Signal Processing for Communication Systems
Pulse-shaping Lab path:Nyquist zero-ISI → Raised cosine → Matched filter + SRRC → Eye diagramsTool: RRC filter & bandwidth calculator Key focus: Let’s learn how to simulate matched filter receiver with square root raised cosine (SRRC) filter, for a pulse amplitude modulation (PAM) system. Simulation Model A basic pulse amplitude modulation (PAM) system as DSP … Read more
Introduction to precoding Intersymbol interference (ISI) is a common problem in telecommunication systems, such as terrestrial television broadcasting, digital data communication systems, and cellular mobile communication systems. Dispersive effects in high-speed data transmission and multipath fading are the main reasons for ISI. To maximize the capacity, the transmission bandwidth must be extended to the entire … Read more
Impulse response and frequency response of PR signaling schemes Consider a minimum bandwidth system in which the filter $latex H(f)$ is represented as a cascaded combination of a partial response filter $latex Q(f)$ and a minimum bandwidth filter $latex G(f)$. Since $latex G(f)$ is a brick-wall filter, the frequency response of the whole system $latex … Read more
Consider the generic baseband communication system model and its equivalent representation, shown in Figure 1, where the various blocks in the system are represented as filters. To have no ISI at the symbol sampling instants, the equivalent filter $latex H(f)$ should satisfy Nyquist’s first criterion. If the system is ideal and noiseless, it can be … Read more
Modified duobinary is the partial-response cousin of duobinary that puts a spectral null at DC. It correlates symbols two baud intervals apart, so the controlled ISI sits on the alternate sample rather than the neighbour. The Nyquist zero-ISI condition is relaxed to The minus sign at lag \(2T\) is what opens the null at DC. … 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