 vices. While an ADC is not a power device, the NF can be 43 is required. At this point the NF is not known but may estimated and should only be considered valid for the set be estimated based on available technology. A good typ- of operating conditions specified. Therefore, if the con- ical NF would be about 3 to 4 dB. This would place the ditions are changed, then the NF will change appropri- conversion gain at 40 dB. Therefore, if the -73 dBm ately. The equation for the equivalent ADC noise figure is: signal is referred back to the antenna, it will be 40 dB smaller or -113 dBm, a very good sensitivity for a chan- NFADC = - Fullscale nel 200 kHz wide. Sample_Rate 10 log - 10 log Digital processing (2.3.10) If it is determined that the conversion gain required to Parts offset the converter noise is large enough that the con- There are two categories of digital parts. Both could be verter is overdriven, this is an indication that a better called DSPs. The traditional DSP is a computational unit converter is required. that consists of program and data memory. A program is executed from the program space operating on data from Channel noise in a receiver I/O ports and data stored in the data memory. This type Once the total receiver noise level has been determined, of DSP is the most common; however, this type of DSP sensitivity of the receiver can be found. If conversion gain is limited in the data throughput. While great advances in is known, then sensitivity with respect to the antenna can parallel computing and core speeds have increased the be found; otherwise, it will be with respect to the ADC rate at which real time data can be processed, general input. In the typical SDR signal chain, a digital tuner or purpose DSPs can only process limited amounts of data. channelizer will follow the ADC. In this block, the desired signal is tuned and all other signals in the Nyquist band are filtered from the spectrum. Typically the data rate is also Fixed function DSP reduced to a speed that is suitable to the data rate