2.1. Estimation of the power of the noise
The estimation of the power of the noise is the first analog measure that should be carried out by the SDR signal analyser (see 3. Moving from simulation to acquisition of real signals). To do so, the USRP has to be configured. On the analog thumb index of the user interface, this can be done selecting the tab “USRP Configuration” and the tab “Power Spectrum Noise” before running the program.
The power of the noise will be estimated by the noise floor of the system. From Figure 17, one can note that the noise floor is reached around 700 MHz. As a consequence, the following parameters of the USRP have been set:
Table 2: Configuration of the USRP to measure the power of the noise
After having run the program, the power of the noise is estimated at around 10 pW. This measurement will allow the approximation of the signal-to-noise ratio in the next section.
Figure 20: Screenshot of the user interface used to measure the power of the noise