Investigation On Power Control Technology Of MANET Based On Opportunistic Spectrum Access

The research on opportunistic spectrum access based MANET involves various respects, wherein the design of power control algorithm is a hotspot at present.In this thesis, we begin by characterizing the key technologies of opportunistic spectrum access based MANET, comprehensively introduce primary power control algorithms in opportunistic spectrum access based MANET. The existed power control algorithms in opportunistic spectrum access based MANET focus on the situation of one single wireless channel, thereafter it can not accommodate to practical wireless networks where there have multiple wireless sub-channels. On the other hand, due to the deficiency of controlling the aggregate interference level received at primary user, the classical multi-channel iterative water-filling algorithm (IWFA) in traditional wireless networks can not satisfy the interference temperature constraint of primary user, thus not suitable for opportunistic spectrum access based MANET.To aim at the above shortage, we focus on the multi-channel power control problem in opportunistic spectrum access based MANET, which is to minimize the transmit power of secondary users while satisfy the interference temperature constraint of primary user and quality of service constraint of secondary user. In order to control the aggregate interference at primary user receiver generated by secondary users, a pricing mechanism is proposed. The main contribution of this thesis can be concluded as follows:1) A punishment price is imposed on per unit interference generated by secondary users. By doing so, transmit powers of secondary users are reduced and the aggregate interference at primary user is mitigated. We propose simultaneous, sequential and asynchronous IWFAs to solve the Nash equilibrium under a given punishment price.2) We formulate the problem of achieving an appropriate punishment price as a nonlinear complementarity problem and propose a price updating algorithm based on sub-gradient projection to calculate an appropriate price that satisfies the interference temperature constraint of primary user while the Nash equilibrium is attained.3) MATLAB simulations are used to compare the performance and the convergence characteristic of the proposed algorithms in distinct network settings. We show that, when compared to the classical algorithm, the proposed algorithms can perfectly satisfy the interference temperature constraint of primary user and are suitable for opportunistic spectrum access based MANET.