Method for allocating a subchannel in an orthogonal frequency division multiple access cellular communication system
A method for allocating a subchannel in a transmitter of an Orthogonal Frequency Division Multiple Access (OFDMA) cellular communication system in which an entire frequency band includes a plurality of bands, each of the bands includes a plurality of bins, and each of the bins includes a plurality of subcarriers. The method includes dividing a predetermined time interval into an Adaptive Modulation and Coding (AMC) subchannel time interval and a diversity subchannel time interval; selecting any one of the plurality of bands in the AMC subchannel time interval; selecting a predetermined number of bins among the plurality of bins in the selected band; and allocating the selected bins to the AMC subchannel.
1. A method for allocating a subchannel by a transmitter in an Orthogonal Frequency Division Multiple Access (OFDMA) communication system in which an entire frequency band includes a plurality of bands, each of the plurality of bands includes a plurality of bins, and each of the plurality of bins includes a plurality of subcarriers, the method comprising:
selecting, by the transmitter, any one of the plurality of bands in an Adaptive Modulation and Coding (AMC) subchannel time interval;
selecting, by the transmitter, a predetermined number of bins among the plurality of bins in the selected band; and
allocating, by the transmitter, the selected bins as an AMC subchannel,
wherein a predetermined time interval is divided into the AMC subchannel time interval and a diversity subchannel time interval.
2. The method of claim 1 , wherein the predetermined time interval is divided into the AMC subchannel time interval and the diversity subchannel time interval according to a ratio of the AMC subchannel time interval to the diversity subchannel time interval, and the ratio is determined
according to a number of receivers requesting allocation of the AMC subchannels.
3. The method of claim 1 , wherein selecting the any one of the plurality of bands in the AMC subchannel time interval comprises selecting the any one of the plurality of bands according to channel quality information fed back from a receiver.
4. The method of claim 1 , wherein a unit time interval of each of the AMC subchannel time interval and the diversity subchannel time interval is a symbol time interval.
5. The method of claim 1 , further comprising:
selecting any one of subcarriers in each of a plurality of groups; and
allocating the selected subcarrier as the diversity subchannel,
wherein the entire frequency band is divided into the plurality of groups in the diversity subchannel time interval.
6. The method of claim 5 , wherein selecting the any one of the subcarriers in each of the plurality of groups comprises selecting the any one of subcarriers in each of the plurality of groups according to a diversity subchannel sequence.
7. The method of claim 1 , wherein subcarriers included in each of the plurality of bins are neighbor subcarriers.
8. The method of claim 1 , wherein the predetermined number of bins allocated as the AMC subchannel are one of neighbor bins and spaced-apart bins.
9. A method for allocating a subchannel by a transmitter in an Orthogonal Frequency Division Multiple Access (OFDMA) communication system in which an entire frequency band includes a plurality of bands, each of the plurality of bands includes a plurality of bins, and each of the plurality of bins includes a plurality of subcarriers, the method comprising:
allocating, by the transmitter, an Adaptive Modulation and Coding (AMC) subchannel in an AMC subchannel time interval; and
allocating, by the transmitter, a diversity subchannel in a diversity subchannel time interval,
wherein a predetermined time interval is divided into the AMC subchannel time interval and the diversity subchannel time interval, and
wherein allocating the diversity subchannel comprises:
selecting any one of the subcarriers in each of a plurality of groups; and
allocating the selected subcarrier as the diversity subchannel,
wherein the frequency band is divided into the plurality of groups in the diversity subchannel time interval.
10. The method of claim 9 , wherein selecting the any one of subcarriers in each of the plurality of groups comprises selecting the any one of subcarriers in each of the plurality of groups according to a diversity subchannel sequence.
11. The method of claim 9 , wherein the predetermined time interval is divided into the AMC subchannel time interval and the diversity subchannel time interval according to a ratio of the AMC subchannel time interval to the diversity subchannel time interval, and the ratio is determined
according to a number of receivers requesting allocation of the AMC subchannels.
12. The method of claim 9 , wherein a unit time interval of each of the AMC subchannel time interval and the diversity subchannel time interval is a symbol time interval.
13. The method of claim 9 , wherein subcarriers included in each of the plurality of bins are neighbor subcarriers.