Abstract: A method for determining and compensating for residual phase noise in a 5G NR DL signal includes converting a block of 5G NR DL time domain signal samples into a block of frequency domain samples for one OFDM data symbol and equalizing and combining the frequency domain samples that fall in an outermost sample accumulation region of each quadrant to form a first composite sample for each quadrant, selecting a signal constellation point belonging to one of the four outermost constellation point decision region as a reference constellation point, rotating at least some of the first composite samples so that the first composite samples are in the same quadrant as the reference constellation point, combining the rotated first composite samples to produce a second composite sample, calculating a phase error between the second composite sample and the reference constellation point, applying phase correction corresponding to the phase error to all subcarriers of the OFDM data symbol, and generating output data from

Abstract: A method for determining and compensating for residual phase noise in a 5G NR DL signal includes converting a block of 5G NR DL time domain signal samples into a block of frequency domain samples for one OFDM data symbol and equalizing and combining the frequency domain samples that fall in an outermost sample accumulation region of each quadrant to form a first composite sample for each quadrant, selecting a signal constellation point belonging to one of the four outermost constellation point decision region as a reference constellation point, rotating at least some of the first composite samples so that the first composite samples are in the same quadrant as the reference constellation point, combining the rotated first composite samples to produce a second composite sample, calculating a phase error between the second composite sample and the reference constellation point, applying phase correction corresponding to the phase error to all subcarriers of the OFDM data symbol, and generating output data from

Abstract: An apparatus in a signal receiver, such as an optical signal receiver, is provided. An adaptive equalizer provides an equalized output indicative of a received signal. A feedback component receives the equalized output and provides feedback to the adaptive equalizer. A carrier recovery component receives the equalized output from the adaptive equalizer provides estimates of symbols. The carrier recovery component is partially or fully disjoint from the feedback component, thus removing the carrier recovery component from equalizer the feedback loop. The feedback component can include an initial carrier recovery component and a phase rotation and detection component. The initial carrier recovery component generates a carrier recovery output based on the equalized output. The phase rotation and detection component performs a phase rotation based on the carrier recovery output.

Abstract: A method for efficient generation of a narrowband IoT uplink signal includes generating an under-sampled sequence of samples of a narrowband IoT uplink signal, identifying symbol boundaries in the sequence of samples that do not correspond to sample times, for each symbol boundary that does not correspond to one of the sample times: extrapolating, from a signal phase value for a sample at a last sample time before the symbol boundary, a signal phase value for a sample at a first sample time after the symbol boundary; calculating and applying a phase jump to the sample at the first sample time after the symbol boundary to generate a new phase value for the sample at the first sample time after the symbol boundary, wherein the phase jump is applied from the phase value extrapolated from the last sample time before the symbol boundary; and using the new phase value for the first sample time after the symbol boundary to calculate amplitude of the sample at the first sample time after the symbol boundary.

Abstract: An apparatus in a signal receiver, such as an optical signal receiver, is provided. An adaptive equalizer provides an equalized output indicative of a received signal. A feedback component receives the equalized output and provides feedback to the adaptive equalizer. A carrier recovery component receives the equalized output from the adaptive equalizer provides estimates of symbols. The carrier recovery component is partially or fully disjoint from the feedback component, thus removing the carrier recovery component from equalizer the feedback loop. The feedback component can include an initial carrier recovery component and a phase rotation and detection component. The initial carrier recovery component generates a carrier recovery output based on the equalized output. The phase rotation and detection component performs a phase rotation based on the carrier recovery output.

Abstract: A method and apparatus is described for estimating a local oscillator frequency offset (LOFO) of a received optical signal in a coherent optical receiver.

Abstract: A method and apparatus is described for estimating a local oscillator frequency offset (LOFO) of a received optical signal in a coherent optical receiver.

Abstract: An apparatus for performing fractionally spaced adaptive equalization with non-integer sub-symbol sampling has an adaptive equalizer that receives a continuous stream of input data having a non-integer, fractional delay between consecutive samples at a non-integer, sub-symbol rate and outputs a stream of equalized data based on tap weights of taps of the adaptive equalizer that are spaced at an interval corresponding to the non-integer, sub-symbol rate. The tap weights are updated independently of the fractional delay between consecutive samples of the input data using an error signal. An equalizer output alignment component downstream of the adaptive equalizer aligns the stream of equalized data with a corresponding transmitted symbol.

Abstract: An apparatus for performing fractionally spaced adaptive equalization with non-integer sub-symbol sampling has an adaptive equalizer that receives a continuous stream of input data having a non-integer, fractional delay between consecutive samples at a non-integer, sub-symbol rate and outputs a stream of equalized data based on tap weights of taps of the adaptive equalizer that are spaced at an interval corresponding to the non-integer, sub-symbol rate. The tap weights are updated independently of the fractional delay between consecutive samples of the input data using an error signal. An equalizer output alignment component downstream of the adaptive equalizer aligns the stream of equalized data with a corresponding transmitted symbol.

Abstract: An apparatus comprising a memory and a processor coupled to the memory, wherein the memory includes instructions that when executed by the processor cause the apparatus to perform the following receive an incoming signal at a sampling rate that is greater than a symbol rate associated with the incoming signal, replicate a plurality of data streams from the incoming signal, apply a plurality of fractional delays for the data streams, and perform an adaptive equalization on a plurality of data blocks generated from the data streams, wherein the fractional delay is applied to the data streams independently of the adaptive equalization, and wherein the adaptive equalization implements taps spaced at a fraction of a symbol interval associated with the incoming signal.

Abstract: An apparatus comprising a memory and a processor coupled to the memory, wherein the memory includes instructions that when executed by the processor cause the apparatus to perform the following receive an incoming signal at a sampling rate that is greater than a symbol rate associated with the incoming signal, replicate a plurality of data streams from the incoming signal, apply a plurality of fractional delays for the data streams, and perform an adaptive equalization on a plurality of data blocks generated from the data streams, wherein the fractional delay is applied to the data streams independently of the adaptive equalization, and wherein the adaptive equalization implements taps spaced at a fraction of a symbol interval associated with the incoming signal.