Abstract: Method and apparatus for block boundary detection is described. A signal is received. The signal is quantized to provide a quantized signal to at least one correlator, the quantized signal being a sequence of samples. The sequence of samples and a reference template including totaling partial results from the at least one correlator are cross-correlated to provide a result, the result being a symbol timing synchronization responsive to the cross-correlation also known as block boundary detection. The cross-correlation is provided in part by combining by exclusive-ORing a regression vector obtained from the sequence of samples and a coefficient term vector obtained from the reference template.

Abstract: Disclosed is a recursive, direct digital synthesizer includes an accumulator module and a Coordinate Rotation Digital Computer (CORDIC) module coupled to the accumulator module. The CORDIC module rotates a signal according to a desired rotation angle specified by the accumulator module. An automatic gain control module is coupled to the CORDIC module. The automatic gain control module can apply a level of gain to the rotated signal.

Abstract: Systems and methods detect a communication received at receiving antennas from transmitting antennas. Each transmitting antenna transmits a symbol in a constellation. A sphere detector performs a depth-first search until the depth-first search terminates in response to a terminate signal requesting the result from the sphere detector. The depth-first search evaluates respective distances of one or mode leaf nodes in response to the communication received at the receiving antennas. The depth-first search selects the result from these nodes in response to the respective distances. The result includes a selected leaf node that identifies a corresponding symbol in the constellation for each transmitting antenna, with this symbol detected as transmitted by the transmitting antenna.

Abstract: Method and apparatus for signal processing to minimize the peak to average power ratio of an Orthogonal Frequency Division Multiplexing (“OFDM”) or Orthogonal Frequency Division Multiple Access (“OFDMA”) signal with bounded error vector magnitude for an integrated circuit are described. An Active Constellation Extension (“ACE”) iteration, using a constellation points adjustment module, is performed. Symbols outside of a bounded region after the ACE iteration are identified. The bounded region is determined responsive to an error vector magnitude target. The symbols identified are translated to the bounded region.

Abstract: A system detects symbols communicated from multiple transmitting antennas to multiple receiving antennas. A first detector determines the symbols from respective partial distances of potential choices for symbols from a constellation. A second detector determines the symbols from respective partial distances of more potential choices. The first and second detectors determine their partial distances from signals received at the receiving antennas. The second detector has a lower bit error rate than the first detector. The potential choices for the second antenna are smaller than the potential choices for the first antenna in response to a signal-to-noise ratio (SNR) being higher than a threshold. An evaluator estimates the SNR of the signals received at the receiving antennas. The evaluator enables the first detector in response to the SNR being lower than the threshold, and the evaluator enables the second detector in response to the SNR being higher than the threshold.

Abstract: An integrated circuit having a circuit for reducing distortion in a power amplifier is disclosed. The integrated circuit comprises a predistortion circuit coupled to receive a signal to be amplified; sample capture buffers coupled to an output of the predistortion circuit and an input/output port of the integrated circuit; and an estimator circuit coupled to the sample capture buffers, wherein the estimator circuit generates parameters for the predistortion circuit based upon the output of the predistortion circuit and an output of the power amplifier received at the input/output port of the integrated circuit. A method of reducing distortion in a power amplifier is also disclosed.

Abstract: An integrated circuit having a circuit for reducing distortion in a power amplifier is disclosed. The integrated circuit comprises a predistortion circuit coupled to receive a signal to be amplified; sample capture buffers coupled to an output of the predistortion circuit and an input/output port of the integrated circuit; and an estimator circuit coupled to the sample capture buffers, wherein the estimator circuit generates parameters for the predistortion circuit based upon the output of the predistortion circuit and an output of the power amplifier received at the input/output port of the integrated circuit. A method of reducing distortion in a power amplifier is also disclosed.

Abstract: A system detects symbols communicated from multiple transmitting antennas to multiple receiving antennas. A first detector determines the symbols from respective partial distances of potential choices for symbols from a constellation. A second detector determines the symbols from respective partial distances of more potential choices. The first and second detectors determine their partial distances from signals received at the receiving antennas. The second detector has a lower bit error rate than the first detector. The potential choices for the second antenna are smaller than the potential choices for the first antenna in response to a signal-to-noise ratio (SNR) being higher than a threshold. An evaluator estimates the SNR of the signals received at the receiving antennas. The evaluator enables the first detector in response to the SNR being lower than the threshold, and the evaluator enables the second detector in response to the SNR being higher than the threshold.

Abstract: Circuits are provided for detecting symbols transmitted from multiple transmitting antennas to multiple receiving antennas. A circuit includes distance blocks, selectors, and an identifier block. Each distance-block includes at least one sub-block, and each sub-block inputs a candidate for a corresponding transmitting antenna. The sub-block determines partial distances for pairings of the candidate and each symbol in a constellation from a partial distance of the candidate and signals received at the receiving antennas. At least one selector assigns each pairing for each candidate for a corresponding transmitting antenna to a bin having a range that includes the partial distance of the pairing. The selector selects candidates for a successive transmitting antenna from the bins having the smaller ranges. The identifier block selects a final candidate that is one of the pairings for a last transmitting antenna having a smaller partial distance.

Abstract: Circuits detect communications from multiple transmitting antennas to multiple receiving antennas. A respective first block for each non-initial transmitting antenna determines partial distances for pairings of a first candidate and a quadrature-phase amplitude. A respective second block for the initial transmitting antenna determines partial distances for combinations of phase amplitudes. A respective second block for each non-initial transmitting antenna determines partial distances for pairings of a second candidate and an in-phase amplitude. A respective first selector for each non-initial transmitting antenna selects the first candidates from the pairings for the respective second block having smaller partial distances. A respective second selector for each non-initial transmitting antenna selects the second candidates from the pairings for the respective first block having smaller partial distances.

