On optimal power allocation for joint spectral sensing and data transmission in CR networks

This paper proposes an optimal power allocation algorithm between a cognitive user (CU) and a primary user (PU) in a power constrained channel. The typical underlay system is characterized by joint spectral sensing for detecting the presence of the PU along with the provision of simultaneous PU and CU transmission. The task is to determine the power sharing between PU and CU with an objective to maximize the probability of detection of PU by CU and CU data transmission jointly, while meeting the limits of total transmit power and threshold of PU throughput. Simulation results show that the proposed scheme provides better detection probability compared to equal power allocation and also better CU throughput maintaining the total power budget and PU throughput constraints. Gain in probability of detection by 3% and in CU throughput by 36% is seen for total power budget of 0 dBW.