Phase noise canceling OFDM receiver

A receiver comprising:

• circuitry configured to receive a signal over a plurality of orthogonal subcarriers;
• a buffer having an input coupled to an output of the circuitry for storing the received signal;
• an arithmetic logic block having an input configured to receive an output of the buffer for canceling an estimate of phase noise from the buffered signal;
• a symbol detector having an input configured to receive an output of the arithmetic logic block for estimating a symbol from the output of the arithmetic logic block;
• a phase noise estimator having a first input configured to receive the estimated symbol from the symbol detector and a second input configured to receive a remainder signal from the symbol detector, the remainder signal being a difference between the buffered signal and the estimated symbol;
• a first feedback loop configured to provide an output of the phase noise estimator to an input of the arithmetic logic block for providing the estimate of phase noise;
• and
• a second feedback loop configured to provide an output of the arithmetic logic block to an input of the buffer for replacing the signal stored in the buffer with a signal modified by the arithmetic logic block.

An apparatus comprising:

• means for estimating a symbol from a buffered received signal, the means for estimating a symbol comprising a symbol estimator;
• means for iteratively estimating phase noise from the estimated symbol and a remainder signal, the remainder signal being a difference between the buffered received signal and the estimated symbol, the means for iteratively estimating phase noise comprising a phase noise estimator and a feedback loop configured to provide an output of the phase noise estimator to an input of the symbol estimator, said phase noise estimator comprising circuitry for executing an inverse Fourier transform on the estimated phase noise and the remainder signals;
• and
• means for canceling the iteratively estimated phase noise from the buffered received signal, the means for canceling the iteratively estimated phase noise comprising a multiplier having an input coupled to the feedback loop and an output coupled to the symbol estimator.

A non-transitory computer readable storage medium embodied with a program of machine-readable instructions, executable by a digital data processor, to perform actions directed toward processing a received signal, the actions comprising:

• estimating a symbol from a buffered received signal;
• determining a decision noise from a difference between the buffered received signal and the estimated symbol;
• estimating phase noise from the decision noise and the estimated symbol;
• and
• canceling the estimated phase noise from the buffered received signal, and estimating a phase noise corrected estimated symbol therefrom;
• storing the phase noise corrected estimated symbol;
• determining a next iterative decision noise from the buffered received signal and the phase noise corrected estimated symbol;
• estimating a next iterative phase noise from the next iterative decision noise and the phase noise corrected estimated symbol;
• and
• canceling the next iterative phase noise from a phase of the phase noise corrected estimated symbol to yield an iteratively phase noise corrected estimated symbol.

A non-transitory computer readable storage medium embodied with a program of machine-readable instructions, executable by a digital data processor, to perform actions directed toward processing a received signal, the actions comprising:

• estimating a symbol from a signal received over a plurality of orthogonal frequency division multiplexed subcarriers;
• iteratively estimating phase noise from the estimated symbol and a remainder signal, the remainder signal being a difference between a buffered signal and the estimated symbol, by an inverse Fourier transform;
• and
• canceling the iteratively estimated phase noise from the signal and estimating a phase noise corrected estimated symbol therefrom;
• determining a next iterative decision noise from the buffered received signal and the phase noise corrected estimated symbol;
• estimating a next iterative phase noise from the next iterative decision noise and the phase noise corrected estimated symbol;
• accumulating all estimated phase noise for the buffered received signal;
• and wherein canceling the estimated phase noise comprises canceling the accumulated estimated phase noise from the buffered received signal and estimating an iteratively phase noise corrected estimated symbol therefrom.

A receiver comprising:

• a symbol detector configured to estimate, from a buffered received signal, an estimated frequency domain symbol and a frequency domain decision noise, wherein the frequency domain decision noise is determined from a difference between the received signal and the estimated frequency domain symbol;
• means for converting the estimated frequency domain symbol and the frequency domain decision noise to the time domain;
• a Kalman filter for estimating phase noise from the time domain converted estimated symbol and frequency domain decision noise;
• a phase error accumulator configured to accumulate all estimated phase noise for the buffered received signal;
• and
• a recursive feedback loop for canceling from the received signal an accumulation of phase noise estimates from the Kalman filter, wherein cancelling the accumulation of the phase noise estimates comprises canceling the accumulated phase noise from the buffered received signal, wherein an iteratively phase noise corrected estimated symbol is estimated therefrom.

A method comprising:

• estimating from a received signal a frequency domain symbol and a frequency domain decision noise, wherein the frequency domain decision noise is determined from a difference between the received signal and the estimated frequency domain symbol;
• converting the estimated frequency domain symbol and the frequency domain decision noise to the time domain;
• filtering the time domain converted estimated frequency domain symbol and the frequency domain decision noise to achieve a phase noise estimate;
• iteratively estimating, converting, and filtering as recited above to achieve at least one iterative estimate of phase noise;
• and
• canceling from the received signal the phase noise estimate and the at least one iterative estimate of phase noise and estimating a phase noise corrected estimated symbol therefrom;
• determining a next iterative decision noise from the received signal and the phase noise corrected estimated symbol;
• estimating a next iterative phase noise from the next iterative decision noise and the phase noise corrected estimated symbol;
• accumulating all estimated phase noise for the received signal;
• and wherein canceling the estimated phase noise comprises canceling the accumulated estimated phase noise from the received signal and estimating an iteratively phase noise corrected estimated symbol therefrom.