Abstract: Present document is related with communication of synchronization signals between base station and terminal. The base station acquires a primary synchronization signal generated using a Constant Amplitude Zero Auto-Correlation (CAZAC) sequence having a root index M and having a length L, and a secondary synchronization signal informing a cell group ID. And, the base station transmits the primary synchronization signal at a last symbol of a specific time domain unit to one or more terminals, and the secondary synchronization signal at a second-to-last symbol of the specific time domain unit to the one or more terminals. Here, the root index M is one among a root index set comprising m0 and m1 meeting “m0+m1=(½*L)*n” or “m0?m1=±(½*L)*n”, where ‘n’ is an integer greater than 0.

Abstract: An electrical circuit includes a local oscillator configured to generate a first reference signal and a second reference signal having a predetermined phase shift with the first reference signal, an I-channel mixer configured to inject the first reference signal to an incoming signal and generate a first output, a compensation mixer configured to multiply the first output with a constant factor to generate a second output, a first low pass filter configured to approximately attenuate frequencies in the second output to generate a third output, and a first correcting filter configured to filter the third output to generate a fourth output. The first correcting filter is configured to reduce a channel impulse response mismatch between the first low pass filter and a second low pass filter, which is configured to attenuate frequencies in a Q-channel of the incoming signal. In specific embodiments, the phase shift includes 45°.

Abstract: All data symbols used in data transmission of a modulated signal are precoded by hopping between precoding matrices so that the precoding matrix used to precode each data symbol and the precoding matrices used to precode data symbols that are adjacent to the data symbol in the frequency domain and the time domain all differ. A modulated signal with such data symbols arranged therein is transmitted.

Abstract: Apparatus, the apparatus having at least one processor and at least one memory having computer-readable code stored thereon which when executed controls the at least one processor to perform a method comprising: obtaining in-phase and quadrature samples of a received radio signal at least first and second discrete instances in time; processing the samples to provide information relating to the amplitude and/or phase of the received radio signal at the first and second instances in time; using the amplitude and/or phase information of the received radio signal at the first and second instances in time to determine whether interference is present on the received radio signal; forwarding the complex signal parameters for processing if interference is determined not to be present; and discarding the complex signal parameters without forwarding them for processing if interference is determined to be present.

Abstract: The present invention relates to a method and arrangement for symbol mapping in wireless communication systems utilizing OFDM transmission technology in combination with advanced coding schemes. In the method according to the present invention, adapted for use in a wireless communication system utilizing OFDM transmission technology, an OFDM grid is defined by at least a first dimension and a second dimensions from the dimensions time, frequency or space. The advanced coding scheme, for example Alamouti coding, outputs symbols that are related via the coding. At least some of the symbols, defining a code related symbol group should experience identical, or at least very similar, radio channels. According to one embodiment of the present invention, symbols from the same code related symbol group is placed as close together in the OFDM grid as possible.

Abstract: A transmission method for transmitting a first modulated signal and a second modulated signal in the same frequency at the same time. Each signal has been modulated according to a different modulation scheme. The transmission method applies precoding on both signals using a fixed precoding matrix, applies different power change to each signal, and regularly changes the phase of at least one of the signals, thereby improving received data signal quality for a reception device.

Abstract: Methods and devices for receiving wireless signals employ compressed sensing-based estimation techniques to receive single-carrier transmissions, exploiting the common sparseness of the wireless channel, enabling signal reception in the presence of significant Delay and Doppler spreads. When implemented for an ATSC or ATSC-M/H mobile TV standard signal, the compressed sensing channel estimation algorithm enables data reception in Delay and Doppler spread conditions beyond the capabilities of conventional channel estimation methods.

Abstract: The present invention employs hierarchical modulation to simultaneously transmit information on different modulation layers using a carrier RF signal. Initially, first data to be transmitted is assigned to a first modulation layer and second data is assigned to a second modulation layer. In one embodiment of the present invention, the first and second data are assigned based on reliability criteria. The first and second modulation layers are hierarchical modulation layers of the carrier RF signal. Once assigned, the first data is transmitted using the first modulation layer of the carrier RF signal and the second data is transmitted using the second modulation layer of the carrier RF signal. In one embodiment of the present invention, information may be transmitted to one end user using one modulation layer, and information may be transmitted to a different end user using a different modulation layer.

