Importance

Loading Importance Indicators...

Abstract

To assign and coordinate radio frequencies at the fixed ports (30, 40, 50, 70) of a frequency-reusing radio communications system (5), most existing methods require pre-engineering or impose high complexity in system controller and port hardware. A simple autonomous procedure performed by each port to determine its own transmitting frequency and corresponding receiving frequency is disclosed. This procedure consists of signal strength measurements and an algorithm which selects the frequency with minimum interference from other ports. In particular, a port turns off (202) its own transmitter (306) and scans (203) all the candidate transmitter frequencies and measures (312) signal powers form the other ports. The frequency channel with the lowest received power is tentatively assigned (204) for downlink transmission by that port. This procedure is repeated by all the ports either independently and asynchronously or with a coordinated schedule. This cycle is repeated for either a predetermined number of iterations that is sufficient to stabilize the frequency-reuse pattern, or until no port requests a change in its assigned frequency for two consecutive cycles thereby indicating the convergence of the algorithm. This algorithm stabilizes rapidly, while adapting to changing operational conditions, such as the installation of new ports, which changes the system configuration, or the addition of new buildings which creates different interference patterns in the signal propagation paths.

Loading the Abstract Image...

First Claim