Abstract: Systems, methods, apparatus, and techniques are provided for retransmitting packets of data. A Radio Link Control (RLC) layer data packet is generated, and the RLC layer data packet is converted to one or more physical (PHY) layer data packets. The one or more PHY layer data packets are transmitted. At least one of a hybrid automatic transmission request (HARQ) acknowledgement (ACK) message and a HARQ negative acknowledgment (NACK) message is received from a receiver in response to transmission of the one or more PHY layer data packets. It is determined whether the at least one of the HARQ ACK message and the HARQ NACK message represents a automatic transmission request (ARQ) ACK message or a ARQ NACK message.

Abstract: Systems and methods are provided for determining channel state information (CSI) at a receiver for feedback to a transmitter to indicate properties of the communication channel. A signal is received at a receiver over a communication channel. An optimization value is determined based on the received signal and a plurality of matrix indicators. An amount of change in wideband properties of the communication channel is determined from the optimization value. Based on the determined amount of change, a CSI including a selected type indicator and a selected subset of the plurality of the matrix indicators is selected.

Abstract: Systems and methods are provided for determining a decoding order in a successive interference cancellation receiver. The method includes receiving, using control circuitry, a plurality of codewords. The method further includes computing at least one ordering metric for at least one of the plurality of codewords based on posterior information associated with the plurality of codewords, and determining the decoding order based on the at least one ordering metric.

Abstract: Systems and methods are provided for processing a signal using simplified channel statistics. In an example implementation, a channel profile for a multipath channel is estimated by detecting, within a given range, a number of channel taps associated with a channel impulse response, and assigning each of those channel taps a uniform amplitude value corresponding to a constant signal strength. A signal may be received through the multipath channel and filtered based on the estimated channel profile.

Abstract: Systems and methods are provided for determining a channel quality indicator (CQI) for receivers that exhibit non-deterministic behavior during the CQI selection process. A codeword is received over a transmission system at a receiver, and a performance measure that is dependent on the CQI is determined for the codeword. The receiver determines an objective function that is based on the CQI and the performance measure, and selects a value for the CQI by performing an optimization technique on the objective function. The optimization technique is performed on the objective function over a range of candidate CQI values, and the selected value for the CQI is the candidate CQI value that optimizes the objective function.

Abstract: In various embodiments, the present disclosure provides transmitters, receivers, and methods of determining channel state information for a maximum likelihood (ML) multiple input multiple output (MIMO) receiver, as well as transmitting and demodulating signals based on the determined channel state information. A ML MIMO receiver receives a first MIMO signal from a MIMO transmitter. Channel characteristics of the first MIMO signal are determined based on decision feedback equalization (DFE) processing. The DFE-determined channel characteristics, or information derived from the DFE-determined channel characteristics, are reported to the MIMO transmitter and the MIMO ML receiver decodes a second MIMO signal based on ML processing. The second MIMO signal is modulated and encoded by the MIMO transmitter according to a modulation and coding scheme in accordance with (1) the DFE-determined channel characteristics or (2) the information derived from the DFE-determined channel characteristics.

Abstract: A communication device is configured to operate in a first wireless communication network that utilizes a communication protocol developed for use in frequency bands that are licensed by a government entity for wireless communication applications. The communication device determines whether one or more communication channels in an unlicensed frequency band are not being utilized by any second wireless communication networks, wherein the government entity does not require licenses to use the unlicensed frequency band. In response to determining that one or more communication channels in the unlicensed frequency band are not being utilized by any second wireless communication networks, the communication device selects a set of one or more communication channels in the one or more communication channels for use by the first wireless communication network, and utilizes the set of one or more communication channels for communications in the first wireless communication network.

Abstract: In a method for generating a physical layer (PHY) data unit for transmission via a communication channel, the PHY data unit conforming to a first communication protocol, a first communication device generates a PHY preamble for the PHY data unit, including: generating a signal field, including the signal field and a duplicate of the signal field in the PHY preamble, and formatting the PHY preamble such that a first portion of the PHY preamble is decodable by a second communication device that conforms to a second communication protocol, but does not conform to the first communication protocol, to determine a duration of the PHY data unit based on the first portion of the PHY preamble. The first communication device generates the PHY data unit to include the PHY preamble and a PHY payload.

Abstract: Systems, methods, apparatus, and techniques are provided for receiving signals over a communications channel, generating a plurality of successive estimates of instantaneous interference present in the communications channel at a respective plurality of samples based on the received signals, producing an average interference estimate of the interference channel based on the plurality of successive estimates, and producing a decoded codeword based on i) the average interference estimate and ii) the received signals.

Abstract: Systems and methods are provided for determining channel state information (CSI) at a receiver for feedback to a transmitter to indicate properties of the communication channel. A signal is received at a receiver over a communication channel. An optimization value is determined based on the received signal and a plurality of matrix indicators. An amount of change in wideband properties of the communication channel is determined from the optimization value. Based on the determined amount of change, a CSI including a selected type indicator and a selected subset of the plurality of the matrix indicators is selected.

Abstract: Systems and methods are provided for determining a decoding order in a successive interference cancellation receiver. The method includes receiving, using control circuitry, a plurality of codewords. The method further includes computing at least one ordering metric for at least one of the plurality of codewords based on posterior information associated with the plurality of codewords, and determining the decoding order based on the at least one ordering metric.

Abstract: Systems and methods are provided for determining a channel quality indicator (CQI) for receivers that exhibit non-deterministic behavior during the CQI selection process. A codeword is received over a transmission system at a receiver, and a performance measure that is dependent on the CQI is determined for the codeword. The receiver determines an objective function that is based on the CQI and the performance measure, and selects a value for the CQI by performing an optimization technique on the objective function. The optimization technique is performed on the objective function over a range of candidate CQI values, and the selected value for the CQI is the candidate CQI value that optimizes the objective function.

Abstract: A method includes calculating a set of first metrics using channel information and one or more precoders, where each of the first metrics corresponds to a respective set of a plurality of sets of codebook precoders, and selecting, based on the set of first metrics and a first selection criteria, a set of codebook precoders from the plurality of sets of codebook precoders. The method also includes, in response to selecting the set of codebook precoders, calculating a set of second metrics and selecting, based on (i) the set of second metrics and (ii) a second selection criteria, a codebook precoder from the selected set of codebook precoders. Each of the second metrics is calculated using a respective codebook precoder in the selected set of codebook precoders. The method also includes causing the selected codebook precoder to be applied to a signal to be transmitted to a communication device.

Abstract: Certain embodiments of the present disclosure allow for detection of a transmitted preamble sequence by processing a correlation of a received signal and a preamble hypothesis in a way that exploits the good correlation properties of the known set of preamble sequences. For certain embodiments, the highest peaks of the correlation output may be compared across all preamble hypotheses to decide which preamble sequence is transmitted.

Abstract: Certain embodiments of the present disclosure allow for detection of a transmitted preamble sequence by processing a correlation of a received signal and a preamble hypothesis in a way that exploits the good correlation properties of the known set of preamble sequences. For certain embodiments, the highest peaks of the correlation output may be compared across all preamble hypotheses to decide which preamble sequence is transmitted.