Closed-loop architecture and protocols for rapid dynamic spreading gain adaptation in CDMA networks
We present a closed-loop architecture and protocols for rapid dynamic spreading gain adaptation and fast feedback between a transmitter and a receiver communicating with each other in CDMA networks. These protocols and architecture do not require the transfer of an explicit control message indicating the change of CDMA spreading gain from transmitter to receiver. Also, with these protocols, the transmitter can change the spreading gain symbol-by-symbol as opposed to frame-by-frame, and feedback information (e.g., the fast-varying channel condition) can be exchanged almost as frequently as the symbol rate; thus, faster adaptation to the time-varying channel conditions of wireless networks and/or the rate variation of traffic is possible than with the existing frame-by-frame approach.