Automatic Gain Control for ADC-Limited Communication

As the date rates and bandwidths of communication systems scale up, the cost and power consumption of highprecision (e.g., 8-12 bits) analog-to-digital converters (ADCs) become prohibitive. One possible approach to relieve this bottleneck is to redesign communication systems with the starting assumption that the receiver will employ ADCs with drastically reduced precision (e.g., 1-4 bits). Encouraging results from information-theoretic analysis in idealized settings prompt a detailed investigation of receiver signal processing algorithms when ADC precision is reduced. In this work, we investigate the problem of automatic gain control (AGC) for pulse amplitude modulation (PAM) signaling over the AWGN channel, with the goal being to align the ADC thresholds with the maximum likelihood (ML) decision regions. The approach is to apply a variable gain to the ADC input, fixing the ADC thresholds, with the gain being determined by estimating the signal amplitude from the quantized ADC output. ...

• Type: Journal
• Year: 2010
• Where: GLOBECOM
• Authors: Feifei Sun, Jaspreet Singh, Upamanyu Madhow
• Keywords: Communication Systems, Communications, GLOBECOM 2010, ML Estimate, Quantized Adc Output