A Novel VLSI Architecture for Multi-Constellation and Multi-Frequency GNSS Acquisition Engine

Abstract

This paper proposes a novel VLSI architecture of GNSS acquisition engine based on shorttime correlation combined with an FFT scheme. The architecture supports multi-constellation systems and multi-frequency satellite signals flexibly by the manner of time-division multiplexing. The supported signals include GPS, BDS, GLONASS, GALILEO, QZSS, IRNSS, and SBAS. Compared with other direct acquisition structures, the search efficiency of the acquisition engine is improved by using the IF playback structure. Based on the characteristics of L1C and B1C signal spread spectrum codes, an efficient generation method and the circuit structure of Legendre sequence which is compatible with L1C and B1C spread spectrum codes are proposed. It can effectively reduce the die area of the spread spectrum code generator and the generation time of the L1C/B1C spread spectrum code. Combining with the acquisition scheme adopted in this paper, the structure of the short-time correlators' array is optimized, and the maximum clock frequency of the acquisition engine is significantly improved. The acquisition engine proposed in this paper is implemented in a 55-nm CMOS technology. The system occupied a silicon area of 2.1 mm 2 and consumes only 72.02-mW power while realizing the maximum clock frequency at about 333.33 MHz.

Area-Efficient Universal Code Generator for GPS L1C and BDS B1C Signals

“…Lastly, Legendre sequence-based codes show excellent correlation characteristics, and they have recently been used in GPS L1C and BDS B1C signals. As the fields of the application of the GNSS have expanded along with the recent development of the industries, studies to provide high precision and additional functions of GNSS receivers have been extensively conducted [8][9][10][11][12][13][14][15][16][17]. In addition to the simple role of receiving signals and performing navigation calculations, advanced signal technologies, such as anti-jamming [8] and anti-spoofing [9], are applied, and studies on multiconstellation and multi-frequency receivers [10][11][12] are being conducted for high-precision high-reliability location calculations.…”

“…In addition to the simple role of receiving signals and performing navigation calculations, advanced signal technologies, such as anti-jamming [8] and anti-spoofing [9], are applied, and studies on multiconstellation and multi-frequency receivers [10][11][12] are being conducted for high-precision high-reliability location calculations. Especially, studies on single code generators that support various codes are actively conducted for the implementation of multi-constellation and multi-frequency receivers so that single receivers can support multiple codes [13][14][15][16][17]. As shown in Table 1, since LFSR-based code generation is the most widely applied, studies on LFSR-based codes have been steadily conducted [10][11][12][13].…”

A novel secondary code acquisition algorithm for the BDS‐3 B1C signal

“…Hence, detailed information about the primary code acquisition method is not the focus. To illustrate the proposed PCM, the two-dimension search method based on short-time coherent integration plus a FFT is considered [18][19][20], as Figure 1 shows. It should be noted, that other search methods such as serial search [21], parallel frequency search [22], and parallel code search [23], are also suitable for primary code acquisition and cooperation with the PCM.…”

A Novel Acquisition Algorithm Based on PMF-apFFT for BOC Modulated Signals

“…ALGORITHMS FOR sBOC(2,1) and cBOC (1,1) In order to evaluate the performance of the proposed algorithm more comprehensively, detection probabilities of PMF-FFT, PCF, SR, ACF and PMF-apFFT algorithm for sBOC(2,1) and cBOC(1,1) are assessed by Monte Carlo simulation in Figure 9, respectively. Whether for sBOC(2,1) or cBOC(1,1), detection probability of the proposed algorithm approximately reaches 1 at SNR= −10dB, which is better than that of other algorithms.…”

“…The contradiction, which is between the increasing demands of navigation frequency resource and the relatively limited frequency sharing ability of the binary phase shift keying (BPSK) modulated signal, has contributed to the wide application of binary offset carrier (BOC) modulation in the modern global navigation satellite system (GNSS) [1], [2]. More than 100 satellites, including GPS, GLONASS, GALILEO and BEIDOU systems, hovering in the sky, among which modern GPS, GALILEO and BEIDOU systems all use BOC modulation signals [3], [4].…”