Abstract: An apparatus, system, and method for performing PDCCH preparation in RF circuitry are described. In one embodiment, power may be provided to a crystal oscillator to exit a first sleep state. One or more clocking signals may be provided to RF circuitry based on output from the crystal oscillator. Calibration and state restoration of the RF circuitry may be performed independent of baseband circuitry. A plurality of algorithms to prepare for receiving data form a wireless communication network may be performed independent of the baseband circuitry. After initiating the plurality of algorithms, state restoration of the baseband circuitry may be performed. Data may be received from a wireless communication network using the RF circuitry. The data may be processed using the baseband circuitry. State retention for the RF circuitry and the baseband circuitry may be performed. Finally, the crystal oscillator may be powered down to enter a second sleep state.

Abstract: A transceiver device may include a transmit path that generates a modulated transmit signal based on a baseband signal, and a receive path that receives a receive signal, which is subject to third-order order distortion caused by intermodulation noise resulting from a continuous wave blocker intermodulating with transmit leakage from the transmit path. The transceiver may also include a compensation path that models portions of the transmit path and the receive path, and generates a replica signal representative of the third-order order distortion according to at least a specified function and the modeled portions of the transmit path and the receive path. The compensation path also filters the replica signal and subtracts the filtered replica signal from the receive signal to eliminate the third-order order distortion caused by the intermodulation noise. The filtering of the replica signal may be performed by programmable finite impulse response filters.

Abstract: This disclosure relates to a system and method for generating single-carrier frequency division multiple access (SC-FDMA) transmissions using a high efficiency architecture. According to some embodiments, frequency resources allocated for a transmission may be determined. The allocated frequency resources may have a bandwidth less than a channel bandwidth of a frequency channel of the transmission, and may be centered around a particular frequency. The frequency may be offset from the center frequency of the channel. A baseband signal located around DC corresponding to the channel center frequency may be generated. The baseband signal may be up-converted to an RF signal using a local oscillator tuned to the frequency around which the allocated frequency resources are centered. The RF signal may be transmitted.

Abstract: Methods and devices are provided for processing a received communication signal by a UE using an analog complex filter and using a single analog-to-digital converter (ADC). A control channel of the communication signal may be decoded to determine the frequency range in which a payload channel is located. The UE may then demodulate only the frequency range containing the payload channel. A complex representation of the received payload channel may be provided to the analog complex filter, with the payload channel shifted to a non-zero frequency IF. The analog complex filter may attenuate any portion of the complex representation that falls near—IF. The UE may then convert only one component path of the filtered complex representation to a digital signal. A complex representation of the digital signal may then be generated, with the payload channel shifted to DC.

Abstract: This disclosure relates to implementing an adaptive sleep schedule for PDCCH decoding. In some embodiments, prior to receiving PDCCH signaling, a user equipment device may schedule wireless communication circuitry to prepare for and decode the PDCCH signaling, which may include dynamically preparing a first interrupt for the wireless communication circuitry to perform the preparing for and the decoding. In response to the first interrupt, the UE may prepare for and decode the PDCCH signaling using the wireless communication circuitry. The UE may analyze the result of the decoding, which may include determining that the PDCCH signaling does not comprise information for the UE. In response to determining that the PDCCH signaling does not comprise information for the UE, the UE may schedule the wireless communication circuitry to shut down, which may include dynamically preparing a second interrupt to shut down the wireless communication circuitry.

Abstract: An apparatus, system, and method for performing PDCCH preparation in RF circuitry are described. In one embodiment, power may be provided to a crystal oscillator to exit a first sleep state. One or more clocking signals may be provided to RF circuitry based on output from the crystal oscillator. Calibration and state restoration of the RF circuitry may be performed independent of baseband circuitry. A plurality of algorithms to prepare for receiving data form a wireless communication network may be performed independent of the baseband circuitry. After initiating the plurality of algorithms, state restoration of the baseband circuitry may be performed. Data may be received from a wireless communication network using the RF circuitry. The data may be processed using the baseband circuitry. State retention for the RF circuitry and the baseband circuitry may be performed. Finally, the crystal oscillator may be powered down to enter a second sleep state.

