Joint Method for XPIC, Equalization and IQ Imbalance Compensation in Space-Air-Ground Broadband Dual-Polarized Systems

In the integrated space-air-ground cooperative sensing and communication scenario, massive sensing data necessitates high-speed transmission, while ensuring reliable data delivery confronts the combined challenges of cross-polarization interference, IQ imbalance, and multipath effects. To address the efficient interference suppression requirements for zero-IF dual-polarized receiver architectures in integrated space-air-ground systems, this paper proposes a fully blind joint processing method in the time domain for broadband dual-polarized signals, incorporating XPIC, equalization, and IQ compensation. Compared to step-by-step processing, the joint processing method can achieve global optimization with faster convergence speed. For different scenarios, the adaptive coefficients of the transversal filter are updated using different algorithms, supporting various modulation schemes including PSK, APSK, and QAM. The reconfigurable loop topology architecture enables dynamic adjustment of processing sequence based on channel conditions. Simulations demonstrate that this method can adapt to multipath signals from LEO satellites and UAVs, tolerate 2 dB amplitude and 12° phase imbalance in IQ components, and provide over 30 dB XPI suppression gain, making it suitable for high-speed data transmission scenarios in integrated space-air-ground cooperative sensing and communication systems.