Signal Processing for Communication Systems
Key focus: As per Nyquist ISI criterion, to achieve zero intersymbol interference (ISI), samples must have only one non-zero value at each sampling instant. Consider an equivalent baseband communication system model with baud rate ( is the symbol period) shown in Figure 1, where the transmitter, channel and the receiver are represented as band-limited filters. … Read more
Key focus: Inter-symbol interference: symbols sent through a dispersive channel, arrive at different time intervals and interfere due to non-constant group delay. Introduction Communication systems have progressed from analog to digital implementation due to the latter’s advantages of bandwidth efficiency and exceptional immunity to noise. The greatest challenge to a communication systems engineer lies in … Read more
Modified Duobinary Signaling is an extension of duobinary signaling. It has the advantage of zero PSD at low frequencies (especially at DC ) that is suitable for channels with poor DC response. It correlates two symbols that are 2T time instants apart, whereas in duobinary signaling, symbols that are 1T apart are correlated. The general … Read more
The condition for zero ISI (Inter Symbol Interference) is which states that when sampling a particular symbol (at time instant nT=0), the effect of all other symbols on the current sampled symbol is zero. As discussed in the previous article, one of the practical ways to mitigate ISI is to use partial response signaling technique … Read more