Infinite Length Results and Design Implications for Time-Domain Equalizers

Infinite Length Results for Channel Shortening Equalizers

Time-domain equalization is crucial in reducing state dimension in maximum likelihood sequence estimation, and inter-carrier and inter-symbol interference in 802.11a and ADSL multicarrier systems. A time-domain equalizer, or TEQ, which is a finite impulse response (FIR) filter, placed in cascade with the channel produces an effective impulse response of ν + 1 samples that is shorter than the ch...

Design methods for time-domain equalizers in DMT transceivers

Time-domain equalizers (TEQ) are used in the discrete multitone (DMT) transceivers in order to reduce the duration of the overall response of the transmission system, so that a shorter-length cyclic prefix could be used. The optimum TEQ is the one that results in maximum bit allocation to each block of DMT. However, the optimum design of TEQs turns out to be a very difficult task. In this paper...

On the relation between time-domain equalizers and per-tone equalizers for DMT-based systems

We reconsider MMSE-based time-domain equalizer (TEQ), bitrate maximizing TEQ and per-tone equalizer design for DMT transmission. It is shown that they can all be formulated either as a constrained linear or a separable nonlinear least-squares problem. These least-squares formulations are then turned into generalized eigenvalue problems that allow to establish a remarkably close relationship bet...

Comparison of Frequency Domain Equalizers to Time Domain Equalizers in WCDMA

Bit rate optimized time-domain equalizers for DMT systems

The discrete multitone (DMT) transceivers have enjoyed great success in high speed data transmission. It is known that when the cyclic prefix is no shorter than the channel impulse response (CIR), the DMT system is IS1 free. For channels with very long CIR such as DSL loops, a time-domain equalizer (TEQ) is typically added at the receiver to shorten the effective impulse response. This paper pr...