US 7,003,022 B2 · Matched filter and receiver for mobile radio communication system

Abstract

A matched filter requiring no high-speed processor and which consumes less power is disclosed. Partial filters 301–30N obtained by dividing number of matched filter taps by N are provided with a controller 341 for controlling which partial filters are enabled. The controller 341 is supplied with maximum amount of delay of an input signal and with symbol timing. On the basis of the maximum amount of delay, the controller 341 enables only the minimum number of partial filters 301–30n that are capable of executing an amount of computation that is required in one symbol period. The enabled partial filters are used multiple number of times per symbol period and the output, each time, integrated sample by sample. Since the disabled partial filters will not operate, it is possible to reduce power consumption and computation time.

Claims8

Dependent claims

A matched filter for obtaining a correlation between a signal received through a multipath transmission line and a spreading code sequence, comprising:

N partial filters, each partial filter having a predetermined number m of taps, that are serially connected;
first adder means for adding outputs of activated partial filters from among the N partial filters;
control means for dividing, based on a time width of effective paths included in the received signal, the spreading code sequence into subsequences, each subsequence having m chips, activating n partial filters from among the N partial filters, wherein n satisfies n*m*Ts≧Td>(n−1)*m*Ts, where Ts represents a sampling period of the received signal and Td represents a maximum delay time of the multipath signal, and supplying the subsequences to the n activated partial filters;
end
second adder means for integrating outputs of the first adder means;
wherein N, m, and n are integers;
m≧2;
and N≧2;
n≧1.

6 more elements

Dependencies are inferred from the claim text.

Matched filter and receiver for mobile radio communication system

Life of this patent

Matched filter and receiver for mobile radio communication system

Life of this patent

Abstract

Claims8