Patent ID: 6396824
Filing Date: 2002-05-28
Classification: G01S,H04B,H04J,H04W

Abstract:
A method for making a range determination between a remote unit and a base station within a CDMA communication system, the method comprising:generating a base generic chip code signal and a base message chip code signal; mixing the base message chip code signal with a data signal as a base data message signal; combining the base generic chip code signal and the base data message signal as a base spread spectrum signal; transmitting the base spread spectrum signal from the base station; receiving the base spread spectrum signal at the remote unit; determining a chip code timing of the received base spread spectrum signal using the generic chip code signal; recovering data from the received base spread spectrum signal using the determined chip code timing and the message chip code signal; transmitting from the remote unit a remote spread spectrum signal having a remote chip code time synchronized to the determined chip code timing; receiving the remote spread spectrum signal at the base station; and determining a range between the base station and the remote unit using a time difference between the base generic chip code signal as generated at the base station and the received remote spread spectrum signal.