Title :
On optimal signal sets for digital communications with finite precision and amplitude constraints
Author :
Honig, Michael L. ; Boyd, Stephen P. ; Gopinath, B. ; Rantapaa, Erik
Author_Institution :
Bell Commun. Res., Morristown, NJ, USA
fDate :
2/1/1991 12:00:00 AM
Abstract :
The maximum data rate that can be reliably communicated given a linear, time-invariant, dispersive channel, a receiver that samples the channel output to within an accuracy of ±d where d >0, and a transmitter with an output amplitude constraint is evaluated. For any dispersive channel the maximum rate depends on d and is finite. The transmitted waveforms must be designed so that two channel outputs associated with two distinct transmitted signals are separated in amplitude at a particular time by d. It is shown that given any channel impulse response with rational Laplace transform, there exists an optimal sets of inputs that are ±A everywhere where A is the maximum allowable amplitude. Furthermore, in any finite time interval, each input changes sign a finite number of times. If the channel impulse response is a single decaying exponential, it is shown that simple binary signaling, in which A or -A, depending on the current message bit, is transmitted during each symbol interval, maximizes the data rate
Keywords :
digital communication systems; signal processing; telecommunication channels; amplitude constraints; binary signaling; channel impulse response; channel output; decaying exponential; digital communications; finite precision constraints; finite time interval; linear dispersive channel; maximum data rate; optimal signal sets; rational Laplace transform; symbol interval; time invariant channel; transmitted signals; transmitted waveforms; transmitter; Additive noise; Channel capacity; Crosstalk; Digital communication; Dispersion; Gaussian noise; Laplace equations; Signal design; Statistics; Transmitters;
Journal_Title :
Communications, IEEE Transactions on