Trellis-Coded Modulation With Pulse Mapping for Noisy Telemetry
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Solution Overview
Problem
Cable bound telemetry systems face limitations in data transmission rates and error protection in noisy communication channels, as traditional coding and modulation methods are not optimized jointly, leading to reduced spectral bandwidth and increased error susceptibility.
Innovation Solution
The integration of trellis-coded modulation (TCM) with a combined pulse modulation scheme, including pulse position and/or duration modulation, along with additional modulation techniques like phase or amplitude modulation, to enhance data transmission rates and error protection without increasing spectral bandwidth.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If traditional coding and modulation methods are used separately, then device complexity is reduced, but data transmission rate and error protection are limited
Solution Approach 1:
The patent combines coding and modulation into a unified trellis-coded modulation (TCM) scheme, where the encoder and modulator are integrated into a single system that jointly optimizes both functions. This merging allows the system to achieve higher data transmission rates and better error protection by exploiting the combined structure, while the complexity is managed through systematic design of the trellis diagram that represents both coding and modulation states.
2Productivity
If traditional coding and modulation methods are used separately, then implementation is simpler, but spectral bandwidth efficiency is reduced
Solution Approach 1:
The TCM scheme merges coding and modulation to improve spectral bandwidth efficiency by jointly optimizing both functions. The trellis diagram integrates code states with modulation symbols, allowing the system to transmit more information per Hz of bandwidth. The encoder produces coded bits that are directly mapped to modulation symbols within the unified trellis structure, maximizing spectral efficiency.
Solution Approach 2:
The patent extends the state representation from traditional coding dimensions to include modulation dimensions. The trellis diagram incorporates both code states and modulation symbol states, creating a multi-dimensional state space that simultaneously represents coding and modulation. This dimensional extension allows the system to exploit additional degrees of freedom for improving spectral bandwidth efficiency.
3Reliability
If traditional coding and modulation methods are used separately, then error protection is reduced, but system design is simpler
Solution Approach 1:
The unified TCM scheme merges coding and modulation to enhance error protection. The trellis diagram structure allows the receiver to perform joint decoding and demodulation, where errors in received symbols are corrected by traversing the trellis to find the most likely transmitted sequence. This joint processing exploits the combined structure to provide better error protection than separate coding and modulation could achieve alone.
Data Source
AI summary
A communication method includes: receiving input data at a transmitter, the transmitter including at least one convolutional encoder and at least one modulator; applying the input data to a trellis-coded modulation (TCM) scheme to encode the input data and produce one or more TCM symbols representing the encoded data; applying the one or more TCM symbols to a second modulation scheme, the second modulation scheme including a pulse modulation in combination with an additional modulation; and generating one or more modulation symbols representing the encoded data based on the second modulation scheme.