99 results about "Diversity methods" patented technology

A signal diversity method of an OFDM system comprises the following steps: carrying out data decoding, modulation and rotation-modulation by a transmitting end, and storing the symbols of the processed data blocks; subjecting the symbols of the data blocks of a plurality of users in a memory to grouping and time-frequency interleaving, OFDM time-frequency resource allocation and Q-path interleaving according to the set number of the users, respectively subjecting the symbols of each data block to IFFT operation and CP addition after zero padding according to the OFDM modulation length, then transmitting the data; and subjecting the symbols of the data blocks to de-CP and FFT operations after a receiving end receives the data, carrying out phase compensation and zero removal, and sequentially subjecting the symbols of the obtained data blocks to Q-path de-interleaving, rotation demodulation, time-frequency de-interleaving and coding to obtain the desired data information. By adopting OFDM technique and rotation modulation technique and by selecting an optimal rotation angle, the method can acquire signal diversity gain and maximal performance improvement, thereby improving the system performance.

Methods and apparatus for implementing a wireless communication transceiver having receive path performance diversity. The transceiver implements a plurality of signal paths that can be configured as space diversity receive paths. Each of the plurality of signal paths includes a distinct RF filter. Each RF filter can be configured to provide a distinct frequency response, and in particular, a distinct jammer rejection profile. One of the RF filters can be configured to provide substantially no in-band jammer rejection. Each additional distinct RF filter can be configured to reject at least one distinct in-band jammer frequency or band of frequencies. A diversity receiver coherently combines the path performance diverse signals from each filter output. A transmitter can time division duplex transmit communications over at least a subset of the signal paths and their associated RF filters.

The invention discloses a channel estimation and diversity method based on train speed and position in train-ground communication, comprising the main steps: according to the obtained speed and position information of a train at current, inquiring channel state experience information corresponding to the position and the speed of the current train in a prestored channel state experience database;taking the information as a primary channel estimation result; verifying by a reference signal; if the verification result is not in a set error range, taking the verification result as a final channel estimation result; and if the verification result has big error, taking the channel estimation result of the previous frame as the final channel estimation result. The method has advantages of low complexity, high efficiency and accurate and reliable channel estimation result.

The present invention discloses a method of adaptive weighting space-time transmit diversity, comprising: symbols to be transmitted at a transmitting end being output after being space-time encoded according to certain regulation, and the current transmission powers of the two antennae being real-timely adjusted according to the given transmission power weight values; after the transmission powers are determined, the space-time encoded output signals being sent out at two independent antennas by transmitting antenna array in terms of the current transmission power; the fading characters of two wireless channels being estimated by the receiver at a receiving end according to the present received signals and then fed back to the transmitting end; the transmitting end receiving and obtaining the fading amplitude characters of two wireless channels through feedback channel, calculating new adaptive weight values of transmission powers, and adjusting transmission powers according to these weight values. The present invention also discloses a system for implementing the above method of adaptive weighting Space-time Transmit Diversity. In term of the method and structure, the transmission powers can be dynamically adjusted in adaptive weighting manner, in order to boost system performance gain.

The invention discloses a cooperation diversity method based on a constellation rotation quasi-orthogonal space-time group code, which mainly solves the problem that the transmission rate of a cooperation method of an orthogonal space-time group code is low. The cooperation transmission procedure comprises: during the broadcasting phase, a source node sends broadcast signals to a relay node and a destination node, the relay node performs the coding and the cyclic redundancy check to the received signals, if the cyclic redundancy check is right, the received signals are involved in the cooperation transmission in the space-time cooperation phase, or else the received signals are not involved in the cooperation transmission; during the space-time cooperation phase, the source node and the relay node calibrated right divide transmitted information into two groups for the constellation mapping, respective transmitted information is generated according to the coding matrix of the quasi-orthogonal space-time group code, and is sent to the destination node; the destination node performs the joint maximum likelihood decoding for received signals in the broadcasting phase and the space-time cooperation phase, and divides the decoding result into two groups for the demodulation. The invention has higher space diversity gain under the condition of same spectrum effectiveness and transmission power compared with the cooperation diversity method of the orthogonal space-time group code.