Abstract: Disclosed are methods and apparatus for initializing an equalizer in a diversity receiver. In one aspect, the initialization includes estimating a channel impulse response (CIR) for each receiver chain of the diversity receiver; determining noise power estimates for each receiver chain based on the CIRs; and adaptively adjusting equalizer taps of each receiver chain based on the noise power estimates. In one aspect, the adaptive adjusting of the equalizer taps is based on scaling the CIR and covariance metrics for the receiver chain with higher noise power by a scale factor determined from the noise power estimates. In another aspect, the adaptive adjusting of the equalizer taps is based adaptive conditioning on the diagonal of the covariance matrix.

Abstract: A system for implementing an orthogonal frequency division multiplexing scheme and providing an improved range extension. The system includes a transmitter for transmitting data to a receiver. The transmitter includes a symbol mapper for generating a symbol for each of a plurality of subcarriers and a spreading module for spreading out the symbol on each of the plurality of subcarriers by using a direct sequence spread spectrum. The symbol on each of the plurality of subcarriers is spread by multiplying the symbol by predefined length sequences. The receiver includes a de-spreader module for de-spreading the symbols on each of the plurality of subcarriers. The de-spreader module includes a simple correlator receiver for obtaining maximum detection. The correlator produces an output sequence of a same length as an input sequence and the de-spreader module uses a point of maximum correlation on the output sequence to obtain a recovered symbol.

Abstract: Embodiments of the present disclosure provide a transmitter, a receiver and methods of operating a transmitter and a receiver. In one embodiment, the transmitter has at least three transmit antennas and includes a feedback decoding portion configured to recover at least one group-based channel quality indicator provided by a feedback signal from a receiver, wherein each group-based channel quality indicator corresponds to one of a set of transmission layer groupings. The transmitter also includes a modulator portion configured to generate at least one symbol stream and a mapping portion configured to multiplex each symbol stream to at least one transmission layer grouping. The transmitter further includes a pre-coder portion configured to couple the transmission layers to the transmit antennas for a transmission. The receiver includes a decoder portion which is configured to use decoded signals from at least one group to decode the other groups.

Abstract: A distributed radio system comprising a first receiver (1) and a second receiver (2) each receiver comprising a tuner (11, 21) adapted to receive radio signals and to transmit tuned radio signals, a first baseband unit (12, 22) coupled to the tuner (11,21) and adapted to receive the tuned radio signals and to partially demodulate the tuned radio signals, the first baseband unit (12,22) being further adapted to transmit partially demodulated signals, a second baseband unit (14, 24). The distributed radio system further comprising a digital communication channel (3) adapted to receive the partially demodulated signals and to redistribute the partially demodulated signals to the second baseband unit (14, 24).

Abstract: An automatic gain control (AGC) method and system for a radio receiver are proposed in which the ACG comprises two AGC loops; a first loop controlling signal gain in the analog portion of the radio receiver, a second loop controlling gain in the digital domain after digitization of the received signal. The analog AGC loop has a slower response time than the digital AGC loop. When applied to a multi-branch diversity receiver, each branch has its own digital AGC loop, but the analog gain can be common to all branches, based on measurement of the analog signal in each branch.

Abstract: Methods and apparatus are disclosed for receiving a diversity transmitted signal using a Rake or G-Rake receiver in a radio system. Signals are diversity transmitted in a first and second symbol period by two or more antennas. One or more receive antennas receive the diverse transmit signals. Weights are generated to account for the correlation between the channels over which the diverse transmit signals are transmitted in the first and second symbol period and are used to weight the received signals. The weighted signals are then fed to a mutual receiver.