Abstract: A wireless user equipment (UE) device may include a receiver and transmitter. The UE device may dynamically vary the fidelity requirements imposed on the analog signal processing performed by the receiver and/or the transmitter in response factors such as: amount of signal interference (e.g., out-of-band signal power); modulation and coding scheme; number of spatial streams; extent of transmitter leakage; and size and/or frequency location of resources allocated to the UE device. Thus, the UE device may consume less power on average than a UE device that is designed to satisfy fixed fidelity requirements associated with a worst case reception scenario and/or a worst case transmission scenario.

Abstract: Power allocation for encoded bits in OFDM systems. OFDM symbol subcarriers may be allocated to a wireless user equipment (UE) device by a base station. A first portion of the allocated subcarriers may include systematic bits and a second portion of the allocated subcarriers may include parity bits according to a coding scheme. Transmit power may be unevenly allocated to the subcarriers allocated to the UE, such that subcarriers including systematic bits are allocated different power than the subcarriers including parity bits. The OFDM symbols including the subcarriers allocated to the UE may be transmitted to the UE by the base station according to the allocated power distribution.

Abstract: An apparatus, system, and method for reliable decoding of control information during LTE wireless transmissions is described. A mobile device may decode the PCFICH blindly, which may include obtaining resource elements (REs) that are reserved for Physical Downlink Control Channel (PDCCH), based on a largest value of a control format indicator (CFI), finding a total number of control channel elements (CCEs) according to the obtained REs, numbering the CCEs, and decoding the PDCCH for the largest value of the CFI over the numbered CCEs. Accordingly, the mobile device does not need to decode the PCFICH specifically. The mobile device may indicate to the NW that the mobile device is a constrained device, and the NW may responsively transmit control information using a reserved control format indication value corresponding to the UE being indicated as a constrained device. The mobile device may then not need to decode the PCFICH, and decode the PDCCH based on the PDCCH occupying a first four OFDM symbols.

Abstract: A transceiver device may include a transmit path that generates a modulated transmit signal based on a baseband signal, and a receive path that receives a receive signal, which is subject to third-order order distortion caused by intermodulation noise resulting from a continuous wave blocker intermodulating with transmit leakage from the transmit path. The transceiver may also include a compensation path that models portions of the transmit path and the receive path, and generates a replica signal representative of the third-order order distortion according to at least a specified function and the modeled portions of the transmit path and the receive path. The compensation path also filters the replica signal and subtracts the filtered replica signal from the receive signal to eliminate the third-order order distortion caused by the intermodulation noise. The filtering of the replica signal may be performed by programmable finite impulse response filters.

Abstract: An estimate of a multiple input, multiple output (MIMO) channel is computed, and an equalizer to be applied to signals received via the MIMO channel is computed. The equalizer is initialized based on the estimate of the MIMO channel. The equalizer is applied to a received signal, and the received signal is demodulated to generate a demodulated signal. The demodulated signal is decoded according to an error correction code to generate decoded data, and the decoded data is re-encoded according to the error correction code to generate re-encoded data. The re-encoded data is re-modulated to generate a re-modulated signal. The received signal is compared to the re-modulated signal, and the equalizer is updated based on the comparison. After updating the equalizer, the equalizer is applied to the received signal.

Abstract: A wireless receiver includes an input module, a channel module, an equalizer module, and a decoder module. The input module receives a message over a wireless communication channel. The message includes a plurality of training fields and first data. The first data includes user data perturbed by the channel. The channel module generates a first matrix indicative of an estimation of properties of the channel. The channel module, as each of the plurality of training fields of the message is being received, recursively computes parameters for equalization based on the plurality of training fields, the first matrix, and a vector indicative of a substream signal-to-noise ratio. The equalizer module generates equalizer coefficients based on the parameters for equalization and applies the equalizer coefficients to the first data of the message to generate compensated first data. The decoder module decodes the compensated first data to recover the user data.

Abstract: Systems and methods are provided for channel estimation using linear phase estimation. These systems and methods enable improved channel estimation by estimating a linear channel phase between received pilot subcarrier signals. The estimated linear phase can then be removed from the received pilot subcarrier signals. After the estimated linear phase is removed from the received pilot subcarrier signals, a channel response can be estimated. A final estimated channel response can be generated by multiplying the results of the linear channel estimation by the estimated linear phase.

