Vakkursus EMS310/311 Course EMS310/311 - Electrical, Electronic ...

3.
3.1 Teken die blokdiagram van ‘n ideale basisband verwysingstelsel (sonder modulasie), met m(t) die intree-
(informasie-)sein met drywing P m=S i [Watt]. Die SWGR-kanaal tel with Gauss-ruis met tweesydige
DrywingsDigtheidSpektrum (DDS) N/2 [W/Hz] by. Aanvaar ‘n perfekte LDF in die ontvanger met bandwydte
B$f m [Hz], waar f m die maksimum informasiefrekwensie voorstel.
Draw the block diagram of an ideal reference baseband communication system (without modulation), with m(t)
the input (information) signal with power P m=S i [Watt]. The AWGN channel adds white Gaussian noise with
two-sided Power-Spectral-Density (PSD) N/2 [W/Hz]. Assume a perfect LPF in the receiver with bandwidth
B$f m [Hz], where f m denotes the maximum information frequency.
Fig. 3-1 Blokdiagram van ideale basisband verwysing-kommunikasiestelsel
Block diagram of ideal reference baseband communication system. (3)
3.2 Bereken die ontvangde informasie-seindrywing S i en die ruisdrywing N o by die uitgang van die
basisbandontvanger, en bepaal ‘n uitdrukking vir die uitgang sein-tot-ruis-verhouding, (SNR) b.
Calculate the received information signal power S i and the noise power N o at the output of the baseband
receiver, and determine an expression for the output signal-to-noise-ratio, (SNR) b.
Bereken P m= S i=S o [W] en N o [W], en gevolglik `n uitdrukking vir (SNR) b.
Calculate P m= S i=S o [W] and N o [W], and hence an expression for (SNR) b:
(SNR) b =
EMS310_Klastoets2_07.wpd LPL/04/07 4 / 7
[6]
(3)