System and method for angular-domain channel estimation of massive MIMO system with low-resolution ADC with time-varying thresholds

A decoder for use in a communication system to receive signals transmitted over a wireless channel, the decoder comprising:

• a plurality of antennas;
• a plurality of radio-frequency (RF) chains coupled the plurality of antennas, each RF chain includes an at least one-bit analog-to-digital converter (ADC) to convert each measurement of an analog signal received by the antenna into at least one bit of information representing a result of a comparison of the measurement with a randomly selected threshold to produce a sequence of bits and a corresponding sequence of thresholds, wherein each bit in the sequence of bits represents a relative value of the measurement of the analog signal with respect to a threshold from the corresponding sequence of thresholds;
• a processor in communication with a memory, coupled to the plurality of RF chains to estimate parameters of the wireless channel using the sequences of bits and the corresponding sequences of thresholds received from the plurality of RF chains, such that the parameters include a two-dimensional channel matrix including angles-of-departure, angles-of-arrival, and channel path spreads, and that the processor is further configured to detect a received symbol using the estimated CSI;
• and
• a random-number generator to generate a random number within a predetermined range, such that the processor selects the randomly selected thresholds based on the random number.

A receiver for use in a wireless communication system to receive signals transmitted over a wireless channel, the receiver comprising:

• a plurality of antennas;
• a plurality of radio-frequency (RF) chains coupled the plurality of antennas, each RF chain includes a one-bit analog-to-digital converter (ADC) to convert each measurement of an analog signal received by the antenna into at least one bit of information representing a result of a comparison of the measurement with a randomly selected threshold to produce a sequence of bits and a corresponding sequence of thresholds, wherein each bit in the sequence of bits represents a relative value of the measurement of the analog signal with respect to a threshold from the corresponding sequence of thresholds;
• and
• a processor coupled to the plurality of RF chains to estimate parameters of the wireless channel using the sequences of bits and the corresponding sequences of thresholds received from the plurality of RF chains,
• wherein the processor estimates the parameters of the wireless channel according to a maximum likelihood criterion
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• wherein zm is a quantized I/Q signals at a m-th receiving antenna, ΓmT denotes an m-th row of the matrix Γ which is a function of a pilot symbol, an angle-of-departure, an angle-of-arrival, and an antenna geometry, h is a vector that contains a real and imaginary parts of a complex channel path gains, λm is the threshold used at the m-th receiving antenna at a given time instance, σ is a noise standard deviation, Φ(⋅) is a cumulative density function (CDF) of a standard Gaussian random variable, K is a number of pilot symbols, Nr is a number of receiving antennas, and ψ groups all unknown wireless channel statistics including an angle-of-departure, an angle-of-arrival, a complex channel path gain, and their angular spreads.