We know that digital signals are stored as binary numbers in memory cells. Let’s see how these digital signals can be transferred in other words - how they can be encoded in to electrical signal shape. When signal has to be sent it has to be modulated.
Pulse Code Modulation (PCM)
Probably simplest and most common modulation [...]

The processing of the various signals is carried out through implements that are together called as DSP hardware. This includes the hardware that is used for transmission of signals, various devices that are used to enhance or filter the signals, analogue to digital and digital to analogue converters and other processing equipment such as computers.
Among [...]

Digital signal processing is the technique used to analyse various digital signals and obtain information form the same. It is also used for transfer of information from one place to another and also involves conversion in between analogue and digital signals.
It finds its application in various areas ranging from broadcasting to medicine.
Let us have a [...]

I am not going to analyse what DSP processors are different from regular microcontrollers as there are many differences that allow to boost performance in many specific tasks like filtering, FFT, etc. One thing is obvious that DSP processors have to perform mathematical calculations rapidly enough to get predictive results. Better result we want – [...]

One of frequently used signal characteristics are energy and power. In signal theory these therms require additional comments because they are a bit different from these what we are used to use in AC or DC systems.
What is power and energy? If wee connect R resistor to voltage U, then resistor will dissipate some power [...]

Sampling is a process when continuous time signal is represented by series of discrete samples while reconstruction is reverse process when these samples re recreating adequate continuous time signal. Bellow the overall process is illustrated.

Sampling is a process when continuous time signal is recorded every T seconds by multiplying by an impulse train.

If signal is [...]

In previous post we discussed about impulse response. Impulse response h(n) is digital system response in time domain. But there is another characterization of discrete system - frequency response H(ejω).
Frequency response can be calculated form impulse response by formula:

This means frequency response is systems transfer coefficient to every frequency value. Frequency response is a complex [...]

Back to DSP thread. Lets talk about digital system equation. Every digital system can be described using this equation.
The output of digital filter generally consist of previous inputs and previous outputs.

y(n-k) is considered as previous outputs;
x(n-p) – previous inputs;
ak and b­p – coefficients;
This equation is convenient to define discrete system and extract various characteristics. Number [...]

Discrete systems in series
Let as say that we have two discrete systems and their impulse responses are h1(n) and h2(n). Then when these discrete systems are connected in series, then overall impulse response:

Where:

As you noticed there were changing made:

This is nothing more than convolution of impulse responses of both discrete systems:

Discrete systems in parallel
If we [...]

Discrete system is nothing more than algorithm, where input is transformed to output. The output is transformed by operator L() which describes discrete system.
Lets see few most common operators of discrete systems.
Delay
This means that output queue is delayed by on sample.

Multiplication
This operator takes each sample of input queue and multiplies by constant a.

Sum operator
Takes two [...]