Method and system of triggering signal analysis combining time and frequency domain trigger criteria

1. A signal analyzer, comprising:

a first tuner configured to tune to a first frequency band and to output first tuner data;

a memory device configured to store the first tuner data;

a spectrum calculator configured to calculate a series of spectra for the first tuner data;

a processor configured to determine when a transmission of interest is present within the first tuner data based on the series of spectra;

a second tuner configured to receive the first tuner data stored in the memory device and to tune to a second frequency band including the transmission of interest, wherein the second tuner outputs second tuner data in response to the first tuner data; and

a transmission start time detector configured to receive the second tuner data and to determine a start time for the transmission of interest from the second tuner data, wherein the transmission start time detector comprises a magnitude trigger configured to receive the second tuner data and to compare the second tuner data to one or more trigger criteria.

2. The signal analyzer of claim 1 , wherein in response to a comparison of the second tuner data with the one or more trigger criteria, the transmission start time detector is configured to output a trigger signal to the processor indicating the start time for the transmission of interest.

3. The signal analyzer of claim 2 , wherein the processor is configured to respond to the trigger signal to cause the memory device to replay to the second tuner a portion of the first tuner data stored in the memory device beginning at a selected memory location corresponding to the start time for the transmission of interest, and to receive a portion of the second tuner data corresponding to the transmission of interest.

4. The signal analyzer of claim 3 , wherein the processor is further configured to perform a signal analysis on the portion of the second tuner data corresponding to the transmission of interest.

5. The signal analyzer of claim 1 , wherein the transmission start time detector comprises the processor.

6. The signal analyzer of claim 1 , further comprising a data processor configured to overlap the first tuner data and to provide the overlapped first tuner data to the spectrum calculator.

7. The signal analyzer of claim 1 , further comprising a spectral data combiner configured to perform at least one of an averaging operation, a peak hold operation, and a combining operation on the series of spectra.

8. The signal analyzer of claim 1 , wherein the processor comprises a general purpose digital microprocessor executing a software algorithm.

9. The signal analyzer of claim 1 , wherein the processor comprises one of a programmable gate array and an application specific integrated circuit.

10. A method, comprising:

tuning a first tuner to a first frequency band and outputting first tuner data from the first tuner;

storing the first tuner data in a memory device;

calculating a series of spectra for the first tuner data;

determining when a transmission of interest is present within the first tuner data based on the series of spectra;

tuning a second tuner to a second frequency band including a frequency of the transmission of interest;

providing the first tuner data from the memory device to the second tuner, and in response thereto outputting second tuner data;

determining a start time for the transmission of interest from the second tuner data;

overlapping the first tuner data to provide overlapped first tuner data; and

calculating the series of spectra from the overlapped first tuner data.

11. The method of claim 10 , further comprising performing at least one of an averaging operation, a peak hold operation, and a combining operation on the series of spectra.

12. The method of claim 10 , wherein determining a start time for the transmission of interest from the second tuner data comprises comparing the second tuner data to one or more trigger criteria.

13. The method of claim 12 , further comprising in response to comparing the second tuner data to the one or more trigger criteria, outputting a trigger signal indicating the start time for the transmission of interest.

14. The method of claim 10 , further comprising generating a trigger signal indicating the start time for the transmission of interest.

15. The method of claim 14 , further comprising, in response to the trigger signal, causing the memory device to provide to the second tuner a portion of the first tuner data stored in the memory device beginning at a selected memory location corresponding to the start time for the transmission of interest, and to output from the second tuner a portion of the second tuner data corresponding to the transmission of interest.

16. The method of claim 15 , further comprising performing a signal analysis on the portion of the second tuner data corresponding to the transmission of interest.

17. The method of claim 14 , further comprising in response to the trigger signal, causing the memory device to provide to the second tuner a portion of the first tuner data stored in the memory device beginning at a selected memory location corresponding to a selected delay after the start time for the transmission of interest, and to output from the second tuner a portion of the second tuner data corresponding to the transmission of interest.

18. The method of claim 17 , further comprising performing a signal analysis on the portion of the second tuner data corresponding to the transmission of interest.