This invention discloses a send/receive and diversity method for an intelligent antenna and a device, in which, a dead zone process of an adaptive intelligent antenna is added to the receiving method. First of all, multiroute search and distribution on time domain to the baseband signals is carried out then to receive every distributed multiroute time delay with one intelligent antenna to process in signal beam weight and tracing de-disturb, de-expansion to renew the beam weight value, finally to carry out multiroute merge to get the data information.

The invention relates to the field of wireless communication and discloses a closed loop macro diversity method based on the disturbance theory in a coordinated multi-point (CoMP) system. The closed loop macro diversity method comprises the following steps: a plurality of base stations serve one user together; under the condition that the channel information and the data information are completelyshared, each base station respectively carries out the design of precoding, and then, a base station controller is used for adjusting the phase position of the precoding vector; and the higher received signal combining gain is obtained by adjusting the phase position of each row of the right singularity matrix of the channel. The channel state information (CSI) can be obtained by up-link feedback(FDD system) or direct channel estimation (TDD system). Compared with the prior art, the invention has higher frequency spectrum efficiency and better interruption probability performance and can notincrease the extra feedback cost and the data sharing cost.

A method of communicating with using an electric power line for a mobile body so that a first device transmits first information to a second device includes: coupling the first device with multiple first coupling points in an electric power line network; coupling the second device with multiple second coupling points; transmitting second information about transmission characteristics from the second device to the first device; modulating multiple transmission waves to be transmitted from the first device via the transmission points by the first device with using a transmission diversity method based on the second information; and demodulating multiple reception waves received by the second device via the reception points by the second device with using a reception diversity method.

A derivation unit derives SNRs corresponding respectively to two repeated OFDM symbols having the same content. The derivation unit generates, from the derived SNRs, a control signal necessary for deriving weighting factors and then outputs this control signal as a combined control signal. An FFT unit performs FFT on a signal combined by a delay symbol synthesizing unit. An equalization unit performs equalization processing on subcarrier signals inputted from the FFT unit. While associating two weighting factors with OFDM symbols of the same content, a synthesis unit weights the OFDM symbols of the same content with the weighting factors and then combines the OFDM symbols of the same content among equalization data.

A novel terrestrial wireless communications technique for terrestrial portable terminals including hand-held mobile devices and fixed wireless instruments, utilizing a spoke-and-hub communications system, having a plurality of individual hubs and/or base-stations all in communications with the portable terminals. The portable terminals and the hubs are assigned to use incompatible polarity formats in terms of circularly polarity (CP) and linearly polarity (LP). In forward links, a signal processed by the LP ground telecommunications hubs is radiated through multiple antennas with various LP polarities to an individual CP user simultaneously. The multiple paths are organized via assignments of a plurality of polarities, frequency slots, and directions by wavefront multiplexing/demultiplexing techniques such that the same communications assets including frequency spectrum may be re-used by other users. The same polarity diversity methods can be extended to peer-to-peer communications.

The present invention discloses down closed loop transmitting diversity method in uplink discontinuance transmission of wireless system. It contains 1, when uplink is not DTX, base station utilizes regular closed loop transmission diversity method to calculate aerial weight(ed) value, weighing aerial and to proceed relevant down link downgoing signal transmission, 2, when uplink enters DTX state, base station takes the measurements to two aerials respectively received uplink SB signal quality in each SBGP cycle, selecting aerial with preferable signal receiving quality as down link signal transmission aerial in relevant SBGP cycle, 3, when uplink exits DTX state, base station recovering utilizing regular closed loop transmission diversity method to calculate aerial weight(ed) value, weighing aerial and to proceed down link downgoing signal transmission, and changing to step 1.Said method raises downlink performance in uplink DTX state.

