Method for encoding analog signals

DETAILED DESCRIPTION It is an object of the present invention to improve the method disclosed in my earlier application Ser.
No.
189,595 such that error propagations occurring as a result of brief signal flow interruptions are substantially avoided while the high quality of the regained analog signal is retained.
This object is inventively achieved in an improvement over the method disclosed in my co-pending application Ser.
No.
189,595 wherein .
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PCM words are additionally replaced by PCM words in the train of the reduced signal flow when the associated signal content, including the required auxiliary code elements, does not exceed the word length which is set by the reference code word.
The subject matter of the improvement is based on the perception that the number of signal reference values occurring in the signal flow significantly increases as a result of the additional transmission of linearly-encoded PCM words in place of .
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PCM words whenever this is possible.
Error propagation given brief signal flow interruptions is thus simultaneously excluded with certainty over a larger number of code words.
For further decreasing error propagation, my earlier method can be improved by replacing a .
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PCM word with a PCM double word when the two PCM words from which the .
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PCM word is to be derived have approximately the same signal content which, including the necessary auxiliary code elements, exceeds the word length prescribed by the reference code word.
The transmission of a number of different types of code words which are generated according to the principles of the method disclosed and claimed herein would normally require at least two auxiliary code elements for their respective identification, which would be counter to the desired reduction of the digital signal flow.
In order to avoid this undesired effect, a control bit sequence with a single-bit allocation per code word is employed to identify the type of code word occurring in the reduced signal flow, namely .
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