Companded Signal Coding by Removing Unused Magnitude Values
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Solution Overview
Problem
Current compression coding methods for VoIP audio transmission, such as logarithm approximation companding PCM, are not sufficiently efficient in reducing the required transmission capacity, especially as the number of lines increases, due to inefficiencies in representing amplitude relationships in signal sequences.
Innovation Solution
A coding method that analyzes signal sequences for missing values within a defined range and transforms them by assigning new numbers, eliminating redundant representations, thereby improving coding efficiency by ensuring no values are absent in high occurrence frequency ranges.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If logarithm approximation companding PCM is used for VoIP audio transmission, then transmission capacity is reduced compared to linear PCM, but coding efficiency is not sufficiently improved and transmission capacity still increases with the number of lines
Solution Approach 1:
The patent transforms the companded signal sequence by reassigning numerical values to eliminate non-occurring values. Specifically, it identifies values in a predetermined range that do not occur in the signal sequence and reassigns new values to maintain magnitude relationships while eliminating gaps in the value distribution, thereby optimizing coding efficiency
Solution Approach 2:
The patent performs preliminary analysis to identify non-occurring values in the companded signal sequence before encoding. By detecting which values within a predetermined range do not occur and preparing a transformation mapping in advance, the system optimizes the coding structure proactively rather than reactively
2Reliability
If two different numbers are assigned to one amplitude in companding, then the magnitude relationship is maintained, but redundant representations increase the amount of codes required
Solution Approach 1:
The patent changes the numerical parameter assignment by eliminating duplicate representations. It identifies cases where multiple companded values map to the same amplitude and reassigns unique values, transforming the signal sequence to have one-to-one correspondence between companded values and amplitudes, thereby reducing code redundancy while preserving magnitude relationships
Data Source
AI summary
An object of the present invention is to achieve high coding efficiency for a companded signal sequence and reduce the amount of codes. A coding method according to the present invention includes an analysis step and a signal sequence transformation step. The analysis step is to check whether or not there is a number that is included in a particular range but does not occur in a second signal sequence (a number sequence that indicates the magnitude (magnitude relationship) of original signals) and output information that indicates the number that does not occur. The signal sequence transformation step is to output a transformed second signal sequence (which is formed by assigning new numbers to indicate the magnitudes of original signals (the magnitude relationship among original signals) excluding the magnitude of the original signal indicated by the number that does not occur and replacing the numbers in the second signal sequence with the newly assigned numbers) in the case where it is determined in the analysis step that there is a number that does not occur. The particular range is defined as a number that indicates a positive value having a minimum absolute value and a number that indicates a negative value having a minimum absolute value, for example.