US 7,257,097 B2 · Apparatus for searching a signal in mobile communication system and method thereof

Abstract

Apparatus and methods for signal search in a mobile communication system can process input signals in parallel. A signal searcher apparatus in a communication system can include a first sequential storage device and a second sequential storage device for respectively storing PN codes and input signals. The signal searcher can include a plurality of despreading devices that despread in parallel the input signals having I and Q components by respectively using the PN codes. In a case where the length of coherent accumulation is a plurality of the number of despreading devices, additional buffers store (e.g., temporarily) the accumulated despreaded signals each having I and Q components that are equal to the number of searched PN offsets. According to preferred embodiments of the present invention, pilot signals searching speed can be increased and/or the length of PN offset and coherent calculation can be increased.

Claims13

Dependent claims

An apparatus for searching a pilot signal that is received through multiple paths in a Code-Division Multiple Access (CDMA) mobile communication system, the apparatus comprising:

a first shift register bank that sequentially stores pseudo noise (PN) codes;
a second shift register bank that sequentially stores input signals, wherein the input signals of an even path are sampled in a first half PN chip and the input signals of an odd path are sampled in a following half PN chip;
first despreading means for despreading the input signals of the even path using the PN codes inputted from the first shift register bank, wherein the first despreading means despreads the input signals of the even path in parallel to output first despreading signals;
second despreading means for despreading the input signals of the odd path using the PN codes inputted from the first shift register bank, wherein the second despreading means despreads the input signals of the odd path in parallel to output second despreading signals;
a coherent accumulator that accumulates the first and the second despreading signals;
energy calculation means for yielding an energy value using accumulated signals from the coherent accumulator;
and
a non-coherent accumulator that determines an average value of the energy value for a prescribed time.

5 more elements

A method for searching a pilot signal received using multiple paths in a Code-Division Multiple Access (CDMA) mobile communication system, the method comprising:

storing pseudo noise (PN) codes sequentially;
storing a set of input signals sequentially from an input signal to a last input signal, wherein the input signals of an even path are sampled in a first half PN chip and the input signals of an odd path are sampled in a following half PN chip;
despreading the set of input signals of the even path in parallel by using the PN codes;
despreading the set of input signals of the odd path in parallel by using the PN codes;
outputting an accumulation signal by accumulating despreaded signals of the even path and despreaded signals of the odd path;
yielding an energy value of the accumulation signal and an average energy value of the energy value, wherein the average energy value is determined over a prescribed time;
and
determining average mean values corresponding to PN offsets after shifting the set of input signals and repeating the despreading, the outputting and the yielding.

5 more elements

Dependencies are inferred from the claim text.

Apparatus for searching a signal in mobile communication system and method thereof

Life of this patent

Apparatus for searching a signal in mobile communication system and method thereof

Life of this patent

Abstract

Claims13