Minimum-Energy LDPC Decoder for Real-Time Mobile Application

Abstract

This paper presents a low-power real-time decoder that provides constant-time processing of each frame using dynamic voltage and frequency scaling. The design uses known capacity-approaching low-density parity-check (LDPC) code to contain data over fading channels. Real-time applications require guaranteed data rates. While conventional fixed-number of decoding-iteration schemes are not energy efficient for mobile devices, the proposed heuristic scheme pre-analyzes each received data frame to estimate the maximum number of necessary iterations for frame convergence. The results are then used to dynamically adjust decoder frequency. Energy use is then reduced appropriately by adjusting power supply voltage to minimum necessary for the given frequency. The resulting design provides a judicious trade-off between power consumption and error level