GPS pseudolite and receiver system using high anti-jam pseudolite signal structure
First Claim
1. A global positioning system (GPS) type navigation system comprising:
- a first pseudolite transmitter adapted to transmit a first phase modulated L-band signal at a first signal pulse repetition rate, the first phase modulated L-band signal being modulated with a short period code having a code epoch of at least about one millisecond, the first signal pulse repetition rate having a first period time duration associated therewith, wherein for each of a plurality of consecutive transmission intervals having the first period time duration the pseudolite transmitter transmits the first phase modulated L-band signal during less than about one half of the first period time duration, and for at least about 1 millisecond so that the first pseudolite transmits an epoch of the short period code during each transmission pulse; and
a receiver adapted to receive the first phase modulated L-band signal.
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Accused Products
Abstract
Disclosed is a GPS pseudolite transmitter, receiver and navigation system. The GPS pseudolite transmitter is adapted to transmit a first phase modulated L-band signal at a first signal pulse repetition rate having an associated first period time duration. The first phase modulated L-band signal is modulated with a short period code having a code epoch of at least about one millisecond. For each consecutive transmission pulse having the first period time duration, the pseudolite transmitter transmits the first phase modulated L-band signal during less than one half of the first period time duration, and for at least about 1 millisecond so that the first pseudolite transmitter transmits an epoch of the short period code during each transmission pulse. A receiver is adapted to receive the first phase modulated L-band signal from the first pseudolite transmitter, at times when it is not integrating phase modulated L-band signals from other GPS pseudolites transmitters, such that cross-correlation with other phase modulated L-band signals is minimized. Furthermore, the receiver is adapted to receive the L-band satellite signal during intervals when no pseudolite signals are being received.
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Citations
17 Claims
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1. A global positioning system (GPS) type navigation system comprising:
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a first pseudolite transmitter adapted to transmit a first phase modulated L-band signal at a first signal pulse repetition rate, the first phase modulated L-band signal being modulated with a short period code having a code epoch of at least about one millisecond, the first signal pulse repetition rate having a first period time duration associated therewith, wherein for each of a plurality of consecutive transmission intervals having the first period time duration the pseudolite transmitter transmits the first phase modulated L-band signal during less than about one half of the first period time duration, and for at least about 1 millisecond so that the first pseudolite transmits an epoch of the short period code during each transmission pulse; and a receiver adapted to receive the first phase modulated L-band signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10)
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11. A pseudolite transmitter for use in a global positioning system (GPS) type navigation system, the pseudolite transmitter comprising:
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an antenna; and signal generating circuitry coupled to the antenna and adapted to generate and transmit through the antenna a first phase modulated L-band signal at a first signal pulse repetition rate, the first phase modulated L-band signal being modulated with a short period code having a code epoch of at least about one millisecond, the first signal pulse repetition rate having a first period time duration associated therewith, wherein for each of a plurality of consecutive transmission intervals having the first period time duration the signal generating circuitry transmits the first phase modulated L-band signal during less than about one half of the first period time duration, and for at least about 1 millisecond so that an epoch of the short period code is transmitted by the pseudolite transmitter during each transmission pulse. - View Dependent Claims (12, 13, 14)
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15. A global positioning system (GPS) receiver comprising:
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an antenna which receives a first phase modulated L-band signal transmitted from a first pseudolite transmitter at a first signal pulse repetition rate, the first phase modulated L-band signal being modulated with a short period code having a code epoch of at least about one millisecond, the first signal pulse repetition rate having a first period time duration associated therewith, wherein for each of a plurality of consecutive transmission intervals having the first period time duration the antenna receives the first phase modulated L-band signal from the first pseudolite transmitter during less than about one half of the first period time duration, and for at least about 1 millisecond so that the received phase modulated L-band signal contains an epoch of the short period code during each transmission pulse; signal processing circuitry coupled to the antenna, the signal processing circuitry receiving the first phase modulated L-band signal from the antenna and providing as an output a first frequency converted signal indicative of the first phase modulated L-band signal; and integration circuitry coupled to the signal processing circuitry, the integration circuitry integrating the first frequency converted signal for less than one half of the first period time duration during each interval. - View Dependent Claims (16, 17)
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Specification