Raw electromagnetic waves are uniform and carry no inherent information. To transmit data, a transmitter must modify the characteristics of a continuous wave—known as the —in a process called modulation . The reverse process at the destination is called demodulation .
Digital Modulation (Binary Data: 1 0 1) Data: [ 1 ] [ 0 ] [ 1 ] ASK (Amplitude): ||||||||| ||||||||| FSK (Frequency): ||||||||| | | | | ||||||||| PSK (Phase Shift): ~~~~~~\_____~~~~~~\_____~~~~~~
An RF transmitter takes the baseband signal, mixes it with a local oscillator to raise it to the desired broadcast frequency, and feeds it into a Power Amplifier (PA) to give the signal enough strength to travel.
: It is highly rated by electrical engineers looking to fill knowledge gaps, as well as programmers and researchers who want a practical, refreshing introduction to signal processing. Key Technical Concepts Covered
At its absolute absolute foundation, wireless communication is about moving information without physical cables. To do this, engineers harness . The Electromagnetic Spectrum
To see how these concepts function at scale, look at how cellular generations have evolved over the decades:
Wireless channels are unpredictable and harsh. As an EM wave travels through space, it falls prey to physical phenomena that degrade its integrity. Wireless systems use sophisticated engineering techniques to overcome these impairments.