題組內容
2. (Total=18%) A pulse communication system is being designed that will transmit
one of two messages, mi and m2, which occur with equal a priori probability.
These messages will be signaled using the following waveforms, and we would
like to select sets of transmitted signals that will either minimize the average
transmitted energy or will minimize the probability of error. Assume that the
channel is corrupted by an additive white Gaussian random process. Assume
here that the inner product of two real-valued function of duration T = 2 is
defined as
Four possible signals, sA(t), sB(t), sc(t), and sD(t) are being considered, and two of
them will be selected as the signal set that will indicate which message had been
sent. The signals are sketched in Fig. 2.


(a) (4%) Compute a set of orthonormal basis functions
using the Gram-Schmidt procedure, where
is proportional to sA(r). The
signals sA(X), sB(t), sc(t), and sD(t) can be expressed as a linear combination of
these basis functions as______________________________________
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______________________________________ where the basis functions are______________________________________
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