Multiplex communications – Wide area network – Packet switching
Patent
1992-08-31
1995-10-24
Olms, Douglas W.
Multiplex communications
Wide area network
Packet switching
375206, H04L 2730
Patent
active
054616107
ABSTRACT:
A technique for reducing multiple access interference (MAI) experienced by receivers of transmissions from a transmitter, e.g., a base station, in a direct-sequence code division multiple access communication system, e.g., a cellular radio system, is disclosed. The technique provides for the precoding of user signature sequences for use in spreading information signals to be transmitted. The use of precoded signature sequences significantly reduces the average level of MAI experienced by the receivers. Despreading of received signals by receivers may be accomplished with the original (i.e., non-precoded) signature sequences. Thus, no changes to receivers are required. The technique includes a feature for determining a set of sequences for both transmitter and receiver from a smaller set of orthogonal sequences.
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AT&T IPM Corp.
Nguyen Chau T.
Olms Douglas W.
Restaino Thomas A.
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