Multipath Testing

Recreate real-world multipath effects

A challenge for many test labs is to emulate multipath effects of signals in a Wi-Fi environment.

This test environment accurately models these multipath effects with a power delay path matching the IEEE TG-n channel model. It supports class B (indoor) NLOS and Expand Line of Sight (LOS) models, along with class D (outdoor) Expand Non-Line of Sight (NLoS) operation.

The broadband nature of the multipath emulator enables the tester to run multi-channel system tests and evaluate automated channel allocation models. This would be impossible using a traditional fader test systems, which only supports one channel at a time.

In class B mode, the Testbed produces two clusters, spaced 20 ns from one another, along with a continually decaying pulse train of taps, which are emitted by each cluster. The spacing of the taps is determined by the required system bandwidth, as specified in the TGac channel model. The system can switch between the following system bandwidth settings: <40 MHz, 40-80 Mhz, 80-160 Mhz, and 160 – 320 MHz. This corresponds to tap spacing of 10 ns, 5 ns, 2.5 ns and 1.25 ns respectively.

An on-board phase shifter provides the ability to exercise the DUT under the full range of multipath conditions (both destructive and constructive interference). This RF environment includes Spectrum Control’s digital Lab assistant to help manage test automation for “out of the box” testing of device performance:

• Throughput
• Jitter
• Packet error rate vs range
• Device orientation
• Plus other aspects of device performance

While the RF conductive test setup shown here emulates a Wi-Fi environment, with a wi-fi access points and user devices, this Multipath RF Testbed can adapted for testing any other wireless technologies such as 5G/LTE, Bluetooth, Zigbee etc. as well.