Nested Construction of Polar Codes for Blind Detection

In this letter, we propose a novel polar coding scheme for blind detection in 5G systems. In the proposed scheme, the codewords for different aggregation levels (ALs) are constructed in a nested fashion, and a low-latency detection scheme is proposed. The nested construction is exploited to help locate the target physical downlink control channel (PDCCH) candidate. Specifically, the user equipment (UE) firstly attempts to decode PDCCH candidates with a lower AL. In case of decoding failure, a set of candidates with a higher AL are properly selected and decoded. Simulation results show that the proposed scheme can significantly reduce the latency of blind detection in 5G systems with miss-detection rate (MDR) performance close to exhaustive search.