In wireless communication systems with antenna arrays the spatiotemporal channel can often be described by a low-rank model. By exploiting this information, corresponding low rank equalizers with reduced complexity can be designed. By applying such low rank equalizers to a set of uplink measurements, we demonstrate that the performance loss associated with the lower complexity is small.

We introduce a novel family of adaptive robust equalizers for highly challenging underwater acoustic (UWA) channel equalization. Since the underwater environment is highly non-stationary and subjected to impulsive noise, we use adaptive filtering techniques based on a relative logarithmic cost function inspired by the “competitive methods” from the online learning literature. To improve the con...

In this paper, we describe methods for computing fractionally spaced blind equalizers directly from second-order statistics of the observations. The equalizers with all possible delays are computed simultaneously, and the one with the best delay is picked by a blind constant modulus index. Our algorithm utilizes the equalizer output whitening property of the blind equalizers, i.e., output white...

Recently much attention has been given to the design of timedomain equalizers or TEQs for discrete multitone modulation (DMT) systems. In this paper, we present a new method for the design of such equalizers which minimizes both the intersymbol interference (ISI) and noise power observed in a DMT system. Furthermore, we show how this method can be used for the design of fractionally spaced equa...

This paper describes the design of switched-current group delay equalizers. The design process is based on the pole-zero mirroring technique; with equalizer z-transfer functions generated using an optimization algorithm. To facilitate the systematic implementation of the equalizers, a model describing the design process is developed. A novel feature of the equalizers implementation is that wave...

We propose low-complexity equalizers for Alamouti space-time coded orthogonal frequency-division multiplexing (OFDM) systems in timeand frequency-selective channels, by extending the approach formerly proposed for single-antenna OFDM systems. The complexity of the proposed algorithm is linear in the number of subcarriers by exploiting the band structure of the frequency-domain channel matrix an...

High-speed downlink packet access (HSDPA) has been developed to upgrade the current WCDMA system in yerms of providing a higher data rate for mobile users. To ensure a downlink speed of up to 14Mbps, the HSDPA system has three main features: adaptive modulation and coding, a hybrid automatic repeat request, and fast scheduling. Because standard documents describe only the specifications of Node...