A new echo canceller for discrete multitone (DMT) systems is presented where each used tone has its own per tone echo canceller (PT-EC) in addition to a per tone equalizer (PTEQ) [1, 2]. This enables us to optimize the Signal-to-Noise Ratio (SNR) for each tone separately by solving a Minimum Mean Square Error (MMSE) problem for each tone. Simulation results confirm improved performance over tim...

The transmission of high-speed data over severely band-limited channels may be accomplished through the use of discrete multitone (DMT) modulation, a modulation technique that has been proposed for a number of new applications. While the performance of a DMT system has been analyzed by a number of authors, these analyses ignore the effect of timing jitter on system performance. Timing jitter be...

Background: How to deal with the time-dispersive channel is the main challenge faced by the short-range optical communication systems. In this work a novel pseudo-noise sequence (PN) assisted pulse-amplitude modulated (PN-PAM) transmission scheme for short-range optical communication systems is proposed in this work. With the help of the PN based channel estimation, minimum-phase pre-filter and...

This paper presents an analysis of the effect of the carrier frequency offset and phase noise on a performance of Wavelet based Filtered Multi-Tone (WFMT) systems for a general AWGN channel. It is well known that the carrier frequency offset in OFDM System yields to significant degradation of the signal-tonoise ratio (SNR). Below I show that a novel WFMT modulation is less sensitive to the freq...

Recent analysis of Multiple-Input Multiple-Output (MIMO) communication systems, for example those involving antenna arrays, has shown that channel capacity increases linearly with the number of antennas. This motivates the investigation of methods for data transmission over slowly time-varying MIMO channels. A low complexity method is introduced that e ectively diagonalizes the MIMO channel. Th...

Recently DFT based discrete multitone modulation (DMT) systems have been widely applied to various applications. In this paper we study a broader class of DMT systems using more general unitary matrices instead of DFT matrices. For this class we will show how to design the optimal DMT systems over fading channels with colored noise. Examples will be given to show the improvement over the tradit...

Discrete Multitone (DMT) modulation is a multicarrier technique which makes efficient use of the channel, maximizing the throughput by sending different numbers of bits on different subchannels. The number of bits on each subchannel depends on the Signal-to-Noise Ratio of the subchannel. The performance of a DMT system can be further increased by using powerful coding techniques. This paper inv...

An all-digital implementation of multicarrier modulation called discrete multitone (DMT) modulation has been standardised for asymmetric digital subscriber line (ADSL), ADSL2, ADSL2+ and VDSL [1][3]. ADSL modems rely on DMT modulation, which divides a broadband channel into many narrowband subchannels and modulated encoded signals onto the narrowband subchannels [4], [5]. With advanced digital ...

An alternative receiver structure is presented for discrete multitone-based systems. The usual structure consisting of a (real) time-domain equalizer in combination with a (complex) 1-tap frequency-domain equalizer (FEQ) per tone, is modified into a structure with a (complex) multitap FEQ per tone. By solving a minimum mean-square-error problem, the signal-to-noise ratio is maximized for each i...

Making use of the Volterra approach, black box modeling is applied to a large scale analog circuitry for an ADSL (asymmetric digital subscriber line) central office application. Reducing the number of free parameters through special assumptions on the Volterra kernels, one ends up with the Hammerstein model. Taking the first few taps of the Volterra kernels and approximating the last taps throu...