초록 ▼

Users or subscribers of a multi-user communications system, such as a spread spectrum communications system, provide signals to the central station or base unit of that system, and receive signals therefrom. Avoidance of interference among those users' signals is needed to ensure proper operation of

Users or subscribers of a multi-user communications system, such as a spread spectrum communications system, provide signals to the central station or base unit of that system, and receive signals therefrom. Avoidance of interference among those users' signals is needed to ensure proper operation of the system. To do so, the data of each user is individually scrambled to randomize the data that different users are transmitting, in order to improve tracking performance at a receiver. The data of each user is scrambled independently, in a manner unique to that user in the system, in order to improve tracking performance and detection performance of a receiver. This scrambling makes the multi-user interference zero mean, and makes it possible to integrate out or average out the multi-user interference. The pattern or sequence used for this scrambling, and the pattern or sequence used for spreading here, are preferably identical except in frequency.

대표청구항 ▼

[ What is claimed is:] [18.] A communication system, comprising:at least one base unit having a transmitter and a receiver;a plurality of subscriber units, each of said plurality of subscriber units having a transmitter and a receiver;scrambling control circuitry for providing scrambling patterns wh

[ What is claimed is:] [18.] A communication system, comprising:at least one base unit having a transmitter and a receiver;a plurality of subscriber units, each of said plurality of subscriber units having a transmitter and a receiver;scrambling control circuitry for providing scrambling patterns which uniquely identify each of said plurality of subscriber units;means within at least one of said base unit and said plurality of subscriber units for scrambling an information signal with one of said scrambling patterns which identifies one of said plurality of subscriber units to produce a communication signal for communicating between said base unit and one of said plurality of subscriber units;means for spreading said communication signal; andmeans within at least one of said base unit and said plurality of subscriber units for despreading and descrambling said communication signal to obtain said information signal;wherein said information signal comprises a frame structure for conveying transmission data, said frame structure includes a frame synchronization flag which indicates a beginning of a frame, a plurality of control bytes and a plurality of transmission data bytes, and wherein said means for scrambling said information signal further comprises:synchronization control circuitry having a first input, a second input and an output, said first input receiving a frame synchronization signal, said second input receiving a clock signal, said synchronization control circuitry multiplexing said first and said second inputs to provide said frame synchronization flag and said plurality of control bytes at said output; anda scrambler having a first input coupled to said scrambling control circuitry for receiving said one of said scrambling patterns, a second input coupled to said output of said synchronization control circuitry for receiving said frame synchronization flag and said plurality of control bytes, and a third input for receiving said plurality of transmission data bytes, said scrambler scrambling at least said plurality of transmission data bytes and combining said at least scrambled plurality of transmission data bytes, said first input, and said second input to provide said frame structure.