초록 ▼

The present invention is directed to the use of bandwidth efficient OCDMA in a multipath environment. The high rate PN code greatly attenuates multipath components that are delayed enough to have significant impact on the degree of orthogonality that may be achieved. By offsetting the carriers by th

The present invention is directed to the use of bandwidth efficient OCDMA in a multipath environment. The high rate PN code greatly attenuates multipath components that are delayed enough to have significant impact on the degree of orthogonality that may be achieved. By offsetting the carriers by the RW chipping rate and using precise network timing to align all accesses to a small fraction of a high rate PN chip duration, it is possible to fully utilize the available bandwidth. The procedure for achieving this time base alignment has been previously disclosed in U.S. patent application Ser. No. 980,957.

대표청구항 ▼

[ What is claimed is:] [1.] In an orthogonal code division multiple access (OCDMA) wireless telephone system having a base station and a plurality of mobile transceiver handsets, sending modulator and receiving demodulator means in said base station and each said mobile transceiver handset, respecti

[ What is claimed is:] [1.] In an orthogonal code division multiple access (OCDMA) wireless telephone system having a base station and a plurality of mobile transceiver handsets, sending modulator and receiving demodulator means in said base station and each said mobile transceiver handset, respectively, the improvement for making said OCDMA system more tolerant of multipath delay spread, comprising, each said sending modulator means having 8 to 64 PN chips per each Rademacher-Walsh (RW) chip, each receiving demodulator means having a correlator for providing a demodulator output signal; and each modulator means including means for setting the PN chipping rate high enough such that said correlators provide processing gain discrimination against multipath signal components delayed more than a small fraction of a RW chip duration.