octoFade-WiFi is a software based 802.11n/ac channel emulator that operates on an input file with IQ samples and produces an output file of IQ samples. octoFade software runs on Linux and Windows PCs and is controllable via an API (applications programming interface).
With the ability to loop on a single Wi-Fi packet to generate an output waveform of arbitrary length, octoFade can be used to create a library of test waveforms that are subject to multipath and Doppler fading per the standard 802.11n/ac channel models and other impairments including AWGN (average white Gaussian noise), spurious, phase noise, IQ imbalance and frequency shift.
octoFade-WiFi software block diagram
Supported RF Instrumentation
octoFade software comes with a set of pre-generated 802.11n/ac packets in the form of IQ sample files. The provided files include 1, 2, 3 and 4 stream transmissions and also tones.
Use these supplied waveforms or captures from off-the-shelf test equipment, such as a VSA (vector signal analyzer), as inputs to octoFade for creating a library of test waveforms. Output waveforms can have 1 to 4 streams, selected sampling rate and arbitrary length.
Output waveforms are created from input waveforms by applying selected 802.11n/ac channel models and other impairments. Output waveforms and can be ‘played’ using a VSG (vector signal generator) to thoroughly test the DUT receiver under a variety of emulated conditions.
The supported models and impairments are as follows:
|802.11n/ac channel model||Distance to 1st wall (avg)||# taps||Delay spread (rms)||Max delay|
|A||test model||1||0 ns||0 ns|
|B||Residential||5 m||9||15 ns||80 ns|
|C||small office||5 m||14||30 ns||200 ns|
|D||typical office||10 m||18||50 ns||390 ns|
|E||large office||20 m||18||100 ns||730 ns|
(indoor or outdoor)
|30 m||18||150 ns||1050 ns|
National Instruments LabVIEW based User Interface for octoFade-WiFi main screen
octoFade WiFi configuration screens for selecting a channel model (left) and for configuring impairments (right)
octoFade-WiFi screen shots showing waveform plot after channel impairments are applied
National Instruments LabVIEW based OFDM signal analysis – EVM measurement and spectrum