Non-coherent Ambient Backscatter Using OFDM Cyclic Prefix

The patent extracts and eliminates the channel estimation process from the backscatter communication system. By using non-coherent detection and processing the cyclic prefix differently from the main signal portion, the system achieves communication without requiring channel estimation, thereby removing the source of excessive power consumption and hardware complexity while maintaining reliability through the inherent properties of the OFDM signal structure

The system uses the cyclic prefix itself as a reference signal for non-coherent detection. The cyclic prefix, which is already present in the OFDM signal structure, serves the dual purpose of timing synchronization and phase reference, eliminating the need for separate training sequences or channel estimation processes. This self-service approach reduces system complexity and power consumption while maintaining communication reliability

The patent removes the channel estimation functionality from the receiver architecture. By adopting non-coherent detection that processes the cyclic prefix and main signal portion differently, the system eliminates the need for complex channel estimation algorithms and associated hardware components, reducing overall system complexity while maintaining reliable communication through the inherent signal structure

The system uses the cyclic prefix as a copy of the end portion of the OFDM symbol to create a self-contained reference system. This copying approach allows the receiver to generate its own phase reference from the signal itself, eliminating the need for external training sequences and complex channel estimation hardware, thereby reducing device complexity while maintaining communication reliability

The patent extracts and eliminates the training sequence requirement from the communication system. By using non-coherent detection with the cyclic prefix as reference, the system achieves reliable communication without transmitting additional training sequences, thereby removing the associated power consumption while maintaining reliability through the inherent OFDM signal structure

The cyclic prefix serves multiple functions simultaneously: it provides timing synchronization, acts as a phase reference for non-coherent detection, and enables the receiver to self-calibrate without external training sequences. This multi-functionality eliminates the need for separate training sequences, reducing power consumption while maintaining communication reliability