Abstract: A receiving device according to the present invention includes: a receiver for receiving an OFDM symbol that is modulated by phase shift keying; an FFT processor for applying an FFT process to the received OFDM symbol to obtain a subcarrier signal; a demapping unit for demapping the subcarrier signal to generate a bit string; a norm calculator for calculating the norm of the subcarrier; a weighting factor generator for generating a weighting factor by taking the statistics of the calculated norm; and a weighting unit for obtaining a soft decision value by weighting the bit string after demapping, based on the particular weighting factor. Thus, the receiving device can obtain a soft decision value to achieve good decoding performance with a small number of known signals and processes.

Abstract: A method uses a set of reference symbols. The method includes receiving a first symbol, comparing the first symbol to the set of reference symbols, and selecting a reference symbol from the set of possible reference symbols. The set of reference symbols are adjusted by a set of respective error factors for each of the reference symbols. The reference symbol is selected when it matches the first symbol. The method also includes adjusting the respective error factor for the reference symbol in accordance with a difference between the first symbol and a remodulated reference symbol in one embodiment.

Abstract: Forward error correction (FEC) m-bit symbol modulation. Any desired FEC, error correction code (ECC), and/or combination thereof generates coded bits for combination with either uncoded bits, separately generated coded bits, and/or combination thereof to generate a number of symbols that undergo mapping to a constellation whose respective constellation points have a mapping characterized by a maximum minimum intra-Euclidean distance between the respective constellation points thereby generating a sequence of discrete-valued modulation symbols. The sequence of discrete-valued modulation symbols may then undergo modulation of any of a number of different operations (e.g., digital to analog conversion [e.g., digital to analog converter (DAC)], scaling, frequency shifting, filtering, etc.) to generate a continuous time signal for transmission via a communication channel. Such a device operative to perform including such functionality, circuitry, capability, etc.

Abstract: Data transmission is disclosed over a transmission channel that is subject to narrowband interferers. An increased overall bit or data transmission rate is achieved by an exemplary method of determining a channel capacity of plural sub-channels of the transmission channel based on a net background noise power estimation. The net background noise power contains only white noise-like contributions and excludes, to a reasonable extent, noise contributions or signal power from narrowband interferers. Hence, the net background noise power can be reduced. For example, an Orthogonal Frequency Division Multiplex (OFDM) signal code construction or bit allocation scheme can be chosen that provides for optimized data transmission at a data rate that approximates or approaches the more realistic channel capacity of an individual sub-channel, resulting in an increased overall bit or data transmission rate.

Abstract: Interference in a received orthogonal frequency division multiplexing (OFDM) symbol, modulated according to selected constellation points sk, is reduced. The symbol includes a set of pilot signals and a set of data signals yk, where k is a number of consecutive subcarriers used for the pilot and the data signals. The pilot signals are thresholded to detect interfering pilot signals, which are then erased. Channels ?k are estimated using remaining pilot signals. The set of data signals are decoded based on the estimated channels ?k, and, for each bit bi in the set of data signals, a logarithmic likely ratio (LLR) log ? ? s k : b i = 0 ? 1 ? y k - H ^ k ? s k ? 2 ? s k : b i = 1 ? 1 ? y k - H ^ k ? s k ? 2 is determined. The LLR is an indicator of the likely interference.

Abstract: A method for performing wireless communications and an associated apparatus are provided, where the method is applied to an electronic device. The method includes the steps of: receiving at least one data stream, wherein each data stream from the at least one data stream is transmitted from a wireless channel; in a first iteration, utilizing a Maximum Likelihood (ML) estimator to perform demapping processing on at least one portion of the at least one data stream to obtain Log-Likelihood Ratios (LLRs) of the first iteration and performing Turbo decoding according to the LLRs of the first iteration to generate resultant LLRs of the first Iteration; and in at least one following iteration, utilizing a Max A Posterior (MAP) estimator to perform demapping processing on at least one portion of the at least one data stream and performing Turbo decoding, successively, in order to cancel interference due to the wireless channel.