Abstract: Methods and apparatus are provided for performing log-likelihood ratio (LLR) computations in a pipeline. Portions of a metric used to compute LLR values are computed in one pipeline part. The portions correspond to all permutations of some received signal streams. The portions are combined with one permutation x2 of the received signal stream that was not included in the previous pipeline computation in a subsequent pipeline part to produce M values associated with a particular bit position. At each subsequent clock cycle, a different permutation of x2 is combined with the previously computed portions producing different M values. State values corresponding to different values of bit positions of the received stream are computed by finding the minimum among the M values, in each clock cycle, that affect a particular bit position. The state values are combined to compute the LLR values for the bit position in a final pipeline part.

Abstract: A wireless receiver includes an input module, a channel module, an equalizer module, and a decoder module. The input module receives a message over a wireless communication channel. The message includes a plurality of training fields and first data. The first data includes user data perturbed by the channel. The channel module generates a first matrix indicative of an estimation of properties of the channel. The channel module, as each of the plurality of training fields of the message is being received, recursively computes parameters for equalization based on the plurality of training fields, the first matrix, and a vector indicative of a substream signal-to-noise ratio. The equalizer module generates equalizer coefficients based on the parameters for equalization and applies the equalizer coefficients to the first data of the message to generate compensated first data. The decoder module decodes the compensated first data to recover the user data.

Abstract: An estimate of a multiple input, multiple output (MIMO) channel is computed, and an equalizer to be applied to signals received via the MIMO channel is computed. The equalizer is initialized based on the estimate of the MIMO channel. The equalizer is applied to a received signal, and the received signal is demodulated to generate a demodulated signal. The demodulated signal is decoded according to an error correction code to generate decoded data, and the decoded data is re-encoded according to the error correction code to generate re-encoded data. The re-encoded data is re-modulated to generate a re-modulated signal. The received signal is compared to the re-modulated signal, and the equalizer is updated based on the comparison. After updating the equalizer, the equalizer is applied to the received signal.

Abstract: A method of operating a multiple-input multiple-output (MIMO) receiver includes wirelessly receiving a message over a communication channel using a plurality of antennas. The message includes first data preceded by a plurality of training fields. The method includes generating a first matrix indicative of an estimation of properties of the communication channel, and determining a second matrix and a third matrix by performing a matrix decomposition of the first matrix. The method includes, as each of the plurality of training fields of the message is being received, recursively computing parameters for equalization based on (i) the plurality of training fields, (ii) the second matrix, and (iii) the third matrix. The method includes generating equalizer coefficients based on the parameters for equalization, and applying the equalizer coefficients to the first data of the message to compensate the first data.

Abstract: Systems and methods are provided for channel estimation using linear phase estimation. These systems and methods enable improved channel estimation by estimating a linear channel phase between received pilot subcarrier signals. The estimated linear phase can then be removed from the received pilot subcarrier signals. After the estimated linear phase is removed from the received pilot subcarrier signals, a channel response can be estimated. A final estimated channel response can be generated by multiplying the results of the linear channel estimation by the estimated linear phase.

Abstract: Methods and apparatus are provided for performing log-likelihood ratio (LLR) computations in a pipeline. Portions of a metric used to compute LLR values are computed in one pipeline part. The portions correspond to all permutations of some received signal streams. The portions are combined with one permutation x2 of the received signal stream that was not included in the previous pipeline computation in a subsequent pipeline part to produce M values associated with a particular bit position. At each subsequent clock cycle, a different permutation of x2 is combined with the previously computed portions producing different M values. State values corresponding to different values of bit positions of the received stream are computed by finding the minimum among the M values, in each clock cycle, that affect a particular bit position. The state values are combined to compute the LLR values for the bit position in a final pipeline part.

Abstract: An estimate of a multiple input, multiple output (MIMO) channel is computed, and an equalizer to be applied to signals received via the MIMO channel is computed. The equalizer is initialized based on the estimate of the MIMO channel. The equalizer is applied to a received signal, and the received signal is demodulated to generate a demodulated signal. The demodulated signal is decoded according to an error correction code to generate decoded data, and the decoded data is re-encoded according to the error correction code to generate re-encoded data. The re-encoded data is re-modulated to generate a re-modulated signal. The received signal is compared to the re-modulated signal, and the equalizer is updated based on the comparison. After updating the equalizer, the equalizer is applied to the received signal.