Channel sounding for wireless communication

• Main Author: Ong, Fabian Jee Wee.
• Other Authors: Lee Yee Hui
• Format: Final Year Project
• Language: English
• Published: 2009
• Subjects: DRNTU::Engineering::Electrical and electronic engineering::Wireless communication systems
• Online Access: http://hdl.handle.net/10356/17840
• Institution: Nanyang Technological University

In designing wireless communication system, the propagation characteristic of a particular environment in which it is deployed plays a significant role in determining the channel parameters. Degradation of transmitted signal might be due to fading and multipath propagation. The intersymbol interference (ISI) is directly related multipath phenomena, where multiple copies of the transmitted signal arrived at the receiver. This in turn affects the system’s bit error rate (BER), which is crucial to digital communication. Indoor channel sounding has been extensively researched based on different system, modulation techniques, frequency bands and bandwidth used. This thesis would include the study of using Vector Network Analyzer (VNA) for a frequency domain measurement. The mean excess delay, rms delay spread and excess delay spread (dB) are parameters which measure the multipath channel. A comprehensive experiment has been conducted to resolve the effect of certain parameters that would determine the optimal resolution of a measurement. Bit error rate (BER) analysis for two commonly used digital modulations, namely the binary phase shift keying (BPSK) and quadrature phase shift keying (QPSK), are covered. Coherent demodulation of coherent PSK requires the availability of a correct phase and carrier frequency at the receiver. Due to the different clock rates between the transmitter and receiver, phase correction needs to be implemented in Matlab environment for post processing of the data to obtain the BER. To conclude, tradeoffs have to be made in order to obtain an optimal resolution of a measurement. In the case of BER, if bandwidth efficiency is more crucial, QPSK would be the preferred choice. In terms of power efficiency, BPSK is chosen.