Abstract: A maximum a posteriori (MAP) decoding apparatus and method are provided, which select a path having a maximum value without calculating all path metrics by generating metric difference vectors based on generated tables, calculating metrics of a path formed through a combination of a state and a branch each having a maximum metric, and calculating an index and a metric of a current state to which a calculation value is to be applied based on a result of comparing a state metric difference vector and a branch metric difference vector.

Abstract: Methods and apparatus are disclosed for estimating a quality of a received data frame in a trellis decoder. The decoder utilizes a trellis diagram to depict the states and stages the decoder transitions through in search of a sequence of bits that closely resemble the received sequence. In the trellis diagram, each state at one stage is connected to a state at the next stage by a branch and a group of connected branches form a path. The decoder selects a winning path by comparing path metrics computed for each of the paths in the trellis diagram and outputs a most-likely sequence of hard bits from the winning path. A count of non-ideal branches over the winning path can be used for calculating the frame quality of the received data frame or the burst quality of a data burst in the received data frame.

Abstract: A receiver is configured to receive a sample of an inter-symbol correlated (ISC) signal, the sample corresponding to a time instant when phase and/or amplitude of the ISC signal is a result of correlation among a plurality of symbols of a transmitted symbol sequence. The receiver may linearize the sample of the ISC signal. The receiver may calculate a residual signal value based on the linearized sample of the ISC signal. The receiver may generate an estimate of one or more of said plurality of symbols based on the residual signal value. The linearization may comprise applying an estimate of an inverse of a non-linear model. The non-linear model may be a model of nonlinearity experienced by the ISC signal in a transmitter from which the ISC signal originated, in a channel through which the ISC signal passed en route to the receiver, and/or in a front-end of the receiver.

Abstract: An apparatus of processing a time domain synchronous orthogonal frequency-division-multiplexing (TDS-OFDM) signal is provided. The apparatus includes a receiving block and a demodulating block. The receiving block receives the TDS-OFDM signal, and generates a down-converted signal according to the received TDS-OFDM signal. The demodulating block is coupled to the receiving block, and demodulates the down-converted signal to generate a transport stream. The demodulating block has a transmission parameter signaling (TPS) decoder implemented for performing a TPS decoding operation to generate a TPS decoding result and verifying a spectrum direction of the received TDS-OFDM signal according to the TPS decoding result.

Abstract: Data communication devices, methods, and systems are discussed in this application. In one embodiment, a receiving apparatus generally comprises a detector, an indicator, and a decision device. The detector can detect a number of data streams contained in a signal received on a single physical channel. Detection can be made by comparing a received signal with one or more predetermined sequences and identifying one or more of the plural predetermined sequences as being likely contained within the received signal. Each data stream can be associated with at least one predetermined sequences. The indicator can provide an indication of the data streams likely contained in the signal based on the identified sequences. A decision device can provide data defining a receiver configuration based on the indication, the receiver configuration being suitable for configuring a decoder to decode only the one or more data streams indicated as being likely contained in the signal.

Abstract: A receiver for processing frequency division multiplexing (FDM) signals, the receiver includes a processor configured to: convert the FDM signals from at least two transmitters into frequency domain signals; determine a first component of the frequency domain signals, the first component of the frequency domain signals comprising a channel noise and a composite residual inter-carrier interference (ICI) contributed by the at least two transmitters; calculate a set of correlation values corresponding to the first component of the frequency domain signals; and process the first component of the frequency domain signals based on the set of correlation values.

Abstract: The present disclosure provides an orthotope sphere decoding method of a multiple antenna system. The method includes: tree mapping a node having highest pruning potential that can be predicted at a root of a tree of orthotope sphere decoding to a root level of the tree, among nodes to be mapped to the tree; and performing tree search of the orthotope sphere decoding on the nodes mapped to the tree.

