CVR: A Continuously Variable Rate LDPC Decoder Using Parity Check Extension for Minimum Latency

Abstract

This paper presents a novel IEEE 802.16e (WiMAX) based decoder that performs close to the 5G code but without the expensive hardware re-development cost. The design uses an extension of the existing WiMAX parity check code to reduce the initial decoding latency and power consumption while keeping the decoder throughput at maximum. It achieves similar Frame Error Rate (FER) compared to 5G (0.1 dB off), and most notably the error curves trend down like 5G instead flooring. At FER= 10−3 there is 0.1 dB gain in the FER code performance compared to WiMAX. An implementation of the design is a modified version of the existing fully-parallel WiMAX decoder that supports multi-rate codeword size and reduces the initial latency by 33%. Additionally, for SNR greater than 3 dB, decoding only the shorter code reduces the power consumption by 34%.