Design of filterbank transceivers for dispersive channels with arbitrary-length impulse response, Journal of Telecommunications and Information Technology, 2003, nr 2

This paper addresses the joint design of transmitter and receiver for multichannel data transmission over dispersive channels. The transmitter is assumed to consist of FIR filters and the channel impulse response is allowed to have an arbitrary length. The design criterion is the maximization of the information rate between transmitter input and receiver output under the constraint of a fixed transmit power. A link to minimum mean squared error designs for a similar setting is established. The proposed algorithm allows a straightforward transmitter design and generally yields a near-optimum solution for the transmit filters. Under certain conditions, the exact solution for the globally optimal transmitter is obtained

Memory truncation and crosstalk cancellation for efficient Viterbi detection in FDMA systems, Journal of Telecommunications and Information Technology, 2001, nr 3

In this paper, the design of optimal receive filter banks for frequency division multiple access (FDMA) over frequency selective channels is investigated. A new design strategy based on the principle of memory truncation, rather than equalization, is presented. Through the receive filters, each subchannel is truncated to a pre-defined length, and the final data recovery is carried out via low complexity Viterbi detectors. Both closed form designs and adaptive techniques are discussed. Design examples are presented for high speed transmission over copper wires. The examples show that memory truncation allows significant performance improvements over the often used minimum mean squared error (MMSE) equalization

Scalable Multiresolution Image Segmentation and Its Application in Video Object Extraction Algorithm

This paper presents a novel multiresolution image segmentation method based on the discrete wavelet transform and Markov Random Field (MRF) modelling. A major contribution of this work is to add spatial scalability to the segmentation algorithm producing the same segmentation pattern at different resolutions. This property makes it suitable for the scalable object-based wavelet coding. The correlation between different resolutions of pyramid is considered by a multiresolution analysis which is incorporated into the objective function of the MRF segmentation algorithm. Allowing for smoothness terms in the objective function at different resolutions improves border smoothness and creates visually more pleasing objects/regions, particularly at lower resolutions where downsampling distortions are more visible. Application of the spatial segmentation in video segmentation, compared to traditional image/video object extraction algorithms, produces more visually pleasing shape masks at different resolutions which is applicable for object-based video wavelet coding. Moreover it allows for larger motion, better noise tolerance and less computational complexity. In addition to spatial scalability, the proposed algorithm outperforms the standard image/video segmentation algorithms, in both objective and subjective tests

Exploring Superframe Co-occurrence for Acoustic Event Recognition

We introduce in this paper a concept of using acoustic superframes, a mid-level representation which can overcome the drawbacks of both global and simple frame-level representations for acoustic events. Through superframe-level recognition, we explore the phenomenon of superframe co-occurrence across different event categories and propose an efficient classification scheme that takes advantage of this feature sharing to improve the event-wise recognition power. We empirically show that our recognition system results in 2.7% classification error rate on the ITC-Irst database. This state-of-the-art performance demonstrates the efficiency of this proposed approach. Furthermore, we argue that this presentation can pretty much facilitate the event detection task compared to its counterparts, e.g. global and simple frame-level representations