Abstract: A low-complexity optimal soft MIMO detector is provided for a general spatial multiplexing (SM) systems with two transmit and NR receive antennas. The computational complexity of the proposed scheme is independent from the operating signal-to-noise ratio (SNR) and grows linearly with the constellation order. It provides the optimal maximum likelihood (ML) solution through the introduction of an efficient Log-likelihood ratio (LLR) calculation method, avoiding the exhaustive search over all possible nodes. The intrinsic parallelism makes it an appropriate option for implementation on DSPs, FPGAs, or ASICs. In specific, this MIMO detection architecture is very suitable to be applied in WiMax receivers based on IEEE 802.16e/m in both downlink (subscriber station) and uplink (base station).

Abstract: Systems, methods, and other embodiments associated with data decoding are described. According to one embodiment, a method includes receiving an output value from one of a first block and a second block that form a pair of concatenated decoding blocks. The method includes determining a value of a modification criteria and modifying the output value based, at least in part, on the value of the modification criteria to form a modified output value. The modified output value is input to one of the first and second decoding blocks.

Abstract: The present invention disclosed a method for operating a software radio receiver. Said method comprises receiving a radio signal, determining a signal quality of said radio signal, selecting a suitable algorithm for a function in the receiver in accordance with said determined signal quality and applying said selected algorithm to the radio signal.

Abstract: Systems and methods for decoding block and concatenated codes are provided, including channel state information estimation such as by using optimum filter lengths based on channel selectivity and adaptive decision-directed channel estimation. These improvements enhance the performance of various communication systems and consumer electronics, including HD Radio receivers and systems.

Abstract: Embodiments of the present invention disclose a data decoding method and apparatus, relate to the field of wireless communications, and can improve a resource utilization rate in a decoding process, thereby improving decoding efficiency. The method of the present invention includes: dividing a to-be-decoded data transport block into N code blocks, where N is an integer greater than or equal to 2; and decoding the N code blocks in parallel according to a reverse direction of encoding. The present invention is applicable to data decoding.

Abstract: A wireless communications device and method carries out a process including estimating channel information based on a received signal; generating pseudo-transmission signal point candidates based on the channel information and/or transmission signal point candidates; and generating a replica of the received signal based on the pseudo-transmission signal point candidates and the estimated channel information. The process further includes performing matrix operations on the basis of the received signal and the replica thereof; selecting pseudo-transmission signal point candidates which have a greater effect on likelihood calculations; reverting the selected pseudo-transmission signal point candidates to original transmission signal point candidates and calculating final likelihoods; and restoring the received signal on the basis of the calculated likelihoods.

Abstract: A system and method for estimating a channel in a wireless receiver is disclosed. The method comprises receiving a block of “n” transmitted symbols, the symbols including pilot symbols and “d” data symbols, estimating a channel using the pilot symbols to create a channel estimate, choosing a group of “m” strongest symbols from the “d” received symbols, compensating the “m” strongest symbols using the channel estimate to create a group of “m” compensated symbols, re-estimating the channel using the group of “m” compensated symbols and pilot symbols; and either (1) repeating the steps of choosing a group of “m” strongest symbols, compensating the group of “m” strongest symbols and re-estimating the channel, or (2) using a latest channel estimate to compensate all symbols within the block. The system comprises a wireless receiver having an estimator programmed according to the method.

Abstract: A method and an apparatus for generating soft-decision information in a multiple antenna system are provided. The method includes determining Q candidate symbol vectors for a first transmission symbol of a received signal vector by performing parallel detection on a received signal vector and a channel matrix, determining a candidate symbol vector having a shortest Euclidean distance to the received signal vector from among the Q candidate symbol vector, as an approximate Maximum Likelihood (ML) symbol vector, determining (Q?1) candidate symbol vectors for each of the remaining transmission symbols of the received signal vector by performing partial parallel detection on the received signal vector and the channel matrix using the approximate ML symbol vector, and calculating Log Likelihood Ratios (LLRs) of bits of the first transmission symbol using the candidate symbol vectors, wherein Q represents a modulation order.

