Articles | Page 3 of 11

How to Design Nyquist and Square-Root Nyquist Pulse Shaping Filters

Square-root Nyquist filters for three different excess bandwidths

The radio spectrum is a very precious resource like real estate and must be utilized judiciously. Pulse shaping filters control the spectral leakage of the transmitted signal in a wireless channel due to the strict restrictions to comply with a…
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Discrete-Time Integrators

A discrete-time integrator implemented through a forward difference and a backward difference technique

An integrator is a very important filter that proves useful in implementation of many blocks of a communication receiver. In continuous-time case, an integrator finds the area under the curve of a signal amplitude. A discrete-time system deals with just…
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Phase Locked Loop (PLL) in a Software Defined Radio (SDR)

A discrete-time PLL with a PI loop filter and an NCO consisting of a phase accumulator and a Look-Up Table (LUT)

IBM Watson and Google DeepMind are the most complex computers that, some believe, will try to run the world in a distant future. A PLL on the other hand is the simplest computer that actually runs so much of the…
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What is Carrier Frequency Offset (CFO) and How It Distorts the Rx Symbols

Three different cases for carrier frequency offset

In Physics, frequency in units of Hz is defined as the number of cycles per unit time. Angular frequency is the rate of change of phase of a sinusoidal waveform with units of radians/second. \begin{equation*} 2\pi f = \frac{\Delta \theta}{\Delta…
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Moving Average Filter

The most commonly used filter in DSP applications is a moving average filter. In today’s world with extremely fast clock speeds of the microprocessors, it seems strange that an application would require simple operations. But that is exactly the case…
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