Space-Frequency Transmit Diversity in Multiband-OFDM Systems
نویسندگان
چکیده
In this paper we investigate the suitability and performance of space-frequency block coded Multi-band orthogonal frequency division multiplexing (MB-OFDM) system under UWB channel model. The employment of transmit diversity techniques based on block codes is expected to achieve enhancement in such systems since it greatly reduces the detrimental effects of multipath fading. In the proposed MB-OFDM UWB system, the space coded symbols are distributed as space-frequency block codes over neighbouring sub-carriers, therefore the space-frequency coding is independent of the time-frequency codes used in MB-OFDM system. The study shows performance improvement obtained by the proposed space-frequency coded MB-OFDM scheme.
منابع مشابه
Channel Compensation for SFBC-OFDM Systems in Broadband Wireless Channels
In this paper, we consider orthogonal space-frequency transmit diversity schemes for OFDM systems in broadband wireless channels. We propose a compensation method to prevent error floor caused by unequal subchannels in the space-frequency block coded OFDM systems for 2 and 3 transmit antennas while providing diversity gain. We will show that for 2 antennas case, the proposed compensation method...
متن کاملCooperative Orthogonal Space-Time-Frequency Block Codes over a MIMO-OFDM Frequency Selective Channel
In this paper, a cooperative algorithm to improve the orthogonal space-timefrequency block codes (OSTFBC) in frequency selective channels for 2*1, 2*2, 4*1, 4*2 MIMO-OFDM systems, is presented. The algorithm of three node, a source node, a relay node and a destination node is formed, and is implemented in two stages. During the first stage, the destination and the relay antennas receive the sym...
متن کاملPractical Pilot Patterns for Coherent Coded OFDM Systems using Space Time Transmit Diversity
In recent times, transmit diversity has been proposed in various forms for many different communication systems. In this paper, we shall investigate, in particular the use of space-time transmit diversity (STTD) for coded OFDM systems using space-time block coding (STBC). With such an approach the STBC receiver must use one or more adjacent pilots to obtain orthogonal channel estimates from the...
متن کاملTransmit Diversity Vs Beamforming for Multi-User OFDM Systems
In an Orthogonal Frequency Division Multiplexing (OFDM) system, downlink beamforming can be implemented either before IDFT (frequency domain) or after IDFT (time domain) module in a base station transmitter. We denote the former scheme as PreIDFT downlink beamforming, and the latter as Post-IDFT downlink beamforming. In this work, we have compared Pre-IDFT downlink beamforming with Space-Time B...
متن کاملSpace Time Turbo Coded OFDM with Joint Transmit and Receive Antenna Selection
This paper discusses the performance of antenna selection technique in space time turbo coded MIMO-OFDM systems. Multiple-input multiple-output (MIMO) technology can either increase the data rate through spatial multiplexing or improve the reliability through diversity. Space-time turbo codes (STTC) have been proposed to provide robust communications in MIMO wireless environment. STTC technique...
متن کامل