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General EMC Design Principles
Published in Christos Christopoulos, Principles and Techniques of Electromagnetic Compatibility, 2022
Most conventional schemes for dealing with error correction assume random errors (e.g., white noise) affecting the system. These are referred to as “random error correcting codes.” However, under certain circumstances, which are not uncommon in EMC situations, errors occur in bursts, i.e., a sequence of bits is damaged. Special techniques referred to as “burst error correcting codes” are available that can detect and correct errors bursts. A particular example is the technique of interleaving. Here a sequence of bits is interleaved (mixed up) before transmission, so that a burst of EMI affects bits in several words not just a few. With this arrangement errors are few and randomly distributed in each word and hence can be corrected using random error correction codes. A deinterleaver then arranges bits in the right sequence after transmission. A detailed treatment of this specialist subject may be found in References 12 and 13.
Why digital?
Published in John Watkinson, The Art of Digital Audio, 2013
As anyone familiar with analog recording will know, magnetic tape is an imperfect medium. It suffers from noise and dropouts, which in analog recording are audible. In a digital recording of binary data, a bit is either correct or wrong, with no intermediate stage. Small amounts of noise are rejected, but inevitably, infrequent noise impulses cause some individual bits to be in error. Dropouts cause a larger number of bits in one place to be in error. An error of this kind is called a burst error. Whatever the medium and whatever the nature of the mechanism responsible, data are either recovered correctly, or suffer some combination of bit errors and burst errors. In Compact Disc and DVD, random errors can be caused by imperfections in the moulding process, whereas burst errors are due to contamination or scratching of the disc surface.
An introduction to digital audio
Published in Michael Talbot-Smith, Sound Assistance, 1999
Scatter codes: These give a high degree of correction for major losses in data, such as a drop-out in tape, or a flaw in the pressing of a CD. The principle is shown in Figure 17.8. The bits in the original sample are scattered according to a pre-arranged code. If there is a major error (a ‘burst error’) then on reassembling the bits the effects of the error are distributed and can be handled by some form of parity. (The more complex parity systems can even go so far as to reinsert the correct bits!) Scatter systems are so effective that on a CD for instance it is possible to have a hole in the disc up to about 2 mm diameter. The reader is strongly advised not to try any experiments, at least not with favourite discs!
A Novel Energy-Efficient MIMO-OFDM Decoder Architecture with Error Detection
Published in IETE Journal of Research, 2023
ECG transmission kernel constants in Table 4 are set to improve the signal to noise ratio for decoding at the receiver end in MIMO-OFDM transceiver on replacing the regular fault-tolerant adders in decoder blocks. These are integrated with a redundancy pattern combined with decoder block. According to the modulation type of QPSK mapper, complex values interleaved are then mapped for transmit diversity, hence two antennas are utilized. The OFDM modulation process then feeds the data to IFFT after space time diversity encoding. In the later stage, error control codes are generated to remove burst error through interleaver. The processed information overlaps with neighboring data through protruding noise along the transmitter unit.