Communications Employing 1-Bit Quantization and Oversampling at the Receiver: Faster-Than-Nyquist Signaling and Sequence Design

Abstract

From circuit perspective, the resolution in time domain might be less difficult to achieve as compared to resolution in amplitude domain. Especially when considering Multigigabit communication the resolution in amplitude has remarkable power consumption. In this investigation some practical communication designs are proposed which exploit the utilization of 1- bit quantization and oversampling at the receiver. The proposed approach is the employment of faster- than-Nyquist QPSK signals in combination with an appropriate sequence design. Two sequence design strategies are proposed, namely the utilization of run-length limited sequences and the utilization of an optimized Markov source via an expectation based Blahut-Arimoto algorithm. Numerical results on the achievable data rate are computed based on an auxiliary channel lower bound which becomes tight in the high SNR regime. The results on the proposed methods and especially the run-length limited sequence based approach show superior performance in terms of achievable rate and spectral efficiency as compared to conventional signaling with independent and uniformly distributed symbols. Furthermore the performance is close to and even above as compared to an analytical result on the achievable rate when sampling the sign of a specific bandlimited process.