This module describes a decision procedure for decoding received signals. The implementation and analysis of a correlation receiver is included.
Demodulation and detection
Detection
Decide which
from the set of
signals was transmitted based on observing
,
the vector composed of
demodulated received signal, that is, the vector of projection of the
received signal onto the
bases.
Note that
If
, that is information symbols are equally likely to
be transmitted, then
Since
for
and for some
then
where
and
's are Gaussian and independent.
where
is the
distance between vectors
and
defined as
where
is the
norm of vector
defined as
This type of receiver system is known as a
correlation (or correlator-type) receiver.
Examples of the use of such a system are found
here . Another type of
receiver involves linear, time-invariant filters and is knownas a
matched
filter receiver. An analysis of the performance of a
correlator-type receiver using antipodal and orthogonal binarysignals can be found in
Performance Analysis .
