This is the last part of our three-part series that explains the meaning of in digital communication context. Calculating Having understood how Gaussian noise comes to affect transmitted symbols, it remains to define an appropriate average signal energy, and hence a signal-to-noise ratio (SNR). A commonly used definition of SNR is , where is the […]
This is the second part of our three-part series that explains the meaning of in digital communication context. Signal Constellations Often, particularly in the specification of signal sets used in modems, we rely on the notion of an orthonormal basis. A set is an orthonormal basis if The linear span of consists of the […]
This is part one of a three-part series that explains the meaning of in digital communication context. Introduction Every student of communications knows that digital communication system performance—for example, bit error rate (BER) or frame error rate (FER)—depends on the signal-to-noise ratio (SNR), with higher SNRs leading to lower BERs and FERs. Sometimes less clear, […]
Introduction Transmission line theory has been around for more than a century. However, the distributed nature of it has kept it interesting for all these years. One interesting subject is the step response in a hybrid lumped-distributed network. While for a purely lumped network it is quite easy to analyze and derive the response equation, for a distributed or a […]
Oscillators are integral parts of many electronic devices. Majority of fundamental signal processing operations such as frequency translation, synchronization, and timing, require stable clocks derived from an electrical oscillator. An oscillator is generally susceptible to any external periodic signal whose frequency is close to the oscillation frequency or its integer harmonics. Without the loss of […]
In digital communication systems, Analog-to-Digital Converter (ADC) is the main interface between the analog domain and the digital domain. The continuous rising demand for high data rate communication systems has been creating the need for wide-band ADCs with a high sampling rate and high accuracy. These ADCs need to achieve high speed and high resolution […]
This is the second part of our "MATLAB tips and tricks" series. As we also mentioned in part 1, MATLAB is the programming language of choice for many engineers, scientists, data analysts, and more. In this post we introduce some interesting MATLAB tips and tricks. They can be used to make writing code easier and shorter, also to write codes that run faster.
Single Carrier Frequency Division Multiple Access (SC-FDMA) is an alternative modulation scheme to Orthogonal Frequency Division Multiple Access (OFDMA) employed in the uplink Long Term Evolution (LTE) cellular wireless communications systems. The SC-FDMA has similar performance and essentially the same overall complexity as OFDMA system. The OFDMA waveform exhibits a high Peak-to-Average Power Ratio (PAPR), requiring the power amplifier to operate with a large back-off from their peak power. This results in the power amplifier to operate with low efficiency and places a significant burden on battery-limited mobile handsets.
hen we first learn about digital microsystems, we often start by figuring out how information can be represented using bits of information, 0 and 1. Representing any number larger than 1 or any fraction requires that we use several bits. Then, we usually proceed to learn about sign-and-magnitude and 2's complement notations. We may also […]
The ABCD representation for a two-port circuit is very convenient for the calculation of cable transfer function. In this post we show how to compute the cable transfer function for a simple transmission line as well as a simple cable with one bridge-tap connection. The method can be extended to more complex cases very easily.