US 6,650,692 B2Granted

CDMA receiver

AssigneeFujitsu Limited

InventorsTakeshi Inoue, Masahiko Shimizu, Takashi Dateki, Koji Matsuyama

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Abstract

A path search unit (1) detects the correlation between a received signal and a desired signal; (2) based on the correlation value, selects a plurality of paths over which the desired signal arrives; (3) if the difference between the detection time of the desired signal arriving via a path selected this time and the previous-time detection signal is within an allowable range, judges that the path selected this time is identical to a path previously allocated to prescribed finger units, and (4) if a path is identical, causes despreading and delay adjustment processing of the desired signal arriving over the selected path to be executed by the same finger unit as previously. A timing control unit calculates the difference between the detection time this time, over the identical path, and a reference time, and, based on the total of the time differences over the identical path, controls the timing lead/lag.

Claims13

Dependent claims

A CDMA receiver, having a plurality of despreading/delay adjustment units, each of which performs despreading processing of a desired signal arriving via an allocated path among multiple paths, adds a delay amount to a despread signal obtained from despreading processing according to the path, and outputs the result, a combining unit which combines the outputs of each despreading/delay adjustment unit, a path search unit which allocates paths to each despreading/delay adjustment unit and a timing control unit which controls timing;

characterized in that
said path search unit comprises:
a correlation detection section, which detects a correlation, in each prescribed time interval, between a received signal and a desired signal;
a path selection section, which selects a plurality of paths over which the desired signal arrives based on the peak level of said correlation, and which employs the peak detection time as the desired signal detection time;
storage means, which stores, as a reference time, the desired signal detection time over a path when this path is newly allocated to a despreading/delay adjustment unit, and which stores the previous-time desired signal detection time for the path;
a path judgment section, which, if the difference between the desired signal detection time in a path selected this time and the previous-time detection time is within an allowable range, judges that the path selected this time is identical to the path previously allocated to the prescribed despreading/delay adjustment unit;
and,
a path allocation section, which performs allocation of paths to each dispreading/delay adjustment unit such that, if the path selected this time is identical to the previously allocated path, despreading and delay adjustment processing of a desired signal arriving over this identical path is caused to be executed by the same despreading/delay adjustment unit as previously;
and,
said timing control unit comprises:
a calculating section, which calculates the difference between the desired signal detection time this time, over said identical path, and said reference time;
and,
a timing control circuit, which controls the timing lead/lag based on the total of said detection time differences for each identical path.

10 more elements

A CDMA receiver, comprising a plurality of despreading/delay adjustment units, each of which performs despreading processing of a desired signal arriving via an allocated path among multiple paths, adds a delay amount to a despread signal obtained from despreading processing according to the path, and outputs the result, a combining unit which combines the outputs of each despreading/delay adjustment unit, a path search unit which allocates paths to each despreading/delay adjustment unit, and a timing control unit which controls timing;

characterized in that
said path search unit comprises:
a correlation detection section which detects a correlation, in each prescribed time interval, between a received signal and a desired signal;
a path selection section, which selects a plurality of paths over which the desired signal arrives based on the peak level of said correlation, and which employs the peak detection time as the desired signal detection time;
a path judgment section which, if the difference between the detection time of the desired signal arriving over a path selected this time and the previous-time detection time is within an allowable range, judges that the path selected this time is identical to the path previously allocated to the prescribed despreading/delay adjustment unit;
and,
a path allocation section which performs allocation of paths to each dispreading/delay adjustment unit such that, if the path selected this time is identical to the previously allocated path, despreading and delay adjustment processing of a desired signal arriving this identical path is caused to be executed by the same despreading/delay adjustment unit as previously;
and,
said timing control unit comprises:
means for storing reference times;
a calculating section, which calculates the difference between the desired signal detection time this time, over said identical path, and said reference time;
and,
a timing control circuit, which controls the timing lead/lag based on the total of said detection time differences for each identical path.

10 more elements

Dependencies are inferred from the claim text.

Facts

Application: 09/943,437Filed 29 Aug 2001 · continuation
Priority: 1 Mar 1999
Published: US 2002/0034215 A121 Mar 2002
Granted: 18 Nov 2003
Term ends: Not estimatedThe source records don’t support an estimate.

Classification4 codes

H04B 1/7117
Constructive combining of multi-path signals, i.e. RAKE receivers: selection, re-selection, allocation or re-allocation of paths to fingers, e.g.…
H04B 1/7093
Correlator structure: matched filter type
H04B 1/712
Constructive combining of multi-path signals, i.e. RAKE receivers: weighting of fingers for combining, e.g. amplitude control or phase rotation…
H04B
Transmission