TY - GEN

T1 - Complexity limited sphere decoder and its ser performance analysis

AU - Eun, Sung Jeon

AU - Jang, Hoon Yang

AU - Dong, Ku Kim

PY - 2007

Y1 - 2007

N2 - It is well known that the sphere decoder has polynomial complexity at high signal to noise ratio (SNR). However, the worst case complexity is exponential leading to severe decoding time delay. In this paper, we present a scheme to overcome the worst case complexity of the sphere decoder. If the number of visited lattice points reaches the threshold, the detected symbol vector is determined between two candidate symbol vectors. One candidate symbol vector is obtained from the demodulated output of ZF receiver which is initial stage of the sphere decoder. The other candidate symbol vector consists of two sub-symbol vectors. The first sub-symbol vector consists of lately visited lattice points running from the most upper layer. The second one contains corresponding demodulated outputs of zero-forcing (ZF) receiver. Between these two candidate symbol vectors, the one with smaller Euclidean distance to the received symbol vector is chosen as detected symbol vector. In addition, we show the upper bound of symbol error rate (SER) performance for the sphere decoder using the proposed scheme. In the simulation, the proposed scheme shows the significant reduction of the worst case complexity while having negligible SER performance degradation.

AB - It is well known that the sphere decoder has polynomial complexity at high signal to noise ratio (SNR). However, the worst case complexity is exponential leading to severe decoding time delay. In this paper, we present a scheme to overcome the worst case complexity of the sphere decoder. If the number of visited lattice points reaches the threshold, the detected symbol vector is determined between two candidate symbol vectors. One candidate symbol vector is obtained from the demodulated output of ZF receiver which is initial stage of the sphere decoder. The other candidate symbol vector consists of two sub-symbol vectors. The first sub-symbol vector consists of lately visited lattice points running from the most upper layer. The second one contains corresponding demodulated outputs of zero-forcing (ZF) receiver. Between these two candidate symbol vectors, the one with smaller Euclidean distance to the received symbol vector is chosen as detected symbol vector. In addition, we show the upper bound of symbol error rate (SER) performance for the sphere decoder using the proposed scheme. In the simulation, the proposed scheme shows the significant reduction of the worst case complexity while having negligible SER performance degradation.

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M3 - Conference contribution

AN - SCOPUS:52249089237

SN - 0769530486

SN - 9780769530482

T3 - Proceedings of Future Generation Communication and Networking, FGCN 2007

SP - 85

EP - 89

BT - Proceedings - CIS Workshops 2007, 2007 International Conference on Computational Intelligence and Security Workshops, CISW 2007

T2 - 2007 International Conference on Future Generation Communication and Networking, FGCN 2007

Y2 - 6 December 2007 through 8 December 2007

ER -