Multi-user communication system architecture with distributed transmitters

Abstract

A new signal processing architecture for base stations and gateways ( ) used in spread spectrum communication systems ( ) that simplifies data transfer, reduces required bus capacity, and does not require special synchronization of signals that are to be combined. A series of transmission modules ( ) are used to transfer data to corresponding ones of a series of analog transmitters ( ) used to form communication circuits for each system user. Each transmission module ( ) employs a series of encoders ( ) and modulators ( ) to form spread communication signals, using appropriate PN spreading codes. Spread spectrum communication signals from each module ( ) for each system user (D), are summed together ( ) and transferred to a single analog transmitter ( ) associated with that module. The signals being combined are automatically synchronized by common timing signals used for elements within each module. The number of processing elements within each module is such that at least one processing path is available for each user or user channel over which it is desired to transmit information through the connected analog transmitter ( ). Data is output from the modules ( ) at a greatly reduced transfer rate which can be more easily accommodated using current technology. This is very useful for satellite based communication systems, or high capacity cellular systems, and this system architecture can be accomplished cost effectively using a series of easily manufactured circuit modules.