09-09-2017, 11:39 AM
A new method of voice coding is proposed for mobile communication. The principle is to selectively invert the polarity of the voice sample according to the scrambling code, soften it with a low-pass filter and feed it to the radio transmitter. To use the principle, the necessary techniques are described, such as filtering, synchronizing and code design coding. The whitened spectrum of the coded voice and a large number of key codes provide high-security communication. The mixer presented here is designed for a mobile radio talk-to-talk adapter. Variation of the speech spectrum by coding is demonstrated and the articulation is measured under no-attenuation and attenuation conditions with signal-to-noise (S / N) variation. These results show that the coding method is suitable for mobile communications with fast synchronization for press radio to speech, noise and fading immunity.
In telecommunications, a mixer is a device that transposes or reverses signals or otherwise encodes a message on the sender side to make the message unintelligible in a receiver not equipped with an appropriate decryption device. While encryption is usually referred to operations performed in the digital domain, encryption usually refers to operations performed in the analog domain. The plot is made by adding components to the original signal or changing some important component of the original signal to make it difficult to extract the original signal. Examples of the latter could include the removal or change of vertical or horizontal synchronization pulses in television signals; the TVs will not be able to display an image of such a signal. Some modern scramblers are actually encryption devices, remaining name due to similarities in use, as opposed to internal operation.
In telecommunications and recording, a mixer (also known as a scrambler) is a device that manipulates a stream of data before transmitting. The manipulations are inverted by a decoder on the receiving side. Scrambling is widely used in satellites, radio relay communications and PSTN modems. An encoder can be placed just before a FEC encoder, or it can be placed after the FEC, just before the modulation or line code. A scrambler in this context has nothing to do with encryption, since the intention is not to make the message unintelligible, but to give transmitted data useful engineering properties.
An encoder replaces sequences (termed bleaching sequences) in other sequences without eliminating undesirable sequences, and as a result changes the probability of occurrence of vexatious sequences. Clearly it is not infallible since there are input sequences that produce all-zeroes, all-or other undesirable periodic output sequences. Therefore, an encoder is not a good substitute for a line code, which, through a coding step, eliminates unwanted sequences.
In telecommunications, a mixer is a device that transposes or reverses signals or otherwise encodes a message on the sender side to make the message unintelligible in a receiver not equipped with an appropriate decryption device. While encryption is usually referred to operations performed in the digital domain, encryption usually refers to operations performed in the analog domain. The plot is made by adding components to the original signal or changing some important component of the original signal to make it difficult to extract the original signal. Examples of the latter could include the removal or change of vertical or horizontal synchronization pulses in television signals; the TVs will not be able to display an image of such a signal. Some modern scramblers are actually encryption devices, remaining name due to similarities in use, as opposed to internal operation.
In telecommunications and recording, a mixer (also known as a scrambler) is a device that manipulates a stream of data before transmitting. The manipulations are inverted by a decoder on the receiving side. Scrambling is widely used in satellites, radio relay communications and PSTN modems. An encoder can be placed just before a FEC encoder, or it can be placed after the FEC, just before the modulation or line code. A scrambler in this context has nothing to do with encryption, since the intention is not to make the message unintelligible, but to give transmitted data useful engineering properties.
An encoder replaces sequences (termed bleaching sequences) in other sequences without eliminating undesirable sequences, and as a result changes the probability of occurrence of vexatious sequences. Clearly it is not infallible since there are input sequences that produce all-zeroes, all-or other undesirable periodic output sequences. Therefore, an encoder is not a good substitute for a line code, which, through a coding step, eliminates unwanted sequences.