# Fast Decoder for Overloaded Uniquely Decodable Synchronous Optical CDMA

## TL;DR

This paper introduces a fast, low-complexity decoder for overloaded optical CDMA systems that achieves near-ML performance with significantly reduced computational effort, enabling efficient errorless communication.

## Contribution

A novel fast decoding algorithm for uniquely decodable optical CDMA codes that simplifies decoding while maintaining near-ML error performance.

## Key findings

- Decoder requires only a few comparisons.
- Achieves 1-2 dB SNR performance loss compared to ML decoder.
- Significantly lower computational complexity than ML decoding.

## Abstract

In this paper, we propose a fast decoder algorithm for uniquely decodable (errorless) code sets for overloaded synchronous optical code-division multiple-access (O-CDMA) systems. The proposed decoder is designed in a such a way that the users can uniquely recover the information bits with a very simple decoder, which uses only a few comparisons. Compared to maximum-likelihood (ML) decoder, which has a high computational complexity for even moderate code lengths, the proposed decoder has much lower computational complexity. Simulation results in terms of bit error rate (BER) demonstrate that the performance of the proposed decoder for a given BER requires only 1-2 dB higher signal-to-noise ratio (SNR) than the ML decoder.