality of a transmission link.

The invention provides a multi-antenna emission diversity method, which includes steps of carrying out diversity coding for conversion symbol obtained by carrying out coding modulation and conversion to the data to be sent, mapping the data on corresponding time space frequency resource and sending. The diversity coding comprises carrying out time space coding and phase rotation to conversion symbol to obtain diversity coding block, and is characterized in that in a same diversity coding block, phase rotation values of a same column are same, phase rotation values of different columns are incomplete same, and phase rotation values of at least a pair of corresponding positions in phase rotation values of corresponding position between at least one diversity coding block and other diversity coding blocks. The invention also provides a multi-antenna emission diversity device. The method and the device of the present invention obtain diversity gain brought by different signal passing through differential channel, thereby increasing diversity gain.

A transmission diversity method comprises: transforming modulating symbol sequence Y to be transmitted with N symbols as one set to generate a transforming sequence X with N symbols as one set, wherein, the transformation enables the any one symbolic information in the modulating symbol sequence Y to be included by a plurality of symbols in the transforming sequence X, and one symbol in the transforming sequence X includes a plurality of symbol information in the modulating symbol sequence Y; mapping the symbols generated by the same transformation in the transforming sequence X into different space-frequency block code SFBC blocks in a diversity coding matrix, diversity coding and transmitting the mapped symbols by using the diversity encoding mode based on SFBC; or mapping the symbols generated by the same transformation in the transforming sequence X into different space time block code STBC blocks, and diversity coding and transmitting the mapped symbols by using the diversity encoding mode based on STBC.

The invention relates to a cooperative diversity positioning method based on a satellite positioning system. A space-time cooperative diversity positioning scheme based on an Alamouti code and MIMO-spread spectrum space diversity coding are designed according to the satellite positioning system. The method concretely comprises the steps that according to space-time cooperative diversity positioning based on the Alamouti code, adjacent satellites in the same track are grouped into satellite pairs so that adjacent satellite cooperative diversity is realized; and cooperative diversity MIMO-spread spectrum space diversity coding aiming at the satellite positioning system is designed based on an MIMO-direct sequence spread spectrum method multi-code model. Compared with methods in the prior art, the method has superiorities that signal gain is enhanced without increasing positioning signal transmitting power so that the service life of the satellites can be effectively prolonged under the premise of guaranteeing anti-interference capability; and cooperative diversity of the adjacent satellites closely combines the positioning satellite constellation characteristics, and robustness of positioning signals is enhanced without changing a space segment structure function or increasing extra burden of the satellites.

Briefly, an apparatus and method to transmit data stream by using a multiple-input-multiple-output (MIMO) transmitters receivers system. The MIMO transmitters receivers system may include a coding mode selector to select a coding mode of each orthogonal frequency division multiplexing (OFDM) sub-carrier symbol of a first and second sub-carriers of a data stream according to a feedback data packet having coding information of the OFDM subcarrier symbol. The coding mode may be selected from a diversity coding mode and a multiplexing coding mode.

A dual antenna transmitter includes a diversity encoding module that receives a data stream and provides a pair of encoded data streams selected to cause generation of overlapping symbols that provide substantially constant signal power to a receiver when the first and second antennas are unobstructed from the receiver. The diversity encoding module may compensate for the state retention of standard modulators thereby enabling the implementation of the Alamouti transmit diversity scheme. A wireless receiver capable of receiving data transmitted from the aforementioned transmitter includes a metric extraction module that repetitively extracts a metric from a transmitted signal at a selected rate to provide a first and a second metric stream, the first metric stream comprising data that is time offset from data in the second metric stream, the time offset corresponding to a differential time delay to the receiver for symbols emitted from the transmitter antennas.

An emit diversity encoded method for common pilot channel of several antennas in WCDMA system features that 2 to the power n-1 radio frames are used as one encode period and Walsh function is used for orthogonal encode of continuous 2 to the power n sign bits as one unit, and distributing it to several antennas.

