Implementation of Correlation Power Peak Ratio Based Signal Detection Method
Jae‐Woo Jung · 2004
To acquire signal, GPS receivers typically apply signal detection algorithm using a pre-set detection threshold. Signal power at a particular search space, usually comprised of PRN, the C/A code phase, and carrier frequency offset, is compared to a pre-determined threshold, and signal detection is declared when the power is above the threshold and verification process which follows is successful. Although this method is suitable for many applications, setting a threshold level for a changing RF environment can be a difficult process. As the environment changes, the GPS signal strength may be attenuated, and the thermal noise floor may fluctuate. Furthermore, when the integration period of GPS signal is extended to mitigate effect of signal attenuation, the threshold level should change as well. To address this difficulty, a detection algorithm based on the ratio between the highest peak and the second highest peak of the correlation power in the C/A code phase search space is developed. This idea was introduced as a detection confidence measure, 'ratio', by Denis Akos, et al.[1]. In this study, a further improvement of the idea and its implementation as a detection method is discussed.