Frequency Reuse Through RF Power Management in Ship-to-Ship Data Networks
NAVAL POSTGRADUATE SCHOOL MONTEREY CA
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A proposed U.S. Navy ship to ship, line of sight, high data rate communication system is analyzed. Because of the limited bandwidth available in the UHF band, it is desired to reuse a frequency channel at the shortest possible range. By limiting the radiated power to the minimum required to establish a desired quality of service, the channel can be reused at considerably shorter ranges than when the transmitter output power is fixed to the maximum available. Frequency reuse, however, introduces the problem of co-channel interference which degrades system performance. A computer simulation was developed to determine the bit error rate BER of a QPSK system in a Ricean fading channel with one co-channel interferer. The simulation generates plots of energy per bit to one sided noise power spectral density ratio EbN0 versus BER. Simulation results are used to compute the minimum range R at which the channel can be reused while maintaining an average BER of 10 to the 6th power. The results show that even when no power control is used the channel can be reused at a range, R, of approximately 45 kilometers. This range can be reduced to less than 20 kilometers if an interfering ship can reduce its output power by 30 dB.
- Radio Communications