Method and apparatus for improving RF coverage area in a wireless network

1. A method comprising:

first determining a period between successive orthogonal frequency division multiple access (OFDMA) frames in a wireless OFDMA channel;

second determining a period between successive packets in a constant bit rate input packet stream; and

when there are multiple OFDMA frames for each packet in said constant bit rate input packet stream, fragmenting each packet for transmission through said wireless OFDMA channel by reducing a number of frequency sub-channels carrying information for a user, increasing a power of said frequency sub-channels, and increasing a number of frames in each packet to carry said information for said user to provide an increased time diversity capacity gain by using at least two of said multiple OFDMA frames to achieve a higher frequency sub-channelization gain than would be achieved by transmitting each packet within a single OFDMA frame.

2. The method of claim 1 , wherein:

fragmenting is only performed when a predetermined modulation and coding scheme (MCS) is being used by a corresponding subscriber station, wherein said MCS changes with time based on changing channel conditions.

3. The method of claim 2 , wherein:

said predetermined MCS is an MCS that is used when said corresponding subscriber station is at a cell edge.

4. The method of claim 1 , wherein:

fragmenting a data packet includes fragmenting said data packet into portions that each fit within a single sub-channel of an OFDMA frame.

5. The method of claim 1 , wherein:

the higher frequency sub-channelization gain is approximated by 10log N/m-10log N/s, wherein N represents the number of frequency sub-channels in a channel bandwidth, m represents the number of frequency sub-channels that a subscriber station uses to transmit the multiple OFDMA frames, and s represents the number of frequency sub-channels that a subscriber station uses to transmit the single OFDMA frame.

6. A method comprising:

determining that an uplink (UL) bandwidth allocation is needed for a wireless device to transmit a data packet to a wireless base station through an OFDMA channel;

when a modulation and coding scheme (MCS) assigned to said wireless device is not a first MCS, scheduling an unfragmented UL bandwidth allocation for said wireless device over a single OFDMA frame; and

when said MCS assigned to said wireless device is said first MCS, scheduling a fragmented UL bandwidth allocation for said wireless device over multiple OFDMA frames to improve frequency sub-channelization gain, wherein said fragmented UL bandwidth allocation reduces a number of frequency sub-channels carrying information for said wireless device, increases a power of said frequency sub-channels, and increases a number of frames in each packet to carry said information for said wireless device to provide an increased time diversity capacity gain.

7. The method of claim 6 , wherein:

said first MCS is an MCS that is assigned when said wireless device is at a cell edge.

8. The method of claim 6 , wherein:

said fragmented UL bandwidth allocation is only scheduled when a maximum transmit power of said wireless device is above, a predetermined threshold level.

9. The method of claim 6 , wherein:

said first MCS is quadrature phase shift keying (QPSK) ½.

10. An apparatus comprising:

a wireless orthogonal frequency division multiple access (OFDMA) transmitter to transmit data to one or more subscriber stations within downlink subframes of OFDMA frames;

a wireless OFDMA receiver to receive data from one or more subscriber stations within uplink subframes of said OFDMA frames; and

a scheduler to schedule communications between said one or more subscriber stations and said apparatus, wherein said scheduler schedules bandwidth (BW) resources within multiple successive OFDMA frames for use by a first subscriber station to transmit a data packet to said apparatus when a channel quality of a channel between said first subscriber station and said apparatus meets a first criterion, to enhance frequency sub-channelization gain, wherein said bandwidth (BW) resources within multiple successive OFDMA frames reduces a number of frequency sub-channels carrying information for said wireless device, increases a power of said frequency sub-channels, and increases a number of frames in each packet to carry said information for said wireless device to provide an increased time diversity capacity gain, and said scheduler schedules BW resources within a single OFDMA frame for use by said first subscriber station to transmit said data packet to said apparatus when a channel quality of said channel between said first subscriber station and said apparatus meets a second criterion, said second criterion being different from said first criterion.

11. The apparatus of claim 10 , wherein:

said channel quality meets said first criterion when a modulation and coding scheme (MCS) assigned to said first subscriber station is a first MCS.

12. The apparatus of claim 11 , wherein:

said channel quality meets said second criterion when said MCS assigned to said first subscriber station is not said first MCS.

13. The apparatus of claim 11 , wherein:

said scheduler only schedules BW resources within multiple successive OFDMA frames for use by said first subscriber station to transmit said data packet to said apparatus when said channel quality for said channel between said first subscriber station and said apparatus meets said first criterion and a maximum transmit power of said first subscriber station is above a predetermined threshold level.

14. The apparatus of claim 11 , wherein:

said first MCS is QPSK ½.

15. A system comprising:

a dipole antenna;

a wireless orthogonal frequency division multiple access (OFDMA) transmitter, coupled to said dipole antenna, to transmit data to one or more subscriber stations within downlink subframes of OFDMA frames;

a wireless OFDMA receiver to receive data from one or more subscriber stations within uplink subframes of said OFDMA frames; and

a scheduler to schedule communications between said one or more subscriber stations and said system, wherein said scheduler schedules bandwidth (BW) resources within multiple successive OFDMA frames for use by a first subscriber station to transmit a data packet to said system when a channel quality of a channel between said first subscriber station and said system meets a first criterion, to enhance frequency sub-channelization gain, wherein said bandwidth (BW) resources within multiple successive OFDMA frames reduces a number of frequency sub-channels carrying information for said wireless device, increases a power of said frequency sub-channels, and increases a number of frames in each packet to carry said information for said wireless device to provide an increased time diversity capacity gain, and said scheduler schedules BW resources within a single OFDMA frame for use by said first subscriber station to transmit said data packet to said system when a channel quality of said channel between said first subscriber station and said system meets a second criterion, said second criterion being different from said first criterion.

16. The system of claim 15 , wherein:

said channel quality meets said first criterion when a modulation and coding scheme (MCS) assigned to said first subscriber station is a first MCS.

17. The system of claim 16 , wherein:

said channel quality meets said second criterion when said MCS assigned to said first subscriber station is not said first MCS.

18. The system of claim 16 , wherein:

said scheduler only schedules BW resources within multiple successive OFDMA frames for use by said first subscriber station to transmit said data packet to said system when said channel quality of said channel between said first subscriber station and said system meets said first criterion and a maximum transmit power of said first subscriber station is above a predetermined threshold level.

19. An article comprising a non-transitory computer readable storage medium having computer executable instructions stored thereon that, when executed by a computing platform, operate to:

determine that an uplink (UL) bandwidth allocation is needed for a wireless device to transmit a data packet to a wireless base station through an OFDMA channel;

when a modulation and coding scheme (MCS) assigned to said wireless device is not a first MCS, schedule an unfragmented UL bandwidth allocation for said wireless device over a single OFDMA frame; and

when said MCS assigned to said wireless device is said first MCS, schedule a fragmented UL bandwidth allocation for said wireless device over multiple OFDMA frames to improve frequency sub-channelization gain, wherein said fragmented UL bandwidth allocation reduces a number of frequency sub-channels carrying information for said wireless device, increases a power of said frequency sub-channels, and increases a number of frames in each packet to carry said information for said wireless device to provide an increased time diversity capacity gain.

20. The article of claim 19 , wherein:

said fragmented UL bandwidth allocation is only scheduled when a maximum transmit power of said wireless device is above a predetermined threshold level.

21. The article of claim 19 , wherein:

said first MCS is quadrature phase shift keying (QPSK) ½.