Energy-Optimized Low-Complexity Control of Power and Rate in Clustered CDMA Sensor Networks with Multirate Constraints

In this paper, we propose a low-complexity scheme for minimizing energy consumption in a clustered multirate CDMA sensor network with multiple receive antennas by jointly controlling the powers and rates of all transmitting sensor nodes. The non-convex bit-energy optimization model is formulated by the sum product of transmit-plus-hardware powers and processing gains. The reason of taking the hardware consumed power into account is because the consumed energy in hardware is significant in a dense sensor network. We first optimized transmit powers by fixing the processing gains. As a consequence, we acquired the optimal transmit power expressed as a function of the processing gains. Next we reformulated a new simplified optimization problem with convexity. Then we can derive two low-complexity and closed-form algorithms for the transmit power and rate, respectively. A numerical example verifies our proposed algorithms have a nice performance in saving energy.