A research of carrier tracking loop for high hopping rate DS/FH receiver

A High Dynamic Velocity Locked Loop for the Carrier Tracking of a Wide-Band Hybrid Direct Sequence/Frequency Hopping Spread-Spectrum Signal

“…Hopping Rates (hops/s) Dynamics SNR (dB) Loop Structures [8] ≤1.2 k Acceleration 30 g ≥13 Second-order PLL [9] 10 k Unspecified Unspecified FLL and PLL Switching [10] 100 k Unspecified ≥0 PLL [11] 10 k Jerk 10 g/s ≥−30 Second-order VLL assisted third-order PLL [12] 9 k Jerk 10 g/s −25 Second-order VLL assisted third-order PLL As indicated in Table 1, the research on tracking algorithms for high dynamic hybrid DS/FH spread spectrum signals has remained relatively scarce in recent years. Nevertheless, it is reassuring to note that numerous research achievements have been made in the tracking of high dynamic DSSS signals in recent times.…”

“…To compare the dynamic adaptability of the standard VLL, the VLL variant described in [11], and the HD-VLL, all three of these systems are simulated and analyzed.…”

“…Firstly, we selected the parameters used in reference [11]: a frequency hopping rate of 10 khops/s, dynamics of 10 g/s, and a CNR of 33 dB-Hz. The three VLLs were simulated with a bandwidth of 5 Hz.…”

“…Although the frequency hopping rate involved is up to 100 khops/s, the information rate is set to be the same as the frequency hopping rate, making it only applicable to scenarios with a higher SNR. The authors of [11,12] employ a tracking scheme based on a velocity locked loop (VLL), which utilizes the coherent integration results of multiple hops for discrimination. The employed scheme simultaneously achieves the requirements of a high hopping rate and low SNR, yet the involved dynamic is merely 10 g/s, where g = 9.8 m/s 2 .…”

“…The employed scheme simultaneously achieves the requirements of a high hopping rate and low SNR, yet the involved dynamic is merely 10 g/s, where g = 9.8 m/s 2 . Table 1 lists the hopping rates, dynamics, SNR, and loop structures involved in [8][9][10][11][12].…”