Emulation and controlled testing of mimo ota channels
AssigneeSpirent Communications, Inc.
InventorJohn Douglas Reed
Life of this patent
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Abstract
The present invention relates to techniques for OTA testing suitable for producing a test signal to emulate a wireless channel while using a limited number of transmit elements. The techniques described herein enable the number of transmit antennas used to emulate a given signal path in an emulated wireless channel to be less than the number of sub-paths used to characterize the angle spread of the given signal path. As a result, a test setup is provided having a relatively small number of transmit antennas which also accurately maintaining the desirable characteristics of the emulated wireless channel.
Claims30
A system for emulating a wireless channel between a transmitter and a receiver, the wireless channel comprising one or more signal paths having respective amplitudes, angles of arrival and angle spreads, the angle spread of a given signal path in the wireless channel represented as a plurality of N sub-paths, the system comprising:
- a set of two or more receive antennas, the set having an effective, non-singular spatial correlation for the given signal path in the wireless channel;
- a plurality of transmit antennas for transmitting transmit signals to the set of receive antennas to emulate the given signal path in the wireless channel, the plurality of transmit antennas being less than N, and wherein the transmit antennas in the plurality are arranged at angular locations relative to the set of receive antennas in dependence upon said effective spatial correlation;
- and
- circuitry coupled to the plurality of transmit antennas to generate the transmit signals and provide the transmit signals to corresponding transmit antennas, wherein the transmit signals provided to the transmit antennas have a signal power in dependence upon said effective spatial correlation.
A method for emulating a wireless channel between a transmitter and a receiver, the wireless channel comprising one or more signal paths having respective amplitudes, angles of arrival and angle spreads, the angle spread of a given signal path in the wireless channel represented as a plurality of N sub-paths, the method comprising:
- determining an effective, non-singular spatial correlation of the given signal path for a set of two or more receive antennas;
- computing angular locations for a plurality of transmit antennas relative to the set of two or more receive antennas in dependence upon said effective spatial correlation, the transmit antennas for transmitting transmit signals to the set of receive antennas to emulate the given path in the wireless channel, the plurality of transmit antennas being less than N;
- and
- generating the transmit signals and providing the transmit signals to corresponding transmit antennas, wherein the transmit signals have a signal power in dependence upon said effective spatial correlation.
Dependencies are inferred from the claim text.