Vector signal generator channel characterization employing orthogonal modulation

A vector signal generator performance characterization system comprising:

• a vector signal generator (VSG) configured to produce a first signal in a first VSG channel and a second signal in a second VSG channel, the first signal comprising a first set of subcarriers of an orthogonal frequency-division multiplexing (OFDM) digital modulation, the second signal comprising a second set of subcarriers of the OFDM digital modulation;
• a power combiner connected to outputs of the first and second VSG channels to receive and combine the first and second signals into a combined signal;
• and
• a digital receiver connected to an output of the power combiner, the digital receiver being configured to receive and demodulate the combined signal to facilitate characterization of a relative performance of the first and second VSG channels,
• wherein the first set of subcarriers excludes a subcarrier of the second set of subcarriers and the second set of subcarriers excludes a subcarrier of the first set of subcarriers, and
• wherein a selected pair of subcarriers of the first subcarrier set is configured by the VSG to be frequency adjacent to one another without an intervening subcarrier of the second subcarrier set and another selected pair of subcarriers of the second subcarrier set is configured by the VSG to be frequency adjacent to one another without an intervening subcarrier of the first subcarrier set to facilitate unwrapping phase within the digital receiver.

A non-transitory computer readable medium encoded with instructions that, when executed by a processor, implement multichannel signal generator performance characterization comprising:

• generating a first signal in a first channel of a multichannel signal generator, the first signal comprising a first set of subcarriers of an orthogonal frequency-division multiplexing (OFDM) digital modulation;
• generating a second signal in a second channel of the multichannel signal generator, the second signal comprising a second set of subcarriers of the OFDM digital modulation;
• receiving and demodulating a combined signal according to the OFDM digital modulation using a digital receiver, the combined signal comprising the first and second signals;
• and
• determining a performance parameter of the second channel relative to the first channel using the received and demodulated combined signal,
• wherein the first set of subcarriers excludes a subcarrier of the second set of subcarriers and the second set of subcarriers excludes a subcarrier of the first set of subcarriers, and
• wherein during generating the first and second signals, a selected pair of the subcarriers of the first subcarrier set is configured to be frequency adjacent to one another without an intervening subcarrier of the second subcarrier set to facilitate unwrapping phase within the digital receiver.