Abstract: Providing for soft error decoding for wireless relay networks is described herein. By way of example, a wireless node in a wireless relay network can receive a direct signal from a source node, and can receive a forwarded version of the source signal from a relay node. An information flag included with the forwarded version is referenced to determine whether the relay node properly received the source signal. If the relay node received the source signal with an error and a destination node received the source signal with an error, soft decision information can be generated from the forwarded version of the source signal and employed to assist with decoding of the source signal at the destination node. The soft-decision information improves end-to-end performance of the wireless relay system, while mitigating complexity and bandwidth requirements for the relay node as compared with conventional signal decoding techniques.

Abstract: Systems and methods are provided for decoding signal vectors in multiple-input multiple-output (MIMO) systems, where the receiver has received one or more signal vectors from the same transmitted vector. For each received signal vector, the receiver evaluates a decoding metric using each possible value of the transmitted signal vector to produce a set of distances. The receiver then combines distances from across the received signal vectors to produce a combined distance associated with each possible value of the transmitted signal vector. Using the combined distances, the receiver may choose among the possible values of the transmit signal vector to determine the actual transmit signal vector.

Abstract: Decoder and communications devices including such decoders can obtain a convolutional coded bit stream including a plurality of coded data bits. According to some implementations, if a signal quality associated with the convolutional coded bit stream is above a predetermined threshold, a decoded value for each information bit may be calculated at least from a modulo 2 sum of a coded data bit added to at least one other coded data bit, at least one previously calculated information bit, or a combination of at least one other coded data bit and at least one previously calculated information bit. Also, according to some implementations, if the signal quality associated with the convolutional coded bit stream is not above the predetermined threshold, the convolutional coded bit stream may be decoded with a conventional convolutional decoding scheme. Other aspects, embodiments, and features are also claimed and described.

Abstract: An apparatus and method for power control are provided. In a receiver in a mobile communication system, a Receive (Rx) signal received through a plurality of antennas is estimated. A power ratio between a traffic channel of the Rx signal and a pilot channel of the Rx signal is determined. A Log Likelihood Ratio (LLR) value is determined using the power ratio between the traffic channel and the pilot channel, a symbol of the traffic channel, and an Rx signal estimation value to which precoding is applied.

Abstract: Certain aspects of the present disclosure provide a system and method for improving performance of HARQ operation in a wireless communication system. The proposed method enables a receiver to update a receive buffer only if newly received values corresponding to a data packet are more reliable than previous values corresponding to the same data packet (that are stored in the receive buffer). The receiver may use the more reliable information (e.g., the newly received values or the previously stored values) for decoding.

Abstract: An error correction data processing apparatus includes a noise predictive calibration circuit operable to calibrate a first set of filter coefficients based on a first data set and a second set of filter coefficients based on a second data set, and includes a first noise predictive detector operable to receive the first set of filter coefficients. The apparatus further includes a decoder operable to perform a first global iteration with the first noise predictive detector and determine a violation check count value, and a second noise predictive detector operable to receive the second set of filter coefficients if the violation check count value is less than a predetermined value or receive the first set of filter coefficients if the violation check count value is greater than the predetermined value.

Abstract: Receivers for recovering ancillary data from parallel concatenated convolutional coding. (PCCC) imbedded in digital television (DTV) signals can utilize the non-systematic (207, 187) Reed-Solomon (RS) codewords included in the DTV signals to facilitate DTV receivers already in the field to continue being able to receive main-service transmissions. Such a receiver attempts to decode each non-systematic (207, 187) RS codeword in a time slot selected for reception. If such RS decoding is successful, indication of such success is used to verify the correctness of bits of the ancillary data or correct them when turbo decoding the PCCC encoding ancillary data in the time slot selected for reception. The updating of ancillary data bits during cycles of turbo decoding updates the non-systematic (207, 187) RS codewords in the time slot selected for reception, increasing the likelihood of RS decoding of those RS codewords being successful during subsequent cycles of turbo decoding.