Abstract: A method of demodulating a plurality of multiplexed modulation signals is provided, including: i) inputting the plurality of multiplexed modulation signals, each of which being outputted from a plurality of outputs of a communication partner, wherein each modulation signal in the multiplexed modulation signals includes a pilot symbol sequence consisting of a plurality of pilot symbols used for demodulation, ii) estimating respective channels of the multiplexed modulation signals based on one or more of the pilot symbol sequences; and iii) demodulating each modulation signal in the plurality of multiplexed modulation signals based on the channel estimation. Each of the pilot symbol sequences is inserted at a same temporal point in each modulation signal among the multiplexed modulation signals. The pilot symbol sequences are orthogonal to each other with zero cross correlation among the modulation signals in the multiplexed modulation signals, and each pilot symbol has a non-zero amplitude.

Abstract: A multi-user multiple-input multiple-output (MIMO) downlink beamforming system with limited feed forward is provided to enable precoding matrix information to be efficiently provided to a subset of user equipment devices, where zero-forcing transmit beamformers are computed at the base station and assembled into a precoding matrix. The precoding matrix is encoded using a compact reference signal codebook for forward link signaling, either by sending bits indicating the index of the transmission matrix used, or by transmitting one or more precoded pilots or reference signals wherein the pilot signals are precoded using vectors uniquely representative of the transmission matrix used which includes candidate reference signal matrices which meet a predetermined condition number requirement, such as a condition number threshold. The precoding matrix information is extracted at the user equipment devices using the compact reference signal codebook and used by the MMSE receiver to generate receive beamformers.

Abstract: A channel estimation method in a multipath channel, and which includes receiving a signal from a channel having multipath; obtaining information related to the number of paths and synchronization information related to each path from the received signal; estimating a channel using the obtained information related to the number of paths and synchronization information related to each path; calculating a metric using at least one impulse response value of a Square Root Raised Cosine (SRRC) filter and the obtained information; calculating an inverse metric of the calculated metric; and removing an inter-path interference from the estimated channel by multiplying the inverse metric with the estimated channel.

Abstract: A method for receiving and storing a packet of symbols. The method decodes the packet of symbols using a first decoding algorithm, and if the first decoding algorithm fails to correctly decode the packet of symbols, then the method decodes the packet of symbols using a second decoding algorithm. If the second decoding algorithm fails to decode the packet of symbols, then a third decoding algorithm is used. The third decoding algorithm can be sub-packet decoding, where a first sub-packet is part of the packet of symbols. If the first sub-packet is decoded successfully, then the method generates a channel estimate using the properly decoded information, and then uses that channel estimate to decode a subsequent sub-packet using the channel estimate, where the second sub-packet is a set of symbols that are a portion of the packet of symbols.

Abstract: The present document provides a method for feeding back channel state information and a user equipment. The method includes: a user equipment determining a second parameter y of a feedback mode according to the number of Channel-State Information-reference signals (CSI-RS) ports configured by a high layer signaling or according to the number of CSI-RS ports and indication information indicating whether to feed back a pre-coding matrix indicator (PMI) and rank indicator (RI); the user equipment determining the feedback mode according to a transmission mode configured by the high layer signaling, a first parameter x of the feedback mode and the second parameter y of the feedback mode; and the user equipment feeding back the channel state information according to the determined feedback mode. The present document improves the system flexibility and performance and reduces the feedback overhead.

Abstract: Provided is a communication system using a space division multi-user multiple input multiple output (SD-MIMO) communication method. A transmission apparatus may transmit, to each of terminals included within a coverage, common control information commonly transmitted to the terminals and individual control information individually transmitted to each of the terminals. The transmission apparatus does not precode the common control information and transmits the non-precoded common control information. The transmission apparatus precodes the individual control information and transmits the precoded individual control information.

Abstract: In a MIMO system using a cross-polarized antenna structure, even if no ideal XPD can be obtained, the interference between different polarized waves can be reduced to allow an effective precoding to be executed. When a MIMO communication is performed between a transmitter and a receiver each using a cross-polarized antenna structure, a channel estimating and precoding selection section of the receiver performs a channel estimation of MIMO channels from the transmitter to the receiver, decides a precoding matrix of a projection matrix for mutually orthogonalizing or substantially orthogonalizing the channel response matrixes for respective different polarized waves, and feeds the determined precoding matrix back to the transmitter. In the transmitter, a precoding processing section applies the precoding matrix to the spatial stream corresponding to one of the polarized waves to perform a precoding, thereby allowing the transmitter to transmit the polarized waves with the orthogonality therebetween maintained.

