Correlation detection apparatus and fourier transform apparatus
First Claim
1. A correlation detection apparatus for detecting a first signal in a time domain including predetermined code, and a correlation between the first signal and the predetermined code, comprising:
- transform means for transforming the first signal in the time domain into a frequency domain;
correlation-signal generation means for generating a correlation signal indicating a correlation between the predetermined code transformed to the frequency domain and the first signal transformed to the frequency domain; and
correlation detection means for inverse-transforming the generated correlation signal into a signal in the time domain and detecting the correlation between the first signal and the predetermined code.
1 Assignment
0 Petitions
Accused Products
Abstract
A correlation detection apparatus which realizes software CDMA inverse-spread processing. A reception circuit receives an RACH preamble from a mobile station, and an A/D converts the preamble into digital received data. An FFT unit FFT-processes the received data to obtain an FFT result. An RACH code storage unit holds an RACH preamble code, and another FFT unit FFT-processes the RACH preamble code to obtain another FFT result. A multiplication unit multiples the FFT result by the other FFT result. An IFFT unit IFFT-processes a result of multiplication input from the multiplication unit to obtain a delay profile. A data decoding unit decodes the received data by using the delay profile, and obtains decoded data.
-
Citations
4 Claims
-
1. A correlation detection apparatus for detecting a first signal in a time domain including predetermined code, and a correlation between the first signal and the predetermined code, comprising:
-
transform means for transforming the first signal in the time domain into a frequency domain;
correlation-signal generation means for generating a correlation signal indicating a correlation between the predetermined code transformed to the frequency domain and the first signal transformed to the frequency domain; and
correlation detection means for inverse-transforming the generated correlation signal into a signal in the time domain and detecting the correlation between the first signal and the predetermined code. - View Dependent Claims (2)
-
-
3. A Fourier transform apparatus for performing Fourier transform by performing an N-stage butterfly operation on MN time-series data by using MN (M is a radix in Fourier transform;
- N=1, 2, . . . ) continuous storage regions, comprising;
data storage means for storing (I;
I=0, 1, . . . , MN−
1) th data into (MN−
1([I/M0]modM)+MN−
2([I/M1]modM)+ . . . + M°
([I/MN−
1]modM);
[X] is an integer not exceeding X;
YmodZ is residue system of integer Y for integer Z)th storage region;
first butterfly-operation processing means for repeating processing of storing respective (MJ+H)th M pieces of data, obtained by performing a (J)th butterfly operation on data stored in (MJ+H;
J=0, 1, . . . , MN−
1, H=0 to M−
1)th M storage regions, into (MN−
1H+MN−
2([J/M1]modM)+ . . . + M°
([J/MN−
1]modM))th M storage regions, (N−
1) times; and
second butterfly-operation processing means for performing processing of storing respective (MJ+H)th M pieces of data, obtained by performing a butterfly operation on the data obtained as a result of the (N−
1)th butterfly operation and stored in the (MJ+H)th M storage regions, into (MN−
1([J/M1]modM)+ . . . + sM°
([J/MN−
1]modM)+H)th M storage regions.
- N=1, 2, . . . ) continuous storage regions, comprising;
-
4. An inverse Fourier transform apparatus for performing inverse Fourier transform by performing an N-stage butterfly operation on MN pieces of time-series data by using MN (M is a radix in inverse Fourier transform;
- N=1, 2, . . . ) continuous storage regions, comprising;
third butterfly-operation processing means for repeating processing of storing respective (MJ+H)th M pieces of data, obtained by performing a (J)th butterfly operation on data stored in (MJ+H;
J=0, 1, . . . , MN−
1−
1, H=0, 1, . . . , M−
1)th M storage regions, into (MN−
1H+MN−
2([J/M1]modM)+ . . . + Mo([J/MN−
1]modM))th M storage regions, (N) times.
- N=1, 2, . . . ) continuous storage regions, comprising;
Specification