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.
With the advances in technology, come significant advances in education. One of the greatest advancements and themes in the education world is the creation of free online schools. The free online schools are essential for democratization of education. And the amazing fact is that not only these schools are free, but they have a surprisingly high quality content.
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.
Dual-loop clock and data recovery (CDR) systems are widely used in today’s gigabit wireline communications. Figure 1 shows the architecture of a dual-loop CDR, consisting of a phase locked loop (PLL) and CDR. The PLL creates a quadrature clock at the data rate of the input data , while the CDR tracks the data phase along each lane of the serial link. The data recovery loop is based on a phase detector (PD), a finite state machine (FSM), and a phase interpolator (PI). A bang-bang PD creates "up" and "down" signals based on the phase of the clock in respect to the input data.
In this post we explain what the gain compression means and why it is important in the design of RF systems. We also explain how to compute single-tone and two-tone 1 dB compression points.
Network coding is a very active field of research currently and is widely believed to be the foundation of the next generation of data networks. It is already being incorporated into some standards. More recently, products (e.g., file sharing platforms) based on network coding are emerging. In this article we briefly explain what it is and how it works.
As an Electrical Engineer, we all need great books to learn from, or use as a reference. And finding a good book, among tens and sometimes hundreds of choices is not easy. In this post we have tried to compile a list of some great Electrical Engineering books. We created the list by contacting some experts in the field, and also by reading a lot of reader's reviews.
What is genetic algorithm? In a nutshell genetic algorithm is a search or optimization algorithm that is inspired by natural selection or the survivor of the fittest. Genetic algorithm is a powerful engineering tool that can be used to solve nonlinear optimization problems, and can increase the search speed significantly. How does it work? Assuming […]