| 摘要 |
A frequency-hopping-communications system, assigned a system bandwidth B, with the system bandwidth B divided into N sets of frequencies, with each set of the N sets of frequencies not having the same frequencies as other sets of the N sets of frequencies, for communicating base-message data to a plurality of remote units. The frequency-hopping-communications system includes a plurality of base stations for communicating base-message data to the plurality of remote units. Each of the base stations has a coverage area divided into a plurality of N concentric regions with each concentric region assigned one of the N sets of frequencies. For communicating with a selected-remote unit located within a particular-concentric region, each base station has a modulator for converting the base-message data to a form suitable for sending over radio waves, a frequency-hopping device for frequency hopping the converted-base-message data over a set of frequencies assigned to the particular-concentric region, thereby generating a frequency-hopped signal, a controller, responsive to the selected-remote unit being located in the particular-concentric region, for controlling the set of frequencies use by said frequency-h hopping device, a power amplifier for amplifying the frequency-hopped signal from the base station to the remote unit, and a base antenna coupled to the power amplifier for radiating the frequency-hopped signal. Each of the remote units has a receiver for recovering from the frequency-hopped signal the base-message data.
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