TCM Transmitter Device Optimizing Spectral Efficiency
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Solution Overview
Problem
Conventional wireless communication systems face challenges in achieving high spectral efficiency while maintaining reliable data transmission for multiple users, particularly in scenarios with varying signal-to-noise ratios, leading to increased transmitted power and single-stream SNR loss.
Innovation Solution
A transmitter device that selects data streams with similar channel quality, encodes and modulates them using Trellis Coded Modulation, scrambles and interleaves them with stream-specific sequences, and superposes signals to optimize spectral efficiency, allowing for efficient power allocation and separation of streams.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If multiple data streams are multiplexed onto the same time-frequency-space resources using overloading, then spectral efficiency is improved, but transmitted power per stream increases
Solution Approach 1:
The transmitter segments the K data streams into multiple groups, where each group is processed by a separate TCM encoder. This segmentation allows independent optimization of each group's power allocation while maintaining overall spectral efficiency gains from multiplexing multiple streams.
Solution Approach 2:
The system changes the parameter of transmitted power per stream by using TCM encoding with different constellation sizes and power allocations for different groups of streams. This allows the system to achieve higher spectral efficiency while controlling the power increase through intelligent parameter selection.
2Productivity
If data streams with similar channel quality are multiplexed together, then spectral efficiency is improved, but separation and detection reliability becomes more difficult
Solution Approach 1:
The transmitter segments K data streams into multiple groups, where each group is encoded by a separate TCM encoder. This segmentation creates distinct encoded structures for different groups, making it easier for the receiver to separate and detect streams even when they have similar channel qualities.
Solution Approach 2:
The TCM encoder acts as an intermediary that transforms the original data streams into encoded forms with distinct structural characteristics. This encoding process introduces separability features that facilitate reliable detection at the receiver, even when multiple streams experience similar channel conditions.
3Reliability
If Trellis Coded Modulation is applied to each data stream, then error protection is improved, but device complexity increases
Solution Approach 1:
The transmitter uses multiple TCM encoders, each processing a specific group of data streams. This segmentation distributes the encoding complexity across multiple specialized units rather than requiring a single complex encoder, making the overall system more manageable and implementable.
Solution Approach 2:
The TCM encoder is designed as a universal building block that can process multiple data streams within each group. This multi-functional encoder design reduces overall complexity by using identical or similar encoder structures repeatedly rather than designing unique encoders for each stream.
4Reliability
If stream-specific scrambling and interleaving are applied, then stream separation is improved, but processing time increases
Solution Approach 1:
The transmitter applies stream-specific scrambling and interleaving as preliminary actions during the encoding process. By performing these separation-enhancing operations upfront at the transmitter, the receiver can more efficiently separate and detect streams without requiring complex real-time processing, thus reducing overall processing time.
Data Source
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AI summary
The present invention relates to a transmitter device and a receiver device. The transmitter device 10 comprises a processor 11 which is communicably coupled with a transmitter unit 12. The processor 11 is configured to receive a set of Z data streams and select K data streams with the same channel quality from the set of Z data streams for transmission, where K≤ Z. Thereafter for each information word and for each data stream k = 0,..., K — 1 the processor 11 encodes, scrambles and superposes so as to obtain a first signal s U . Further, for each information word and for each data stream k = 0,..., K — 1 the processor 11 interleaves, encodes, scrambles and superposes so as to obtain a second signal s v . The first signal s U and the second signal s V are combined by the processor 11 into a single signal s for transmission. The transmitter unit 12 of the transmitter device 10 is configured to transmit the transmission signal s over a radio channel of the wireless communication system 30. The receiver device 20 comprises a receiver unit 21 and a processor 22 configured to decode the transmitted signal. Furthermore, the present invention also relates to corresponding methods, a computer program, and a computer program product.