Multicode Transmitter Signal Splitting Orthogonal Coding
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Solution Overview
Problem
Conventional radar and communication systems are vulnerable to detection and jamming by spoofers, and signals with low detectable transmit power are not effective in reducing this vulnerability without impacting receiver performance.
Innovation Solution
A multicode transmitter system that splits a signal into low power portions, codes them with orthogonal waveforms, and transmits these coded signals, allowing a correlated receiver to decode and combine them for enhanced power density while appearing as low power to uncorrelated receivers or targets, thereby reducing detectability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a conventional transmitter transmits signals with high power, then the receiver performance is maintained, but the detectable transmit power is high making the system vulnerable to spoofers
Solution Approach 1:
The transmitter divides the high-power signal into N separate low-power signal portions, each transmitted through a different antenna element. Each portion is coded with a unique orthogonal code sequence. This segmentation reduces the detectable power at each antenna element while maintaining the total transmitted power, making the system less detectable to spoofers without compromising receiver performance.
Solution Approach 2:
Each antenna element transmits a signal with locally optimized properties (low power with specific orthogonal code), while the overall system maintains high effective power through coherent combining at the receiver. The local quality of each transmitted portion is low power, but the global quality remains high due to the constructive interference of all N portions at the intended receiver.
2Object-affected harmful factors
If the signal is split into multiple low power portions and coded with orthogonal waveforms, then the detectable transmit power is reduced, but the device complexity increases
Solution Approach 1:
The transmitter is divided into N independent coding modules, each responsible for coding one signal portion with a unique orthogonal code. This modular segmentation allows the complexity to be distributed across N simple, identical units rather than one complex unit, making the system more manageable and scalable.
Solution Approach 2:
The system changes the parameter of the transmitted signal by applying different orthogonal code sequences to each signal portion. This parameter change (coding) allows the signal to be recognized and coherently combined at the receiver, enabling the system to achieve low detectable power without sacrificing receiver performance or requiring overly complex processing.
3Object-affected harmful factors
If orthogonal coding is applied to reduce detectable power, then spoofers cannot easily detect and jam the signals, but the difficulty of detecting and measuring the signal increases
Solution Approach 1:
The transmitter pre-applies orthogonal codes to each signal portion before transmission. This preliminary coding action ensures that only the intended receiver, which possesses the matching decoding keys, can successfully detect and combine the signals. Spoofers without the correct codes cannot detect or jam the signals effectively, as the orthogonal coding masks the signal structure from unauthorized detection.
Solution Approach 2:
The orthogonal codes act as an intermediary layer between the transmitted signal and the receiver. This intermediary encoding transforms the signal into a form that is difficult for spoofers to detect or intercept, while still allowing the authorized receiver to easily detect and process the signal through correlation with the known code sequences.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The system maintains receiver performance while significantly reducing detectable transmit power, making it less detectable to spoofers and minimizing Radio Frequency Interference (RFI), with power density enhanced by a factor of N for correlated receivers.
Implementation Method 1
the complete received signal has a power density N times higher when utilizing the correlator, than when not using the correlator
Implementation Method 2
correlating, with a correlator, the decoded signal to produce a complete received signal
Implementation Method 3
splitting, with a splitter, a signal into at least two low power portions
Implementation Method 4
the coding comprises convolving each low power portion of the signal with a respective different code
Implementation Method 5
the different codes are orthogonal waveforms
Implementation Method 6
summing, with a summer, at least two coded low power portions of the signal to produce a resultant coded signal
Implementation Method 7
transmitting, with a transmitter antenna element, the resultant coded signal towards a target object
Implementation Method 8
receiving, with a receiver antenna element, a reflected resultant coded signal, where the resultant coded signal reflects off the target object
Implementation Method 9
the decoding comprises convolving the reflected resultant coded signal with a complex conjugate of a sum of the different codes
Data Source
AI summary
Systems, methods, and apparatus for transmitting and receiving signals are disclosed. In one or more embodiments, the disclosed method involves splitting a signal into low power portions. The method further involves coding the low power portions to produce coded low power portions, where the coding comprises convolving each low power portion with a respective different code. Also, the method involves summing the coded low power portions to produce a resultant coded signal. In addition, the method involves transmitting the resultant coded signal towards a target object. Additionally, the method involves receiving a reflected resultant coded signal, where the resultant coded signal reflects off the target object to produce the reflected resultant coded signal. Also, the method involves decoding the reflected resultant coded signal to produce a decoded signal. Further, the method involves correlating the decoded signal to produce a complete received signal.