Control Data Transmission With Inner Coded Modulation for Low PAPR
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Solution Overview
Problem
Current 5G mobile communication systems face challenges in transmitting small payloads with low probability of error at very low signal-to-noise ratios, particularly due to high peak-to-average power ratio (PAPR) and sub-optimal decoding algorithms in control channels like PUCCH, which result in interference and distortion.
Innovation Solution
A transmitter device and method that employs a binary code generator, binary interleaver, and inner coded modulation unit to generate and modulate binary codes, spreading coded bits across multiple vectors, and using single-carrier or multi-carrier modulation to transmit control data, optimizing energy efficiency and coding gain while reducing PAPR.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If peak windowing, scaling, or clipping is used to reduce PAPR, then peak-to-average power ratio is reduced, but interference and distortions are generated in the OFDM modulated signal
Solution Approach 1:
The patent extracts the problematic PAPR reduction operations (peak windowing, scaling, clipping) from the transmission chain and replaces them with a fundamentally different approach: spreading sequences and optimized modulation schemes that achieve low PAPR inherently without generating interference or distortions
Solution Approach 2:
The patent changes the fundamental parameters of the transmission scheme by introducing spreading sequences with specific autocorrelation properties and using optimized modulation constellations, transforming the system from one requiring aggressive PAPR reduction to one that naturally maintains low PAPR
2Device complexity
If sub-optimal reduced-complexity decoding algorithms are used, then decoding complexity is reduced, but detection accuracy deteriorates in low signal-to-noise ratio conditions
Solution Approach 1:
The patent applies preliminary actions by designing the spreading sequences and modulation schemes upfront to have optimal correlation properties, which enables the receiver to achieve high detection accuracy through simple correlation-based decoding without requiring complex iterative algorithms
Solution Approach 2:
The patent uses excessive spreading factors (spreading sequences longer than the minimum required), which provides processing gain that dramatically improves detection accuracy in low SNR conditions while keeping the decoding operation simple as it only requires correlation
3Device complexity
If separate channel estimation and quasi-coherent detection are used, then implementation is simplified, but detection performance is sub-optimal
Solution Approach 1:
The patent merges channel estimation and detection into a single unified operation by using the known spreading sequences as reference signals, allowing the receiver to estimate channel effects and detect data symbols simultaneously through correlation processing rather than through separate sequential steps
4Device complexity
If a fully non-coherent receiver is used, then implementation is simplified, but complexity increases for longer bit lengths
Solution Approach 1:
The patent replaces the mechanical complexity of fully non-coherent reception with a coherent detection approach that uses known spreading sequences as references, substituting the need for complex blind estimation algorithms with simpler correlation-based detection that maintains efficiency even for longer bit lengths
Data Source
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AI summary
There is provided a transmitter device (1) for transmitting a digital input message (m) corresponding to control data through a communication channel (3), the message comprising a number B of bits, said transmitter device comprising: - a binary code generator (10) to generate a binary code fi , i = 0, 1 ..., E' - 1 from the B bits of the message; - a binary interleaver (11) to apply interleaving to said binary code, which provides an interleaved binary code gi , i = 0, 1 ..., E - 1; - an inner coded modulation unit (12) to apply inner coded modulation to a message ml = 0,1, ..., 2 B' - 1 comprising B' bits taken from the interleaved binary code (gi ), which provides an inner modulation code comprising K-length inner coded modulated vectors (dk',s ) representing frequency-domain samples; - modulators (14) configured to apply single-carrier or multi-carrier modulation to the inner coded modulated vectors (dk',s ) which provides a modulated sequence (Cl (ml )) transmitted by the transmitter device.