Abstract: The description herein relates to pilot designs for an Orthogonal Frequency Division Multiplexing (OFDM) based communication system. In at least one embodiment, the communication system is one operating according to the IEEE 802.16m, or WiMax, standard. In general, an OFDM transmitter operates to insert pilot symbols into a resource of a transmit frame according to a predetermined staggered pilot symbol pattern defining pilot symbol locations within the resource of the transmit frame. The predetermined pilot symbol pattern is defined such that pilot symbols are located at or near time boundaries of the resource, at or near frequency boundaries of the resource, or both. By doing so, when generating a channel estimate for the communication channel between the OFDM transmitter and an OFDM receiver based on the pilot symbols, extrapolations needed to estimate the channel near the boundaries of the resource are optimized, thereby improving overall channel estimation accuracy.

Abstract: Systems and methodologies are described that facilitate constructing unitary matrices that may be utilized in linear precoding for multiple-input multiple-output (MIMO) wireless communication systems. Each unitary matrix may be generated by combining (e.g., multiplying) a diagonal matrix with a Discrete Fourier Transform (DFT) matrix. The unitary matrices may be utilized to provide feedback related to a channel and/or control transmission over a channel based upon obtained feedback.

Abstract: A method and device for decoding in a differential orthogonal space-time block coded system are disclosed. The disclosed method includes: (a) receiving signals from a transmitter during a particular time slot segment, where the signals are encoded by differential orthogonal space-time block coding; (b) transforming to reception signals for two sub-systems by using a sum operation and a difference operation of the signals received in step (a), where the transformed reception signals for the two sub-systems maintain an orthogonality of an orthogonal space-time block coded system; and (c) performing decoding using the reception signals for the two sub-systems transformed in step (b). The method provides the advantage of lowering the level of operational complexity for decoding in a communication system that employs differential orthogonal space-time block coding.

Abstract: In general, the subject matter described in this disclosure can be embodied in methods, systems, and program products for transmitting data over discontiguous portions of radio frequency spectrum. Data that is to be wirelessly transmitted to a remote computing device is received. A first signal that encodes the data across a band of radio frequencies is generated. The first signal is split into multiple signals, each of the multiple signals being associated with a different portion of the band of radio frequencies. Each of the multiple signals is filtered to isolate each respective one of the multiple signals to its associated portion of the band of radio frequencies. At least one of the multiple signals is frequency translated. Each of the multiple signals are combined after the filtering of each of the multiple signals. The second signal is provided for wireless transmission by an antenna.

Abstract: A method includes, in a mobile communication terminal, receiving from at least first and second base stations, which cooperate in a coordinated transmission scheme, signals that are transmitted over respective first and second communication channels. Respective channel measures are calculated for the communication channels based on the received signals. First and second feedback data, which are indicative of the respective channel measures of the first and second communication channels, are formulated such that the first feedback data has a first data size and the second feedback data has a second data size, different from the first data size. The first and second feedback data are transmitted from the mobile communication terminal to at least one of the base stations.

Abstract: A system for parallel radio frequency (RF) testing. The system includes a plurality of signal generators, a plurality of signal analyzers, a data bus connected to the plurality of signal generators, and a controller. The controller has a connection to the data bus so as to be in electronic communication with the plurality of signal generators, and has a plurality of point to point links to respective ones of the signal analyzers so as to be in electronic communication with the plurality of signal analyzers.

Abstract: Methods and apparatus are described for processing data in a wireless communication network. Iterative estimation techniques are used to enable tracking of time-varying communication channels. A signal is transmitted over a channel in the network, the signal comprising a sequence of symbols carried on a plurality of sub-carriers. Boot-up estimator (304) estimates, in a time domain, parameters of a model of the channel based on the received signal. A domain converter (206) transforms at least one of the estimated parameters from the time domain to provide at least one transformed parameter in a second domain. An equalizer (210) and decoder (212) determine estimates of symbols from the received signal using the at least one transformed parameter, and tracking estimator (314) updates the estimated model parameters during reception of the signal using at least one estimated symbol.

