duces an NSD of -169.87 dBm/Hz. Integrating indicating that the noise due to the intermodulation this over 1.25 MHz will provide the total energy that may product can equal the thermal noise. be contained in the spurious signal without adversely Integrating the noise of 3.84 MHz gives a total in- effecting performance of the receiver. The total power in termodulation noise of -108.1 dBm. Again allowing for 1.25 MHz is -108.9 dBm/Hz. This is the spurious level the noise figure of the Rx chain of 4.13 dB allows this reflected to the antenna that will not cause blocking in noise to increase to about -104 dBm. Comparison to the the receiver. Since the receiver is blind as to how the CW tone then gives an input referred IP3 of-20 dBm. spurious signal is generated, this number is valid for Reflecting this to the ADC gives an IP3 of+10 dBm or an single- or two-tone blocking. Therefore, since the two intermodulation performance of -74 dBc. CW tones were at -45 dBm, the input referred to IP3 is Since this receiver may also be used for reception of a found to be -13 dBm or -63.9 dBc. Likewise the narrowband signal, a quick check of narrowband -45 dBm Correlated CDMA Signal 2f1-f2 -117 dBm/ 9600 Hz dBm/Hz dBm/Hz Filtered 2 -178 dBm/Hz Spread 2f1-f2 -117 dBm Signals Figure 2.3-16 CDMA2000 two-tone blocking requirements. Software defined radio CHAPTER 2.3 -48 dBm Correlated CDMA Signal -180.8 dBm/Hz -115 dBm/ -115 dBm 2f1-f2 9600 Hz dBm/Hz dBm/Hz Filtered 2 Doubly Spread 2f1-f2 Signals Figure 2.3-17 UMTS intermodulation performance requirements. performance is a good idea. Total noise referenced to not limited to interoperability, investment retention, and the antenna can be calculated in a 30 kHz band to be great flexibility. As with any software project, quite 125 dBm. If 5 dB of SNR is required, this is reason- often the potential is only limited by the imagination of ably good performance. In terms of intermodulation the designer. The great advantage is that as in any soft- rejection, to achieve unrestricted performance a