▶ C'mon over to realpars.com where you can learn PLC programming faster and easier than you ever thought possible!
=============================
▶ Check out the full blog post over at
realpars.com/w...
=============================
In this video, we will continue with where we left off discussing wave modulation in Part 1, “How does Wireless Radio Communication work?”, where we also discussed electromagnetism and how radio waves are transmitted and received. (realpars.com/w...)
In this video, we will discuss radio modulation, what is pathloss and how to decrease it, line of sight propagation, path profiles, and path profile engineering.
Modulation is a technique of converting and mixing data into radio waves by adding this information to a carrier or base signal.
This is accomplished by a modulator in which, mixes the data signal with a carrier signal. A carrier wave is a wave of constant frequency, like a sine wave.
The now modulated and amplified signal which emanates from the antenna propagates through the air towards the receiving station antenna where the modulated signal is demodulated, separating the data from the carrier signal.
So, in other words, modulation alters the shape of a carrier wave to encode the speech or sound and data information we want to be transported by hopping on a normal signal wave.
A wave can be identified by its frequency, measured in oscillation per second, its wavelength measured in units of lengths, and its amplitude or power measured in “dB” or “m”.
This means the wavelength is inversely proportional to frequency, in that, the longer the wavelength, will result in a lower frequency. Or, the shorter the wavelength, will result in a higher frequency.
There are essentially three basic types of modulation.
The difference between these modulation methods is how the carrier wave is modulated, hence altered.
Amplitude (or AM) modulation is where the amplitude of the carrier signal is modulated or changed in proportion to the data signal.
And with Frequency (or FM) modulation, the frequency, or the number of times per second the wave changes direction determines how the carrier signal is modulated or altered.
Ok, now let’s discuss how far a radio wave will travel or propagate, and what are the elements interfering, or attenuates, the signal, with a brief introduction to pathloss.
The transmitter radiates a signal having a specific power based on the size and type of an antenna. The signal as it travels begins to weaken or attenuate based on the environment and landscape the signal travels. The phenomenon known for how the electromagnetic wave weakens is known as pathloss.
The receiver only captures a certain portion of the signal based on the power used at transmission and depending on the different obstructive factors, such as distance or free space, obstacles such as buildings and mountains for example.
As electromagnetic waves propagate and travel further and further away, the initial power at which the transmitted signals spreads out over a large area. In the beginning, the entire transmitted power is confined to a small spherical area or bubble.
To illustrate the degradation of the signal, if the receiver is close to the transmitter it will capture more power and if the receiver is further away from the transmitter the receiving antenna can only capture a smaller fraction of the transmitted power.
There are several parameters involved with attenuation, they are distance, wavelength, and the transmit power.
Pathloss (or L) depends on distance and wavelength.
Power loss is the weakening of the signal no matter how much power is transmitted.
How can we overcome path loss? One way is to use an RF Line-of-Sight tool.
Check out this free online tool from SCADACORE at:
(bit.ly/Line-of...)
The RF Line-of-Sight tool is very helpful in mapping long-distance radio communications for remote SCADA monitoring remote sites and data acquisition applications.
The online tool considers antenna height and the topographical patterns of the earth to calculate the line-of-sight of a radio path.
=============================
Missed our most recent videos? Watch them here:
realpars.com/c...
realpars.com/f...
realpars.com/w...
=============================
To stay up to date with our last videos and more lessons, make sure to subscribe to this KZitem channel:
goo.gl/Y6DRiN
=============================
TWEET THIS VIDEO ctt.ac/DdeIf
=============================
Follow us on Facebook: / therealpars
Follow us on Twitter: / realpars
Follow us on LinkedIn / realpars
Follow us on Instagram / realparsdotcom
#RealPars #PLC #modulation
Негізгі бет How Can We Improve Wireless Radio Modulation?
Пікірлер: 18