Characterization of the Effects of CW and Pulse CW Interference on the GPS Signal Quality

Abstract

In the Global Positioning System (GPS), code division multiple access (CDMA) signals are used. Because of the spectral characteristics of the CDMA signal, each particular type of interference (signals to be rejected) has a different effect on the quality of the received GPS satellite signals. In this paper, the effects of three types of interference are studied on the carrier-to-noise ratio (C/N 0 ) of the received GPS signal as an indicator of the quality of that signal; continuous wave (CW) and pulse CW. For CW interference, it is analytically shown that the C/N 0 of the signal can be calculated using a closed formula after the correlator in the receiver. This result is supported by calculating the C/N 0 using the I and Q data from a software GPS receiver. For pulsed CW, a similar analysis is performed to characterize the effect of parameters such as pulse repetition period (PRP) and also duty cycle on the received signal quality.It is specifically shown that for equal interference power levels, in the cases where the PRP is far less than the pseudorandom noise code period, the signal degradation increases with increasing the duty cycle whereas it doesn't change when the two periods are equal or the PRP is far bigger than the code period.

CW interference mitigation in GNSS receiver based on frequency-locked loop

“…The first set of simulations demonstrates the theoretical analysis of the interference estimation error for the proposed algorithm with the metrics described in Section 4. In addition, the second set of designed simulations shows the applicative performance in terms of the range measurement for the proposed algorithm [20]. This is because the basic function of a GNSS receiver is to determine its location, which can be obtained by estimating the received signal's time of arrival [21].…”

Increase of Carrier-to-Noise Ratio in GPS Receivers Caused by Continuous-Wave Interference

“…Another topic of research is the effect of CWI on the effective C/N 0 [12][13][14][15]. The increased use of personal private devices (PPDs) [16], [17] has generated greater interest in the effects of CWI on civilian receivers.…”

“…The increased use of personal private devices (PPDs) [16], [17] has generated greater interest in the effects of CWI on civilian receivers. However, the effective C/N 0 models developed for partial-band interference in [1] cannot be applied to CWI because bandwidth of CWI is too narrow to use continuous spectral density of navigation signal [14]. The spectrum of navigation signals should be modeled as a line spectrum in the presence of CWI because of the pseudo-random noise (PRN) code repetition [15].…”

“…An important conclusion in [15] was that CWI induces the maximum loss in the effective C/N 0 when the frequency of the CWI coincides with the worst spectral line of the navigation signal. In [13][14][15], wrongly applying continuous power spectrum density in [1] to continuous-wave Dirac delta function is removed. However, the effect of the CWI on the PLL tracking was neglected.…”

Analysis of Multipath and CW Interference Effects on GNSS Receivers with EMLP Discriminator

“…The multipath error envelope (MEE) is a common way of assessing the multipath performance of a given signal/receiver combination [3]. CW interference is typical radio frequency interference (RFI) which is another error source for GNSS receivers [4,5]. The post-correlati on effects of narrowband interference and partial-band interference have been analyzed in [4,6].…”