Master station and method for high-efficiency wi-fi (hew) communication with a minimum ofdma bandwidth unit

Abstract

Embodiments of a master station and method for communicating in a Wi-Fi network in accordance with a high-efficiency Wi-Fi (HEW) technique are generally described herein. In some embodiments, the master station is configured to communicate with scheduled stations using the antennas within a bandwidth comprising one or more 20 MHz Wi-Fi channels using a plurality of minimum orthogonal frequency division multiple access (OFDMA) bandwidth units during an OFDMA control period during which the master station has exclusive control of a wireless medium. Each minimum OFDMA bandwidth unit may comprise a predetermined number of subcarriers that do not include guard subcarriers of the channel wherein the guard subcarriers are provided at band edges of the bandwidth, the guard subcarriers being in addition to the subcarriers of each of the minimum OFDMA bandwidth units. In some embodiments, no guard subcarriers are provided between the minimum OFDMA bandwidth units within a 20 MHz channel.

What is claimed is: 
     
         1 . A master station comprising hardware processing circuitry including physical-layer circuitry and medium-access control layer circuitry and configured to communicate in a Wi-Fi network, the hardware processing circuitry configured to:
 communicate with scheduled stations within a bandwidth comprising one or more channels using a plurality of minimum orthogonal frequency division multiple access (OFDMA) bandwidth units during an OFDMA control period during which the master station has exclusive control of a wireless medium,   wherein each minimum OFDMA bandwidth unit comprises a predetermined number of subcarriers that do not include guard subcarriers of the channel.   
     
     
         2 . The master station of  claim 1  wherein the guard subcarriers are provided at band edges of the bandwidth, the guard subcarriers being in addition to the subcarriers of each of the minimum OFDMA bandwidth units, and
 wherein no guard subcarriers are provided between the minimum OFDMA bandwidth units of a channel. 
 
     
     
         3 . The master station of  claim 1  wherein each channel is a 20 MHz channel, and
 wherein when the channel is a wideband channel and comprises two or more adjacent 20 MHz channels, no guard subcarriers are provided between adjacent minimum OFDMA bandwidth units of the two or more adjacent 20 MHz channels. 
 
     
     
         4 . The master station of  claim 3  wherein for processing signals of a 20 MHz channel with a 64-point FFT, the predetermined number of data and pilot subcarriers for each minimum OFDMA bandwidth unit is fourteen (14) with a subcarrier spacing of 312.5 KHz, and
 wherein each minimum OFDMA bandwidth unit occupies a bandwidth of 4.375 MHz. 
 
     
     
         5 . The master station of  claim 3 , wherein for processing with a 20 MHz channel with a 256-point FFT, the predetermined number of data and pilot subcarriers for each minimum OFDMA bandwidth unit is fourteen (14), and
 wherein each minimum OFDMA bandwidth unit occupies a bandwidth of 1.09375 MHz.   
     
     
         6 . The master station of  claim 4  wherein each channel is a 20 MHz channel comprising four minimum OFDMA bandwidth units,
 wherein the channel utilized by the master station for communicating with the scheduled stations during the OFDMA control period comprises one or more adjacent 20 MHz channels, 
 wherein for communicating with scheduled stations during the OFDMA control period using a channel comprising a single 20 MHz channel, the single 20 MHz channel is configured to provide four minimum OFDMA bandwidth units for a total of 56 data subcarriers, in addition to a DC subcarrier and seven (7) guard subcarriers at the band edges. 
 
     
     
         7 . The master station of  claim 6  wherein for communicating with scheduled stations during the OFDMA control period using a wideband channel comprising two or more adjacent 20 MHz channels, the master station is configured to allocate the minimum OFDMA bandwidth units of the two or more adjacent 20 MHz channels without guard subcarriers therebetween. 
     
     
         8 . The master station of  claim 7  wherein for communicating with scheduled stations during the OFDMA control period using a wideband bandwidth comprising two contiguous 20 MHz channels for a bandwidth of 40 MHz, the master station is configured to allocate up to eight minimum OFDMA bandwidth units of fourteen (14) subcarriers each for a total of 112 data and pilot subcarriers, a DC subcarrier and seven (7) guard subcarriers at the band edges. 
     
     
         9 . The master station of  claim 8  wherein for communicating with scheduled stations during the OFDMA control period using a wideband channel comprising four contiguous 20 MHz channels for a bandwidth of 80 MHz, the master station is configured to allocate up to seventeen (17) minimum OFDMA bandwidth units of fourteen (14) subcarriers each for a total of up to 238 data and pilot subcarriers, a DC subcarrier and seven (7) guard subcarriers at the band edges. 
     
