A Virtual MIMO Path-Time Code for Cognitive Ad Hoc Networks

Cognitive radio networks (CRNs) consisting of opportunistic links greatly elevate the networking throughput per bandwidth in future wireless communications. In this letter, we show that by encoding a data packet into several coded packets and transmitting in various time slots, the end-to-end transmission in the CRN can be equivalently formulated as a physical-layer multiple-input multiple-output (MIMO) communication problem. Two coding schemes are proposed in such a virtual MIMO scenario to enhance the end-to-end communication reliability by exploiting the path diversity. The closed-form expression of the theoretical error rate analysis validates that the proposed path-time codes can significantly improve the error rate performance.