On the Limits of Communication Performance with One-Bit Analog-To-Digital Conversion

As communication systems scale up in speed and bandwidth, the power consumption and cost of high-precision (e.g., 6-12 bits) analog-to-digital conversion (ADC) becomes the limiting factor in modern receiver architectures based on digital signal processing. In this paper, we consider the effects of lowering the precision of the ADC on the performance of the communication link. We focus on the most extreme scenario, in which the receiver employs one-bit ADC at baseband. While this constraint impacts every aspect of design ranging from synchronization and channel estimation to demodulation and decoding, in this initial exposition, we focus on the Shannon-theoretic limits imposed by one-bit ADC for an ideal discrete-time real baseband additive white Gaussian noise (AWGN) channel. Results are obtained both for non-spread and spread spectrum systems. While binary phase shift keying (BPSK) is optimal in a non-spread system, we obtain less predictable results for spread spectrum system, including the sub-optimality of BPSK and non-monotonicity of mutual information with signal-to-noise ratio for a fixed constellation