Communication with 1-Bit Quantization and Oversampling at the Receiver: Spectral Constrained Waveform Optimization

Abstract

In case of wideband communications the analog-to-digital converter becomes a power consumption implementation bottleneck. Alternatively, transmission schemes based on coarse (1-bit) quantization and oversampling at the receiver can be beneficial. In this regard, information is conveyed in the zero-crossings. However, in presence of spectral constraints the waveform design becomes a challenge. In this work, faster-than-Nyquist BPSK signaling is considered, where runlength limited sequences are applied in order to engineer intersymbol interference. In addition, to further improve the achievable rate, the waveform is optimized by applying a suboptimal design criterion which corresponds to a convex optimization problem. A rate improvement of 10 to 20 percent by optimizing the waveform is observed, in comparison to Gaussian pulses, considering the spectral mask for the IEEE 802.11ad standard. For all cases, the simulation results show that using run-length limited input sequences is superior in terms of achievable rate as compared to independent uniformly distributed input symbols.