Improving Receiver Detection in Long-Code Direct Sequence Spread Spectrum Systems Using Adaptive Thresholding

Document Type : Original Article

Authors

1 Department of Electrical Engineering, Imam Hossein University, Tehran, Iran

2 Imam Hossein Comprehensive University

10.22034/tjee.2026.66864.5009

Abstract

Long-code direct sequence spread spectrum (Long-DSSS) systems play an important role in advanced communications and next-generation cellular networks due to their high security and resistance to interference. However, traditional detection methods based on fixed thresholding face significant performance degradation under variable channel conditions, severe noise, and low signal-to-noise ratio (SNR). In this research, a novel approach based on the combination of the double folding (DF) technique and adaptive CFAR (Constant False Alarm Rate) thresholding is presented. DF accelerates synchronization by increasing the coherent integration time, while CFAR eliminates the limitations of fixed thresholding by dynamically and in real time adjusting the threshold according to the statistical characteristics of the signal and noise. To evaluate performance, various CFAR algorithms such as CA-CFAR and OS-CFAR were tested in homogeneous and heterogeneous environments in the presence of pulsed and random jammers. Simulation results show that the proposed method, in addition to reducing the Bit Error Rate (BER), provides more stable performance compared to conventional methods and can lead to improved reliability and security of communications in next-generation cellular networks.

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