What is claimed is:
1. A method for transmitting a signal from a transmitting site to a receiving site, comprising:
at the transmitting site:
a. frequency translating the signal to a translated signal;
b. spread spectrum encoding the translated signal into a spread signal;
c. transmitting the spread signal;
and at the receiving site:
d. receiving the spread signal as a received signal;
e. spread spectrum decoding the received signal into an intermediate frequency signal; and
f. frequency translating the intermediate frequency signal to a replica of the signal.
2. The method of claim 1, wherein at the transmitting site, the step of frequency translation comprises single sideband modulation, and at the receiving site, the step of frequency translation comprises single sideband demodulation.
3. The method of claim 2, wherein the step of spread spectrum encoding comprises mixing the translated signal with a pseudo random sequence, and the step of spread spectrum decoding comprises mixing the received signal with a pseudo random sequence.
4. The method of claim 3, comprising the further steps of up converting the spread signal before transmission and down converting the received signal before spread spectrum decoding.
5. A method for transmitting a signal, comprising:
a. frequency translating the signal to a translated signal;
b. spread spectrum encoding the translated signal into a spread signal; and
c. transmitting the spread signal.
6. The method of claim 5, wherein the frequency translation step comprises single sideband modulation.
7. The method of claim 6, wherein the spread spectrum step comprises mixing the translated signal with a pseudo random sequence.
8. The method of claim 7, comprising the further step of up converting the spread signal before transmission.
9. A method for receiving a signal that has been frequency translated and spread spectrum encoded, comprising:
a. receiving the frequency translated and spread spectrum encoded signal as a received signal;
b. spread spectrum decoding the received signal into an intermediate frequency signal; and
c. frequency translating the intermediate frequency signal to a replica of the signal.
10. The method of claim 9, wherein the frequency translation step comprises single sideband demodulation.
11. The method of claim 10, wherein the spread spectrum decoding step comprises mixing the received signal with a pseudo random sequence.
12. The method of claim 11, wherein the signal has been frequency translated after spread spectrum encoding, comprising the additional step of down converting the received signal before spread spectrum decoding.
13. A system for transmitting a signal from a transmitting site to a receiving site, comprising:
a. a transmit frequency translator for translating the signal to a translated signal;
b. a spread spectrum encoder for spreading the spectrum of the translated signal to a spread signal;
c. a transmitter for transmitting the spread signal;
d. a receiver for receiving the spread and transmitted signal as a received signal;
e. a spread spectrum decoder for decoding the received signal into an intermediate frequency signal; and
f. a receive frequency translator for translating the intermediate frequency signal to a replica of the signal.
14. The system of claim 13, wherein the transmit frequency translator comprises a single sideband modulator, and the receive frequency translator comprises a single sideband demodulator.
15. The system of claim 14, wherein the spread spectrum encoder comprises a mixer for mixing the translated signal with a pseudo random sequence, and the spread spectrum decoder comprises a mixer for mixing the received signal with a pseudo random sequence.
16. The system of claim 15, further comprising an up convertor for up converting the spread signal before transmission, and a down converter for down converting the received signal before spread spectrum decoding.
17. A system for transmitting a signal, comprising:
a. a frequency translator for translating the signal to a translated signal;
b. a spread spectrum encoder for encoding the translated signal into a spread signal; and
c. a transmitter for transmitting the spread signal.
18. The system of claim 17, wherein the frequency translator comprises a single sideband modulator.
19. The system of claim 18, wherein the spread spectrum encoder comprises a mixer for mixing the translated signal with a pseudo random sequence.
20. The system of claim 19, further comprising an up convertor for up converting the spread signal before transmission.
21. A system for receiving a signal that has been translated in frequency and spread spectrum encoded, comprising:
a. a receiver for receiving the translated and spread signal as a received signal;
b. a spread spectrum decoder for decoding the received signal into an intermediate frequency signal; and
c. a frequency translator for translating the intermediate frequency signal to a replica of the signal.
22. The system of claim 21, wherein the frequency translator comprises a single sideband demodulator.
23. The system of claim 22, wherein the spread spectrum decoder comprises a mixer for mixing the received signal with a pseudo random sequence.
24. The system of claim 23, wherein the signal has been frequency translated after it has been spread spectrum encoded, and before receiving, additionally comprising a down converter in the receiver, so that the received signal is thereby down converted.
25. An improved method for transmitting a source signal, in a system having a spread spectrum encoder for encoding a spread signal from a signal input, and a transmitter for transmitting the spread signal, wherein the improvement comprises frequency translating the source signal to a translated signal and inputting the translated signal to the spread spectrum encoder.
26. The method of claim 25, wherein the frequency translation step comprises single sideband modulation.
27. An improved method for receiving a signal that has been spread spectrum encoded, in a system for receiving the spread spectrum encoded signal as a received signal, and spread spectrum decoding the received signal into an output signal, wherein the improvement comprises frequency translating the output signal.
28. The method of claim 27, wherein the frequency translation step comprises single sideband demodulation.
29. An improved system for transmitting a source signal, having a spread spectrum encoder for encoding a spread signal from a signal input, and a transmitter for transmitting the spread signal, wherein the improvement comprises a frequency translator for translating the source signal to a translated signal and inputting the translated signal to the spread spectrum encoder.
30. The system of claim 29, wherein the frequency translator comprises a single sideband modulator.
31. An improved system for receiving a signal that has been spread spectrum encoded, having a receiver for receiving the spread spectrum signal as a received signal, and a spread spectrum decoder for decoding the received signal into an output signal, wherein the improvement comprises a frequency translator for translating the output signal.
