COMMUNICATION APPARATUS, COMMUNICATION SYSTEM, AND COMMUNICATION METHOD

• US 20090147866A1
• Filed: 11/18/2005
• Published: 06/11/2009
• Est. Priority Date: 11/19/2004
• Status: Active Grant

• Current Assignee: INVT SPE LLC (SoftBank Group Corp.)
• Original Assignee: Matsushita Electric Industrial Company Limited (Panasonic Holdings Corporation)
• Inventors: She, Xiaoming, Li, Jifeng
• Granted Patent: US 7,848,439 B2
• Time in Patent Office: Days
• US Class Current: 375/260
• CPC Class Codes: H04L 1/0005 applied to payload information
• CPC Class Codes: H04L 1/0011 applied to payload information
• CPC Class Codes: H04L 1/0036 arrangements specific to the receiver
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/0039 Frequency-contiguous, i.e. with no allocation of frequencies for one user or terminal between the frequencies allocated to another
• CPC Class Codes: H04L 5/0044 allocation of payload
• CPC Class Codes: H04L 5/0053 Allocation of signaling, i.e. of overhead other than pilot signals
• CPC Class Codes: H04L 5/006 Quality of the received signal, e.g. BER, SNR, water filling
• CPC Class Codes: H04L 5/0064 Rate requirement of the data, e.g. scalable bandwidth, data priority
• CPC Class Codes: H04L 5/0096 Indication of changes in allocation

Abstract

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.

Claims

1. A communication apparatus comprising:

a channel estimating section that carries out channel estimation per subband;

a parameter deciding section that decides modulation parameters and coding parameters per subband group comprised of a plurality of subbands based on the channel estimation result;

a parameter information transmission section that transmits to a communicating party, parameter information that is information for the modulation parameters and the coding parameters decided at the parameter deciding section;

a receiving section that receives a received signal containing data modulated and encoded per subband group at a 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 per subband group using the modulation parameters and coding parameters decided at the parameter deciding section and obtains the data contained in the received signal.

2. The communication apparatus of claim 1, further comprising a pattern storage section that stores patterns for selecting subbands constituting the subband groups in advance, 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.

3. The communication apparatus of claim 2, wherein the parameter deciding section decides the modulation parameters and the coding parameters per subband group constituted from the patterns for selecting a plurality of subbands neighboring on the frequency axis.

4. The communication apparatus of claim 2, wherein the parameter deciding section decides the modulation parameters and the coding parameters per subband group constituted from the patterns for selecting the plurality of subbands at predetermined intervals from subbands arranged on the frequency axis.

5. The communication apparatus of claim 2, wherein the parameter deciding section decides the modulation parameters and the coding parameters per subband group constituted from the patterns selecting all subbands per predetermined time domain.

6. The communication apparatus of claim 1, wherein the parameter deciding section finds the modulation parameters per subband within the subband group, and decides a modulation parameters with a highest classification within the found modulation parameters as the modulation parameters for the subband group.

7. The communication apparatus of claim 1, wherein the parameter deciding section decides the coding parameters in such a manner that the 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.

8. The communication apparatus of claim 1, wherein the parameter deciding section decides the coding parameters in such a manner that the number of information bits obtained by assigning a weight to the sum of the 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.

9. A base station apparatus that are a communicating party of the communication apparatus of claim 1, the base station apparatus comprising an adaptive modulating/coding section that modulates and encodes 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 modulated and encoded data subjected to modulation and coding at the adaptive modulating/coding section.

10. A communication system comprising a base station apparatus transmitting modulated and encoded data and a communication terminal apparatus receiving the data, the communication terminal apparatus comprising:

a channel estimating section that carries out channel estimation per subband;

a parameter deciding section that decides modulation parameters and coding parameters per subband group comprised of a plurality of subbands based on channel estimation results;

a parameter information transmission section that transmits parameter information that is information for the modulation parameters and the coding parameters decided at the parameter deciding section;

a receiving section that receives a received signal containing data modulated and encoded per subband group at the base station apparatus using parameters of parameter information transmitted at the parameter information transmission section; and

a data extracting section that modulates and decodes a received signal received at the receiving section per subband group using the modulation parameters and the coding parameters of the parameter information and extracts the data contained in the received signal, wherein the base station apparatus comprises an adaptive modulating/coding section that modulates and encodes data in accordance with the modulation parameters and coding parameters of the parameter information transmitted by the transmission section; and

a data transmission section that transmits data modulated and encoded at the adaptive modulating/coding section.

11. A communication method comprising the steps of:

carrying out channel estimation per subband;

deciding modulation parameters and coding parameters per subband group comprised of a plurality of subbands based on the channel estimation results;

at a communication terminal apparatus, transmitting parameter information that is information for the decided modulation parameters and coding parameters;

at a base station apparatus, receiving the parameter information transmitted by the communication terminal apparatus;

modulating and coding data in accordance with the modulation parameters and the coding parameters of the received parameter information;

at the base station apparatus, transmitting the modulated and encoded data;

at the communication terminal apparatus, receiving a received signal containing the data transmitted by the base station apparatus; and

modulating and decoding the received signal per subband group using the modulation parameters and the coding parameters of the parameter information, and extracting data contained in the received signal.

12. The communication method of claim 11, further comprising storing patterns for selecting subbands constituting the subband groups in advance,

wherein the modulation parameters and the coding parameters are decided per subband group comprised of the selected subbands based on the stored patterns.