Abstract: A method and system for estimating noise variance. A method for noise variance estimation comprises receiving a first multi-sample symbol and receiving a second multi-sample symbol. The first multi-sample symbol is subtracted from the second multi-sample symbol to produce a set of noise samples. The set of noise samples is used to produce a noise variance estimate. The noise variance estimate is applied in various tasks (e.g. channel estimation, log-likelihood ratio computation, and/or minimum mean squared error equalization) to process data provided to a user.

Abstract: Systems and methods for dual-carrier modulation (DCM) encoding and decoding for communication systems. Some embodiments comprise a DCM encoder for applying a pre-transmission function to at least one 16-QAM input symbol and mapping resulting transformed symbols onto at least one larger constellation prior to transmission. Some embodiments joint decode, by a DCM decoder, a predetermined number of received data elements and compute a set of log-likelihood ratio (LLR) values for at least eight bits from a resulting at least one transformed symbol.

Abstract: Embodiments of the disclosure provide a cross coupled position engine architecture for sensor integration in a Global Navigation Satellite System. In one embodiment, a data processing engine for processing inertial sensor data within a positioning system receiver is disclosed. The data processing engine includes a first input for receiving the sensor data, and a second input for receiving a positioning data. The data processing system also includes a memory and a processor. The processor of the data processing system is coupled to the memory and to the first and second input. The processor of the data processing system is configured to calculate a net acceleration profile data from the inertial sensor data and from the positioning data. The net acceleration profile data calculated by the processor of the data processing system is used for the Global Positioning System (GPS) receiver to subsequently calculate a position and a velocity data.

Abstract: A method and apparatus for detecting symbols in a Multiple-Input Multiple-Output Orthogonal Frequency Division Multiplexing (“MIMO-OFDM”) system. A MIMO-OFDM receiver includes a first detector that estimates a symbol of a first MIMO-OFDM sub-carrier and a second detector that estimates a symbol of a second MIMO-OFDM sub-carrier. The second detector differs in complexity from the first detector. A detector control block is coupled to the detectors. The detector control block assigns the first detector to process the first MIMO-OFDM sub-carrier and assigns the second detector to process the second MIMO-OFDM sub-carrier. The detector control block computes a list metric for a sub-carrier. Based on the list metric the detector control block assigns a candidate symbol list length to the detector processing the sub-carrier. Alternately, the detector control block assigns one of a variety of detector types to a sub-carrier based on the sub-carrier list metric.

Abstract: Embodiments provide a system and method for efficiently classifying different channel types in an orthogonal frequency division multiplexing (OFDM) system. Embodiments quantify the frequency selectivity in a channel by measuring the variation in a particular channel statistic across sub-carriers in an OFDM system, involve minimal complexity in implementation, and can be used in a variety of scenarios. One embodiment is a method for classifying channels in an OFDM system, comprising measuring variation of at least one channel statistic across sub-carriers, quantifying the variation to determine a measurement value, and applying the measurement value to at least one threshold to classify the channel.

Abstract: Systems and methods for providing multiple-input multiple-output (MIMO) detection, comprising a leaf node predictor for receiving a processed communications stream, computing at least one channel metric corresponding to the communications stream for a given channel realization by optimizing a predetermined probability, and analytically generating at least one parameter to output, which at least one parameter corresponds to at least one predicted best leaf node candidate for the given channel realization. The leaf-node predictor may generate, in real-time and without using a look-up table, at least one parameter directly from a given channel metric. Some embodiments analytically generate at least one parameter value for use by a MIMO detector corresponding to a channel metric and store the generated at least one parameter value and corresponding channel metric in a look-up table.

Abstract: A navigation system determines its usage mode. In some embodiments, a method comprises determining a usage mode of a navigation system based on at least one of an acceleration indicator, a speed indicator, and a magnet sensor. The usage mode is at least one of a pedestrian mode, a vehicular mode, an aerial mode, a train mode, and a marine mode. The method further comprises configuring a navigation subsystem based on the usage mode.

Abstract: A method for building a look-up table for a receiver in a multiple-input multiple-output (MIMO) detection system simulates a MIMO detector over many channel realizations, tracks channel metric and parameter values used for each channel realization resulting from such simulating, and stores, in a look-up table, best values of the tracked values used for a particular channel metric.

Abstract: Embodiments provide systems and methods for a novel multiple-input multiple-output (MIMO) equalization technique that produces a channel matrix that contains partly real coefficients and partly complex coefficients, referred to herein as a hybrid-MIMO equalization. MIMO detectors can exploit the hybrid-MIMO equalization to reduce complexity. Some embodiments provide systems and methods for equalizing a communication channel comprising receiving as an input a channel output vector, dividing the input into two vectors, a first vector that remains a complex number and a second vector that contains only real numbers, separating the second vector into its real and imaginary components, and regrouping the first and second vectors into a hybrid channel output vector that contains both real and complex coefficients.

Abstract: A Multiple-input Multiple-Output (MIMO) receiver is provided. The MIMO receiver comprises a parameterized sphere detector having two search modes. During a first search mode, the parameterized sphere detector enumerates a number of best candidate vectors up to a fixed parameter value. During a second search mode, the parameterized sphere detector enumerates additional candidate vectors using a greedy search until a predetermined number of candidate vectors have been enumerated.

