Then we use the data bit extrinsic information [L.sup.i.sup.e2,k] of decoder 2 and the
parity bit extrinsic information [L.sup.p.sup.e1,k] or [L.sup.p.sup.e2,k] to calculate the desired information of [s.sub.k] which is soft decision detected (44) and final output detection of data dk which is hard decision detected (45) using the foll owing equation,
Parity bit checking was widely used for its simplicity and ease of implementation, but is by no means a foolproof means of error detection.
Using a simplistic example: 10011100 is transferred (where the last bit is a parity bit using an even scheme) and received as 11111100.
Source nodes are combination of information bits S1 to S6 and parity bits [P.sub.1] to [P.sub.3].
The proposed scheme punctures the extended parity bits according to the compression ratio and estimates the punctured parity bits using the modified decoding scheme at the decoder, whereas the algorithm described in [18] does not do estimation.
In other words, decoder I receives the message bits and the corresponding
parity bits (generated by the encoder I) and generates an extrinsic information about the systematic bits.
Usually both component RSC codes are half rate, giving one
parity bit and one systematic bit output for every input bit.
In this case we have to determine the weakest
parity bits for which CIM should be applied.
The generated Y is corrected with the transmitted
parity bits through channel decoding.
At the point of double error detection of the extended Hamming Decipher, an even parity of syndrome
parity bit serves as the indicator for the entire encoded bits.
This can be achieved by using gated power ML technique and
parity bit respectively.
DC bit is the overall
parity bit for this Hamming code.
