|M.Sc Student||Assaf Uri|
|Subject||Aspects in Soft Decision Decoding of Reed-Solomon|
|Department||Department of Electrical Engineering||Supervisor||Dr. Bross Shraga|
- Turbo Product Codes received some attention in recent papers, and were applied mainly for binary codes and binary signaling.
- If utilized for decoding low-rate codes, The performance of Kaneko algorithm greatly depends on the practical limit of test patterns. Therefore, for complexity reasons, Kaneko algorithm is relevant mainly for high-rate codes.
- We propose a sub-optimal symbol reliability which utilizes a predetermined parameter instead of the noise variance, with minimal impairment to the decoder’s performance.
- In order to avoid useless decoding iterations, we suggest to maintain a storage of all the decoded codewords. We discuss the complexity of such procedure and the situations at which it may be beneficial.
- The complexity of K-V algorithm is found to be O(cost3). Since the complexity is independent of the code rate, K-V algorithm is attractive mainly for low-rate codes.
- We prove a surprising flaw in K-V algorithm, i.e. at low SNR and high-rate codes K-V algorithm may fail to output the transmitted codeword even if there are no errors in the received codeword at all.
- We discuss choice of decoding parameters, mainly cost. The lack of monotony with respect to cost is discussed.
Turbo Product Codes
- Turbo product codes decoding algorithm is adjusted for RS codes and MPSK signaling.
- Turbo product code (TPC) with RS code as component codes and MPSK modulation outperforms standard Kaneko algorithm with similar code rate and complexity with only two full iterations.