PS-NMPC: PSS–SSS Noncoherent Mirror-Product Combining for Reliable 5G NR SSB Detection

This letter proposes PSS–SSS noncoherent mirror-product combining (PS-NMPC) for fifth-generation new radio (5G NR) synchronization signal block (SSB) timing detection, thereby recovering the detection loss of single-component mirror-product correlation (MPC). By exploiting the deterministic PSS–SSS separation, the proposed method noncoherently combines two structure-aligned MPC outputs and thereby avoids the carrier-frequency-offset (CFO)-dependent phase cancellation of coherent combining. For the SSS-bearing symbol, an exact MPC analysis separates the deterministic SSS contribution from the physical broadcast channel (PBCH) and demodulation reference signal (DM-RS) perturbation, while standardized waveform tests bound the associated peak loss by 0.49 dB. Theoretical analysis yields a 3.01-dB ideal output-statistic gain and a 97.6% reduction in front-end search operations relative to conventional PSS search. Simulations using complete standard-compliant Case-C SSB observations show an approximately 3-dB improvement over MPC and operation within 2 dB of conventional PSS correlation without a local PSS template. The proposed PS-NMPC method also maintains robust performance under the tested CFO, fading, and detection-threshold variations.