DirAc: An Integrated Circuit for Direct Acquisition of the M-Code Signal

Research on global positioning system M‐code acquisition method and the acquisition performance

“…Thus, the difference of data modulating odd and even chips results in the energy cancellation. That is why the P(Y)-code acquisition methods in [8][9][10][11][12][13][14][15] and the M-code acquisition methods in [14][15][16]23], which do not consider TDDM, are inapplicable to M-code signal. Hence, to make use of frequency-domain correlation, the coherent integrations of odd and even chips of despread received signal must be separately performed.…”

“…Process c E in the same manner and we obtain a USB even chip correlation result sequence q U,E (1) of length N + 1. Here, FFT-based frequency-domain correlation of received www.ietdl.org and local signals is implemented [8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24]. The correlation is called short-time correlation.…”

“…Therefore, the TDDM technique makes the P(Y)-code acquisition methods unsuitable for M-code signal. Similarly, because the previous M-code acquisition methods in [14][15][16]23] do not consider the effect of TDDM, they are inapplicable either. Reference [17] proposed to correlate received signal with odd and even chips of local signal, respectively, by time-gated correlators.…”

“…It is notable that all the previous M-code acquisition methods use the BPSK-like technique to deal with the BOC problem. In addition, in some references [14][15][16]23], the M-code signal that is not using TDDM is discussed, but the latest M-code signal indeed utilises TDDM for its excellent performance [1, [17][18][19][20]. In this paper, the M-code signal refers to the one of using TDDM unless otherwise noted.…”

Performance Evaluation of the Direct Acquisition of GPS-like VBOC Signals against Noise and Interference

“…The vulnerabilities of the GPS C/A code as discussed in [12]- [15] have been exaggerated mainly because the assessment of the performance of the C/A code is based on a cross-correlator type receiver [4]- [8].…”