The present invention discloses down transmission diversity method in uplink discontinuance transmission of wireless system. It contains 1, when uplink is not DTX, base station utilizes regular closed loop transmission diversity method to calculate aerial weight(ed) value, weighing aerial and to proceed relevant down link downgoing signal transmission, 2, when uplink enters DTX state, base station utilizing time switching diversity to proceed relevant down link signal transmission, 3, when uplink exits DTX state, base station recovering utilizing regular closed loop transmission diversity method to calculate aerial weight(ed) value, weighing aerial and to proceed down link downgoing signal transmission, and changing to step 1.Adopting said method, closed loop transmission diversity base station diversity mode is switched to down time switching diversity to make downlink performance to obtain certain down diversity gain in both of uplink DTX and non - DTX.

The invention includes steps: (1) dividing input sequence in frequency domain into odd and even sub sequences in length N/2 according to sequence number of sub carrier wave; (2) carrying out inversed discrete Fourier transform for continuous two frames of the said sub sequence, storing result to buffer; (3) calculating buffered data so as to obtain four signals in time domain in transmitting chain; (4) inserting different PN sequences as frame head into TDS-OFDM guard gaps of four transmitting chain respectively, building up integrated signal frame of each transmitting chain from the frame head and frame body obtained from previous step; (5) after forming filtering, D/A conversion, and process at front end, signal frames are transmitted out through four antennae at prearranged channel bandwidth. Advantages are: simple, quick, accuracy, holding transmission efficiency, more suitable to channel of dual selections of time and frequency, supporting 'soft failure'etc.

The invention relates to a double-relay wireless communication system diversity method. In the communication process, a method for selecting a relay comprises the following steps: estimating the channel condition of the relay selected in the previous communication process before the current communication is carried out, and using the relay continuously if the channel condition of the relay meets the preset conditions; and otherwise, estimating the channel condition of the other relay, and then selecting a link with the best channel condition for communication from the two relays. A system applying the method has the advantages of low complexity and good transmission performance; and both the complexity and transmission performance of the system are preferably considered.

The invention discloses a diversifying method of an MIMO-OFDM system based on space-frequency coding, when the transmitting antenna is more than 2, better frequency gain effect can still be obtained. The diversifying method comprises that: after rearranging data in a data packet needed to be transmitted, a transmitting party carries out space-frequency coding to the data and then transmits the data; the rearrangement is used for causing the data transmitted by each antenna on sub-carriers with the same frequency points to be different; when receiving the data, a receiving party carries out de-rearrangement according to the rearrangement manner of the transmitting party after the receiving of all the data packets is finished, and carries out space-frequency decoding after the same user data is obtained on the corresponding sub-carriers so as to obtain the original user data.

The invention relates to a reception diversity method and a system thereof. The method comprises the following steps of: converting radio frequency signals received by n receiving antennae into n paths of base band signals; performing timing and carrier deviation estimation on each path of base band signal, and weighting and combining evaluated estimation values so as to obtain a united timing and carrier deviation estimation value of each path of base band signal; weighing and averaging the united timing and carrier deviation estimation value and a timing and carrier deviation estimated value so as to obtain average timing and average carrier deviation estimated values of each path of base band signal; and correcting each path of base band data, performing channel estimation and balancing on the base band data, performing de-mapping, de-interlacing, channel decoding and code descrambling, and outputting a processed transport stream. The method ensures synchronization and channel estimation quality under the condition that signals received by one or more paths of antennae are very poor, ensures receiving performance and is easy to implement.

The invention provides capability of closed loop diversity for CDMA system of using single bit closed loop power control already. Controlling closed loop power and sending closed loop diversity can be realized at same time through redefining command of feedback, adding a pair of antennas, a phase shifter, power divider and relevant control circuit at base station under condition of not increasing additional feedback load at mobile station, and not increasing additional assistant pilot frequency at base station. Mobile station does not need to estimate channel conditions from two antennas respectively, does not need to know number of antenna at base station. When there is only one pair of antenna at base station, it still is a single bit closed loop power control system; when there is two pair of antenna at base station, it possesses function for sending closed loop diversity automatically.

