Spread spectrum intercept apparatus and method

• US 5,103,460 A
• Filed: 09/12/1990
• Issued: 04/07/1992
• Est. Priority Date: 10/17/1989
• Status: Expired due to Fees

• Current Assignee: Clarence H. Stewart, Juanita H. Stewart
• Original Assignee: Clarence H. Stewart, Juanita H. Stewart
• Inventors: Stewart, Clarence H.
• Primary Examiner(s): Gregory, Bernarr E.
• Application Number:
  US07/581,337
• Time in Patent Office: 573 Days
• Field of Search: 375/1, 380/34
• US Class Current: 375/131
• CPC Class Codes: H04B 1/713 using frequency hopping

Abstract

An apparatus for detecting an intercept signal having spread spectrum modulation, having a first antenna, a second antenna, a first channelizer, a second channelizer, parametric encoders, a spread hopper processor and a nonspread hopper processor. The first antenna outputs a first sample of the intercept signal. The second antenna outputs a second sample of the intercept signal. The first channelizer channelizes the spectrum of the first sample of the intercept signal into a first plurality of spectrum segments, with each spectrum segment having a corresponding segment signal, respectively. The second channelizer channelizes the spectrum of the second sample of the intercept signal into a second plurality of spectrum segments having the same center frequencies and bandwidths as the first plurality of spectrum segments. Each spectrum segment of the second plurality of spectrum segments has a corresponding segment signal, respectively. The parametric encoders measure a corresponding plurality of frequencies and times of arrival of each of the first plurality of segment signals, respectively, and estimates a plurality of segment phase angles between corresponding segment signals having the same center frequency, of the first and second plurality of segment signals from the first and second channelizers, respectively.

Claims

1. An apparatus for detecting an intercepted signal having spread spectrum modulation, comprising:

a first antenna for receiving a first sample signal of the intercepted signal;

a second antenna for receiving a second sample signal of the intercepted signal;

first means coupled to said first antenna for channelizing the spectrum of the first sample signal of the intercepted signal into a first plurality of spectrum segments, with each spectrum segment having a corresponding segment signal, respectively;

second means coupled to said second antenna for channelizing the spectrum of the second sample signal of the intercepted signal into a second plurality of spectrum segments having the same center frequencies and bandwidths as the first plurality of spectrum segments, with each spectrum segment of the second plurality of spectrum segments having a corresponding segment signal, respectively;

means coupled to said first channelizing means and said second channelizing means for measuring a corresponding plurality of frequencies and times of arrival of each of the first plurality of segment signals, respectively, and for generating a plurality of correlation function phase signals which represent the phase angles between corresponding segment signals having the same center frequency, of the first and second plurality of segment signals from said first channelizing means and said second channelizing means, respectively; and

means coupled to said measuring and estimating means for generating from the plurality of frequencies, times of arrival and phase angles, a frequency estimate, a time of arrival estimate and a phase estimate of an angle of arrival, respectively, of the intercepted signal.

2. An apparatus for detecting an intercepted signal having spread spectrum modulation, comprising:

a first antenna for receiving the intercepted signal;

a second antenna for receiving the intercepted signal;

first means coupled to said first antenna for channelizing the spectrum of the intercepted signal into a first plurality of spectrum segments, with each spectrum segment having a corresponding segment signal, respectively;

second means coupled to said second antenna for channelizing the spectrum of the intercept signal into a second plurality of spectrum segments having the same center frequencies and bandwidths as the first plurality of spectrum segments, with each spectrum segment of the second plurality of spectrum segments having a corresponding segment signal, respectively;

a correlation function phase detector coupled to said first and second channelizing means and responsive to segments signals from corresponding cells of the first and second plurality of spectrum segments, for generation a correlation function phase signal.

3. The apparatus for detecting an intercepted signal having spread spectrum modulation as set forth in claim 2 further comprising:

means for measuring a corresponding plurality of frequencies of each of the first plurality of segment signals; and

means coupled to said measuring means for generating from the plurality of frequencies a frequency estimate of the intercepted signal.

4. The apparatus for detecting an intercepted signal having spread spectrum modulation as set forth in claim 2 further comprising:

means for measuring a corresponding plurality of times of arrival of each of the first plurality of segment signals; and

means coupled to said measuring means for generating from the plurality of times of arrival, a time of arrival estimate of the intercepted signal.

