Performance of LDPC coded spread OFDM with clipping
2005 (English)In: Proceedings of the 8th International Symposium on Communication Theory and Applications: ISCTA 2005, 2005, 156-161 p.Conference paper (Refereed)
We present the performance of OFDM systems with coding, spreading, and clipping. Low-Density Parity-Check (LDPC) codes give coding gains and spreading by the Walsh Hadamard transform gives gains in terms of increased frequency diversity as well as reduced peak-toaverage power ratio (PAPR) of the transmitted OFDM signal. By evaluating both the IFFT transform (OFDM) and the Walsh Hadamard transform in a single step, the number of operations needed for the spread OFDM system is actually less than for the conventional OFDM system. Reducing than for the conventional OFDM system. Reducing the PAPR is important in systems with clipping since it is related to the probability of clips. Each clip introduces clipping noise to the system which reduces the performance. Results of a clipped OFDM system with LDPC coding and spreading for an ETSI indoor wireless channel model are presented and compared with other systems. It is shown that there is a gain by spreading for LDPC coded OFDM systems, and especially for systems with clipping.
Place, publisher, year, edition, pages
2005. 156-161 p.
Research subject Signal Processing
IdentifiersURN: urn:nbn:se:ltu:diva-27300Local ID: 0b563d00-95b2-11db-8975-000ea68e967bOAI: oai:DiVA.org:ltu-27300DiVA: diva2:1000483
International Symposium on Communication Theory and Applications : 17/07/2005
Godkänd; 2005; 20061227 (ysko)2016-09-302016-09-30Bibliographically approved