OFDM communication apparatus and OFDM communication method
View Patent ↗An OFDM communication apparatus that can set an optimum repetition number to data to be transmitted, thereby improving the error rate characteristic and hence the communication quality. In this apparatus, a repetition number deciding part ( 153 ) decides, based on quality information outputted from a quality information extracting part ( 152 ), a required repetition number. A systematic bit repetition number deciding part ( 154 ) decides, based on the repetition number notified of by the repetition number deciding part ( 153 ), an optimum repetition number for the systematic bit. A parity bit repetition number deciding part ( 155 ) operates similarly. Repetition parts ( 103 - 1, 103 - 2 ) repeat the bits in accordance with instructions from the systematic bit repetition number deciding part ( 154 ) and from the parity bit repetition number deciding part ( 155 ).
1. An OFDM communication apparatus comprising:
a setting section that sets a number of repetitions of data to be transmitted according to a type of the data to be transmitted, wherein the data to be transmitted is subjected to multilevel modulation; and
a transmission section that repeats the modulated data based on the number of repetitions to generate the repeated transmission data, assigns the repeated transmission data to a plurality of subcarriers so that the data having a larger contribution to error correction capability and the data having a smaller contribution to error correction capability are not mixed in the plurality of subcarriers, and transmits the repeated transmission data on the plurality of subcarriers.
2. The OFDM communication apparatus according to claim 1 , wherein:
the data to be transmitted is channel coded and includes the data having the larger contribution to error correction capability and the data having the smaller contribution to error correction capability; and
the setting section sets a larger number of repetitions for the data having the larger contribution to error correction capability than a number of repetitions for the data having the smaller contribution to error correction capability.
3. The OFDM communication apparatus according to claim 2 , wherein:
the channel coding is turbo coding;
the data having the larger contribution to error correction capability is a systematic bit; and
the data having the smaller contribution to error correction capability is a parity bit.
4. The OFDM communication apparatus according to claim 3 , wherein the setting section sets the number of repetitions of the systematic bit and the number of repetitions of the parity bit based on a ratio of the systematic bit and the parity bit that maximizes error correction capability.
5. The OFDM communication apparatus according to claim 1 , wherein the setting section sets the number of repetitions of each type of data to be transmitted so that a total number of repetitions of all the data to be transmitted becomes a predetermined value.
6. The OFDM communication apparatus according to claim 1 , wherein the setting section sets a plurality of numbers of repetitions for specific data to be transmitted and uses the plurality of numbers of repetitions equally in a plurality of OFDM symbols.
7. A communication terminal apparatus comprising the OFDM communication apparatus according to claim 1 .
8. A base station apparatus comprising the OFDM communication apparatus according to claim 1 .
9. An OFDM communication method comprising:
setting a number of repetitions of data to be transmitted according to a type of the data to be transmitted, wherein the data to be transmitted is subjected to multilevel modulation;
repeating the modulated data based on the number of repetitions to generate the repeated transmission data;
assigning the repeated transmission data to a plurality of subcarriers so that the data having a larger contribution to error correction capability and the data having a smaller contribution to error correction capability are not mixed in the plurality of subcarriers; and
transmitting the repeated transmission data on the plurality of subcarriers.