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The peak at time = 5 is a measure of the time shift between the recorded waveforms, which is also the value needed for equation 3. Figure 4b shows the same type of simulation for a wide-band waveform from the emitter. The time shift is 5 time units because the geometry and wave speed is the same as the Figure 4a example.
The AoA can be calculated by measuring the time difference of arrival (TDOA) between individual elements of the array. Generally this TDOA measurement is made by measuring the difference in received phase at each element in the antenna array. This can be thought of as beamforming in reverse. In beamforming, the signal from each element is ...
Various techniques for calculating the direction of arrival, such as angle of arrival (AoA), time difference of arrival (TDOA), frequency difference of arrival , or other similar associated techniques. Limitations on the accuracy of estimation of direction of arrival signals in digital antenna arrays are associated with jitter ADC and DAC. [3]
Angle of arrival (AOA) requires at least two towers, locating the caller at the point where the lines along the angles from each tower intersect. Time difference of arrival (TDOA) works like GPS using multilateration, except that it is the networks that determine the time difference and therefore distance from each tower (as with seismometers).
Pseudo-range multilateration, often simply multilateration (MLAT) when in context, is a technique for determining the position of an unknown point, such as a vehicle, based on measurement of biased times of flight (TOFs) of energy waves traveling between the vehicle and multiple stations at known locations.
Frequency difference of arrival (FDOA) or differential Doppler (DD), is a technique analogous to TDOA for estimating the location of a radio emitter based on observations from other points. (It can also be used for estimating one's own position based on observations of multiple emitters).
OTDOA (Observed Time Difference Of Arrival) is a positioning feature introduced in rel9 E-UTRA (LTE radio). It's a multilateration method in which the User Equipment (UE) measures the time difference between some specific signals from several eNodeBs and reports these time differences to a specific device in the network (the ESMLC).
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