Quantization scheme for energy detector of soft decision cooperative spectrum sensing in cognitive radio

Abstract

Cognitive radio technique enables unlicensed users to use the spectrum assigned to licensed users. Therefore, a highly accurate sensing technique to know the presence of licensed users is essential. For such a purpose, soft decision cooperative spectrum sensing techniques are proposed. In a soft decision cooperative spectrum sensing, the cognitive base station collects the received signal energy information from multiple users. Since the bandwidth of the control channel used for collecting the energy information is limited, it is necessary to quantize the received signal energy information in each user. In this paper, we propose a quantization scheme based on the probability of false alarm for the soft decision cooperative spectrum sensing. The quantization criterion is analytically derived, and the theoretical expression for the resultant probability of false alarm is presented with taking the quantization error into account.