| 摘要 |
A time-efficient real-time correlator is provided for use in a receiver of a wireless communications system. The correlator correlates a signal received by the receiver with a pseudo-random number (PN) code in order to determine the time delay of the received signal. The correlator requires no memory for storing samples of the received signal. A shift register having only W storage elements is utilized for storing the samples of the PN code sequence, where W is a positive integer corresponding to the length of the correlation window. W+1 correlation results storage elements are utilized to store correlation result values. When the correlator receives a current sample of the incoming signal, the current sample r(j) is multiplied by each of the samples of the PN code sequence to obtain products. The correlation result values stored in the correlation results storage elements are added to the products and the resulting sum is stored in the correlation results storage elements. Once M samples of the received signal have been correlated with the PN code samples, the correlation result values contained in the correlation result storage elements are mature. These correlation result values may then be processed to determine the time delay of the received signal. The correlator has increased throughput and decreased memory requirements, thereby enabling real-time operations to be performed in a time-efficient manner while also requiring fewer resources.
|