A system and method of processing frequency-diversity coded signals with a low sampling rate less than the Nyquist rate for ultra-wideband devices are described. The frequency-diversity coding system comprises a frequency-diversity encoder, one or more first transformation device, a summation device, a signal filter, a sampling device, a second transformation device and a frequency-diversity decoder. The frequency-diversity encoder encodes a plurality of information blocks to output matrix elements. The first transformation devices convert the matrix elements into a plurality of OFDM symbols. The summation device superposes a plurality of frequency bands to generate a transmitted signal. The signal filter eliminates noise in the received signal. The signal filter comprises a low-pass filter for removing the noise in the received signal. The sampling device coupled to the signal filter samples the received signal by a sampling rate less than a Nyquist rate. The sampling rate is equal to the bandwidth of one subcarrier of the OFDM symbols. Additionally, the frequency-diversity decoder coupled to the second transformation device interprets the received signal to decode the information blocks.

The invention relates to a time-frequency joint channel estimation method of time-domain synchronous orthogonal frequency division multiplexing (TDS-OFDM) space-frequency coding, which belongs to the technical field of digital information transmission. The steps are: 1) transmit antennas T1 and T2 to perform space-frequency diversity coding; 2) alternately transmit transmission parameter signaling (TPS) information carried on OFDM subcarriers on T1 and T2 according to certain rules; 3) Time-frequency joint channel estimation is performed by using time-domain PN sequence and frequency-domain TPS information; 4) Sending information is recovered through space-frequency decoding. The transmission space-frequency coding time-frequency joint channel estimation method described in the present invention hardly changes the original transmitter system, the processing method is simple, fast and accurate, maintains the transmission efficiency of the system, and supports "soft failure", increasing reliability . At the same time, the present invention does not lose its generality, and can be easily transplanted to other multi-carrier terrestrial digital television broadcasting systems.

The invention discloses a data transmitting method, a data transmitting device and a data communication system. The method combines the quasi-orthogonal diversity coding technology and hybrid automatic repeat request technology, thereby effectively improving the combination performance in hybrid automatic repeat. The method mainly comprises: transmitting source signals by combining spatial diversity and spatial multiplexing at least twice in the first transmission period, wherein the channel for transmitting the source signals is represented in a matrix form of quasi-orthogonal diversity. Through the method, the quasi-orthogonal diversity coding technology and the automatic repeat request in the mixed use of the spatial diversity and spatial multiplexing can be designed to be combined to reduce the interference among the signal flows.

The invention provides a multi-antenna emission diversity method, which includes steps of carrying out diversity coding for conversion symbol obtained by carrying out coding modulation and conversion to the data to be sent, mapping the data on corresponding time space frequency resource and sending. The diversity coding comprises carrying out time space coding and phase rotation to conversion symbol to obtain diversity coding block, and is characterized in that in a same diversity coding block, phase rotation values of a same column are same, phase rotation values of different columns are incomplete same, and phase rotation values of at least a pair of corresponding positions in phase rotation values of corresponding position between at least one diversity coding block and other diversity coding blocks. The invention also provides a multi-antenna emission diversity device. The method and the device of the present invention obtain diversity gain brought by different signal passing through differential channel, thereby increasing diversity gain.

Good transmission characteristics are achieved in the presence of fading with a transmitter that employs a trellis coder followed by a block coder. Correspondingly, the receiver comprises a Viterbi decoder followed by a block decoder. Advantageously, the block coder and decoder employ time-space diversity coding which, illustratively, employs two transmitter antennas and one receiver antenna.

