Communication apparatus, communication system, and communication method
View Patent ↗A communication apparatus capable of improving the spectrum usage rate of a system, especially, the spectrum usage rate in connection with both a fast fading and a channel estimation error as compared with the conventional sub-band adaptive method, while reducing the degree of the difficulty in achieving the adaptation, and further reducing the feedback overhead. In this apparatus, a sub-band group AMC parameter selecting part ( 318 ) selects an AMC parameter of each sub-band. An adaptive reception control part ( 503 ) must control an adaptive demodulating/decoding part ( 311 ), while controlling a parallel/serial converter ( 312 ) in a stage preceding the adaptive demodulation and decoding processes, and combining received symbols in the same sub-band group for demodulation and decoding.
1. A communication apparatus comprising:
a channel estimating section that carries out a channel estimation per subband;
a parameter deciding section that decides modulation parameters and coding parameters per subband group comprised of a plurality of the subbands, based on a result of the channel estimation per subband;
a parameter information transmission section that transmits, to a communicating party, parameter information indicating the modulation parameters and the coding parameters decided at the parameter deciding section;
a receiving section that receives a signal containing data modulated and encoded on a per subband group basis at the communicating party using the modulation parameters and the coding parameters of the parameter information transmitted at the parameter information transmission section;
a data obtaining section that demodulates and decodes the received signal received at the receiving section on a per subband group basis using the modulation parameters and the coding parameters decided at the parameter deciding section, and obtains the data contained in the received signal; and
a pattern storage section that stores in advance patterns for selecting subbands constituting the subband groups wherein the parameter deciding section decides the modulation parameters and the coding parameters per subband group comprised of the subbands selected based on the patterns stored in the pattern storage section.
2. The communication apparatus of claim 1 , wherein the parameter deciding section decides the modulation parameters and the coding parameters per subband group constituted from a pattern, among the patterns, for selecting a plurality of the subbands neighboring on a frequency axis.
3. The communication apparatus of claim 1 , wherein the parameter deciding section decides the modulation parameters and the coding parameters per subband group constituted from a pattern, among the patterns, for selecting a plurality of the subbands at predetermined intervals from subbands arranged on a frequency axis.
4. The communication apparatus of claim 1 , wherein the parameter deciding section decides the modulation parameters and the coding parameters per subband group constituted from a pattern, among the patterns, for selecting all of the subbands per predetermined time domain.
5. The communication apparatus of claim 1 , wherein the parameter deciding section finds the modulation parameters per subband within the subband group, and decides modulation parameters with a highest classification within the found modulation parameters as the modulation parameters for the subband group.
6. The communication apparatus of claim 1 , wherein the parameter deciding section decides the coding parameters in such a manner that a number of information bits that are able to be assigned to all of the subbands within the subband group is assigned to the subband group.
7. A base station apparatus that is the communicating party of the communication apparatus of claim 1 , the base station apparatus comprising an adaptive modulation and coding section that modulates and encodes the data in accordance with the modulation parameters and the coding parameters of the parameter information transmitted by the transmission section, and a data transmission section that transmits the data modulated and encoded at the adaptive modulation and coding.
8. A communication apparatus comprising:
a channel estimating section that carries out a channel estimation per subband;
a parameter deciding section that decides modulation parameters and coding parameters per subband group comprised of a plurality of the subbands based on a result of the channel estimation per subband;
a parameter information transmission section that transmits to a communicating party, parameter information indicating the modulation parameters and the coding parameters decided at the parameter deciding section;
a receiving section that receives a signal containing data modulated and encoded per subband group at the communicating party, using the modulation parameters and coding parameters of the parameter information transmitted at the parameter information transmission section; and
a data obtaining section that demodulates and decodes the received signal received at the receiving section on a per subband group basis, using the modulation parameters and the coding parameters decided at the parameter deciding section, and obtains the data contained in the received signal;
wherein the parameter deciding section decides the coding parameters in such a manner that a number of information bits obtained by assigning a weight per subband group to a sum of information bits that are able to be assigned to all of the subbands within the subband group, is assigned to the subband group.
