Error detecting and correcting codes in Digital Electronics belong to the class of channel codes. When data is transmitted through a channel, noise induced in the channel by various sources such as lightning corrupts it. With analog data transmission human brain can recover to some extent the original data from its noise-corrupted version. However, in digital data transmission, if some bits are lost by noise, then in all probability, the entire data may be lost.
It has been found that error detecting and correcting codes help in recovering lost data from noise. Error-detecting and correcting codes are binary source codes that contain at the transmitter just before their transmission. At the receiving end, the added error codes are used to recover the original data transmitted. It can be seen that this process is similar to the identification of a person at a crowded railway station or aerodrome; the sending party will inform the receiving party well in advance regarding the identification marks of the person sent to the receiving station. The receiving party will look for the person with these identification marks among the crowd. In a similar way, error codes help to identify transmitted data in the presence of noise. Error-detecting and correcting codes generally belong to the class of:
1. Linear Block Codes (LBC).
2. Convolutional Codes (CC).
Only basic concepts of these codes are given here. Detained explanations are available in textbooks on Information Theory and Coding. We begin our discussion with LBC.
It has been found that error detecting and correcting codes help in recovering lost data from noise. Error-detecting and correcting codes are binary source codes that contain at the transmitter just before their transmission. At the receiving end, the added error codes are used to recover the original data transmitted. It can be seen that this process is similar to the identification of a person at a crowded railway station or aerodrome; the sending party will inform the receiving party well in advance regarding the identification marks of the person sent to the receiving station. The receiving party will look for the person with these identification marks among the crowd. In a similar way, error codes help to identify transmitted data in the presence of noise. Error-detecting and correcting codes generally belong to the class of:
1. Linear Block Codes (LBC).
2. Convolutional Codes (CC).
Only basic concepts of these codes are given here. Detained explanations are available in textbooks on Information Theory and Coding. We begin our discussion with LBC.