초록 ▼

A method and system for allocating a set of orthogonal PN code sequences of variable length among user channels operative at different data rates in a spread spectrum communication system is disclosed herein. PN code sequences are constructed that provide orthogonality between users so that mutual i

A method and system for allocating a set of orthogonal PN code sequences of variable length among user channels operative at different data rates in a spread spectrum communication system is disclosed herein. PN code sequences are constructed that provide orthogonality between users so that mutual interference will be reduced, thereby allowing higher capacity and better link performance. In an exemplary embodiment, signals are communicated between a cell-site and mobile units using direct sequence spread spectrum communication signals. Information signals communicated on the cell-to-mobile link channels are encoded, interleaved, and modulated with orthogonal covering of each information symbol. Orthogonal Walsh function codes of varying length are employed to modulate the information signals. Code assignments are made on the basis of channel data rates in a manner which results in improved utilization of the available frequency spectrum. A substantially similar modulation scheme may be employed on the mobile-to-cell link.

대표청구항 ▼

[ I claim:] [1.] A system for modulating an information signal in a spread spectrum communication system, comprising:means for selecting an orthogonal function from a set of functions, said set of functions including a plurality of orthogonal functions, in accordance with a predefined characteristic

[ I claim:] [1.] A system for modulating an information signal in a spread spectrum communication system, comprising:means for selecting an orthogonal function from a set of functions, said set of functions including a plurality of orthogonal functions, in accordance with a predefined characteristic of said information signal;means for generating an orthogonal function signal representative of said selected orthogonal function;means for generating a pseudorandom noise (PN) signal of a predetermined PN code; andmeans for combining said orthogonal function signal, said PN signal and said information signal, and for providing a resultant first modulation signal.