9. A communication system comprising a base station apparatus transmitting modulated and encoded data and a communication terminal apparatus receiving the data, wherein
the communication terminal apparatus comprises:
a channel estimating section that carries out a channel estimation per subband;
a parameter deciding section that decides modulation parameters and coding parameters per subband group comprised of a plurality of the subbands based on a result of the channel estimation per subband;
a parameter information transmission section that transmits parameter information indicating the modulation parameters and the coding parameters decided at the parameter deciding section to the base station apparatus;
a receiving section that receives a signal containing the data modulated and encoded on a per subband group basis at the base station apparatus using parameters of the parameter information transmitted at the parameter information transmission section; and
a data extracting section that demodulates and decodes the received signal received at the receiving section on a per subband group basis using the modulation parameters and the coding parameters of the parameter information, and extracts the data contained in the received signal; and
a pattern storage section that stores in advance patterns for selecting subbands constituting the subband groups; and
the base station apparatus comprises:
an adaptive modulation and coding section that modulates and encodes the data in accordance with the modulation parameters and the coding parameters of the parameter information transmitted by the transmission section; and
a data transmission section that transmits the data modulated and encoded at the adaptive modulation and coding section; and
the parameter deciding section decides the modulation parameters and the coding parameters per subband group comprised of the subbands selected based on the patterns stored in the pattern storage section.
10. A communication method comprising:
a channel estimating step of carrying out a channel estimation per subband;
a parameter deciding step of deciding modulation parameters and coding parameters per subband group comprised of a plurality of the subbands, based on a result of the channel estimation per subband;
a parameter information transmitting step of, at a communication terminal apparatus, transmitting parameter information indicating the decided modulation parameters and coding parameters;
an information receiving step of, at a base station apparatus, receiving the parameter information transmitted by the communication terminal apparatus;
a modulating and encoding step of modulating and coding data in accordance with the modulation parameters and the coding parameters of the received parameter information;
a data transmitting step of, at the base station apparatus, transmitting the modulated and encoded data;
a signal receiving step of, at the communication terminal apparatus, receiving a signal containing the data transmitted by the base station apparatus; and
a data extracting step of demodulating and decoding the received signal on a per subband group basis, using the modulation parameters and the coding parameters of the parameter information, and extracting data contained in the received signal,
wherein the parameter deciding step decides the modulation parameters and the coding parameters per subband group comprised of the subbands selected based on the patterns stored in a storage section for selecting the subbands constituting the subband group.
11. A communication system comprising a base station apparatus transmitting modulated and encoded data and a communication terminal apparatus receiving the data, wherein:
the communication terminal apparatus comprises:
a channel estimating section that carries out a channel estimation per subband;
a parameter deciding section that decides modulation parameters and coding parameters per subband group comprised of a plurality of the subbands, based on a result of the channel estimation per subband;
a parameter information transmission section that transmits parameter information indicating the modulation parameters and the coding parameters decided at the parameter deciding section, to the base station apparatus,
a receiving section that receives a signal containing data modulated and encoded on a per subband group basis at the base station apparatus using parameters of the parameter information transmitted at the parameter information transmission section; and
a data extracting section that demodulates and decodes the received signal received at the receiving section on a per subband group basis, using the modulation parameters and the coding parameters of the parameter information, and extracts the data contained in the received signal, and
the base station apparatus comprises:
an adaptive modulation and coding section that modulates and encodes the data in accordance with the modulation parameters and the coding parameters of the parameter information transmitted by the transmission section; and
a data transmission section that transmits the data modulated and encoded at the adaptive modulation and coding section; and
the parameter deciding section decides the coding parameters in such a manner that a number of information bits obtained by assigning a weight per subband group to a sum of information bits that are able to be assigned to all of the subbands within the subband group, is assigned to the subband group.