초록 ▼

Disclosed are methods and apparatus for use in a synchronous CDMA communications system (10) that employs orthogonal pn spreading codes. The methods are intended for synchronizing transmissions from a subscriber unit (SU 14) to a radio base unit (RBU 12), and include the steps of: (a) transmitting i

Disclosed are methods and apparatus for use in a synchronous CDMA communications system (10) that employs orthogonal pn spreading codes. The methods are intended for synchronizing transmissions from a subscriber unit (SU 14) to a radio base unit (RBU 12), and include the steps of: (a) transmitting individual ones of a plurality of bursts from the SU to the RBU, each burst being transmitted with a different pn spreading code timing alignment; (b) receiving individual ones of the plurality of bursts with the RBU and determining a power estimate of each received burst; and (c) in response to a determined power estimate of one of the bursts exceeding a threshold, sending a message from the RBU to the SU. The message indicates that the SU is to use for subsequent transmissions the pn spreading code timing alignment that was employed when transmitting the burst that exceeded the threshold. In a preferred embodiment of this invention the step of transmitting transmits an indication of the pn spreading code timing alignment used when transmitting a given one of the bursts. Each burst is transmitted with a pn spreading code timing alignment that differs by 1/2 chip from a previous pn spreading code timing alignment.

대표청구항 ▼

[ What is claimed is:] [11.] A synchronous CDMA communications system using orthogonal pn spreading codes, said synchronous CDMA communications system comprising at least one subscriber unit (SU) and at least one radio base unit (RBU), said synchronous CDMA communications system further comprising a

[ What is claimed is:] [11.] A synchronous CDMA communications system using orthogonal pn spreading codes, said synchronous CDMA communications system comprising at least one subscriber unit (SU) and at least one radio base unit (RBU), said synchronous CDMA communications system further comprising apparatus for synchronizing transmission from the SU to the RBU, said apparatus being comprised of:means in said SU for transmitting individual ones of a plurality of bursts to the RBU, each burst being transmitted with a different pn spreading code timing alignment;means in said RBU for receiving individual ones of the plurality of bursts and for determining a power estimate of each received burst; andmeans, responsive to a determined power estimate of one of the bursts exceeding a threshold, for sending a message from the RBU to the SU, the message indicating that the SU is to use for subsequent transmissions the pn spreading code timing alignment that was employed when transmitting the one of the bursts.