Multiplex communications – Communication over free space – Having a plurality of contiguous regions served by...
Patent
1996-12-03
1999-03-16
Pham, Chi H.
Multiplex communications
Communication over free space
Having a plurality of contiguous regions served by...
370335, 370350, H04J 1300
Patent
active
058838880
ABSTRACT:
During a "make before you break" handoff performed within a CDMA communications system, duplicate downlink communications are generated and routed through different base stations for delivery to the mobile station. At the mobile station, the duplicate signals are received and the frame sequence numbers of the substantially simultaneously received frames therein are compared. If the sequence numbers do not match, the duplicate signals are identified as not being synchronously received by the mobile station. In response thereto, the mobile station signals the communications network on the uplink with a timing adjustment message, and appropriate timing modifications are made with respect to the transmission of the duplicate signals in order to provide for substantially synchronous reception. Diversity combination and decoding are then performed on the received signals. Alternatively, the mobile station buffers the earlier arriving signal and waits for the later arrival of the sequence number matching frame of the duplicate signal before engaging in diversity combining and decoding of the received signals.
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Pham Chi H.
Telefonaktiebolaget LM Ericsson
Yao Kwang B.
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