Method and apparatus for subchannel assignment for suppressing interantenna interference in OFDMA system

An apparatus for subchannel assignment in an Orthogonal Frequency Division Multiplexing Access (OFDMA) system-based distributed wireless communication system equipped with antennas that are geographically distributed in a coverage area and can simultaneously communicate with multiple Subscriber Stations (SSs), comprising:

• a processor in communication with a memory, the memory including code providing instruction to said processor to execute:
• (a) selecting and obtaining access to antennas that satisfy a data transmission rate that an SS requires and with which the SS can communicate;
• (b) re-queuing an antenna that transmits maximum power to the SS within the coverage area as a high priority, antenna;
• and
• (c) assigning subchannels to the high priority antenna, wherein the assigning of subchannels comprises the steps of
• finding subchannels used by adjacent antennas to the high priority antenna, located in sub areas adjacent to a sub area in which the high priority antenna is centered;
• and
• assigning, to the high priority antenna, subchannels excluding those used by the adjacent antennas, while assigning other subchannels to the high priority antenna even if the other subchannels are used by antennas in the coverage area located in sub areas that are non-adjacent to the sub area of the high priority antenna.

A computer program stored in a tangible non-transitory computer readable medium causing a processor in an Orthogonal Frequency Division Multiplexing (OFDM) type wireless communications system to execute the steps of:

• (a) selecting and obtaining access to antennas that satisfy a data transmission rate that an SS requires and with which the SS can communicate by determining:
• c
• k
• ,
• p
• =
• 1
• N
• ⁢
• ∑
• n
• =
• 1
• N
• ⁢
• c
• k
• ,
• n
• ,
• p
• ,
• ∀
• p
• ;
• wherein ck,p represents the number of bits per symbol;
• p
• ′
• =
• arg
• ⁢
• ⁢
• max
• p
• ⁢
• (
• c
• k
• ,
• p
• )
• wherein p represents an antenna;
• (b) re-queuing an antenna that transmits maximum power to an SS within a coverage area as a high priority antenna, as:
• p
• ′
• =
• arg
• ⁢
• ⁢
• max
• p
• ⁢
• (
• c
• k
• ,
• p
• )
• wherein p represents an antenna;
• and
• c
• p
• =
• 1
• N
• ⁢
• ∑
• k
• =
• k
• 1
• k
• 
• K
• p
• 
• ⁢
• c
• k
• ,
• p
• (c) assigning subchannels to the highest priority antenna wherein the assigning comprises
• finding subchannels used by antennas located in adjacent sub areas to a sub area within which the high priority antenna is centered;
• assigning subchannels different from the found subchannels to the high priority antenna and expressed as;
• n
• ′
• =
• arg
• ⁢
• ⁢
• max
• n
• ∈
• (
• U
• -
• V
• p
• -
• U
• p
• )
• ⁢
• (
• c
• k
• ,
• n
• ,
• p
• )
• ,
• where
• Up is a set of subchannels assigned to the antenna p, and
• Vp is a set of subchannels used by antennas adjacent to the antenna p);
• and
• assigning other subchannels to the high priority antenna even if the other subchannels are used by antennas located in sub areas of the coverage area that are non-adjacent to the sub area of the high priority antenna.

A method for determining subchannels associated with each of a plurality of geographically distributed antennas in a coverage area of an Orthogonal Frequency Division Multiplexing type wireless communication system serving a plurality of Subscriber Stations (SSs), comprising:

• receiving information regarding each of the antennas for determining the data transmission rate required;
• designating an antenna transmitting maximum power to an SS as a high priority antenna;
• re-queuing each of the remaining antennas in an order with regard to the designated antenna;
• assigning subchannels to the high priority antenna by finding subchannels used by antennas located in adjacent sub area to a sub area within which the high priority antenna is centered and assigning subchannels to the high priority antenna excluding the found subchannels while assigning other subchannels to the high priority antenna even if the other subchannels are used by antennas in the coverage area located in sub areas that are non-adjacent to the sub area of the high priority antenna.

An apparatus for determining subchannels associated with each of a plurality of geographically distributed antennas in a coverage area of an Orthogonal Frequency Division Multiplexing type wireless communication system serving a plurality of Subscriber Stations (SSs), comprising:

• a processor in communication with a memory, the memory containing code which when accessed by the processor causes the processor to execute the steps of:
• receiving information regarding each of the antennas for determining the data transmission rate required;
• designating an antenna transmitting maximum power to an SS as a high priority antenna;
• re-queuing each of the remaining antennas in an order with regard to the designated antenna;
• assigning subchannels to the high priority antennas by finding subchannels used by antennas located in adjacent sub areas to a sub area within which the high priority antenna is centered and assigning subchannels to the high priority antenna excluding the found subchannels while assigning other subchannels to the high priority antenna even if the other subchannels are used by antennas in the coverage area located in sub areas that are non-adjacent to the sub area of the high priority antenna.