Orthogonal 16-QPSK Modulation via Angular Momentum Modes
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Solution Overview
Problem
Current modulation schemes, such as QPSK, face limitations in increasing data rate beyond two bits per Hz without increasing energy per bit, as they resort to non-orthogonal waveforms which compromise efficiency and error rates.
Innovation Solution
The use of orthogonal angular momentum (OAM) modes allows for independent modulation on multiple propagation modes, enabling two orthogonal QPSK constellations on the same frequency, thereby doubling the data rate while maintaining the same Bit Error Rate (BER) with reduced energy per bit.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If non-orthogonal waveforms are used to increase data rate beyond QPSK, then data rate increases, but Bit Error Rate increases and energy efficiency decreases
Solution Approach 1:
The patent introduces a new orthogonal dimension using Angular Momentum modes (different values of m) to accommodate multiple independent QPSK constellations. Instead of increasing bits per symbol within the same waveform space, the invention expands into additional orthogonal dimensions defined by different angular momentum states, allowing simultaneous transmission of multiple data streams without interference.
Solution Approach 2:
The patent segments the single QPSK constellation into multiple independent QPSK constellations, each modulated on a different orthogonal Angular Momentum mode. This segmentation allows each constellation to maintain its own error performance characteristics while collectively achieving higher data rates through parallel transmission across multiple orthogonal channels.
2Productivity
If non-orthogonal waveforms are used to increase data rate, then data rate increases, but energy per bit increases
Solution Approach 1:
By transitioning to another orthogonal dimension (Angular Momentum space), the system can transmit multiple independent data streams simultaneously without the energy penalties associated with non-orthogonal signaling. Each Angular Momentum mode provides an independent channel that maintains the energy efficiency of conventional QPSK while multiplying the overall data rate.
Solution Approach 2:
The patent makes the communication system multi-functional by enabling simultaneous operation of multiple independent QPSK constellations on different Angular Momentum modes. This universal approach allows the system to achieve higher data rates while maintaining the energy efficiency characteristics of orthogonal signaling, as each mode can be independently optimized.
3Reliability
If traditional orthogonal modulation schemes are used, then Bit Error Rate is maintained, but data rate is limited to two bits per Hz
Solution Approach 1:
The patent resolves this contradiction by exploiting the Angular Momentum dimension as an additional orthogonal degree of freedom. Each Angular Momentum mode (characterized by quantum number m) provides an independent orthogonal channel that can carry a separate QPSK constellation, thereby maintaining the reliability benefits of orthogonal signaling while multiplying the data rate through parallel transmission across multiple m modes.
Solution Approach 2:
The patent segments the single orthogonal channel into multiple independent orthogonal channels based on different Angular Momentum modes. Each segmented channel maintains the low Bit Error Rate characteristics of traditional orthogonal QPSK, while the collective throughput across all segmented channels achieves data rates far exceeding the two bits per Hz limitation of conventional schemes.
Data Source
AI summary
An apparatus, method and article of manufacture comprise a transceiver coupled to a phased array of antenna elements that are configured into pluralities of antenna elements to generate N modes of orthogonal radio waves where N is equal to or greater than 2. The coupling is via a plurality of 16-quadrature phase shift key (16-QPSK) modulators, each which is coupled to a respective one of the pluralities of antenna elements to modulate data onto a respective one of the N modes of orthogonal radio waves, to cause each of the N modes to operate as an independent data channel. For the case of N=2 modes, two 16-QPSK modulators generate independent 16-QPSK constellations, one for the first of the two modes and one for the second of the two modes, such that two 16-QPSK constellations are independent of each other, are orthogonal, and are on the same frequency.