Invention Grant
US5734674A Pseudorandom-noise receiver having automatic switching between regular
and anti-jamming modes
失效
伪随机噪声接收机具有常规和抗干扰模式之间的自动切换
- Patent Title: Pseudorandom-noise receiver having automatic switching between regular and anti-jamming modes
- Patent Title (中): 伪随机噪声接收机具有常规和抗干扰模式之间的自动切换
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Application No.: US720862Application Date: 1996-10-02
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Publication No.: US5734674APublication Date: 1998-03-31
- Inventor: Patrick C. Fenton , Thomas J. Ford
- Applicant: Patrick C. Fenton , Thomas J. Ford
- Applicant Address: CAX Calgary
- Assignee: NovAtel Inc.
- Current Assignee: NovAtel Inc.
- Current Assignee Address: CAX Calgary
- Main IPC: G01S1/00
- IPC: G01S1/00 ; H04B1/7085 ; H04B1/709 ; H04K1/00 ; H04K3/00
Abstract:
A receiver for pseudorandom noise (PRN) encoded signals consisting of a sampling circuit, multiple carrier and code synchronizing circuits, and multiple digital autocorrelators. The sampling circuit provides digital samples of a received composite signal to each of the several receiver channel circuits. The synchronizing circuits are preferably non-coherent, in the sense that they track any phase shifts in the received signal and adjust the frequency and phase of a locally generated carrier reference signal accordingly, even in the presence of Doppler or ionospheric distortion. The antocorrelators in each channel form a delay lock loop (DLL) which correlates the digital samples of the composite signal with locally generated PRN code values to produce a plurality of (early, late), or (punctual, early-minus-late) correlation signals. The time delay spacing between the (early, late), and (punctual, early-minus-late) correlation signals are dynamically adjusted, such that in an initial acquisition mode, the delay spacing is relatively wide, on the order of approximately one PRN code chip time; once PRN code lock is achieved, the code delay spacing is narrowed to a fraction of a PRN code chip time.
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