TY - JOUR
T1 - Equalization for discrete multitone transceivers to maximize bit rate
AU - Arslan, Güner
AU - Evans, Brian L.
AU - Kiaei, Sayfe
N1 - Funding Information:
Manuscript received June 1, 2000; revised July 17, 2001. B. Evans was supported by a gift from Motorola. G. Arslan was sponsored by a Turkish Government Higher Education Council (YÖK) Fellowship administered by Yıldız Technical University, Istanbul, Turkey. The associate editor coordinating the review of this paper and approving it for publication was Prof. Lang Tong.
PY - 2001/12
Y1 - 2001/12
N2 - In a discrete multitone receiver, a time-domain equalizer (TEQ) reduces intersymbol interference (ISI) by shortening the effective duration of the channel impulse response. Current TEQ design methods such as minimum mean-squared error (MMSE), maximum shortening SNR (MSSNR), and maximum geometric SNR (MGSNR) do not directly maximize bit rate. In this paper, we develop two TEQ design methods to maximize bit rate. First, we partition an equalized multicarrier channel into its equivalent signal, noise, and ISI paths to develop a new subchannel SNR definition. Then, we derive a nonlinear function of TEQ taps that measures hit rate, which the proposed maximum bit rate (MBR) method optimizes. We also propose a minimum-ISI method that generalizes the MSSNR method by weighting the ISI in the frequency domain to obtain higher performance. The minimum-ISI method is amenable to real-time implementation on a fixed-point digital signal processor. Based on simulations using eight different carrier-serving-area loop channels, 1) the proposed methods yield higher bit rates than MMSE, MGSNR, and MSSNR methods; 2) the proposed methods give three-tap TEQs with higher bit rates than 17-tap MMSE, MGSNR, and MSSNR TEQs; 3) the proposed MBR method achieves the channel capacity (as computed by the matched filter bound using the proposed subchannel SNR model) with a five-tap TEQ; and 4) the proposed minimum-ISI method achieves the bit rate of the optimal MBR method.
AB - In a discrete multitone receiver, a time-domain equalizer (TEQ) reduces intersymbol interference (ISI) by shortening the effective duration of the channel impulse response. Current TEQ design methods such as minimum mean-squared error (MMSE), maximum shortening SNR (MSSNR), and maximum geometric SNR (MGSNR) do not directly maximize bit rate. In this paper, we develop two TEQ design methods to maximize bit rate. First, we partition an equalized multicarrier channel into its equivalent signal, noise, and ISI paths to develop a new subchannel SNR definition. Then, we derive a nonlinear function of TEQ taps that measures hit rate, which the proposed maximum bit rate (MBR) method optimizes. We also propose a minimum-ISI method that generalizes the MSSNR method by weighting the ISI in the frequency domain to obtain higher performance. The minimum-ISI method is amenable to real-time implementation on a fixed-point digital signal processor. Based on simulations using eight different carrier-serving-area loop channels, 1) the proposed methods yield higher bit rates than MMSE, MGSNR, and MSSNR methods; 2) the proposed methods give three-tap TEQs with higher bit rates than 17-tap MMSE, MGSNR, and MSSNR TEQs; 3) the proposed MBR method achieves the channel capacity (as computed by the matched filter bound using the proposed subchannel SNR model) with a five-tap TEQ; and 4) the proposed minimum-ISI method achieves the bit rate of the optimal MBR method.
KW - Channel shortening
KW - FIR filter design
KW - Maximum bit rate equalizer
KW - Minimum intersymbol interference equalizer
KW - Time domain equalization
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U2 - 10.1109/78.969519
DO - 10.1109/78.969519
M3 - Article
AN - SCOPUS:0035674375
SN - 1053-587X
VL - 49
SP - 3123
EP - 3135
JO - IRE Transactions on Audio
JF - IRE Transactions on Audio
IS - 12
ER -