Select Mark parity and the parity bit is always 1.

The remaining parity bits are then encoded based, at least in part, on the first bit value assigned to the first parity bit.

A comparator then compares the first parity bit with the second parity bit and a parser parses the received data in response to the comparison.

Moreover, the receiver comprises odd parity means (43 and 46) which form a parity bit of the state of the masked Viterbi decoding, the parity bit controlling the block (44 and 45) forming the transition metrics.

No parity : means that no parity bit is sent at all.

The parity bit is punctured such that parity bits of different patterns are formed between adjacent frames.

The system includes a first parity generator used to generate a first parity bit on the data to be communicated.

The symbols may comprise bit-pairs, each of a systematic bit and parity bit.

The carries generated by the summing operation are coupled to a second parity tree (12) along with the message parity bits and the second parity tree generates a second parity bit therefrom.

Each coded parity bit is input to a puncturing unit (24).

A method for monitoring at least one telephony communication n-bit channel, wherein one of the bits is a parity bit, includes sampling the parity bit of the n-bit channel.

The puncturing unit (106) judges if only the parity bit is to be punctured according to the regularity of the arrangement of the information bits and the parity bit in each frame and then performs puncturing.

Each byte is transmitted with a parity bit (odd parity) at the end.

The decoder (1200) also receivers the parity bit data from the first data source (1120), and corrects errors in the estimate by applying the parity bit data to the estimate.

The control units (22-1 to 22-K) reduce the power of the parity bit by reducing the amplitude of the channel corresponding to the parity bit among the I channel and Q channel inputted.