Does an MVUB estimator exist? Suppose there exist three unbiased estimators:
θ̂1
θ
1
,
θ̂2
θ
2
, and
θ̂3
θ
3
. Two possibilities exist, as shown in Figure 1 and Figure 2.
There is no simple, general procedure for finding the MVUB
estimator.
In the next several lectures we will discuss several
approaches:
- Determine the so-called Cramer-Rao
lowerbound (CRLB) and verify that the estimator
achieves it.
- Apply the Rao-Blackwell theorem
(we talked about this earlier in the course).
- Further restrict the estimator to a class of
estimators (e.g., linear or polynomial
functions of the data).
- The Cramer-Rao Lower Bound
- Linear Statistical Models
- Maximum Likelihood Estimation
- Bayesian Estimation
- Waveform Estimation - Wiener and Kalman Filters
- Adaptive Filtering