US 6,807,161 B2 · Method and apparatus for signal combining in a high data rate communication system

Abstract

Reverse link busy bits are independently generated by each base station and indicate whether a base station has reached a reverse link capacity limit. A remote station combines multipath components of the reverse link busy bits in its Active Set and in response transmits a reverse link signal only when all of the reverse link busy bits indicate that the base stations in the Active Set have reverse link capacity. In an embodiment, the remote station weights the reverse link busy signals in accordance with the signal strength of the transmitting base station and determines whether to transmit based on the weighted sum of the busy signals. In an embodiment, the remote station weights the reverse link busy signals in accordance with the signal strength of the transmitting base station and determines a maximum reverse link data rate based on the weighted sum of the busy signals.

Claims68

Dependent claims

A remote station comprising:

a means for weighing reverse link busy signals from a plurality of base stations in accordance with a signal strength of one of the plurality of base stations transmitting one of the reverse link busy signals;
and
a means for determining whether to transmit on a reverse link based on a weighted sum of the reverse link busy signals.

A remote station, comprising:

an antenna that receives a forward link signal;
a receiver;
a transmitter;
a duplexer coupled to the antenna and transmitter, the duplexer providing the forward link signal to the receiver;
and
a traffic demodulator configured to demodulate the received signal to provide forward link traffic data to the user of the remote station, wherein the traffic demodulator includes:
a searcher configured to search potential PN offsets for strong forward link signals and assigns a plurality of PN despreaders a plurality of PN offsets to demodulate;
a plurality of PN despreaders, wherein each of the PN despreaders is configured to despread the received signal in accordance with a different PN offset and provides the result to a corresponding demultiplexer;
a plurality of demultiplexers configured to separate a pilot bust portion and forward link traffic data of the despreaded received signal and provides the demodulated pilot symbols to a synchronization (SYNC) element and the forward link traffic data to a plurality of Walsh demodulators;
a plurality of synchronization elements configured to determine adjustments to the frequency and phase of corresponding Walsh demodulators;
a plurality of Walsh demodulator configured to demodulate the despreaded receive signals in accordance with a Walsh sequence WT and provide demodulated forward link symbols;
and
a soft combiner configured to soft combine the demodulated forward link symbols, thereby accumulating the multipath components of the base station transmitting the forward link signal to the remote station.

10 more elements

A remote station, comprising:

an antenna that receives a forward link signal;
a receiver;
a transmitter;
a duplexer coupled to the antenna and transmitter, the duplexer providing the forward link signal to the receiver;
and
a reverse link busy bit demodulator configured to demodulate the received signal to provide an estimate of the reverse link busy bits transmitted by each of the base stations in communication with the remote station, wherein the reverse link busy bit demodulator includes:
a searcher configured to search potential PN offsets for strong forward link signals and assigns a plurality of PN despreaders a plurality of PN offsets to demodulate;
a plurality of PN despreaders, wherein each of the PN despreaders is configured to despread the received signal in accordance with a different PN offset and provides the result to a corresponding demultiplexer;
a plurality of demultiplexers configured to separate a pilot bust portion and overhead data of the despreaded received signal and provide the demodulated pilot symbols to a synchronization (SYNC) element and the overhead data to a plurality of Walsh demodulators;
a plurality of synchronization elements configured to determine adjustments to the frequency and phase of corresponding Walsh demodulators;
a plurality of Walsh demodulator configured to demodulate the despreaded receive signals in accordance with a Walsh sequence W17 and provide demodulated forward link symbols;
a soft combiner configured to soft combine the demodulated forward link symbols, thereby accumulating the multipath components of the base station transmitting the forward link signal to the remote station;
and
a rate determination logic configured to determine reverse link transmission.

11 more elements

A remote station, comprising:

an antenna that receives a forward link signal;
a receiver;
a transmitter;
a duplexer coupled to the antenna and transmitter, the duplexer providing the forward link signal to the receiver;
and
a reverse link power control demodulator configured to demodulate the received signal to provide forward link traffic data to the user of the remote station, wherein the traffic demodulator includes:
a searcher configured to search potential PN offsets for strong forward link signals and assigns a plurality of PN despreaders a plurality of PN offsets to demodulate;
a plurality of PN despreaders, wherein each of the PN despreaders is configured to despread the received signal in accordance with a different PN offset and provides the result to a corresponding demultiplexer;
a plurality of demultiplexers configured to separate the pilot bust portion and the overhead data of the despreaded received signal and provides the demodulated pilot symbols to a synchronization (SYNC) element and the overhead data to a plurality of Walsh demodulators;
a plurality of synchronization elements configured to determine adjustments to the frequency and phase of corresponding Walsh demodulators;
a plurality of Walsh demodulators, each Walsh demodulator configured to demodulate the despreaded receive signal with a Walsh code that is specific for transmission of power control signals for a corresponding base station, thereby providing demodulated power control commands from each base station;
a plurality of soft combiners configured to soft combine the demodulated power control commands, thereby accumulating the multipath components of the base station transmitting the forward link signal to the remote station;
and
a power control combiner configured to combine the combined power control commands from each base station.

11 more elements

Dependencies are inferred from the claim text.

Facts

Application

10/300,392Filed 19 Nov 2002 · division

Priority

2 Jul 1999

Published

US 2003/0076795 A124 Apr 2003

Granted

19 Oct 2004

Term ends

Not estimatedThe source records don’t support an estimate.

Classification7 codes

H04W 28/22
Negotiating wireless communication parameters: negotiating communication rate
H04B 7/264
Using code-division multiple access [CDMA] or spread spectrum multiple access [SSMA]: for data rate control
H04L 1/0002
Systems modifying transmission characteristics according to link quality, e.g. power backoff: by adapting the transmission rate
H04W 52/40
TPC being performed in particular situations: during macro-diversity or soft handoff

Method and apparatus for signal combining in a high data rate communication system

Life of this patent

Method and apparatus for signal combining in a high data rate communication system

Life of this patent

Abstract

Claims68