System Overview We consider an iterative decoding and detection system for magnetic recording channels. The system uses a zero-forcing equalizer to shape the channel response to a target polynomial, called a partial-response (PR) polynomial. We assume that the noise at the input to the equalizer is AWGN. Hence, noise enhancement and coloration occur at the output of the equalizer. The output of...

In this paper a technique for increasing the convergence rate of fractionally spaced channel equalizer is proposed. Instead of symbol-spaced updating of the equalizer filter, a mechanism has been devised to update the filter at a higher rate. This ensures convergence of the equalizer filter at a higher rate and therefore less time-consuming. The proposed technique has been simulated and tested ...

In this paper, we propose an adaptive IIR equalizer based on prefiltering techniques. The proposed equalizer has a cascade structure of an ARMA prefilter and an adaptive FIR equalizer. The ARMA prefilter is designed based on the transfer function estimated by the gradient-type instrumental variable algorithm. Simulation results are shown to confirm the performance of the proposed adaptive IIR e...

A family of sub-optimal Bayesian equalizers is proposed in two versions: feed-forward and decision feedback. We show that this family of equalizers provides a range of gradual choices concerning the tradeoff between equalizer complexity and symbol error rate (SER). We also point out the SER equivalence between the simplest proposed structure (the simplest equalizer of the family) and Wiener lin...

The recent digital transmission systems impose the application of channel equalizers with short training time and high tracking rate. These requirements turn our attention to adaptive algorithms, which converge rapidly. From this point of view the best choice is the recursive least squares (RLS) equalizer. Unfortunately this equalizer has high computational complexity and stability problems. Th...

This paper presents a performance comparison between a constrained least mean squared algorithm for MIMO CDMA decision feedback equalizer and linear equalizer. Both algorithms are constrained on the length of spreading sequence, number of users, variance of multiple access interference as well as additive white Gaussian noise (new constraint). An important feature of both algorithms is that mul...

A finite impulse response (FIR) equalizer is practically employed in conjunction with the Viterbi detector for data detection process in magnetic recording channels. However, the FIR equalizer with a large number of taps is required at high density storage channels. It is well-known that an infinite impulse response (IIR) filter with a small number of taps can closely approximate such an FIR fi...

A novel low complexity soft-input soft-output equalizer is proposed for reducing the effects of intersymbol interference channels. The equalizer uses a bi-directional multipass algorithm to successively improve a soft interference canceler/adaptive linear filter combination. The resulting transmitted symbol estimates are calculated with computational complexity of cubic order in channel memory ...

A frequency domain adaptive equalizer, operating with fewer than 2 Sa/Symbol is investigated. Steady state performance and dynamic operation are demonstrated without equalizer training. We find that the equalizer exhibits no penalty as low as 1.1 Sa/Symbol. OCIS codes: (060.4510) Optical communications, (060.1660) Coherent communication.