Abstract: A method and apparatus for generating a signal to noise ratio (SNR) estimate. A conditional probability distribution function (CPDF) is rectified to suppress the condition, thereby creating a biased CPDF. Conditional offset moments are computed through an analysis of the asymmetry generated by the rectification. The conditional offset moments are then utilized to reduce the bias generated by the rectification to enhance the SNR estimate.

Abstract: Method and apparatus for peak-to-amplitude ratio reduction are described. A data carrying signal waveform with sub-carrier signals (S1-1 through S1-M) is obtained. An initial peak reduction waveform (S2(m)) is obtained by selection of a portion of the sub-carrier signals (S1-1 through S1-M) for non-data carrying. The initial peak reduction waveform (S2(m)) is refined by at least one recursive iteration which combines the initial peak reduction waveform (S2(m)) with a circularly time-shifted version thereof to obtain a resultant peak reduction waveform having a peak side lobe amplitude less than that of the initial peak reduction waveform (S2(m)).

Abstract: A circuit detects symbols transmitted from multiple transmitting antennas to multiple receiving antennas. A distance block for an initial transmitting antenna in an ordering of the transmitting antennas determines a distance value for each symbol in a constellation. A selector block selects a limited number of candidates for the initial transmitting antenna from the symbols having smaller distance values. For each first and successive second transmitting antenna in the ordering, a distance-selector block selects a candidate for the second transmitting antenna for each candidate for the first transmitting antenna. The candidate for the second transmitting antenna is a pairing having a smaller distance value among the pairings of the candidate for the first transmitting antenna and the symbols. An identifier block selects a last candidate having a smaller distance value among the candidates for a last transmitting antenna in the ordering. The last candidate includes the detected symbols.

Abstract: Method and apparatus for transmission of information is described. A first transceiver has transmitter reconfigurable logic and a second transceiver has receiver reconfigurable logic. The first transceiver communicates with the second transceiver via a communication channel. The transmitter reconfigurable logic is configured to transmit preamble information and to receive a measurement of the preamble information. The receiver reconfigurable logic is configured to measure the preamble information and to transmit the preamble information measured. The preamble information is communicated via the first transceiver to the second transceiver via the communication channel. The receiver reconfigurable logic of the second transceiver measures the preamble information communicated. The measurement of the preamble information is sent via the receiver reconfigurable logic of the second transceiver to the first transceiver via the communication channel.

Abstract: Partial reconfiguration of programmable logic for supporting a Multiple-input, Multiple-Output Orthogonal Frequency Division Multiplexing (“MIMO-OFDM”) communication system is described. A PHY block in a programmable device may be instantiated generally in part in programmable logic of the programmable device. Control information is obtained for a network node when deployed and/or from a wireless transmission of a packet or frame, which is demodulated in the PHY block. Responsive to the control information demodulated, bitstream information is obtained to configure the portion of the PHY block using the programmable logic of the programmable device.

Abstract: Method and apparatus for block boundary detection is described. A signal is received. The signal is quantized to provide a quantized signal to at least one correlator, the quantized signal being a sequence of samples. The sequence of samples and a reference template including totaling partial results from the at least one correlator are cross-correlated to provide a result, the result being a symbol timing synchronization responsive to the cross-correlation also known as block boundary detection. The cross-correlation is provided in part by combining by exclusive-ORing a regression vector obtained from the sequence of samples and a coefficient term vector obtained from the reference template.

Abstract: Method and apparatus for digital frequency synthesis are described. A frequency synthesizer has an accumulator, an adder, and a predictive filter. The adder is configured to subtract a predicted error from a phase profile signal. A quantized version of the phase profile signal is separated from an error portion thereof. The predictive filter, set for a fraction of a sample frequency bandwidth, is coupled to receive the error portion for generation of a next predicted error. A storage device has digital representations of sinusoidal signals accessible responsive to the quantized version of the phase profile signal. A digital-to-analog converter is coupled to receive a digital representation of a sinusoidal signal obtained from the storage device to provide an analog sinusoidal signal. An anti-imaging filter is coupled to receive the analog sinusoidal signal and configured to filter out noise.

Abstract: Method and apparatus for packet detection is described. More particularly, a signal having sub-signals is received. The signal is quantized (“re-quantized”) to provide a quantized signal to processing units, where the quantized signal is a sequence of samples. A cross-correlation is done between the sequence of samples and a reference template, including totaling partial results from the processing units to provide a result. The result is a symbol timing synchronization responsive to the cross-correlation, which is provided in part by combining by addition or subtraction a regression vector obtained from the sequence of samples and a coefficient term vector obtained from the reference template.

Abstract: Various embodiments are disclosed for transferring data between blocks in a design during simulation. Operation of at least one high-level block in the design is simulated in a high-level modeling system (HLMS). A hardware-implemented block in the design is co-simulated on a hardware simulation platform. A first vector of data received by a co-simulation block is transferred to the simulated hardware-implemented block via a transfer function.

Abstract: Crest factor reduction in a multiband transmitter is described. Component signals (xi[n]) are respectively obtained from constituent signals. The component signals (xi[n]) are respectively associated with sub-bands. A superposed signal associated with the component signals (xi[n]) is clipped to obtain a clipping noise error signal. The clipping noise error signal is applied to the component signals (xi[n]) using a least squares estimation to project clipping noise error onto the sub-bands.