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Performance Limitation of HSDPA MIMO by Pre-Coding Induced Phase Distortion

Authors:
Wolfgang Aichmann

Keywords: W-CDMA; HSDPA; MIMO; pre-coding; raised cosine filter;

Abstract:
In multiple-input multiple-output (MIMO) antenna systems both strength of the data layers as well as separation of them is achieved by pre-coding the transmitted signal with different factors for different layers and different antennas. In W-CDMA systems, the selection of these factors is decided anew every transmission time interval, which causes a phase distortion with every change. Due to raised cosine filtering this phase distortion is broadened even if the physical channel is flat in frequency, which distorts the affected symbols and thus limits the maximum bit rate to be transmitted in such cases if no counter measures are taken. If the pre-coding weights of adjacent time intervals are known by the receiver, the distortion can be removed by the equalizer; otherwise high code rates should be avoided by the scheduler.

Pages: 123 to 128

Copyright: Copyright (c) IARIA, 2013

Publication date: July 21, 2013

Published in: conference

ISSN: 2308-4219

ISBN: 978-1-61208-284-4

Location: Nice, France

Dates: from July 21, 2013 to July 26, 2013