Method for supporting various multi-antenna schemes in BWA system using multiple antennas
Disclosed is a method for using various multiple antenna schemes in a baseband wireless access system is provided. According to the method, a downlink MAP message is constructed in order to support various multiple antenna schemes based on a multiple-input multiple output (MIMO), which is one of the multiple antenna schemes, so that compatibility with exiting MIMO technology having no MIMO feedback can be achieved and overhead occurring in transmission of an MAP information element can be reduced. Further, it is possible to efficiently support spatial multiplexing technology capable of transmitting multiple layers having different modulation and coding in a MIMO system.
1. A method for supporting various Multiple Input Multiple Output (MIMO) technology in a Broadband Wireless Access (BWA) system, the method comprising the steps of:
communicating with a mobile station, by a base station, by using a downlink MAP message comprising a first field indicating a MIMO technology and a precoding technology, a second field indicating a number of layers determined by a number of sets of encoders and modulators, and a third field indicating a number of output streams of a space time coding encoder,
wherein the second field and the third field are used to indicate a transmission matrix used for encoding.
2. The method as claimed in claim 1 , wherein the first field indicates whether an antenna grouping MIMO mode and an antenna selection MIMO mode are set up.
3. The method as claimed in claim 2 , wherein the downlink MAP message comprises a plurality of antenna grouping indexes, each representing a matrix indicated according to the number of layers and the number of output streams, when the first field is set to a value indicating the antenna grouping MIMO mode.
4. The method as claimed in claim 2 , wherein the downlink MAP message comprises a plurality of antenna selecting indexes each representing a matrix indicated according to the number of layers and the number of output streams, when the first field is set to a value indicating the antenna selecting MIMO mode.
5. The method as claimed in claim 1 , wherein the downlink MAP message comprises a matrix indicator field indicating the transmission matrix.
6. The method as claimed in claim 1 , wherein the downlink MAP message comprises a field indicating whether a MIMO mode is changed.
7. The method as claimed in claim 1 , wherein the downlink MAP message comprises a field indicating the number of CQI channels allocated to the mobile station, a field indicating a type of a feedback information transmitted from the mobile station, and a field indicating allocation information of the CQI channel.
8. An apparatus for supporting various Multiple Input Multiple Output (MIMO) technology in a Broadband Wireless Access (BWA) communication system, the apparatus comprising:
a base station for communicating with a mobile station by using a downlink MAP message comprising a first field indicating a MIMO technology and a precoding technology, a second field indicating a number of layers determined by a number of sets of encoders and modulators, and a third field indicating a number of output streams of a space time coding encoder, and wherein the second field and the third field are used to indicate a transmission matrix used for encoding
9. The method-apparatus as claimed in claim 8 , wherein the first field indicates whether an antenna grouping MIMO mode and an antenna selection MIMO mode are set up.
10. The apparatus as claimed in claim 9 , wherein the downlink MAP message comprises a plurality of antenna grouping indexes, each representing a matrix indicated according to the number of layers and the number of output streams, when the first field is set to a value indicating the antenna grouping MIMO mode.
11. The apparatus as claimed in claim 9 , wherein the downlink MAP message comprises a plurality of antenna selecting indexes, each representing a matrix indicated according to the number of layers and the number of output streams, when the first field is set to a value indicating the antenna selecting MIMO mode.
12. The apparatus as claimed in claim 8 , wherein the downlink MAP message comprises a matrix indicator field indicating the transmission matrix.
13. The apparatus as claimed in claim 8 , wherein the downlink MAP message comprises a field indicating whether a MIMO mode is changed.
14. The apparatus as claimed in claim 8 , wherein the downlink MAP message comprises a field indicating the number of COI channels allocated to the mobile station, a field indicating a type of a feedback information transmitted from the mobile station, and a field indicating allocation information of the COI channel.