초록 ▼

A communication system includes base communication units (105, 155) facilitating a communication link with portable communication units (110) in motion relative to base communication units. The relative motion between base communication units (105, 155) and portable communication units (110) introdu

A communication system includes base communication units (105, 155) facilitating a communication link with portable communication units (110) in motion relative to base communication units. The relative motion between base communication units (105, 155) and portable communication units (110) introduces Doppler frequencies into communication links (115, 165). When portable communication units (110) travel in a predictable direction (119), frequency offsets for Doppler compensation are generally predictable. However, when portable communication units (110) move erratically in relationship to a base communication unit (105, 155), frequency offsets for Doppler compensation are not easily calculated. Incorporation of velocity vector data into the frequency offset calculation for Doppler compensation provides reliable tracking and Doppler frequency compensation for erratic motion of portable communication units (110).

대표청구항 ▼

In a communication system having a portable communication unit in motion with a dynamic velocity vector, a method for tracking and compensating erratic Doppler frequency shift in a communication link employing a frequency offset for Doppler compensation, said method comprising the steps of: measurin

In a communication system having a portable communication unit in motion with a dynamic velocity vector, a method for tracking and compensating erratic Doppler frequency shift in a communication link employing a frequency offset for Doppler compensation, said method comprising the steps of: measuring a present velocity vector of said portable communication unit; calculating a differential velocity vector between said present velocity vector and a previous velocity vector, said previous velocity vector being an earlier iterative stored sample of a velocity vector; supplementing standard frequency offset generation with said differential velocity vector, said standard frequency offset generation providing adequate tracking of non-erratic Doppler frequency shift; and generating said frequency offset using said standard frequency offset generation and said differential velocity vector.