Research on Performance Enhancement of Qpsk Communication System in Block Fading Channel Based on MRC Technology

This paper addresses the bit error rate (BER) performance issue of QPSK modulation systems in block fading channels by proposing an optimized scheme combining convolutional coding and diversity reception techniques. A communication link incorporating pilot insertion, block fading modeling, maximum ratio combining (MRC), and selection combining (SC) is constructed via MATLAB simulation. The synergistic effects of coding gain and diversity techniques on system anti-jamming capability are analyzed. Experimental results show that the combination of a 1/2 coding rate convolutional code and MRC technology reduces the system BER to the order of $10^{-5}$ at $E_{b} / N_{0}=12 d B$, achieving a performance improvement of approximately $\mathbf{5} \boldsymbol{d} \boldsymbol{B}$ compared to uncoded systems. This study provides theoretical and practical insights for designing high-reliability wireless communication systems.