Title :
Uniform decomposition of mutual information using MMSE decision feedback detection
Author :
Zhang, Jian-Kang ; Davidson, Timothy N. ; Wong, Kon Max
Author_Institution :
Dept. of Electr. & Comput. Eng., McMaster Univ., Hamilton, Ont.
Abstract :
We consider efficient techniques for the design of a transceiver for a matrix channel with minimum mean square error (MMSE) decision-feedback (DF) detection when perfect channel information is available at both the transmitter and receiver. By combining the canonical property of the MMSE-DF detector and our recently developed equal-diagonal QRS decomposition of a matrix we obtain a uniform decomposition of mutual information in which each of the synthesized scalar subchannels has the same mutual information (under the assumption of error-free feedback). To assist our analysis of this uniform decomposition, we provide a new QR interpretation of the MMSE-DF receiver. This enables us to show that the natural detection order is optimal (in an SINR sense), and that for the proposed transmitter, the MMSE-DF detector is asymptotically equivalent to the maximum likelihood detector when the SNR is high. We also derive a low-complexity quadratic recursive algorithm for the characterization of all eligible S-factors in the QRS decomposition. When coupled with our QR interpretation of the MMSE-DF detector, this enables us to efficiently design the optimal transmitter and to efficiently implement the MMSE-DF receiver
Keywords :
feedback; least mean squares methods; matrix decomposition; maximum likelihood detection; multiuser detection; transceivers; MMSE decision feedback detection; MMSE-DF receiver; QR interpretation; canonical property; eligible S-factors; equal-diagonal QRS matrix decomposition; error-free feedback; low-complexity quadratic recursive algorithm; matrix channel; maximum likelihood detector; minimum mean square error; mutual information; optimal transmitter design; perfect channel information; synthesized scalar subchannels; transceiver design; uniform decomposition; Arithmetic; Detectors; Feedback; Matrix decomposition; Maximum likelihood detection; Mean square error methods; Mutual information; Signal to noise ratio; Transceivers; Transmitters;
Conference_Titel :
Information Theory, 2005. ISIT 2005. Proceedings. International Symposium on
Conference_Location :
Adelaide, SA
Print_ISBN :
0-7803-9151-9
DOI :
10.1109/ISIT.2005.1523429