Receiver and receiving method in spread spectrum communication system
An over-sampling circuit is provided at a front stage of a digital matched filter, and a received signal is over-sampled with it. Synchronous acquisition of the received spread spectrum signal is implemented by adding the data obtained by the over-sampling, inputting it into the digital matched filter, and then performing a correlation thereon.
1. A spread spectrum communication receiver which implements a synchronous acquisition of a received spread spectrum signal, comprising:
an over-sampling circuit for implementing an N-times over-sampling for one chip of the received signal (N is integer larger than 1); and
a digital matched filter for obtaining a correlation between the received signal and a spread code pattern installed therein,
wherein N pieces of data obtained by the over-sampling are added, the added data is divided by the sampling number N so as to equalize the added data, and the equalized data is input to the digital matched filter.
2. A spread spectrum communication receiver which implements a synchronous acquisition of a received spread spectrum signal, comprising:
an over-sampling circuit for implementing an N-times over-sampling for one chip of the received signal (N is integer number larger than 1); and
a digital matched filter for obtaining a correlation between the received signal and a spread code pattern installed therein,
wherein N pieces of data obtained by the over-sampling are added, the added data is input to the digital matched filter, the digital matched filter has the same number of stages as one in a case that provides no over-sampling, and operates at a chip rate.
3. A spread spectrum communication receiver according to claim 1 , wherein the digital matched filter has the same number of stages as one in a case that provides no over-sampling, and operates at a chip rate.
4. A spread spectrum communication receiver according to claim 2 , wherein the over-sampling circuit includes an adder for adding the N pieces of data obtained by over-sampling.
5. A spread spectrum communication receiver according to claim 2 , further comprising a root nyquist filter or a low pass filter for removing inter symbol interference of the received signal.
6. A spread spectrum communication receiver according to claim 5 , wherein the received signal filtered by the root nyquist filter or the low pass filter is input to the over-sampling circuit.
7. A spread spectrum communication receiver according to claim 2 , further comprising a detector that detects a maximum correlation value among correlation values obtained by the digital matched filter.
8. A spread spectrum communication receiver according to claim 5 , further comprising a detector that detects a maximum correlation value among correlation values obtained by the digital matched filter.