Spread-spectrum method and system for communication between a base station and a plurality of mobile units

摘要

A method of communication between a base station with at least a mobile unit communication apparatus, a base station and a mobile unit communication apparatus employing the method are disclosed. The base station has a plurality of antennas for the antenna diversity. Transmission data is spectrum-spread with a pn code for a target mobile unit communication apparatus and a pilot signal is also spectrum-spread with a pn code every antenna, which are frequency-multiplexed. A mobile unit de-spectrum-spreads the pilot signal with one of pn codes selected, which corresponds the transmitting antenna. The pilot signal and data may be time-division-multiplexed in a time slot. Data of the used antenna is transmitted by the base station by a position of null data in the time slot, or differentially coded which is detected by a null data detection circuit or by the delayed detection. Data of the antenna used may be transmitted by a mobile unit communication apparatus. The antenna transmitting the data may be detected at the mobile unit communication apparatus by detecting an error from error check codes. In the downward time slot, the spectrum-spread pilot signal is frequency-multiplexed with spectrum-spread data and in the upward time slot, the spectrum-spread pilot signal is time-division-multiplexed with the spectrum-spread data.