Coded modulation method, which takes tailbits and their coding into account
A method is presented for the coded modulation of digital data, a modulation being carried out that is coded in multiple stages. In this context, the useful bits for the coded modulation are divided into parallel signal streams, and each signal stream is fed to a specific coder to carry out the channel coding. In the respective coder, the useful bits have tail bits added to them, which, in contrast to the useful bits, are channel-coded using a variable code rate, to achieve a preestablished bit number for a specific coder, so that all signal streams that are coded in parallel contain the same number of bits.
1. A method for providing coded modulation of digital data having useful bits, the method comprising:
performing multi-stage coded modulation of the digital data, wherein the useful bits are divided into parallel signal streams;
subjecting each of the parallel signal streams by a respective coder of a plurality of coders to channel coding, wherein the useful bits are channel coded using at least one fixed code rate;
adding tail bits to the useful bits, wherein the tail bits ensure that each coder of the plurality of coders is in a recognizable defined state;
channel coding the tail bits in the respective coder using a variable code rate to provide a pre-established bit number for the respective coder, so that the parallel signal streams contain a same number of coded bits; and
assigning channel-coded data to signal space points to generate at least one modulation symbol.
2. The method of claim 1 , wherein the variable code rate of the tail bits is provided by variable puncturation.
3. The method of claim 2 , wherein all puncturation schemas are made available to a transmitter and a plurality of receivers.
4. The method of claim 3 , wherein the at least one fixed code rate and a transmission rate are signaled to the plurality of receivers.
5. The method of claim 2 , wherein all puncturation schemas of the tail bits are calculated by calculation methods made available to a transmitter and a plurality of receivers.
6. The method of claim 5 , wherein the at least one fixed code rate and a transmission rate are signaled to the plurality of receivers.
7. The method of claim 1 , wherein channel coding is provided by convolutional coding.
8. The method of claim 1 , wherein the number of coded bits is generated by a number of the at least one modulation symbol multiplied by a stage level of the modulation and divided by a number of stages.
9. A transmitter for providing coded modulation of digital data having useful bits, the transmitter comprising:
a first arrangement to provide multi-stage coded modulation of the digital data, wherein the useful bits are divided by a mulitplexer into parallel signal streams;
a second arrangement to subject each of the parallel signal streams by a respective coder of a plurality of coders to channel coding, wherein the useful bits are channel coded using at least one fixed code rate;
a third arrangement to add tail bits to the useful bits, wherein the tail bits ensure that each coder of the plurality of coders is in a recognizable defined state;
a fourth arrangement to channel code the tail bits in the respective coder using a variable code rate to provide a pre-established bit number for the respective coder, so that the parallel signal streams contain a same number of coded bits; and
a fifth arrangement to assign channel-coded data to signal space points to generate at least one modulation symbol;
wherein the plurality of coders correspond to a number of stages of the multi-stage coded modulation.
10. A receiver for receiving coded modulation of digital data having useful bits, the receiver comprising:
an evaluation arrangement to evaluate a signaling for demodulating modulation symbols and for a channel coding;
wherein the modulation symbols and the channel coding are provided by a method for providing coded modulation of digital data having useful bits, the method including:
performing multi-stage coded modulation of the digital data, wherein the useful bits are divided into parallel signal streams;
subjecting each of the parallel signal streams by a respective coder of a plurality of coders to channel coding, the useful bits being channel coded using at least one fixed code rate;
adding tail bits to the useful bits, wherein the tail bits ensure that each coder of the plurality of coders is in a recognizable defined state;
channel coding the tail bits in the respective coder using a variable code rate to provide a pre-established bit number for the respective coder, so that the parallel signal streams contain a same number of coded bits; and
assigning channel-coded data to signal space points to generate at least one modulation symbol; and
wherein all puncturation schemas of the tail bits are made available to a transmitter and a plurality of receivers.