Method and system for switching and detecting PN codes for fast acquisition of burst signal
First Claim
Patent Images
1. A method for effecting PN code sequence changes, the method comprising:
- determining an interceptor threat level;
determining a first transmitter PN code sequence associated with said interceptor threat level, wherein determining the first transmitter PN code sequence associated with said interceptor threat level further comprises;
changing the first transmitter PN code sequence to a second transmitter PN code sequence;
encoding a second transmitter PN signal with the second transmitter PN code sequence;
transmitting the second transmitter PN encoded signal, wherein transmitting the second transmitter PN encoded signal further comprises transmitting the second transmitter PN encoded signal during a second time frame;
encoding a first transmitter PN signal with the first transmitter PN code sequence;
transmitting the first transmitter PN encoded signal, wherein transmitting the first transmitter PN encoded signal further comprises transmitting the first transmitter PN encoded signal during a first transmitter time frame;
receiving the first transmitter PN encoded signal, wherein receiving the first transmitter PN encoded signal further comprises receiving the first transmitter PN encoded signal during a first receiver time frame; and
PN decoding the first transmitter PN encoded signal.
1 Assignment
0 Petitions
Accused Products
Abstract
A method and system is disclosed for generating and detecting variable sequence PN codes. PN-Code sequence changes based on varying interceptor threat levels are generated at a rate fast enough to avoid exploitation while maintaining a reasonable correlation search window. The PN code sequence is phase shifted by N-chips based on the severity of the threat environment. A synchronized receiver demodulates the PN encoded signal by correlating over every possible phase of the PN code sequence. The receiver includes first and second correlators and threshold detectors adapted to detect PN signals with varying PN code sequence changes.
40 Citations
16 Claims
-
1. A method for effecting PN code sequence changes, the method comprising:
-
determining an interceptor threat level; determining a first transmitter PN code sequence associated with said interceptor threat level, wherein determining the first transmitter PN code sequence associated with said interceptor threat level further comprises; changing the first transmitter PN code sequence to a second transmitter PN code sequence; encoding a second transmitter PN signal with the second transmitter PN code sequence; transmitting the second transmitter PN encoded signal, wherein transmitting the second transmitter PN encoded signal further comprises transmitting the second transmitter PN encoded signal during a second time frame; encoding a first transmitter PN signal with the first transmitter PN code sequence; transmitting the first transmitter PN encoded signal, wherein transmitting the first transmitter PN encoded signal further comprises transmitting the first transmitter PN encoded signal during a first transmitter time frame; receiving the first transmitter PN encoded signal, wherein receiving the first transmitter PN encoded signal further comprises receiving the first transmitter PN encoded signal during a first receiver time frame; and PN decoding the first transmitter PN encoded signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
-
-
10. A communications system, the communications system comprising:
-
a transmitter, wherein the transmitter comprises; a transmitter controller adapted to determine an interceptor threat level; a first transmitter PN generator adapted to generate a first transmitter PN code sequence associated with said interceptor threat level; a transmitter modulator adapted to encode a first transmitter PN signal with the first transmitter PN code sequence; a transmitter antenna adapted to transmit the first transmitter PN encoded signal, wherein the transmitter antenna adapted to transmit the first transmitter PN encoded signal further comprises; the transmitter antenna adapted to transmit the first transmitter PN encoded signal during a first transmitter time frame; a receiver, the receiver comprising; a receiver antenna adapted to receive the first transmitter PN encoded signal during a first receiver time frame; a receiver demodulator adapted to PN decode the first transmitter PN encoded signal; and a second transmitter PN generator for generating a second transmitter PN code. - View Dependent Claims (11, 12)
-
-
13. A program storage device readable by a machine, tangibly embodying a program of instructions executable by the machine to perform a for effecting PN code sequence changes, the instructions comprising:
-
determining an interceptor threat level; determining a first transmitter PN code sequence associated with said interceptor threat level, wherein instructions determining the first transmitter PN code sequence associated with said interceptor threat level further comprises; changing the first transmitter PN code sequence to a second transmitter PN code sequence; encoding a second transmitter PN signal with the second transmitter PN code sequence; transmitting the second transmitter PN encoded signal, wherein transmitting the second transmitter PN encoded signal further comprises transmitting the second transmitter PN encoded signal during a second time frame; encoding a first transmitter PN signal with the first transmitter PN code sequence; and transmitting the first transmitter PN encoded signal, wherein transmitting the first transmitter PN encoded signal further comprises transmitting the first transmitter PN encoded signal during a first transmitter time frame. - View Dependent Claims (14, 15, 16)
-
Specification