32. The system of claim 31, wherein the frequency translator comprises a single sideband demodulator.
33. An improved system for modulating a signal exhibiting a bimodal power spectrum with a pseudo random signal to spread the power spectrum of said signal throughout a predetermined bandwidth, the improvement comprising reducing the effect of receiver correlation noise by pre-modulating the signal with a further signal to effect a separation of the bimodal portions of said power spectrum so that said bimodal portions lie outside the region of greatest correlation noise.
34. The system of claim 33, wherein said separation is determined by the frequency of said further signal.
35. The system of claim 34, wherein the frequency of said further signal is selected to separate said bimodal portions of said signal toward the edges of said predetermined bandwidth.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method of modeling random dopant fluctuations (RDF) in a semiconductor device, the method comprising:
defining a first volume in a layer of a semiconductor device;
calculating a probability of finding at least one dopant atom in the first volume, based on a dopant distribution of the layer;
in the case that the calculated probability is equal to or greater than a pre-determined threshold, defining at least one additional volume in the layer substantially equal to the first volume; and
in the case that the calculated probability is less than the pre-determined threshold:
aggregating the first volume with a second volume adjacent the first volume, the second volume being substantially equal to the first volume; and
recalculating a probability of finding at least one dopant atom in the aggregated first and second volumes, based on the dopant distribution of the layer.
2. The method of claim 1, further comprising:
in the case that the recalculated probability is equal to or greater than the pre-determined threshold, defining at least one additional volume in the layer substantially equal to the aggregated first and second volumes.
3. The method of claim 2, further comprising:
determining a revised dopant distribution for the layer based on the recalculated probability using a Poisson distribution; and
applying the revised dopant distribution to each of the first and second volumes.
4. The method of claim 1, further comprising:
in the case that the recalculated probability is less than the pre-determined threshold:
reaggregating an additional volume with the previously aggregated volumes, the additional volume being adjacent to at least one of the volumes making up the previously aggregated volumes; and
further recalculating a probability of finding at least one dopant atom in the aggregated additional volume and the previously aggregated volumes based on the dopant distribution of the layer.
5. The method of claim 4, wherein the additional volume is substantially equal to at least one of the already aggregated volumes.
6. The method of claim 4, further comprising:
in the case that the further recalculated probability is less than the pre-determined threshold:
iteratively looping the reaggregating and further recalculating steps until the further recalculated probability is equal to or greater than the pre-determined threshold; and
defining at least one additional volume in the layer substantially equal to the reaggregated volumes.
7. The method of claim 6, further comprising:
determining a revised dopant distribution for the layer based on the further recalculated probability using a Poisson distribution; and
applying the revised dopant distribution to each volume making up the reaggregated volumes.
8. The method of claim 1, further comprising:
choosing, as the first volume, a node of a finite element mesh applied to the layer.
9. The method of claim 8, wherein the node is expected to have a lowest dopant concentration of the layer, based on the dopant distribution.
10. The method of claim 9, wherein the second volume has a dopant concentration greater than or equal to the dopant concentration of the first volume.
11. The method of claim 6, wherein applying the revised dopant distribution includes recalculating a probability of finding at least one dopant atom in the first volume, based on the revised dopant distribution.
12. A computer program product for modeling random dopant fluctuations (RDF) in a semiconductor device, the computer program product comprising a computer-readable storage medium having program code embodied therewith, the program code being executable by a processor of a computing device to perform a method comprising:
defining a first volume in a layer of a semiconductor device;
calculating a probability of finding at least one dopant atom in the first volume, based on a dopant distribution of the layer;
in the case that the calculated probability is equal to or greater than a pre-determined threshold, defining at least one additional volume in the layer substantially equal to the first volume; and
in the case that the calculated probability is less than the pre-determined threshold:
aggregating the first volume with a second volume adjacent the first volume, the second volume being substantially equal to the first volume; and
recalculating a probability of finding at least one dopant atom in the aggregated first and second volumes, based on the dopant distribution of the layer.
13. The computer program product of claim 12, wherein the method further comprises:
in the case that the recalculated probability is equal to or greater than the pre-determined threshold, defining at least one additional volume in the layer substantially equal to the aggregated first and second volumes.
14. The computer program product of claim 13, wherein the method further comprises:
determining a revised dopant distribution for the layer based on the recalculated probability using a Poisson distribution; and
applying the revised dopant distribution to each of the first and second volumes.
15. The computer program product of claim 12, wherein the method further comprises:
in the case that the recalculated probability is less than the pre-determined threshold:
reaggregating an additional volume with the previously aggregated volumes, the additional volume being adjacent to at least one of the volumes making up the previously aggregated volumes; and
further recalculating a probability of finding at least one dopant atom in the aggregated additional volume and the previously aggregated volumes based on the dopant distribution of the layer.
16. The computer program product of claim 15, wherein the additional volume is substantially equal to at least one of the already aggregated volumes.
17. The computer program product of claim 15, wherein the method further comprises:
in the case that the further recalculated probability is less than the pre-determined threshold:
iteratively looping the reaggregating and further recalculating steps until the further recalculated probability is equal to or greater than the pre-determined threshold; and
defining at least one additional volume in the layer substantially equal to the reaggregated volumes.
18. The computer program product of claim 17, wherein the method further comprises:
determining a revised dopant distribution for the layer based on the further recalculated probability using a Poisson distribution; and
applying the revised dopant distribution to each volume making up the reaggregated volumes.
19. The computer program product of claim 12, wherein the method further comprises:
choosing, as the first volume, a node of a finite element mesh applied to the layer.
20. The computer program product of claim 19, wherein the second volume has a dopant concentration greater than or equal to the dopant concentration of the first volume.