tailieunhanh - Báo cáo hóa học: " Research Article Space-Time Convolutional Codes over Finite Fields and Rings for Systems with Large Diversity Order"

Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Research Article Space-Time Convolutional Codes over Finite Fields and Rings for Systems with Large Diversity Order | Hindawi Publishing Corporation EURASIP Journal on Wireless Communications and Networking Volume 2008 Article ID 624542 7 pages doi 2008 624542 Research Article Space-Time Convolutional Codes over Finite Fields and Rings for Systems with Large Diversity Order Mario de Noronha-Neto1 and B. F. Uchoa-Filho2 1 Telecommunications Systems Research and Development Group Federal Center of Technological Education of Santa Catarina 88103-310 Sao Jose SC Brazil 2 Communications Research Group-GPqCom Department of Electrical Engineering Federal University of Santa Catarina 88040-900 Florianopolis SC Brazil Correspondence should be addressed to B. F. Uchoa-Filho Received 26 October 2007 Revised 18 March 2008 Accepted 6 May 2008 Recommended by Yonghui Li We propose a convolutional encoder over the finite ring of integers modulo pk Zpk where p is a prime number and k is any positive integer to generate a space-time convolutional code STCC . Under this structure we prove three properties related to the generator matrix of the convolutional code that can be used to simplify the code search procedure for STCCs over Zpk. Some STCCs of large diversity order 4 designed under the trace criterion for n 2 3 and 4 transmit antennas are presented for various PSK signal constellations. Copyright 2008 M. de Noronha-Neto and B. F. Uchoa-Filho. This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use distribution and reproduction in any medium provided the original work is properly cited. 1. INTRODUCTION Since the discovery of space-time trellis codes STTCs by Tarokh et al. 1 much research has been done in this area. Some authors 2-5 have concentrated their efforts to generate STTCs through an encoding structure wherein the inputs are binary symbols the encoding operations are realised modulo 2k where k is any positive integer and the 2k -ary outputs are matched to a 2k -ary signal constellation. .