Impact of Cooperative Space-Time/Frequency Diversity in OFDM Based Wireless Sensor Systems over Mobile Multipath Channels

Published: August 01, 2016


Hamid Gharavi


Cooperative linear dispersion coding (LDC) can support arbitrary configurations of source nodes and destination nodes in virtual multi-input multi-output (MIMO) systems. In this paper, we investigate two spatial diversity applications of cooperative LDC for orthogonal frequency division multiplexing (OFDM) based wireless sensor systems in order to achieve space-time/frequency (ST/SF) diversity gains when transmitting over time-/frequency-selective fading channels. Cooperative LDC-aided ST/SF-OFDMis flexible in configuring various numbers of cooperative source nodes and time-slots or frequency-tones. Our results show that the ST-OFDM scheme is sensitive to exploiting diversity gains, subject to the impact of varying channel Doppler spreads; while the performance of SF-OFDM is mainly subject to delay spread. Specifically, when the system involves more than two cooperative nodes, the cooperative LDC-aided ST/SF-OFDM outperforms the cooperative orthogonal block codes (e.g. Tarokh’s codes) aided ST/SF-OFDM, when communicating over a higher Doppler/delay spread.
Citation: IET Wireless Sensor Systems
Volume: 6
Issue: 4
Pub Type: Journals


Cooperative transmission, OFDM, MIMO, wireless networks, ST-OFDM, SF-OFDM
Created August 01, 2016, Updated February 19, 2017