Scalable Sweep Wide-Area Modulation for Low-SINR Signal Recovery
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Solution Overview
Problem
Existing communication systems face challenges in efficiently transmitting information over wide areas with low complexity, power consumption, and robustness against interference, often requiring trade-offs that impact signal quality and global performance.
Innovation Solution
A transmitter employs Constant Amplitude Zero Auto-Correlation (CAZAC) sequences and Symbol Modulated and Extended (SME) signals, combined with OFDM principles, to modulate and extend signals for long-range communication, using operations like time reversal, phase shifts, and frequency shifts, along with adaptive modulation and coding schemes to mitigate interference.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of stationary object
If conventional modulation schemes are used to transmit information over wide areas, then transmission distance is extended, but signal quality deteriorates and complexity increases
Solution Approach 1:
The transmitted signal is divided into multiple blocks, each processed independently with specific operations (time reversal, conjugation, frequency shift) applied to different blocks. This segmentation allows the receiver to combine multiple received blocks to recover the original symbol, improving reliability over long distances without requiring complex continuous modulation schemes
Solution Approach 2:
The patent applies time reversal operation to signal blocks before transmission. By reversing the time domain sequence of signal blocks and combining them at the receiver, the system achieves robust long-range transmission with simplified modulation, resolving the contradiction between transmission distance and signal quality
2Reliability
If complex modulation and demodulation operations are performed to maintain signal quality, then signal quality is maintained, but device complexity and power consumption increase
Solution Approach 1:
The demodulation process applies inverse operations to the transmitted signal blocks. By using time reversal and conjugation operations that are mathematically simple to implement, the receiver can recover signals over long distances without requiring complex demodulation algorithms, thus maintaining signal quality while minimizing device complexity
Solution Approach 2:
The patent transmits multiple copies of the same information symbol through different signal blocks that have undergone various simple transformations. The receiver combines these copies to recover the original symbol, achieving high reliability through redundancy rather than through complex error correction or sophisticated demodulation techniques
3Productivity
If energy is concentrated in narrow bandwidth for efficient transmission, then transmission efficiency improves, but robustness against interference and noise deteriorates
Solution Approach 1:
The patent spreads signal energy across both frequency and time dimensions by applying frequency shifts and time reversal operations to different signal blocks. This dual-dimensional spreading maintains transmission efficiency while providing robustness against interference and noise through diversity in the time-frequency domain
4Measurement precision
If power variation over time is increased to improve signal detection, then signal detection capability improves, but Peak-to-Average-Power-Ratio increases leading to higher power consumption
Solution Approach 1:
The patent employs periodic transmission of multiple signal blocks with structured power distribution. By cycling through different signal blocks with controlled power variations and combining them at the receiver, the system achieves good signal detection capability while maintaining reasonable average power consumption through periodic rather than continuous peak power transmission
Data Source
AI summary
In one aspect, an apparatus comprises: a radio frequency (RF) front end circuit to receive and process an RF signal comprising a packet, the RF front end circuit to output a digital signal comprising the packet; and a baseband circuit coupled to the RF front end circuit. The baseband circuit may comprise: a demodulator to receive the digital signal comprising a plurality of extended and modulated symbols and to: perform a plurality of operations on at least some of a first block of the plurality of extended and modulated symbols according to a reverse recipe of operations to obtain a processed first block of the plurality of extended and modulated symbols; aggregate the processed first block of the plurality of extended and modulated symbols into an aggregated symbol; and demodulate the aggregated symbol to obtain at least one soft value.