TEL AVIV UNIVERSITY Gaddi Blumrosen

X
W T 1
W T N
11
1 1
N 1
Figure 4: Received and transmitted channel model scheme
2.5 ST System Performance Evaluation
After describing our system model, we will introduce in this chapter a way of
evaluating system performance by means of error probability at the receiver. We will
later see that most ST techniques are aimed to minimize the receiver error probability.
We have to emphasize that in communication systems it is sometimes used to refer to
system capacity as another measure for system performance, i.e. maximization of the
mutual information between receiver and transmitter enhance system performance as
in e.g., [10], [11]. In certain model assumptions, such as Single User in Gaussian
fading channel BPSK modulation, the two performance measures coincide. These two
measures are also related received SNR maximization.
2.5.1 AWGN error probability bounds
.
.
.
Non Perfect Side Information
1 M
NM
N t N r
In a non-fading scenario, for SISO, the error probability of an un-coded BPSK signal,
denoted also as AWGN SISO bound, is given by:
Perr( b) Q(
2 b)
(2.47)
Eb
Where, b is the received SNR per bit, b , b is the bit energy and is the
N0
noise power spectral density.
In case of multiple antennas, either in reception or transmission, denoted by N, where
receive diversity is being exploited by optimal MRC combining or in case of ideal
E 0 N
.
.
.
N 1
N M
W R 1
W R M
Perfect Side Information
X ˆ