Abstract: To provide a receiving device, a receiving method, and a receiving program, which are capable of reducing performance degradation in a case where the spatial correlation of a channel becomes high. A transmission signal candidate search unit searches for a transmission signal in a direction in which reception performance is degraded, in MIMO signal detection. A transmission signal candidate generation unit generates transmission signal candidates while suppressing degradation due to the spatial correlation of a channel. In a decision unit, using the transmission signal candidates generated in the transmission signal candidate generation unit, a maximum likelihood sequence is obtained. The maximum likelihood sequence is obtained as transmission signal candidates where a metric is calculated and the metric becomes a minimum.

Abstract: A method of operation of a communication system includes: utilizing an estimation module estimating a log-likelihood ratio for a transmission; and utilizing a slicing module, coupled to the estimation module, slicing a constellation by: reading the log-likelihood ratio from the estimation module, defining a threshold within the constellation, and adjusting the threshold based on the log-likelihood ratio for determining a symbol.

Abstract: A detection process for a receiver of a wireless communication system based on Multiple-Input Multiple-Output antennas (nT, nR), said receiver processing observations symbols y derived from symbols x transmitted by an emitter through a channel H; characterized in that it involves: —a preprocessing which only depends on the channel H, said preprocessing involving: —a first QRD decomposition (61) for the purpose of decomposing said channel H into two Qext and Rext matrices, with QextHQext=/and Rext being upper triangular; —a lattice reduction (62) for the purpose of generating Qext, Rext and a transformation matrix T; —a second QRD decomposition (63) applied on the matrix Rext T?1 for the purpose of generating two matrixes Q?ext and R?ext, —a loading phase (64, 65, 66) comprising a linear detection process of the observations y for the purpose of generating a value xcenter; —a neighborhood search (67-70) performed in the Original Domain Neighborhood (ODN) with a search center being equal to the result xcenter o

Abstract: A signal processing apparatus is disclosed which includes: a detection section configured such that based on a result of the error correction of a signal generated by a single carrier system, the detection section detects the presence or absence of spectrum inversion in the signal; and a selection section configured such that if the detection section detects the spectrum inversion, the selection section selects the spectrally inverted signal as the signal subject to the error correction, and that if the detection section does not detect the spectrum inversion, then the selection selects the spectrally uninverted signal as the signal subject to the error correction.

Abstract: A method of processing a signal within a receiver can include generating, using the receiver, a candidate list including at least one entry for a signal. Each entry can include a candidate symbol vector and an L1-Norm error metric. The method can include, for each entry, generating an L1-Norm transformation from the L1-Norm error metric, wherein the L1-Norm transformation depends upon a function of a number of receiving antennas of the receiver. The signal can be decoded using the candidate list including the L1-Norm transformations.

Abstract: A method of generating normalized bit log-likelihood ratio (LLR) values. A signal is received in a frequency band after transmission over a media, wherein the signal includes at least one complex data symbol having a plurality of information bits, and the complex data symbol is transmitted on at least one frequency channel. Initial LLR values are calculated for each of the plurality of information bits based on bit-to-symbol mapping of modulation and noise variance information from the complex data symbol. An average signal to noise ratio (SNR) of the frequency channel is calculated. Each initial LLR value is normalized by dividing by the average SNR to generate a plurality of normalized LLR values. The normalized LLR values may be quantized to provide a finite-bit representation.

Abstract: The present invention employs a look up table based implementation for the metric computations which eliminate redundancy and substantially reduce the number of multiplications. Moreover, inventive method exploits the fact that the un-normalized constellation symbols are complex integers so that the product of a real-number and an un-normalized constellation symbol can be implemented by only additions. The inventive method also enables a greater efficiency for whitening colored noise prior to demodulation, one of which involves no square-root operation. The invention results in less complexity, faster operation, lower power consumption, without sacrificing performance.

