Title: Modelling, analysis and performance evaluation of DSSS-based communications in WSNs over frequency-selective fading channels
Authors: Jianjie Tian; Stevan Berber; Gerard Rowe
Addresses: Department of Electrical and Computer Engineering, University of Auckland, Auckland, New Zealand ' Department of Electrical and Computer Engineering, University of Auckland, Auckland, New Zealand ' Department of Electrical and Computer Engineering, University of Auckland, Auckland, New Zealand
Abstract: Wireless channels should be considered to have frequency-selective nature for systems operating in indoor environments. However, a comprehensive analysis for communications over frequency-selective channels, giving a proper mathematical model and closed-form error expressions, practically does not exist. Thus, this paper develops a detailed mathematical model of DSSS-based, band-pass communications in WSNs operating over frequency-selective channels. The channel is modelled by a modified Saleh-Valenzuela model, which is composed of a primary channel and a number of secondary channels. For the sake of accommodating the delays in the channel, all signals are presented and processed in discrete time domain form which will be suitable for direct processing for designs in digital technologies. Furthermore, a chip-interleaving technique has been used to mitigate fading effects in frequency-selective channels. Closed-form expressions are derived for scenarios of binary and chaotic spreading sequences. Theoretical findings are confirmed by Matlab simulations.
Keywords: direct sequence spread spectrum; discrete time domain; binary and chaotic sequences; frequency-selective fading; chip-interleaving; wireless sensor networks.
International Journal of Wireless and Mobile Computing, 2017 Vol.12 No.3, pp.207 - 216
Received: 08 Nov 2016
Accepted: 30 Jan 2017
Published online: 27 Jun 2017 *