High-Order Modulation Bit Allocation for Multi-User Spectral Efficiency
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Solution Overview
Problem
Existing communication systems face challenges in efficiently transmitting signals to multiple users over the same radio resource, particularly in GERAN networks, where high-order modulation schemes are not optimally adapted to varying demodulation performance levels and active terminal counts, leading to suboptimal signal quality and error rates.
Innovation Solution
Defining signal constellations with multiple points that correspond to combinations of bits, allowing for dynamic allocation of bits based on demodulation performance levels and adapting constellation order to the number of active terminals, enabling efficient data transmission and reception across multiple communication terminals.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If high-order modulation schemes are used to transmit signals to multiple users over the same radio resource, then spectral efficiency is improved, but signal quality and error rates deteriorate due to varying demodulation performance levels
Solution Approach 1:
The patent segments the bit representation in each constellation point into multiple subsets, where each subset is allocated to a different user. This allows different users to receive different portions of the bit information from the same high-order modulation symbol, enabling multiple users to simultaneously access the same radio resource with differentiated signal quality requirements.
Solution Approach 2:
The patent applies local quality by allocating different subsets of bits to different users based on their individual demodulation performance levels. Users with better channel conditions can be allocated subsets that are more sensitive to modulation variations, while users with poorer conditions receive subsets that are more robust, thereby optimizing signal quality for each user locally.
2Productivity
If high-order modulation schemes are used to increase data transmission capacity, then productivity is improved, but device complexity increases due to dynamic bit allocation and constellation adaptation
Solution Approach 1:
The patent implements dynamic bit allocation where the assignment of bit subsets to users changes based on channel conditions, user requirements, and system state. This dynamic allocation allows the system to adapt to varying conditions and optimize performance while maintaining manageable complexity through structured allocation rules.
Solution Approach 2:
The patent creates a universal modulation framework that can serve multiple users simultaneously with different requirements using a single high-order constellation. This multi-functional approach allows the same modulation scheme to accommodate various user scenarios (different channel qualities, data rates, and reliability requirements) without requiring separate modulation schemes for each user.
3Device complexity
If fixed modulation schemes are used for multi-user transmission, then device complexity is reduced, but adaptability to varying terminal capabilities and channel conditions deteriorates
Solution Approach 1:
The patent changes the allocation parameters of bits within the constellation points based on terminal capabilities and channel conditions. By dynamically adjusting which subsets of bits are allocated to which users, the system adapts to varying terminal requirements while maintaining the same underlying high-order modulation scheme, thus achieving adaptability without increasing fundamental system complexity.
Data Source
AI summary
A method for communication includes defining a signal constellation including multiple constellation points in a signal space, such that each constellation point corresponds to a signal representing a respective combination of values of at least three bits, wherein three or more subsets of the bits in each of the constellation points are respectively allocated to three or more data streams. A sequence of signals is received, each signal selected from the signal constellation. The received sequence of the signals is demodulated, and one of the three or more data streams is reconstructed based on the demodulated signals.