Adding error correction and coding to a radar system
View Patent ↗A method for transmitting a radar signal comprises the step of transmitting a series of pulses, each of the pulses being separated in time by an interpulse period, and each of the pulses in the series being modulated in accordance with a different character of a first code
1. A method for transmitting a radar signal comprising the step of:
transmitting a series of pulses, each of the pulses being separated in time by an interpulse period, and each of the pulses in the series being modulated in accordance with a different character of a first code,
wherein each of the series of pulses comprise a plurality of sub-pulses of substantially equal pulse width.
2. The method of claim 1 , wherein the modulation is binary phase modulation.
3. The method of claim 1 , wherein the series of pulses comprise a batch.
4. The method of claim 3 , wherein a length of the first code is equal to a number of pulses in the batch.
5. The method of claim 1 , wherein there is a one-to-one correspondence between a pulse and a character in the first code.
6. The method of claim 1 , wherein in the first code is a pseudo-noise code.
7. The method of claim 1 , wherein the first code is a Walsh code.
8. The method of claim 1 , wherein the first code is a Turbo code.
9. The method of claim 1 , wherein the first code is a Gold code.
10. The method of claim 1 , further comprising the steps of:
receiving electromagnetic energy during a plurality of interpulse periods between the pulses in the series; and
decorrelating the received electromagnetic energy in accordance with the first code.
11. The method of claim 1 , further comprising the step of coding each pulse in the series of pulses by modulating each pulse with a pulse code, the pulse code comprising a plurality of pulse code characters, a portion of each pulse being modulated in accordance with a pulse code character.
12. The method of claim 11 , wherein the step of modulating each pulse with a pulse code is performed using a type of modulation that is a same type of modulation that is used to modulate each pulse in accordance with the first code.
13. The method of claim 12 , wherein the type of modulation is binary phase modulation.
14. A method for operating a plurality of radar transmitters in proximity to each other comprising the steps of:
assigning a code to each of a plurality of radar transmitters, the code assigned to each one of the radar transmitters being different from codes assigned to other radar transmitters in the plurality of transmitters; and
transmitting a series of pulses from each of the transmitters, each of the series of pulses being interpulse modulated in accordance with said code assigned to the transmitter, wherein each of the series of pulses comprise a plurality of sub-pulses of substantially equal pulse width.
15. The method of claim 14 , wherein each of the plurality of transmitters is located on a single vehicle.
16. The method of claim 14 , wherein at least one transmitter is located on a first vehicle and at least one transmitter is located on a second vehicle.
17. The method of claim 14 , wherein the interpulse modulation is binary phase modulation.
18. The method of claim 14 , wherein the each of the series of pulses comprises a batch.
19. The method of claim 18 , wherein a length of the first code is equal to a number of pulses in the batch.
20. The method of claim 14 , wherein there is a one-to-one correspondence between a each pulse and a single character in the first code.
21. The method of claim 14 , wherein in the first code is a pseudo-noise code.
22. The method of claim 14 , wherein the first code is a Walsh code.
23. The method of claim 14 , wherein the first code is a Turbo code.
24. The method of claim 14 , wherein the first code is a Gold code.
25. The method of claim 14 , further comprising the steps of:
receiving electromagnetic energy during a plurality of interpulse periods between the pulses in the series at each of the transmitters; and
decorrelating electromagnetic energy received in the receiving step in accordance with a respective code at each of the transmitters.
26. The method of claim 14 , further comprising the step of coding each pulse in the series with an intrapulse modulation scheme.
27. The method of claim 26 , wherein the intrapulse modulation and the interpulse modulation are performed using a same type of modulation.
28. A radar system comprising:
a transmitter, the transmitter being connectable to an antenna, the transmitter being configured to transmit a series of pulses, the series of pulse being interpulse modulated in accordance with a first code wherein each of the series of pulses comprise a plurality of sub-pulses of substantially equal pulse width; and
a receiver, the receiver being connectable to the antenna, the receiver being configured to receive echoes from the series of pulses from the antenna and to decorrelate the echoes in accordance with the first code.
29. The radar system of claim 28 , wherein the transmitter includes a binary phase modulator for modulating the series of pulses.
30. The radar system of claim 28 , wherein the receiver is configured to batch the echoes received from the series of pulses.
31. The radar system of claim 30 , wherein a length of the first code is equal to a number of pulses batched by the receiver.
32. The radar system of claim 28 , wherein a length of the first code is greater than a number of pulses batched by the receiver.
33. The radar system of claim 28 , wherein in the first code is a pseudo-noise code.
34. The radar system of claim 28 , wherein the first code is a Walsh code.
35. The radar system of claim 28 , wherein the first code is a Turbo code.
36. The radar system of claim 28 , wherein the first code is a Gold code.
37. The radar system of claim 28 , wherein the transmitter is further configured to intrapulse modulate each pulse in accordance with a pulse code.
38. The radar system of claim 36 , wherein the intrapulse modulation is performed using a same type of modulation as the interpulse modulation.
39. The radar system of claim 37 , wherein the type of modulation is binary phase modulation.
40. A radar transmitter comprising:
an oscillator;
a pulse former connected to the oscillator, the pulse former being configured to provide a series of pulses at an output, the pulses being separated in time, wherein each of the series of pulses comprise a plurality of sub-pulses of substantially equal pulse width; and
a modulator connected to the output of the pulse former, the modulator being configured intrapulse modulate the series of pulses in accordance with a first code.
41. The radar transmitter of claim 37 , wherein the modulator is a bi-phase modulator.
42. The radar transmitter of claim 40 , wherein the first code is a Walsh code.
43. The radar transmitter of claim 40 , wherein the first code is a Turbo code.
44. The radar transmitter of claim 40 , wherein the first code is a Gold code.
45. The radar transmitter of claim 40 , wherein the first code is a pseudo-noise code.
46. The radar transmitter of claim 40 , wherein the modulator is further configured to intrapulse modulated each pules of the series in accordance with a pulse code.
47. The radar transmitter of claim 46 , wherein the pulse code is a Barker code.