Browsing by Author "Lee, Chun Fang"

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A low-complexity design method for DMT time domain equalizers
(2006)
Lee, Chun Fang
;
Wu, Wen Rong
;
電信工程研究所
;
Institute of Communications Engineering
The time-domain equalizer (TEQ) is a commonly used device to shorten the channel impulse response in a discrete multitone (DMT) receiver. With a capacity maximization criterion, a TEQ design method called minimum intersymbol interference (minISI) has shown to have nearly optimum performance. However, the minISI design method require high computational complexity. adversely affecting its real-world implementation. In this papers we propose a low-complexity method to overcome this problem. The main idea is to use a subset of the subchannels, instead of all,. for capacity maximization. With a simple equally-spaced sampling method, the number of subchannels required for calculation can be effectively reduced. Simulations show that the performance of the proposed algorithm is almost the same as the original minISI while its computation is dramatically reduced.
A multistage IIR time domain equalizer for OFDM systems
(2007)
Lee, Chun Fang
;
Wu, Wen Rong
;
電信工程研究所
;
Institute of Communications Engineering
The time-domain equalizer (TEQ) is a commonly used device to shorten the channel impulse response in an orthogonal frequency division multiplexing (OFDM) receiver. With a SSNR maximization criterion, the MSSNR TEQ method is one attractive method with its supreme performance. However, the MSSNR method suffers from high computation complexity when employing the TEQ with long taps. We first demonstrate the MSSNR method and the Steiglitz McBride method for translating the prescribed FIR to an IIR form. Then we propose a multistage TEQ method with the Steiglitz McBride method. Based on the structures, we analyze the computational complexity. Simulations show that the proposed method is almost the same performance as the existing ones and its computation can be reduced dramatically.