Abstract: An orthogonal frequency division multiplexing (OFDM) signal transmission apparatus which transmits OFDM signals by using a plurality of transmission antennas includes a subcarrier setting device which sets signals for subcarriers so as to use some of the subcarriers of the OFDM signals as pilot subcarriers to transmit pilot signals and use the remaining subcarriers as data subcarriers to transmit data signals, the subcarrier setting device changing polarities of signals for the pilot subcarriers for each transmission antenna.

Abstract: A system for selecting optimal phase combinations for RF beamformers in a MIMO hybrid receiving systems augmented by RF Distribution Network. The system addresses the issue of providing beamforming gains for a plurality of layers using one common set of weights for each beamformer. The specification may be based on channel estimation of all layers as viewed by all receiving antennas, and maximizing metrics that capture the total received power.

Abstract: A method in a Multiple-Input Multiple-Output (MIMO) transmitter includes selecting a transmission mode from a group of modes including a spatial multiplexing mode and a transmit diversity mode. A rate matching parameter is set depending on at least the selected transmission mode. Data for transmission is formatted in one or more transport blocks, each transport block including multiple code blocks having respective lengths, in symbols, that are respective integer multiples of the rate matching parameter. The code blocks of a given transport block are mapped onto time-frequency resource elements in accordance with the selected transmission mode, such that each resource element contains data originating from only a respective one of the code blocks of the given transport block. The code blocks of the given transport block are transmitted over the time-frequency resource elements to a receiver.

Abstract: Various embodiments associated with multiple signal editions is described. A plurality of sensors can be deployed in an environment. These sensors can be used to capture a signal of interest (SOI). However, when the signal is weak or difficult to sense, what an individual sensor captures may be of little value. Therefore, multiple sensors can be used together to capture the signal (e.g., different editions of the SOI). Further, it is possible that the demodulation scheme of the signal is not known, such as when the signal is from an unknown network (e.g., a network of an enemy). A mathematical operation can be performed upon signal editions such that a result does not include noise. This result can be used in determining the demodulation scheme of the signal.

Abstract: The present invention provides a communication circuit, a communication network, and a connecting apparatus that can realize communication with very high reliability using a simple wiring system, that includes a communication line 2 comprising three or more signal lines 2a,2b,2c, a signal distributing section 4, that is connected to one end of the communication line 2, for distributing and transmitting a signal input into an input terminal 3i to respective signal lines 2a,2b,2c, and a majority selection receiving circuit 5, that is connected to the other end of the communication line 2, for comparing a plurality of reception signals received via the signal lines 2a,2b,2c and selecting reception signals which are most matched with one another as true so as to output them to an output terminal 30.

Abstract: The invention relates to a method of receiving a signal corresponding to a multicarrier signal transmitted via at least one transmission channel, the method comprising an estimation step (11) of estimating said channel and delivering overall information about said channel in the frequency domain, referred to as a “frequency response” and comprising frequency samples. According to the invention, such a method also comprises: a sharing step (12) of sharing said frequency samples in at least two frequency sample vectors; a transform step (13) of transforming said frequency sample vectors from the frequency domain to a transform domain and delivering, for at least one frequency sample vector, a partial response of said channel in said transform domain; and a feedback step (14) of transmitting a return signal back to said transmitter, the return signal conveying samples extracted from said partial responses and representative of said channel in said transform domain.

Abstract: A first wireless device including a receiver and a transmitter. The receiver includes a channel estimation module configured to receive, from a second wireless device over a communication channel, a training packet and estimate a quality of the communication channel based on the training packet, and a modulation and coding scheme (MCS) determination module configured to determine an MCS based on one or more of the training packet and the estimated quality of the communication channel. The transmitter is configured to transmit, to the second wireless device over the communication channel, an indication of the MCS determined by the MCS determination module.

