Resource allocation and routing in MIMO-WPM cognitive radio ad-hoc networks

In this paper, we reconsider the resource allocation and routing problem in multi-hop Multiple-Input Multiple-Output (MIMO) Wavelet Packet Modulation (WPM) Cognitive Radio (CR) ad-hoc networks. We comply with four principles to design our resource allocation scheme with the goal to maximize the capacity of entire network. First, Primary Users (PUs) have higher priority to access to the subcarrier in private bands, while PUs and Secondary Users (SUs) have the equal opportunity in public bands. Second, the MIMO channel of each link on each subcarrier in each time slot is decomposed by Block Diagonal Geometric Mean Decomposition (BD-GMD) into multiple sub-channels with identical gains. In addition, the sub-channel gain of one link is determined by all other links sharing the same source node on the same subcarrier in the same time slot. Third, PUs have the privilege of higher signal to interference and noise ratio (SINR) threshold for the successful decoding in private bands, but PUs and SUs have the same SINR threshold in public bands. Fourth, the interference caused by one link to all other links having the same destination node should be avoided, moreover, the power of all other links is not assumed to be known but also need to be allocated at the same time. Based on our proposed resource allocation scheme, we investigate a multicast routing strategy that aims to maximize network throughput. Numerical results demonstrate that our proposed resource allocation and routing scheme can noticeably improve network throughput.