Method for increasing spectrum efficiency in an OFDM based multi-bandwidth wireless system
View Patent ↗A method is provided for operating a multi-bandwidth OFDMA system that can achieve an enhanced bandwidth efficiency due to windowing without significantly impacting the underlying physical design of the receive filters. The method comprises establishing a bandwidth over which the radio resources transmit signals, the bandwidth being comprised of an edge-band and a center-band. Narrow band radio resources are assigned to a portion of the bandwidth that is at least partially within the edge-band.
1. A method for managing radio resources of an orthogonal frequency division multiple access (OFDMA) wireless communication system configured to provide wireless connectivity to multiple mobile units that communicate using different bandwidths, the method comprising:
allocating radio resources to at least one first mobile unit in at least one of two edge-bands when the bandwidth capability of said at least one first mobile unit is less than or approximately equal to the bandwidth of the edge bands; and
allocating radio resources to at least one second mobile unit in a center-band when the bandwidth of the center band is large enough to support the bandwidth capability of said at least one second mobile unit and the bandwidth of the edge bands is insufficient to support the bandwidth capability of said at least one second mobile unit because the bandwidth capability of said at least one second mobile unit is greater than the bandwidth of the edge bands, wherein the center band is bracketed by the edge bands.
2. The method of claim 1 , wherein allocating radio resources to said at least one second mobile unit comprises scheduling said at least one second mobile unit on at least one frequency within the center-band.
3. The method of claim 2 , wherein scheduling said at least one second mobile unit on at least one frequency within the center-band comprises allocating a sub-frame or tone in the center-band to said at least one-second mobile unit.
4. The method of claim 1 , wherein allocating radio resources to said at least one first mobile unit comprises scheduling said at least one first mobile unit on at least one frequency within the edge-band.
5. The method of claim 4 , wherein scheduling said at least one first mobile unit on at least one frequency within the center-band comprises allocating a sub-frame or tone in the edge-band to said at least one first mobile unit.
6. The method of claim 1 , wherein allocating radio resources to said at least one first mobile unit and said at least one second mobile unit comprises at least one of a directly mapping user data to subframes or tones, pre-coding the user data before performing an inverse fast Fourier transform and mapping user data to the subframes or tones, or separately multiplexing the inverse fast Fourier transformed user data and mapping the user data to the subframes or tones.
7. The method of claim 1 , wherein the bandwidth of the edge bands is approximately 1.25 MHz and wherein allocating radio resources to said at least one first mobile unit in said at least one of the two edge-bands comprises allocating radio resources to said at least one first mobile unit when the bandwidth capability of the first mobile unit is approximately 1.25 MHz.
8. The method of claim 7 , wherein the bandwidth of the center band is greater than or equal to 10 MHz, and wherein allocating radio resources to said at least one second mobile unit in the center band comprises allocating radio resources to said at least one second mobile unit when the bandwidth capability of the second mobile unit is greater than 1.25 MHz.