Discontinued Product
R&S®ABFS Baseband Fading Simulator
Saving costs through real-world fading tests
The characteristics of a radio channel can strongly impair signal transmission between a transmitter and in particular a moving receiver. The Baseband Fading Simulator
Advantages of baseband fading simulation
Conventional fading simulators normally convert the signal of the radio channel to the IF, perform fading and then reconvert the signal to its RF frequency. It is, however, less costly to loop in the simulator prior to the fi rst conversion to the carrier frequency, i.e. to simulate at baseband level (I and Q) and then convert to the correct frequency in the test system (see Fig. 3). Signals will therefore not be impaired by the effects of multiple conversion. This baseband fading simulation makes upgrading to new networks or standards easy.
Fig 1: Fading simulation in baseband
The flexible concept of the
The
Furthermore, an offset voltage for each I and Q input or output can be entered to compensate for external DC offset voltages.
Together with a baseband source (e.g. the I/Q Modulation Generator
Fig 2: Fading of a baseband signal from R&S® AMIQ with Fading Simulator R&S® ABFS
Fit for the future
The Baseband Fading Simulator
It comprises all scenarios and statistical models for simulating sporadic fading as specified in the test regulations of mobile radio standards (e.g. GSM, 3GPP WCDMA or CDMA2000®).
The
Fig 3: The R&S CMU 200 with option R&S CMU-B17 in combination with the Fading Simulator R&S ABFS for receiver tests under fading conditions