Diversity receiver in a CDMA cellular telephone system

In a cellular communication system in which user information signals are communicated to an intended recipient user by a cell-site using spread spectrum communication signals, wherein said cell-site transmits a spread spectrum pilot signal of a predetermined code phase, and wherein said cell-site transmitted spread spectrum communication signals and pilot signal are susceptible to multipath propagation, a recipient user spread spectrum receiver comprising:

• searcher means for receiving an input signal which includes multiple path propagations of a pilot signal transmitted by a cell-site wherein each multiple path propagation pilot signal travels a different propagation path and has a corresponding path dependent offset in code phase, for scanning at different code phases so as to detect a presence of at least one of said multiple path propagation pilot signals, for measuring signal strength of each detected multiple path propagation pilot signal, for determining code phase of each detected multiple path propagation pilot signal, and for providing searcher control signals representative of multiple path propagation pilot signals of greatest signal strength and corresponding code phase;
• and
• receiver means for receiving said searcher control signals, for receiving said input signal which further includes multiple path propagations of spread spectrum communication signals transmitted by said cell-site each corresponding to a respective multiple path propagation pilot signal, for, in response to said searcher control signals, spread spectrum processing certain ones of said multiple path propagations of said spread spectrum communication signals corresponding to said multiple path propagation pilot signals of greatest signal strength so as to extract corresponding intended recipient user information signals therefrom, and for providing corresponding output signals representative of said extracted intended recipient user information signals.

In a cellular communication system in which user information signals are communicated to an intended recipient user by at least one cell-site using spread spectrum communication signals, wherein each cell-site transmits a spread spectrum pilot signal of a same spreading code and predetermined different code phase, and wherein each cell-site transmitted spread spectrum communication signals and pilot signal are susceptible to multipath propagation, a recipient user spread spectrum receiver comprising:

• searcher means for receiving an input signal including multiple path propagations of at least one pilot signal wherein each pilot signal is transmitted by a respective one of a plurality of cell-sites and wherein each multiple path propagation pilot signal travels a different propagation path and has a corresponding path dependent offset in code phase, for scanning at different code phases so as to detect a presence of at least one of said multiple path propagation pilot signals, for measuring signal strength of each detected multiple path propagation pilot signal, for determining code phase of each detected multiple path propagation pilot signal, and for providing searcher control signals representative of multiple path propagation pilot signals of greatest signal strength and corresponding code phase;
• and
• receiver means for receiving said searcher control signals, for receiving said input signal which further includes multiple path propagations of spread spectrum communication signals transmitted by at least one of said plurality of cell-sites wherein each multiple path propagation of said spread spectrum communication signals corresponds to a respective multiple path propagation pilot signal, for, in response to said searcher control signals, spread spectrum processing certain ones of said multiple path propagations of said spread spectrum communication signals corresponding to said multiple path propagation pilot signals of greatest signal strength so as to extract corresponding intended recipient user information signals therefrom, and for providing corresponding output signals representative of said extracted intended recipient user information signals.

In a cellular communication system in which user information signals are communicated to an intended recipient user by at least one cell-site using spread spectrum communication signals, wherein each cell-site transmits a spread spectrum pilot signal of a same spreading code and predetermined different code phase, and wherein each cell-site transmitted spread spectrum communication signals and pilot signal are susceptible to multipath propagation, a method for acquiring and processing intended recipient user spread spectrum communication signals comprising the steps of:

• receiving input signals including (a) multiple path propagations of at least one pilot signal wherein each pilot signal is transmitted by a respective one of a plurality of cell-site and wherein each multiple path propagation pilot signal travels a different propagation path and has a corresponding path dependent offset in code phase and (b) multiple path propagations of spread spectrum communication signals transmitted by at least one of said plurality of cell-sites wherein each multiple path propagation of said spread spectrum communication signals corresponds to a respective multiple path propagation pilot signal;
• scanning said input signals at different code phases so as to detect a presence of at least one of said multiple path propagation pilot signals;
• measuring signal strength of each detected multiple path propagation pilot signal;
• determining code phase of each detected multiple path propagation pilot signal;
• providing a searcher signal representative of multiple path propagation pilot signals of greatest signal strength and corresponding code phase;
• spread spectrum processing, in response to said searcher signal, ones of said multiple path propagations of said spread spectrum communication signals corresponding to said multiple path propagation pilot signals of greatest signal strength so as to extract corresponding intended recipient user information signals therefrom;
• and
• providing corresponding output signals representative of said extracted intended recipient user information signals.