Direct Sequence Spread Spectrum System Noise and Interference Immunity Analysis

Abstract

The paper focuses on the noise and interference immunity properties of the direct spread spectrum systems in order to find out the best receiver structure for the terrestrial mobile communications considering limitations in energy consumption, computing resources and weight and size characteristics of mobile device in decentralized network. A DSSS system with two suitable receiver structures suitable for the mobile communication device was simulated. The simulation results show that direct spread spectrum systems have high immunity to pulse interference and the receiver structure with narrowband filtering on radio frequency shows better immunity to narrowband interference. It was proposed that for the case of high level narrowband interference a DC voltage compensation before the detector should be performed. The DSSS system with suggested compensation block can operate with the interference level which is larger than signal level in radio channel proportional to spreading factor.