Abstract: A test system includes: a signal processor configured to generate a plurality of orthogonal baseband sequences; a signal generator configured to supply the plurality of orthogonal baseband sequences to a corresponding plurality of RF transmitters of a device under test (DUT), wherein the RF transmitters each employ the corresponding orthogonal baseband sequence to generate a corresponding RF signal on a corresponding channel among a plurality of channels of the DUT such that the RF transmitters output a plurality of orthogonal RF signals at a same time; a combiner network configured to combine the plurality of orthogonal RF signals and to output a single signal under test; and a single channel measurement instrument configured to receive the single signal under test and to measure independently therefrom at least one characteristic of each of the RF transmitters. Orthogonal RF test signals may be used similarly to test RF receivers of the DUT.