Abstract: A multi-antenna communication method. A transmitter accepts a plurality of n data sources, and a plurality of MT independent data streams are prepared for transmission through a plurality of MT different antennae. The transmitter introduces a sub-symbol offset between symbols in the plurality of MT independent data streams transmitted by adjacent ones of the plurality of MT different antennae. Receivers for receiving and processing the M? independent data streams are also provided.

Abstract: A method includes, in a mobile communication terminal, receiving downlink signals from at least two antennas. A signal covariance matrix for the received signals is calculated. Each diagonal element of the signal covariance matrix is enlarged by a respective antenna-specific value that depends on a respective antenna associated with the diagonal element. Equalizer coefficients are computed based on the signal covariance matrix having the enlarged diagonal elements. The received downlink signals are equalized using the equalizer coefficients.

Abstract: A method for transmitting a sounding reference signal in a MIMO wireless communication system and an apparatus therefor are disclosed. The method for transmitting sounding reference signals (SRSs) in a MIMO wireless communication system comprises receiving sounding reference signal parameters from a base station; receiving information of the number of sounding reference signals which will be transmitted at a transmission time instant from the base station; if a plurality of sounding reference signals are provided, generating the sounding reference signals corresponding to each of the plurality of antennas by using the sounding reference signal parameters; and transmitting the generated sounding reference signals to the base station through their corresponding antennas at a specific transmission instant.

Abstract: The sampling mixer circuit comprises: a clock generating circuit that outputs four-phase control signals the periods of which are in accordance with the carrier frequency of an input signal and the phases of which are different from one another; a voltage-to-current converting circuit that converts a voltage signal based on the input signal to a current signal; four-system charge sharing circuits in which the current signal as converted is input to a plurality of capacitors in accordance with the different phases based on the four-phase control signals and in which charges are exchanged among the plurality of capacitors; and a phase-to-phase capacitor that is selectively connected, on the basis of the four-phase control signals, to the respective ones of nodes, which are other than the input nodes of the current signal, in the four-system charge sharing circuits.

Abstract: A data communication network to transmit and/or receive data using soft-decision information is provided. A target access point in a data communication network may compute soft-decision information with respect to information bits corresponding to a transmission symbol, and transmit the computed soft-decision information to a destination device or an access point connected to the destination device. The destination device or the access point connected to the destination device may combine soft-decision information of a plurality of access points, and detect information bits based on the combined soft-decision information.

Abstract: Data may be transmitted from a RAN node to a wireless terminal using a MIMO antenna array. A plurality of unmapped symbol blocks may be generated. Symbols of a first one of the plurality of unmapped symbol blocks may be mapped to first and second mapped symbol blocks so that the first mapped symbol block includes symbols of the first unmapped symbol block and so that the second mapped symbol block includes symbols of the first unmapped symbol block. The symbols of the first and second mapped symbol blocks may be precoded to provide precoded symbols of respective first and second MIMO precoding layers using a MIMO precoding vector. Each of the precoded symbols of the first and second MIMO precoding layers may be transmitted through the MIMO antenna array to the wireless terminal using a same TFRE. Related devices and terminals are also discussed.

Abstract: Embodiments of a system and methodology are disclosed for aperiodic (i.e., non-periodic) feedback of channel-side information, such as channel rank information, to a base station by having the receiver/UE initiate the feedback instead of using a scheduled feedback approach. The autonomous feedback of channel-side information may use one of several different types of physical channel structures for uplink scheduling requests, such as those being discussed for inclusion in the emerging LTE platform standard.

Abstract: A multi user receiver configured to receive a signal including multiple symbol streams assigned to various users is described. The multiple symbol streams include at least one first symbol stream assigned to a user of the multi user receiver and at least one second symbol stream assigned to another user, wherein a modulation alphabet applied for the at least one second symbol stream is unknown at the multi user receiver. The multi user receiver includes a symbol stream election unit configured to elect a symbol stream of the multiple symbol streams, an equalizer configured to provide an equalized symbol of the elected symbol stream, and a detector configured to generate a detected symbol from the equalized symbol on the basis of a constellation, wherein, if the second symbol stream is elected, the constellation is a mixed constellation including constellation points of at least two of multiple predefined modulation alphabets.

