반복 수신기 구조를 위한 저 복잡도 MAP 알고리즘

학위논문(석사) - 한국정보통신대학교 : 공학부, 2008.2, [ ii, 47 p. ]Wireless communication systems user error correcting code (ECC) techniques for high receiver performance, so receiver requires detector to compensate wireless channel effect and decoder to extract original information from coded information. Hence, the receiver of coded system has concatenated structure with detector and decoder naturally. Since both detector and decoder are required to estimate same original message, it is expected that detector and decoder can show their capabilities with improved quality when they take a signal processing iteratively like turbo engine. This idea causes iterative signal processing (ISP) techniques based on turbo principle. ISP was first developed as a decoding algorithm of turbo codes. After amazing appearance of turbo codes, ISP became general receiver technique and has applied to various wireless communication systems for improving receiver performance. If soft-decision is possible in receiver, ISP is also possible with iterative receiver structure. In recent, iterative techniques are not optional but essential because it is a applicable to wide area of communication system. In this thesis, we focus on iterative receiver techniques with maxi-mum a \It{a posteriori} (MAP) algorithm. MAP algorithm is frequently used for soft-decision method in iterative receiver because of high performance. However, Map algorithm requires so high complexity that implementation is very hard. Thus, we propose a new MAP algorithm with reduced trellis search, so complexity decreases. Receiver can achieve exact MAP performance with proposed MAP algorithm. Since maximum likelihood (ML) detection is not practical in multiple input multiple output(MIMO) channel because of high implementation complexity, trellis-based detection is frequently used for achieving high performance with maximum likelihood sequence detection(MLSD) based on Viterbi algorithm instead of conventional ML. If receiver knows trellis structure of MIMO channel, trellis-base...한국정보통신대학교 : 공학부

Performance Analysis of a Chaotic OOK

본 논문에서는 non-coherent 수신기에서 혼돈 신호를 이용한 OOK (on-off keying) 시스템의 성능을 AWGN (additive white Gaussian noise) 채널에서 분석하였다. 기존의 Gaussian 접근 방법을 이용한 성능 분석으로는 정확한 성능분석에 한계가 있다. 하지만 본 논문에서는 이러한 접근 방법을 이용하지 않고 랜덤 프로세스를 이용하여 좀 더 정확한 성능 분석을 하고자 하였다