A Rate 8/10 DC Balanced CODE With Local Parity
Original Publication Date: 1985-Feb-01
Included in the Prior Art Database: 2005-Feb-18
This article discloses a code, similar to that disclosed in European Patent Application Publication No. 0,097,763, but which, at the cost of a slightly higher low frequency content, can tolerate a lower signal-to-noise ratio. Both codes are binary rate 8/10 codes in which no more than 5 of one symbol occur in an unbroken run. In any fragment of a transmission under the present code, the count of each of the two symbols differs by at most 8 as opposed to 6 in the case of the prior code, providing a self-clocking DC-free code that has all the desired secondary features of the prior code, plus the characteristic that each 10-bit word has even parity. This may be exploited in an error detection scheme, an error correction scheme, or ideally using a maximum likelihood detector.