초록 ▼

The location of a transmitter can be determined using a proxy receiver, such as a natural landmark or man-made structure, which reflects and/or refracts the signal from a transmitter toward a receiver. A processor is operatively connected to the receiver and determines the location of the transmitte

The location of a transmitter can be determined using a proxy receiver, such as a natural landmark or man-made structure, which reflects and/or refracts the signal from a transmitter toward a receiver. A processor is operatively connected to the receiver and determines the location of the transmitter based on a multilateration calculation that includes the Time of Arrival of the transmitted signal at the proxy receiver and the known or calculated location of the proxy receiver as inputs.

대표청구항 ▼

The location of a transmitter can be determined using a proxy receiver, such as a natural landmark or man-made structure, which reflects and/or refracts the signal from a transmitter toward a receiver. A processor is operatively connected to the receiver and determines the location of the transmitte

The location of a transmitter can be determined using a proxy receiver, such as a natural landmark or man-made structure, which reflects and/or refracts the signal from a transmitter toward a receiver. A processor is operatively connected to the receiver and determines the location of the transmitter based on a multilateration calculation that includes the Time of Arrival of the transmitted signal at the proxy receiver and the known or calculated location of the proxy receiver as inputs. roduce a digital input signal; a processor configured to generate a time-stretched signal by representing each of a number of samples of the digital input signal as a plurality of time-stretched samples, said processor generating digital time-stretched signal components of the polarization agile signal from the time-stretched signal and polarization data, and time compressing the digital time-stretched signal components to produce digital signal components of the polarization agile signal; and a digital-to-analog converter device configured to receive the digital signal components and generate corresponding analog signal components of the polarization agile signal. 13. The apparatus of claim 12, further comprising a memory device coupled to said processor and configured to store samples of the digital input signal and the time-stretched signal. 14. The apparatus of claim 13, wherein: said analog-to-digital converter samples the input signal at a sampling rate of N samples per signal cycle, where N is a positive number; and said memory device stores each of the N samples in M memory locations, such that M×N samples are stored for each signal cycle, where M is a positive integer. 15. The apparatus of claim 14, wherein a phase resolution of the time-stretched signal is a function of the sampling rate and the number of memory locations M in which each of said number of samples is stored. 16. The apparatus of claim 12, wherein an effective phase resolution of the time-stretched signal is greater than that of the digital input signal. 17. The apparatus of claim 12, wherein the polarization data includes first and second polarization phase data and said processor includes: a signal inverter configured to inverter values of samples of the time-stretched signal to produce an inverted signal; a first data shifter configured to shift samples of the inverted signal by a number of sample positions in accordance with the first polarization phase data to produce a shifted signal; a first adder configured to add the time-stretched signal and the shifted signal to produce a first digital time-stretched signal component of the polarization agile signal; a second adder configured to add the inverted signal and the shifted signal to produce a sum signal; and a second data shifter configured to shift samples of the sum signal by a number of sample positions in accordance with the second polarization phase data to produce a second digital time-stretched signal component of the polarization agile signal. 18. The apparatus of claim 17, wherein the first and second digital time-stretched signal components respectively correspond to the horizontal and vertical polarization components of the polarization agile signal. 19. The apparatus of claim 12, wherein the polarization data comprises phase values representing polarization phase and amplitude information. 20. The apparatus of claim 12, wherein the polarization data comprises integer values representing numbers of memory location shifts. 21. The apparatus of claim 12, wherein said digital-to-analog converter device comprises plural digital-to-analog converters. 22. The apparatus of claim 12, further comprising: a down converter configured to convert an input radio frequency signal to an intermediate frequency to produce the input signal. 23. The apparatus of claim 12, further comprising: an up converter configured to convert the analog signal components of the polarization agile signal from an intermediate frequency to a transmission frequency. 24. The apparatus of claim 23, further comprising a dual-polarization antenna configured to receive the analog signal components and transmit the polarization agile signal at the radio frequency. 25. An apparatus for generating a polarization agile signal, comprising: means for time stretching a digital input signal by representing each of a number of samples of the digital input signal as a plurality of time-stretched samples;