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1

Transmitter diversity antenna selection techniques for wireless channels utilizing differential space-time block codes

Tran L. C., Wysocki T. A., Mertins A., Seberry J.

Journal of Telecommunications and Information Technology

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2006

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nr 2

79-96

EN

The paper deals with transmitter diversity antenna selection techniques (ASTs) for wireless channels utilizing differential space-time block codes (DSTBCs). The proposed ASTs tend to maximize the signal-to-noise ratio (SNR) of those channels. Particularly, we propose here the so-called general (M,N;K) AST/DSTBC scheme for such channels. Then, based on this AST, we propose two modified ASTs which are more amenable to practical implementation, namely the restricted (M,N;K) AST/DSTBC scheme and the (N + —N,N;K) AST/DSTBC scheme. The restricted (M,N;K) AST/DSTBC scheme provides relatively good bit error performance using only one feedback bit for transmission diversity purpose, while the (N+ —N,N;K) AST/DSTBC scheme shortens the time required to process feedback information. These techniques remarkably improve bit error rate (BER) performance of wireless channels using DSTBCs with a limited number (typically 1 or 2) of training symbols per each coherent duration of the channel. Simulations show that the proposed AST/DSTBC schemes outperform the DSTBCs without antenna selection even with only 1 training symbol.

2

Fully spatial and SNR scalable, SPIHT-based image coding for transmission over heterogenous networks

Danyali H., Mertins A.

Journal of Telecommunications and Information Technology

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2003

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nr 2

92-98

EN

This paper presents a fully scalable image coding scheme based on the set partitioning in hierarchical trees (SPIHT) algorithm. The proposed algorithm, called fully scalable SPIHT (FS-SPIHT), adds the spatial scalability feature to the SPIHT algorithm. It provides this new functionality without sacrificing other important features of the original SPIHT bitstream such as: compression efficiency, full embeddedness and rate scalability. The flexible output bitstream of the FS-SPIHT encoder which consists of a set of embedded parts related to different resolutions and quality levels can be easily adapted (reordered) to given bandwidth and resolution requirements by a simple parser without decoding the bitstream. FS-SPIHT is a very good candidate for image communication over heterogenous networks which requires high degree of scalability from image coding systems.

3

Design of filterbank transceivers for dispersive channels with arbitrary-length impulse response

Mertins A.

Journal of Telecommunications and Information Technology

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2003

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nr 2

11-16

EN

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.

4

Memory truncation and crosstalk cancellation for efficient Viterbi detection in FDMA systems

Mertins A.

Journal of Telecommunications and Information Technology

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2001

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nr 3

29-35

EN

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.