Code-Aided Overlapped Parallel Interference Cancellation Mechanism in Asynchronous DS-CDMA Systems

The rapid development of satellite communication techniques has promoted research on satellite Internet of Things (SatIoT) networks with multiuser connectivity. Simultaneous transmission in satellite networks results in severe multiple-access interference (MAI), which is primarily caused by inevitable factors such as near-far effect and nonorthogonal phenomena. However, the performance of existing interference cancellation algorithms is commonly limited by degraded signal qualities and limited hardware resources. To address this problem, we propose a code-aided overlapped parallel interference cancellation mechanism, which provides significant improvements over conventional methods. This innovative mechanism improves energy estimation accuracy and optimizes interference reconstruction in asynchronous DS-CDMA channels. In addition, we integrate a channel coding scheme, forming an outer iterative structure for interference cancellation procedure with decoder feedback. Through these optimizations, the approach demonstrates up to 5 dB gain in Eb/N0 at bit error rate (BER) of 10^-5 in an additive white Gaussian noise (AWGN) channel. At the same time, it maintains computational complexity of the receiver system within feasible bounds.