Abstract: A mobile wireless communications device may include an antenna, and a receiver coupled to the antenna and being configured to use a modulation having memory for a received message in a block structure. The block structure may include a pair of mini-probes and a body therebetween. The receiver may be configured to demodulate the received message by determining a corresponding set of received signal characteristic values based upon the pair of mini-probes, and determining a decode starting point in the body based upon the set of received signal characteristic values. The receiver may be configured to demodulate the received message by at least, from the decode starting point, decoding the body in a first time direction, and decoding the body in a second time direction based upon a result of the decoding in the first direction.

Abstract: Log-likelihood ratios produced by a decoder are incorporated into a soft symbol to soft bit estimation process and are used to perform improved channel estimation and impairment covariance estimation. In an example method, a plurality of soft bits and corresponding probability metrics for a series of received unknown symbols are generated. Estimates of the received unknown information symbols are then regenerated, as a function of the soft bits and corresponding probability metrics. An estimate of the average amplitude of the received unknown information symbols, or an estimate of the propagation channel response experienced by the received unknown information symbols, or both, are calculated, as a function of the regenerated symbol estimates. The results are applied to produce demodulated symbols for a second decoding iteration for the series of received unknown symbols.

Abstract: A decoding device includes: a determination unit that determines whether or not a decoding ending condition is satisfied at an interval shorter than an interval of one decoding process in repeated decoding and ends the process in the middle of the one decoding process in a case where the decoding ending condition is satisfied.

Abstract: Systems and methods for decoding block and concatenated codes are provided, including channel state information estimation such as by using optimum filter lengths based on channel selectivity and adaptive decision-directed channel estimation. These improvements enhance the performance of various communication systems and consumer electronics, including HD Radio receivers and systems.

Abstract: Techniques are provided for decoding tail-biting convolutional codes by using information within the received data stream that traditionally has not been used or been available to the convolutional decoder, e.g., cyclic redundancy check (CRC) and bit information known by both the transmitter and receiver. Further, a single parallel trace-back is used that reduces implementation complexity. In addition, the least reliable decisions made during forward processing may be reversed in order to generate additional possible codeword candidates. These techniques can be used to reduce false detection rates (FDRs) and/or detection error rates (DERs).

Abstract: The present disclosure presents methods and apparatuses for enhanced received signal processing using signal-based channel impulse response (CIR) estimation. For example, according to an example method presented herein, a user equipment (UE) or a component therein may receive a signal corresponding to a transmitted signal sent by a network entity, wherein the transmitted signal comprises at least a data channel, estimate chip contents of the transmitted signal, based on the received signal including the data channel, to obtain estimated chip contents, and compute an estimated channel impulse response (CIR) based on at least the estimated chip contents. Based on this estimated CIR, the UE may thereafter reprogram a received signal reconstruction filter, perform interference cancellation procedures, and/or adjust one or more equalizer taps. By performing such functions, the UE may exhibit improved communication characteristics and enable a more robust user experience.

Abstract: A receiver system and method for recovering information from a symbol data sequence Y. The symbol data sequence Y corresponds to a symbol data sequence X that is transmitted onto the channel by a transmitter. The symbol data sequence X is generated by the transmitter based on associated information bits. At the receiver, a set of two or more processors operate in parallel on two or more overlapping subsequences of the symbol data sequence Y, where each of the two or more overlapping subsequences of the symbol data sequence Y corresponds to a respective portion of a trellis. The trellis describes redundancy in the symbol data sequence Y. The action of operating in parallel generates soft estimates for the associated information bits. The soft estimates are useable to form a receive message corresponding to the associated information bits.

Abstract: Systems and methods for computing log likelihood ratios in a communication system are described. A demodulated symbol may be received. A set of scalars may be determined based on a modulation order, a signal-to-noise ratio for the symbol, and a bit of the symbol. At least one log likelihood ratio for the bit may be approximated using a piecewise linear process based on the scalars and the symbol.