Abstract: A method and system for generating a set of candidate symbols. A system includes a Multiple Input Multiple Output (“MIMO”) receiver. The receiver includes a candidate generation look-up table (“LUT”) that provides a list of candidate values for a transmitted symbol selected from a constellation of symbols. The candidate generation LUT stores candidate lists for a portion of the constellation of symbols. The portion of the constellation for which candidate lists are stored is selected according to a symmetry of the constellation. The LUT preferably provides a secondary constellation superimposed on a decision region of a primary constellation. The LUT also preferably includes an inner point of the primary constellation and outer points of the primary constellation. The primary and secondary constellations are preferably compressed by application of quadrant, mirror, and inner-point symmetries.

Abstract: A method and system for performing Multiple-Input Multiple-Output (“MIMO”) detection that reduces complexity by decomposing MIMO detection problem into two less complex problems, Candidate List generation and Interference Cancellation (“CLIC”). Embodiments of the CLIC framework parse an N element channel output into a first set containing S elements and a second set containing N?S elements. A first list of candidate vectors is generated from the first set of elements. A set of interference cancelled elements is generated by using the first list of candidate vectors to cancel interference from the second set of elements. A second list of candidate vectors is generated from the set of interference cancelled elements. A minimum cost is computed for each bit of the candidate vectors and from the costs a log-likelihood ratio is computed.

Abstract: Systems and methods for dual-carrier modulation (DCM) encoding and decoding for communication systems. Some embodiments comprise a DCM encoder for applying a pre-transmission function to at least one 16-QAM input symbol and mapping resulting transformed symbols onto at least one larger constellation prior to transmission. Some embodiments joint decode, by a DCM decoder, a predetermined number of received data elements and compute a set of log-likelihood ratio (LLR) values for at least eight bits from a resulting at least one transformed symbol.

Abstract: Embodiments provide systems and methods for improved multiple-input, multiple-output (MIMO) detection comprising generating at least one list of candidate vectors by employing lattice enumeration which approximates hyperellipsoid detection search space and calculating a reliability of the candidate vectors. At least one advantage to embodiments is that improved detection occurs because detection can be performed in a search space defined by the eigenvectors (which define the general shape of an ellipsoid/hyperellipsoid, depending upon number of dimensions) and eigenvalues (which provide the appropriate scaling in each direction of the eigenvectors) of the effective channel.

Abstract: In at least some embodiments, an electronic device includes a navigation system receiver and a receiver motion estimator coupled to the navigation system receiver. The receiver motion estimator determines and provides a receiver motion estimation to the navigation system receiver to reduce complexity of a satellite signal search operation performed by the navigation system receiver.

Abstract: Embodiments of the invention provide a system and method of hybrid automatic repeat-request (HARQ) processing. A viterbi decoder is coupled to and follows a descrambler. After the signal has been de-scrambled, it can be stored in a memory in case it needs to be recombined with another packet. This means that the log-likelihood ratios LLRs for each transmitted bit are stored in memory using a finite number of bits (for example, between 4 and 12 bits). If the packet that is currently being processed contains retransmitted information, then the de-scrambled output stored from a previous packet containing the same information can be loaded and combined with the current packet.

Abstract: Embodiments of the invention provide a method of detecting movement to aid GNSS receivers. By detecting when the user is stationary, the Doppler frequency estimation can be corrected or the SNR can be boosted more both of which lead to improved performance. The embodiments allow a GNSS receiver to process signals in when the signal level would otherwise be too low—for example indoors. The embodiments can improve performance when one or more satellites are temporarily blocked but one or more satellites are still being tracked.

Abstract: A system and method for operating an FM system and wireless networking system coexistent in a mobile wireless device. A mobile wireless device includes a frequency modulation (“FM”) system that includes an FM transmitter and, optionally, an FM receiver. The mobile wireless device also includes a wireless networking system having a network receiver. The FM system is configured to disable the FM transmitter if an amplitude of a modulating signal provided to the FM transmitter is below a predetermined threshold.

Abstract: A system and method for operating a wireless transmitter and a global navigation satellite (“GNSS”) receiver coexistent in a mobile wireless device. A mobile wireless device includes a GNSS receiver and a wireless networking system. The wireless networking system includes a wireless transmitter. The wireless transmitter provides a first interference level signal to the GNSS receiver. The first interference level signal indicates a level of interference that the GNSS receiver can expect due to operation of the transmitter.

Abstract: Systems and methods for hybrid automatic repeat-request (HARQ) communication, comprising a transmitter employing hybrid automatic repeat-request (HARQ) and able to retransmit an incorrectly received packet without differently re-encoding data bits. The transmitter is further able to select at least one bit from any in a set to forward in at least one retransmission. The set contains any bits punctured from an original transmission corresponding to the retransmission. Other embodiments transmit, by a transmitter using hybrid automatic repeat-request (HARQ), a packet containing at least one punctured bit, select—without differently re-encoding data bits—at least one bit from any in a set to forward in at least one re-transmission of an incorrectly received packet, and retransmit the packet with at least one different punctured bit. The set contains any bits punctured from an original transmission corresponding to the re-transmission.