Path-Metric-Based False Alarm Reduction in Blind Detection of Polar Codes

In blind detection, the user equipment attempts to decode a set of candidate groups to find its own control information. False alarm (FA) refers to an event in which decoding is successful even though a signal is not transmitted, and is one of several critical issues occurring in a blind detection problem. For CRC-aided polar code, with the limited number of CRC bits, FA occurs when the CRC check passes even though there is no signal. In this paper, we propose a technique to efficiently reduce FA events using two detection metrics which are specially suited to low rate and high rate codes. Simulation results show that the application of the proposed DMs outperform the conventional schemes. To be specific, at high rates, the proposed scheme reduces 90% of FA compared to the standard CRC-based detection.