Wireless Receiver Soft Demodulation After Scramble Phase Rotation
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Solution Overview
Problem
Conventional wireless receiving apparatuses are limited to using hard decision values for decoding after the trans-decoding process, as they perform descramble and trans-decoding processes in a bit-based manner, preventing the use of soft decision values for data processing.
Innovation Solution
A wireless receiving apparatus that includes a phase rotation module and a demodulator, capable of performing phase rotation and demodulation using a replica signal to calculate a soft decision value, allowing for the use of soft decision values in the decoding process without degrading signal performance or increasing processing complexity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If hard decision values are used for decoding after trans-decoding process, then bit-based processing is simplified, but decoding accuracy deteriorates
Solution Approach 1:
Instead of converting soft decision values to hard decision values before decoding (conventional approach), the patent inverts the process by performing phase rotation and demodulation on soft decision values to generate new soft decision values, then directly using these for decoding without hard decision conversion. This inversion maintains accuracy while simplifying the processing path.
Solution Approach 2:
The patent changes the parameter representation from hard decision (binary) to soft decision (continuous values with phase information). By maintaining soft decision values through the processing chain and only converting to hard decisions at the final output stage, the system achieves higher decoding accuracy without significant complexity increase.
2Measurement precision
If phase rotation and demodulation are performed using replica signal, then soft decision value calculation is enabled, but computational complexity increases
Solution Approach 1:
The patent performs phase rotation using a pre-generated replica signal that contains the expected phase characteristics. By preparing the replica signal in advance and using it for phase compensation, the system enables soft decision value calculation without requiring complex real-time computations during the main processing flow.
3Adaptability or versatility
If bit-based descramble and trans-decoding processes are performed, then processing simplicity is maintained, but soft decision value usage is prevented
Solution Approach 1:
The patent inverts the conventional processing order by performing phase rotation and demodulation before the descramble and trans-decoding processes. This allows soft decision values to flow through the entire processing chain including descrambling and trans-decoding, enabling their utilization without requiring fundamental restructuring of the processing architecture.
Data Source
AI summary
According to one embodiment, a wireless receiving apparatus includes a receiver, a phase rotation module and a demodulator. The receiver receives a first signal, the first signal being processed a bit conversion, a scramble and an M-phase shift keying modulation processes. The phase rotation module multiplies a first symbol obtained from the first signal with an amount of phase rotation determined by a scramble sequence used for the scramble, to obtain a second symbol. The demodulator demodulates the second symbol by referring to signal points of N-PSK replica signal generated based on a data rate and the bit conversion process and calculates a likelihood obtained from demodulation as a soft decision value.