To improve the performance of short-range wireless communications, channel quality must

be improved by avoiding interference and multi-path fading. Frequency hopping spread

spectrum (FHSS) is a transmission technique where the carrier hops frequency to

frequency. For frequency hopping a mechanism must be designed so that the data can be

transmitted in a clear channel and avoid congested channels. Adaptive frequency hopping is

a system which is used to improve immunity toward frequency interference by avoiding

using congested frequency channels in hopping sequence. Mathematical modelling is used

to simulate and analyze the performance improvement by using frequency hopping spread

spectrum with popular modulation schemes, and also the hopping channel situations are

investigated.-To improve the performance of short-range wireless communications, channel quality must

be improved by avoiding interference and multi-path fading. Frequency hopping spread

spectrum (FHSS) is a transmission technique where the carrier hops　frequency to

frequency. For frequency hopping a mechanism must be designed so that the data can be

transmitted in a clear channel and avoid congested channels. Adaptive frequency hopping is

a system which is used to improve immunity toward frequency interference by avoiding

using congested frequency channels in hopping sequence. Mathematical modelling is used

to simulate and analyze the performance improvement by using frequency hopping spread

spectrum with popular modulation schemes, and also the hopping channel situations are

investigated.