The invention discloses a constellation point diversity-based frequency offset estimation method in a 5G mobile communication system. The method comprises the following steps: 1, acquiring a time slotOFDM symbol; 2, carrying out divergence pre-compensation on OFDM symbols; 3, combining DMRS information of two time slots to carry out channel estimation and equalization on the OFDM symbol after divergence pre-compensation; and 4, estimating the frequency offset of the equalized OFDM symbol by using a constellation point diversity method. According to the invention, the problem that the DMRS only exists in one symbol in the prior art is overcome; according to the method, the problem of inaccurate frequency offset estimation caused by the fact that a channel value estimated by utilizing a DMRS cannot represent the channel condition of 14 OFDM symbols in one time slot is solved. The precision of frequency offset estimation is improved. Meanwhile, the defect that extra known training sequences need to be sent in the prior art is overcome. The occupation of bandwidth and power resources of the frequency offset estimation method in a 5G mobile communication system is reduced.

Disclosed herein is a diversity method for activating or deactivating a diversity function depending on the amount of power remaining in a power supply device and a mobile communication terminal incorporating the same. In an embodiment of the present invention, when the amount of power remaining in a power supply device is smaller than a reference value for the activation of a transmission/reception diversity function, which has been previously stored in memory, the transmission/reception diversity function is deactivated, and when the amount of power remaining in a power supply device is equal to or larger than the reference value, the transmission/reception diversity function is activated. In another embodiment, when the amount of power remaining in a power supply device is smaller than a reference value for the activation of a transmission or reception diversity function, which has been previously stored in memory, the transmission or reception diversity function is deactivated.

A method of recovering unknown aberrations in an optical system includes collecting intensity data produced by the optical system, generating an initial estimate of a phase of the optical system, iteratively performing a phase retrieval on the intensity data to generate a phase estimate using an initial diversity function corresponding to the intensity data, generating a phase map from the phase retrieval phase estimate, decomposing the phase map to generate a decomposition vector, generating an updated diversity function by combining the initial diversity function with the decomposition vector, generating an updated estimate of the phase of the optical system by removing the initial diversity function from the phase map. The method may further include repeating the process beginning with iteratively performing a phase retrieval on the intensity data using the updated estimate of the phase of the optical system in place of the initial estimate of the phase of the optical system, and using the updated diversity function in place of the initial diversity function, until a predetermined convergence is achieved.

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 discloses a macro diversity method, a system and equipment of a united inspection method by using multi-cells, being used for transmitting the data of an uplink transmission block and comprising the following steps: chip grade inspection data of user equipment acquired through united inspection in varied cells are uploaded to a wireless network controller; macro diversity user equipment is confirmed by the wireless network controller according to the uploaded uplink chip grade inspection data and a user equipment macro diversity link is established; and the macro diversity link of the data of the transmission block acquired through the united inspection of the user equipment is maintained according to the configuration of the wireless network controller and the uplink chip grade inspection data. The user data of adjacent cells obtained through the united inspection are directly sent to an upper grade which carries out dispreading and combination by the macro diversity method, the system and the equipment of the invention, thus omitting the process of establishing, managing and maintaining the transmission channels of varied users respectively between a base station and the controller of the base station, not only reducing the process of management and maintenance but also greatly saving resources for maintenance.

The invention discloses a transform domain diversity method based on a single-carrier frequency-division multiple access system. The method comprises the steps of (1), generating sending data blocks;(2), acquiring data blocks after a transform domain is diversified; (3), acquiring the data blocks after a weighted transform domain is diversified; (4), acquiring time domain sending signals; (5), receiving time domain sending signals; (6), acquiring transform domain data blocks; (7), weighting the transform domain data blocks; and (8), acquiring transform domain combined data blocks. According to the method, each sending data block before copying is taken as a unit and after all sending data blocks are longitudinally arranged and copied, the data blocks after the transform domain is diversified are acquired, so the method has the advantage that the diversity signal correlation is low. The data blocks after the transform domain is diversified are weighted through utilization of a weighting sequence, repetition characteristics of the data blocks after the transform domain is diversified are changed, low envelope fluctuation characteristics of transmission signals are kept, and the capability of resisting channel frequency selective fading is improved.