Abstract: A disk drive is configured to decode data written over a plurality of data tracks using joint self-iterating soft equalization and an iterative turbo 2-D MAP-based detection, by performing soft self-iterating linear 2-D MMSE equalization on received input samples; computing MMSE estimates for coefficients of a 2-D equalization filter based on a-priori values, mean of the a-priori values, the 2-D filter and the received input samples; updating the coefficients of the 2-D filter using a variance based on the a-priori values when carrying out a first iteration and based on an extrinsic LLR when carrying out subsequent iterations; determining values of the individual bits in the input samples using the updated coefficients; computing an output LLR of each individual received sample based on the computed MMSE estimate, the mean and the variance, and computing the extrinsic LLR by subtracting a priori LLR from the output LLR.

Abstract: A method for operating a decoder includes receiving a complex signal representative of a received symbol from among a plurality of symbols. The received symbol includes a plurality of bits and corresponds to a respective point on a constellation map. Likelihood metrics are generated for the received symbol, with each likelihood metric reflecting a likelihood of the received symbol corresponding to one of the points on the constellation map. The likelihood metrics are arranged in columns and rows. Common likelihood metrics are determined for each column and for each row. The common likelihood metrics are compared to determine a best likelihood metric for the bits in the received symbol that are to be compared by columns, and to be compared by rows.

Abstract: The present inventions are related to systems and methods for data processing, and more particularly to systems and methods for detecting patterns in a data stream.

Abstract: In one aspect, the present disclosure provides an advantageous generalization of a SLIC receiver structure, by allowing multiple solutions to survive at any one or more of the serial stages included in the SLIC receiver. Where any given stage produces multiple solutions, the next stage of the SLIC receiver processes those multiple input solutions to produce multiple output solutions. Consequently, the contemplated SLIC receiver effectively builds a tree structure with as many levels as there are stages in the SLIC receiver. Such operations allow the SLIC receiver to form two or more solution threads spanning the stages, and to make an improved overall demodulation decision for a received symbol vector by selecting the best solution thread. Further, the additional complexity of allowing multiple survivor solutions at one or more SLIC stages is controlled in one or more embodiments, using survivor pruning for example.

Abstract: The detector comprises a plurality of detection stages connected to a summator for providing a summation signal as a logarithmic representation of the input signal to a first input of a data slicer and an input of an average filter having an output connected to a second input of the data slicer. The data slicer has a data slicer output for providing an extracted digital data signal in dependence on a comparison of the summation signal and an output signal of the average filter. The average filter receives a first pre-charge voltage and a second pre-charge voltage depending on an output signal of a carrier detector circuit detecting a carrier signal of the input signal.

Abstract: Techniques to calibrate downlink and uplink channels to account for differences in the frequency responses of transmit and receive chains are described. In one embodiment, pilots are transmitted on downlink and uplink channels and used to derive estimates of the downlink and uplink channel responses, respectively. Sets of correction factors are then determined based on estimates of downlink and uplink channel responses. A calibrated downlink channel is formed using a first set of correction factors for the downlink channel, and a calibrated uplink channel is formed using a second set of correction factors for the uplink channel. The first and second sets of correction factors may be determined using a matrix-ratio computation or a minimum mean square error computation. The calibration may be performed in real-time based on over-the-air transmission. Other aspects, embodiments, and features are also claimed and described.

Abstract: A joint soft output ML receiver that is able to reduce interference based on partial transmission information (i.e., without knowing the existence of other layers or other users and their modulation schemes) is described. In one implementation, the partial information based joint ML receiver can achieve performance that is similar to full information based joint ML receivers even when full information regarding the interfering UE is not available at the desired UE due to transparent Multi-user Multiple Input and Multiple Output (MU-MIMO) transmission (such as with TM 8 and TM 9 transmissions in EUTRA LTE).