Patent ID: 7890821

Claim:
A communications test system comprising: a test traffic generator circuit adapted to generate a first sequence of discrete digital test signals according to a medium access control protocol; a test traffic analyzer circuit adapted to process a second sequence of discrete digital test signals according to said medium access control protocol; a digital baseband signal generation circuit adapted to convert said first sequence of discrete digital test signals into a first set of digital baseband signals for transmission to a device under test (DUT); a digital baseband signal reception circuit adapted to convert a second set of digital baseband signals received from said DUT into said second sequence of discrete digital test signals; a first digital channel emulator circuit adapted to accept said first set of digital baseband signals, and is further adapted to condition said first set of digital baseband signals in a digital domain prior to analog conversion, a transmit analog converter circuit adapted to accept and convert said first set of digital baseband signals conditioned by said first digital channel emulator circuit to transmitted analog signals, and transmit said transmitted analog signals to said DUT; and a receive analog converter circuit adapted to receive a set of received analog signals from said DUT, convert said set of received analog signals to said second set of digital baseband signals, and pass said second set of digital baseband signals to said digital baseband signal reception circuit; wherein said first digital channel emulator circuit is adapted to introduce effects of transmission channel impairments into said first set of digital baseband signals, and further adapted to be operative without intervening stages of analog-to-digital or digital-to-analog conversion between said first digital channel emulator circuit and said test traffic generator circuit.