5. An apparatus for detecting an intercepted signal having spread spectrum modulation, comprising:

a first antenna for receiving a first sample signal of the intercepted signal;

a second antenna for receiving a second sample signal of the intercepted signal;

a first channelizer for channelizing the spectrum of the first sample signal of the intercepted signal into a first plurality of spectrum segments, with each spectrum segment having a corresponding segment signal, respectively;

a second channelizer for channelizing the spectrum of the second sample signal of the intercepted signal into a second plurality of spectrum segments having the same center frequencies and bandwidths as the first plurality of spectrum segments, with each spectrum segment of the second plurality of spectrum segments having a corresponding segment signal, respectively;

a parametric encoder for measuring a corresponding plurality of frequencies and times of arrival of each of the first plurality of segment signals, respectively, and for generating a plurality of correlation function phase signals which represent the phase angles between corresponding segment signals having the same center frequency, of the first and second plurality of segment signals from said first channelizing means and said second channelizing means, respectively; and

means coupled to said measuring and estimating means for generating from the plurality of frequencies, times of arrival and phase angles, a frequency estimate, a time of arrival estimate and a phase estimate of an angle of arrival, respectively, of the intercepted signal.

6. An apparatus for detecting an intercepted signal having spread spectrum modulation, comprising:

a first antenna for receiving the intercepted signal;

a second antenna for receiving the intercepted signal;

a first channelizer for channelizing the spectrum of the intercepted signal into a first plurality of spectrum segments, with each spectrum segment having a corresponding segment signal, respectively;

a second channelizer for channelizing the spectrum of the intercepted signal into a second plurality of spectrum segments having the same center frequencies and bandwidths as the first plurality of spectrum segments, with each spectrum segment of the second plurality of spectrum segments having a corresponding segment signal, respectively;

a correlation function phase detector for generating a correlation function phase signal from the first plurality of spectrum segments and the second plurality of spectrum segments.

7. The apparatus for detecting an intercepted signal having spread spectrum modulation as set forth in claim 6 further comprising:

means for measuring a corresponding plurality of frequencies of each of the first plurality of segment signals; and

means coupled to said measuring means for generating from the plurality of frequencies a frequency estimate of the intercepted signal.

8. The apparatus for detecting an intercepted signal having spread spectrum modulation as set forth in claim 6 further comprising:

means for measuring a corresponding plurality of times of arrival of each of the first plurality of segment signals; and

means coupled to said measuring means for generating from the plurality of times of arrival, a time of arrival estimate of the intercepted signal.

9. A method for detecting an intercepted signal having spread spectrum modulation, comprising the steps of:

receiving at a first antenna a first sample signal of the intercepted signal;

receiving at a second antenna a second sample signal of the intercepted signal;

channelizing the spectrum of the first sample signal of the intercepted signal into a first plurality of spectrum segments, with each spectrum segment having a corresponding segment signal, respectively;

channelizing the spectrum of the second sample signal of the intercepted signal into a second plurality of spectrum segments having the same center frequencies and bandwidths as the first plurality of spectrum segments, with each spectrum segment of the second plurality of spectrum segments having a corresponding segment signal, respectively;

measuring a corresponding plurality of frequencies and times of arrival of each of the first plurality of segment signals, respectively;

generating a plurality of correlation function phase signals which represent the phase angles between corresponding segment signals having the same center frequency, of the first and second plurality of segment signals from said first channelizing means and said second channelizing means, respectively; and

generating from the plurality of frequencies, times of arrival and phase angles, a frequency estimate, a time of arrival estimate and a phase estimate of an angle of arrival, respectively, of the intercepted signal.

10. A method detecting an intercepted signal having spread spectrum modulation comprising the steps of:

receiving at a first antenna the intercepted signal;

receiving at a second antenna the intercepted signal;

channelizing the spectrum of the intercepted signal into a first plurality of spectrum segments, with each spectrum segment having a corresponding segment signal, respectively;

channelizing the spectrum of the intercepted signal into a second plurality of spectrum segments having the same center frequencies and bandwidths as the first plurality of spectrum segments, with each spectrum segment of the second plurality of spectrum segments having a corresponding segment signal, respectively;

generating a correlation function phase signal from the first plurality of spectrum segments and the second plurality of spectrum segments.

11. The method for detecting an intercepted signal having spread spectrum modulation as set forth in claim 10 further comprising the steps of:

measuring a corresponding plurality of frequencies of each of the first plurality of segment signals; and

generating from the plurality of frequencies a frequency estimate of the intercepted signal.

12. The method for detecting an intercepted signal having spread spectrum modulation as set forth in claim 10, further comprising the steps of:

measuring a corresponding plurality of times of arrival of each of the first plurality of segment signals; and

generating from the plurality of times of arrival, a time of arrival estimate of the intercepted signal.