Globally Constrained Power Control Across Multiple Channels in Wireless Data Networks

We investigate multi-channel transmission schemes for packetized wireless data networks. The transmitting unit transmits concurrently in several orthogonal channels (for example, distinct FDMA bands or CDMA codes) with randomly fluctuating interference and there is a global constraint on the total power transmitted across all channels at any time slot. Incoming packets to the transmitter are queued up in separate buffers, depending on the channel they are to be transmitted in. In each time slot, one packet can be transmitted in each channel from its corresponding queue. The issue is how much power to transmit in each channel, given the interference in it and the packet backlog, so as to optimize various power and delay costs associated with the system. We formulate the general problem taking a dynamic programming approach. Through structural decompositions of the problem, we design practical novel algorithms for allocating power to various channels under the global power constraint.