Abstract: A signal received via a fading channel is decoded in radio frequency receiver by first demodulating the signal to a baseband signal, and serial to parallel converting the baseband signal to a precoded signal. Then, a channel matrix is estimated from the precoded signal, and symbols are detected in the precoded signal using the channel matrix. The decoding uses probabilistic data association. The detecting initializes a probability distribution for each symbol, and selects an ordering in which to update the probability distributions. The probability distribution for each symbol are updated according to the ordering, until a termination condition is reached, and then demapped and parallel to serial converted to estimate a sequence of bits used to generate the signal.

Abstract: A method for selecting antenna elements at a base station can include selecting multiple transmit antenna elements from several antenna elements according to a work mode of the base station. The work mode can be an open-loop or a closed-loop working mode. In open-loop mode the base station does not receive feedback information regarding channel quality from a mobile station. In closed-loop mode feedback information is received. For example, for control signaling, or when the speed of a mobile station is very high, the base station may determine that the working mode is open-loop. When the information being transmitted is data for a specific mobile station and the mobile station is moving at a speed under a threshold, the base station may select or determine the working mode to be the closed-loop working mode. Antenna elements are selected, for example, according to a spatial correlation appropriate to the work mode.

Abstract: Example embodiments comprise a diversity receiver, and corresponding method, for measuring a differential phase between a first local oscillator of a first antenna and a second local oscillator of a second antenna in the presence of a primary interference signal and at least one secondary interference signal. The method may comprise receiving a primary communication signal, a primary reference signal and additional reference signals, and processing these signals such that a summation signal does not substantially comprise the at least one secondary interference signal. The estimation of differential phase is achieved by a phase shift calculation between processed signal components, using that a summation of all signal components equals, or is approximately equal to, a predetermined signal.

Abstract: The present invention relates to a method for allowing a terminal to transmit CSI for downlink transmission from a base station through an uplink comprises the steps of: receiving a downlink signal through a downlink channel; generating CSI that contains one or more indicators among an RI, a PMI, and CQI for the downlink channel; and transmitting the CSI through an uplink channel, wherein the CSI can contain one or more pieces of information among a first type of CSI which is determined on the basis of a rank N that is determined by the terminal and a second type of CSI which is determined on the basis of a rank that is restricted by a reference value M.

Abstract: Methods and apparatus for power reduction in a wireless device having multiple receive paths are described herein. A wireless device configured for any one of multiple operating modes may utilize multiple receive signal paths to improve the receive signal quality in each of the operating modes. The wireless device may be configured to dynamically reconfigure a modulation coding scheme to compensate for varying signal qualities in some modes. The wireless receiver may be configured in other operating modes where the modulation coding scheme is fixed for a duration of the operating mode. The wireless device can conserve power when it is operating in a mode supporting a constant modulation coding scheme. The wireless device can determine a signal metric value of the received signals and can selectively power down or deactivate a receive signal path based on the value of the signal metric.

Abstract: Techniques are provided herein to estimate parameters of a wireless communication channel. At each of a first plurality of antennas of a first wireless communication device, a transmission is received that is associated with each of one or more spatial streams transmitted via a second plurality of antennas of a second wireless communication device. The transmission comprises at least first and second training fields which are configured for channel estimation. Multidimensional channel information between the first plurality of antennas and the second plurality of antennas is computed from receive values in the first and second training fields for one more dimension above a number of the spatial streams transmitted by the second wireless communication device and up to a lesser of a number of the first plurality of antennas and a number of the second plurality of antennas.

Abstract: A codebook C is provided in a MIMO transmitter as well as a MIMO receiver. The codebook C will include M codewords ci, where i is a unique codeword index for each codeword ci. Each codeword defines weighting factors to apply to the MIMO signals, and may correspond to channel matrices or vectors to apply to the MIMO signals prior to transmission from the respective antennas of the MIMO transmitter. The present invention creates codeword subsets Si for each codeword ci of the codebook C. Each codeword subset Si defines L codewords cj, which are selected from all the codewords ci in the codebook C. The codewords cj in a codeword subset Si are the L codewords in the entire codebook that best correlate with the corresponding codeword ci.