phased.TOAEstimator
Description
The phased.TOAEstimator
creates a time-of-arrival System object™ to estimate times-of-arrival (TOA) or time-differences of arrival (TDOA) of
signals at known anchor points. The System object then uses time estimates to perform 2-D or 3-D target positioning of objects.
Anchors can encompass receivers or transmitter such as cellular base stations, Wi-Fi® access points, ground radar stations, or sonobuoys with known positions and a
target whose position is to be determined.
To estimate TOA or TDOA and estimate target positions:
Create the
phased.TOAEstimator
object and set its properties.Call the object with arguments, as if it were a function.
To learn more about how System objects work, see What Are System Objects?
Creation
Description
creates a TOA or
TDOA estimator System object
estim
= phased.TOAEstimatorestim
.
creates a TOA or TDOA estimator estim
= phased.TOAEstimator(Name
=Value
)estim
System object with each specified property Name
set to the specified
Value
. You can specify additional name-value pair arguments in any
order as
(Name1
=Value1
,...,NameN
=ValueN
).
Properties
Usage
Syntax
Description
estimates the time of arrival (TOA) or time difference of arrival (TDOA) of signals
Y
= estim(X
,freqspacing
)Y
at anchors from the channel estimation matrix
X
. This syntax assumes that the anchors and the target are time-synchronized.
If the
Measurement
property is set to'TOA'
, the object estimates the TOA between each anchor and the target.If the
Measurement
property is set to'TDOA'
, the object performs TOA estimation first and then uses the TOA measurements to calculate TDOA.
The freqspacing
represents the channel frequency
spacing.
performs TOA or TDOA estimation when the anchors and target are not time-synchronized. The
TOA and TDOA estimation results Y
= estim(X
,freqspacing
,delayoffset
)Y
are compensated by the
delayoffset
ar. To enable this syntax, set the
DelayOffsetInputPort
property to true
.
[
outputs the measurement variances Y
,var
] = estim(X
,freqspacing
,delayoffset
,...)var
. To enable this syntax, set the
VarianceOutputPort
property to true
.
[
calculates the output measurement variances Y
,var
] = estim(X
,freqspacing
,…,npow
)var
for input Gaussian
white noise power npow
.
[
outputs the FFT-based TOA response Y
,...,toaresp
,toagrid
] = estim(X
,freqspacing
,...)toaresp
and the TOA grid
toagrid
. To enable this syntax, set the
TOAResponseOutputPort
property to true
.
[
outputs the estimated target position Y
,...,tgtposest
,tgtposcov
] = estim(X
,freqspacing
,...,anchorpos
)tgtposest
and the estimated
target position covariance tgtposcov
. This syntax also accepts anchor
positions anchorpos
as input. To enable this syntax, set the
TargetPositionOutputPort
property to
true
.
Input Arguments
Output Arguments
Object Functions
To use an object function, specify the
System object as the first input argument. For
example, to release system resources of a System object named obj
, use
this syntax:
release(obj)
Examples
Algorithms
References
[1] Reza Zekavat and R. Michael Buehrer, Handbook of Position Location: Theory, Practice, and Advances, 2019
[2] Andreas F. Molisch. Wireless Communications: From Fundamentals to Beyond 5G, 3rd Edition, 2023
[3] Y. T. Chan and K. C. Ho, "A simple and efficient estimator for hyperbolic location," in IEEE Transactions on Signal Processing, vol. 42, no. 8, pp. 1905-1915, Aug. 1994
[4] P. Stoica and A. Nehorai, "MUSIC, maximum likelihood, and Cramer-Rao bound," in IEEE Transactions on Acoustics, Speech, and Signal Processing, vol. 37, no. 5, pp. 720-741, May 1989
Version History
Introduced in R2024a