Radio channel emulators or radio channel simulators (also called fading simulators) are tools for
air interface
The air interface, or access mode, is the communication link between the two stations in mobile or wireless communication. The air interface involves both the physical and data link layers (layer 1 and 2) of the OSI model for a connection.
Physi ...
testing in
wireless communication
Wireless communication (or just wireless, when the context allows) is the transfer of information between two or more points without the use of an electrical conductor, optical fiber or other continuous guided medium for the transfer. The mos ...
. In a test environment,
radio
Radio is the technology of signaling and communicating using radio waves. Radio waves are electromagnetic waves of frequency between 30 hertz (Hz) and 300 gigahertz (GHz). They are generated by an electronic device called a transm ...
channel emulators replace the real-world radio channel between a radio
transmitter
In electronics and telecommunications, a radio transmitter or just transmitter is an electronic device which produces radio waves with an antenna. The transmitter itself generates a radio frequency alternating current, which is applied to ...
and a
receiver by providing a faded representation of a transmitted signal to the receiver inputs. As technology moves forward to take advantage of more complex channel characteristics such as
MIMO
In radio, multiple-input and multiple-output, or MIMO (), is a method for multiplying the capacity of a radio link using multiple transmission and receiving antennas to exploit multipath propagation. MIMO has become an essential element of w ...
, the
channel model
A communication channel refers either to a physical transmission medium such as a wire, or to a logical connection over a multiplexed medium such as a radio channel in telecommunications and computer networking. A channel is used for info ...
ing needed to accurately emulate the
radio
Radio is the technology of signaling and communicating using radio waves. Radio waves are electromagnetic waves of frequency between 30 hertz (Hz) and 300 gigahertz (GHz). They are generated by an electronic device called a transm ...
environment becomes even more critical to a test setup. Radio channel emulators enable creation of mathematical models representing the physical radio signal transmission medium.
[Pätzold, M. 2002. Mobile Fading Channels: Modelling, Analysis & Simulation.]
Typical use cases
MIMO Testing
The complex nature of a
MIMO
In radio, multiple-input and multiple-output, or MIMO (), is a method for multiplying the capacity of a radio link using multiple transmission and receiving antennas to exploit multipath propagation. MIMO has become an essential element of w ...
system creates unique measurement challenges in order to provide a test environment that fully simulates a real-world wireless channel. The radio channel emulator must have
channel model
A communication channel refers either to a physical transmission medium such as a wire, or to a logical connection over a multiplexed medium such as a radio channel in telecommunications and computer networking. A channel is used for info ...
s that accurately simulate multiple
antenna performance, including correlation between
antenna elements.
See also
*
Fading
In wireless communications, fading is variation of the attenuation of a signal with various variables. These variables include time, geographical position, and radio frequency. Fading is often modeled as a random process. A fading channel is ...
*
Channel model
A communication channel refers either to a physical transmission medium such as a wire, or to a logical connection over a multiplexed medium such as a radio channel in telecommunications and computer networking. A channel is used for info ...
References
Radio electronics
{{radio-comm-stub