DocumentCode :
2111304
Title :
Transform-domain delayed LMS algorithm and architecture
Author :
Wu, An-Yeu ; Wu, Cheng-Shing
Author_Institution :
Dept. of Electr. Eng., Nat. Central Univ., Chung-Li, Taiwan
Volume :
5
fYear :
1998
fDate :
31 May-3 Jun 1998
Firstpage :
194
Abstract :
The least mean square (LMS) algorithm is one of the most widely applied adaptive methods in communication systems due to its simplicity. In applications that require high-speed sampling rate and very long tap FIR filter, the delayed LMS (DLMS) is usually employed. However, the value of the delay stage (D) will lead to degradation of the convergence speed, which is not acceptable in fast time-varying communication channels. In this paper, we propose a new DLMS algorithm called “transform-domain DLMS (TD-DLMS)” to overcome the aforementioned speed degradation. It is derived based on the multirate FIR filtering structure, and the operations are performed in the transform domain. By doing so, the delay stage (D) in the DLMS can be reduced to D/M-1+2 log2 (2M), where M is the decimation factor. As a result, we can reduce the value of D that causes slow convergence rate in the DLMS. Besides, since the adaptive filtering is performed in the transform domain, we can apply the technique of “power normalization” to further improve the convergence rate
Keywords :
FIR filters; adaptive filters; delays; least mean squares methods; FIR filter; adaptive methods; convergence rate; decimation factor; delay stage; delayed LMS; high-speed sampling rate; multirate FIR filtering structure; power normalization; speed degradation; transform-domain DLMS; transform-domain delayed LMS algorithm; Adaptive filters; Convergence; Degradation; Delay; Estimation error; Feedback; Filtering; Finite impulse response filter; Least squares approximation; Sampling methods;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Circuits and Systems, 1998. ISCAS '98. Proceedings of the 1998 IEEE International Symposium on
Conference_Location :
Monterey, CA
Print_ISBN :
0-7803-4455-3
Type :
conf
DOI :
10.1109/ISCAS.1998.694441
Filename :
694441
Link To Document :
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