Efficient Distributed Algorithms for Dynamic Access to Shared Multiuser Channels in SINR-Constrained Wireless Networks

摘要

In wireless networks, simultaneously active transmitters typically operate in separate communication channels to avoid mutual interference. This study focuses on the challenge of increasing the capacity of a wireless network by enabling multiple transmissions in each available channel. Active transmitters are assumed to maintain the receiver signal-to-noise-and-interference ratio (SINR) at a predetermined target value via power control to promote the quality of wireless connections. To this end, we propose distributed medium access algorithms that allow every transmitter-receiver pair to determine whether a target SINR is physically achievable through iterative power control in a given shared channel. The proposed algorithms are shown by theoretical analysis to be fast, accurate, and energy efficient. Numerical simulations demonstrate their ability to outperform related medium access schemes based on random access, carrier sensing, controlled power up, or invariant channel probing. Our major contribution consists of solving the open problem of accurate real-time computation of the spectral radius of an unknown network information matrix. This makes our framework applicable not only to testing target SINR achievability, but also to other aspects of wireless engineering such as energy efficiency, power control stability, and handover prioritization, in which knowledge of the spectral radius plays a key role.