A wireless communication network is configured to provide distributed diversity transmissions, wherein different diversity-coded versions of the same information signal are transmitted from each of two or more network sectors. The diversity-coded versions of the information signal are based on space-time or space-frequency codes, and the information signal may comprise a dedicated channel signal targeted to an individual user or a broadcast signal targeted to one or more users. Thus, spaced-apart network transmitters, which may be located at the same cell site, or at different cell sites, are configured to transmit diversity-coded versions of a given information signal and, in this manner, the advantages of space-time and / or space frequency transmission coding may be applied across multiple sectors of a communication network. Such transmissions may be used to improve soft and softer handoff reception of dedicated channel signals, and to improve reception of Broadcast-Multicast Services (BCMCS) signals, or the like.

The invention discloses a visible light communication method, which comprises the steps of: at a transmitting end, subjecting a data stream to OFDM coding based on space diversity coding, modulating OFDM codes to obtain a visible light signal by means of a single LED light source, and transmitting the visible light signal; at a receiving end, converting the received visible light signal into an analog electric signal by means of a single photodiode, converting the analog electric signal into a digital signal, demodulating the digital signal by means of OFDM data symbols to obtain OFDM data symbols, demodulating the OFDM data symbols based on space diversity coding, and restoring the original data stream. The visible light communication method fully utilizes the technical features of the signal space diversity coding, encodes real portions and virtual portions of transmitted signals so that the real portions and virtual portions are independent from each other, realizes the purpose of forming a diversity effect by just using a single receiver for receiving in a multi-path interference environment, effectively improves the transmission capability of signals in a frequency selective fading channel, improves the adaptability of a visible light communication system and enhances the system performance integrally.

In one aspect, a method to enhance coverage in a heterogeneous wireless network wireless communication is disclosed. The method includes generating a reference signal indicating a plurality of transmit antenna ports and generating modulation symbols. Modulation symbols are assigned to each of the plurality of transmit antenna ports, in accordance with a spatial diversity coding scheme for the plurality of transmit antenna ports. At least one of the modulation symbols assigned to at least one of the plurality of transmit antenna ports is muted prior to transmission in accordance with the spatial diversity coding scheme. The non-muted modulation symbols and the reference signal are transmitted on the other of the plurality of transmit antenna ports.

The invention relates to a cooperative diversity positioning method based on a satellite positioning system. A space-time cooperative diversity positioning scheme based on an Alamouti code and MIMO-spread spectrum space diversity coding are designed according to the satellite positioning system. The method concretely comprises the steps that according to space-time cooperative diversity positioning based on the Alamouti code, adjacent satellites in the same track are grouped into satellite pairs so that adjacent satellite cooperative diversity is realized; and cooperative diversity MIMO-spread spectrum space diversity coding aiming at the satellite positioning system is designed based on an MIMO-direct sequence spread spectrum method multi-code model. Compared with methods in the prior art, the method has superiorities that signal gain is enhanced without increasing positioning signal transmitting power so that the service life of the satellites can be effectively prolonged under the premise of guaranteeing anti-interference capability; and cooperative diversity of the adjacent satellites closely combines the positioning satellite constellation characteristics, and robustness of positioning signals is enhanced without changing a space segment structure function or increasing extra burden of the satellites.

Disclosed is a four-antenna diversity transmitting device based on a GMC system, a transmitting method and a receiving device and a receiving method. In the transmitting device, a shaping filter pack module divides the whole channel bandwidth intp a plurality of orthogonal sub-channels, and each sub-channel is corresponding to a subfilter, then each pixel symbol in the column vector of the signalis respectively mapped onto the corresponding sub-channel, and then a multi-antenna diversity coding module converts the parallel symbol data sequence into the similar Alamouti structure and the signal pack with the diversity degree 4, finally four antennas are adopted to transmit the signal pack in eight block time, while in the receiving device, the minimum mean-squared error is adopted to balance the received signal, then the signal sequence is processed with the sub-belt matching filter, to generate the symbol data sequence of outputting a plurality of sub-belts in parallel, thereby obtaining the full diversity gain and effectively ensuring the communication quality of the chain, also realizing the peak-to-average power ratio and the reduction of the carrier frequency deviation error suseptibility.