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Bipolar Encoding
In telecommunication, bipolar encoding is a type of return-to-zero (RZ) line code, where two nonzero values are used, so that the three values are +, −, and zero. Such a signal is called a duobinary signal. Standard bipolar encodings are designed to be DC-balanced, spending equal amounts of time in the + and − states. The reason why bipolar encoding is classified as a return to zero (RZ) is that when a bipolar encoded channel is idle the line is held at a constant "zero" level, and when it is transmitting bits the line is either in a +V or -V state corresponding to the binary bit being transmitted. Thus, the line always returns to the "zero" level to denote optionally a separation of bits or to denote idleness of the line. Alternate mark inversion One kind of bipolar encoding is a paired disparity code, of which the simplest example is alternate mark inversion. In this code, a binary 0 is encoded as zero volts, as in unipolar encoding, whereas a binary 1 is encoded alter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ami Encoding
AMI or Ami may refer to: Arts, entertainment and media *AMI-tv, a Canadian TV channel **AMI-télé, the French-language version *AMI-audio, a Canadian audio broadcast TV service *''Ami Magazine'', an Orthodox Jewish news magazine Businesses and organizations * AMI Insurance, in New Zealand * AMI Semiconductor, acquired by Onsemi * Accessible Media Inc., a Canadian media company for the visually impaired * African Minerals Limited (AMI.L) * Alternative Miss Ireland, a Dublin beauty pageant * Amazon Malaria Initiative * American Meat Institute, a trade association * American Media, Inc., now A360media, a publisher * American Megatrends Inc., a computer company * American Monetary Institute, a non-profit * American Mustache Institute, an advocacy organization * Anugerah Musik Indonesia, an annual Indonesian music award ceremony * ''Armes-Militaria-Informations'', a Belgian magazine, later Fire (magazine), ''Fire'' * ''Associació de Municipis per la Independència'' (Associati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Robbed-bit Signaling
In communications systems, robbed-bit signaling (RBS) is a scheme to provide maintenance and line signaling services on many T1 digital carrier circuits using channel-associated signaling (CAS). The T1 carrier circuit is a type of dedicated circuit currently employed in North America and Japan. Context The T1 circuit is divided into 24 channels, each carrying 8,000 samples per second, each 8 bits long. The Super Frame (SF) consist of 12 frames of 24 channels. The DS1 designation consist of 24 frames called, Extended Super Frame (ESF). In either designation, these channels are multiplexed together and sample at 8000bit/s. In the superframe, ten frames are utilized entirely for voice/data and two are utilized partially for voice. Hence, each of the two partial frames yields bit/s = 56kbit/s for voice data per channel, compared to the bit/s = 64kbit/s per channel in the other frames. Intuitively, 5 out of 6 frames have 8-bit resolution equal to 64kbit/s (8 bits × 8,000 samples pe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polar Encoding
In telecommunication, a non-return-to-zero (NRZ) line code is a binary code in which ones are represented by one significant condition, usually a positive voltage, while zeros are represented by some other significant condition, usually a negative voltage, with no other neutral or rest condition. For a given data signaling rate, i.e., bit rate, the NRZ code requires only half the baseband bandwidth required by the Manchester code (the passband bandwidth is the same). The pulses in NRZ have more energy than a return-to-zero (RZ) code, which also has an additional rest state beside the conditions for ones and zeros. When used to represent data in an asynchronous communication scheme, the absence of a neutral state requires other mechanisms for bit synchronization when a separate clock signal is not available. Since NRZ is not inherently a self-clocking signal, some additional synchronization technique must be used for avoiding bit slips; examples of such techniques are a ru ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
MLT-3 Encoding
MLT-3 encoding (Multi-Level Transmit) is a line code (a signaling method used in a telecommunication system for transmission purposes) that uses three voltage levels. An MLT-3 interface emits less electromagnetic interference and requires less bandwidth than most other binary or ternary interfaces that operate at the same bit rate (see PCM for discussion on bandwidth / quantization tradeoffs), such as Manchester code or Alternate Mark Inversion. MLT-3 cycles sequentially through the voltage levels −1, 0, +1, 0. It moves to the next state to transmit a 1 bit, and stays in the same state to transmit a 0 bit. Similar to simple NRZ encoding, MLT-3 has a coding efficiency of 1 bit/baud, however it requires four transitions (baud) to complete a full cycle (from low-to-middle, middle-to-high, high-to-middle, middle-to-low). Thus, the maximum fundamental frequency is reduced to one fourth of the baud rate. This makes signal transmission more amenable to copper wires. The lack of tr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
NICAM
Near Instantaneous Companded Audio Multiplex (NICAM) is an early form of lossy compression for digital audio. It was originally developed in the early 1970s for point-to-point links within broadcasting networks.Croll, M.G., Osborne, D.W. and Spicer, C.R. (1974), ''Digital sound signals: the present BBC distribution system and a proposal for bit-rate reduction by digital companding''. IEE Conference publication No. 119, pp. 90–96 In the 1980s, broadcasters began to use NICAM compression for transmissions of stereo TV sound to the public. History Near-instantaneous companding The idea was first described in 1964. In this, the 'ranging' was to be applied to the analogue signal before the analogue-to-digital converter (ADC) and after the digital-to-analogue converter (DAC). The application of this to broadcasting, in which the companding was to be done entirely digitally after the ADC and before the DAC, was described in a 1972 BBC Research Report. Point-to-point links NI ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
