Date Added: May 2012
This paper considers multi-sensor multi-antenna spectrum sensing. First, it is assumed that all users are able to send their raw data to the fusion center. In this case the global optimal solution is the Likelihood Ratio Test (LRT) using all the raw data. A simple closed-form expression for the LRT is found. Although LRT is optimal, it is hardly useful in practice due to its reliance on the knowledge of primary user's channels and noise powers of all users. Thus a method using the estimated channels and noise powers is proposed, which is called Generalized LRT (GLRT). Secondly, the Optimal Fusion Scheme (OFS) is found if each user computes its test statistic based on an eigen-value based detection and sends the test statistic to the fusion center.