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

## TL;DR

This paper introduces a novel LDPC decoder extension that reduces latency and power consumption while maintaining high throughput and near-5G error performance, using an innovative parity check extension for WiMAX-based systems.

## Contribution

It proposes a new parity check extension for WiMAX LDPC decoders that significantly reduces latency and power consumption without sacrificing decoding performance.

## Key findings

- Latency reduced by 33%
- Power consumption decreased by 36% at SNR > 3dB
- Achieves FER close to 5G with only 0.1dB difference

## Abstract

This brief 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 processing latency and power consumption while keeping the decoder throughput at maximum. It achieves similar Frame Error Rate (FER) compared to 5G (0.1dB 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 latency by 33%. Additionally, for SNR greater than 3dB, decoding only the shorter code reduces the power consumption by 36%.

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Source: https://tomesphere.com/paper/1904.12016