     
         10 . The master station of  claim 9  wherein for communicating with scheduled stations during the OFDMA control period using a wideband channel comprising a bandwidth of eight contiguous 20 MHz channels for a bandwidth of 160 MHz, the master station is configured to allocate up to thirty-six (36) minimum OFDMA bandwidth units of fourteen (14) subcarriers each for a total of up to data and pilot subcarriers, a DC subcarrier and seven (7) guard subcarriers at the band edges. 
     
     
         11 . The master station of  claim 9  wherein for communicating with scheduled stations during the OFDMA control period using a wideband channel comprising two non-contiguous 80 MHz wideband channels for a bandwidth of 160 MHz,
 wherein for each 80 MHz wideband channel, the master station is configured to allocate up to seventeen (17) minimum OFDMA bandwidth units of fourteen (14) subcarriers each for a total of up to 238 data and pilot subcarriers, a DC subcarrier and seven (7) guard subcarriers at the band edges. 
 
     
     
         12 . The master station of  claim 2  wherein the master station is configured to allocate bandwidth to the scheduled stations based on the minimum OFDMA bandwidth unit for communication with the master station during the control period,
 wherein the scheduled stations are high-efficiency wireless (HEW) stations and the master station is an access point configured for HEW communications with the HEW stations and configured for legacy communications with legacy stations, 
 wherein the minimum OFDMA bandwidth units are configurable to be time and frequency multiplexed within the control period, and 
 wherein during the control period: 
 packets are received from the scheduled stations in accordance with an uplink SDMA technique using OFDMA, or 
 packets are transmitted to the scheduled stations in accordance with downlink multiplexing technique using OFDMA, 
 wherein the master station is further configured to: 
 transmit, during an initial portion of the control period, a master-sync transmission that includes a multi-device preamble arranged to signal and identify data fields for the plurality of scheduled stations, 
 wherein the master-sync transmission identifies parameters of the minimum OFDMA bandwidth units for use by the scheduled stations for communicating with the master station during the control period, and 
 wherein communications during the control period use the minimum OFDMA bandwidth unit. 
 
     
     
         13 . The master station of  claim 1  wherein the guard subcarriers are provided at band edges of the bandwidth, the guard subcarriers being in addition to the subcarriers of each of the minimum OFDMA bandwidth units, and
 wherein extra subcarriers are provided between the minimum OFDMA bandwidth units of a channel. 
 
     
     
         14 . A method for communicating in a Wi-Fi network performed by a master station, the method comprising:
 communicating with scheduled stations within a bandwidth comprising one or more channels using a plurality of minimum orthogonal frequency division multiple access (OFDMA) bandwidth units during an OFDMA control period during which the master station has exclusive control of a wireless medium,   wherein each minimum OFDMA bandwidth unit comprises a predetermined number of subcarriers that do not include guard subcarriers of the channel.   
     
     
         15 . The method of  claim 14  wherein the guard subcarriers are provided at band edges of the bandwidth, the guard subcarriers being in addition to the subcarriers of each of the minimum OFDMA bandwidth units, and
 wherein no guard subcarriers are provided between the minimum OFDMA bandwidth units of a channel. 
 
     
     
         16 . The method of  claim 14  wherein each channel is a 20 MHz channel, and
 wherein when the channel is a wideband channel and comprises two or more adjacent 20 MHz channels, no guard subcarriers are provided between adjacent minimum OFDMA bandwidth units of the two or more adjacent 20 MHz channels. 
 
     
     
         17 . The method of  claim 16  wherein for processing signals of a 20 MHz channel with a 64-point FFT, the predetermined number of data and pilot subcarriers for each minimum OFDMA bandwidth unit is fourteen (14) with a subcarrier spacing of 312.5 KHz, and
 wherein each minimum OFDMA bandwidth unit occupies a bandwidth of 4.375 MHz. 
 
     
     
         18 . A non-transitory computer-readable storage medium that stores instructions for execution by one or more processors to perform operations for communicating in a Wi-Fi network performed by a master station, the operations to configure the master station to:
 communicate with scheduled stations within a bandwidth comprising one or more channels using a plurality of minimum orthogonal frequency division multiple access (OFDMA) bandwidth units during an OFDMA control period during which the master station has exclusive control of a wireless medium,   wherein each minimum OFDMA bandwidth unit comprises a predetermined number of subcarriers that do not include guard subcarriers of the channel.   
     
     
         19 . The non-transitory computer-readable storage medium of  claim 18  wherein the guard subcarriers are provided at band edges of the bandwidth, the guard subcarriers being in addition to the subcarriers of each of the minimum OFDMA bandwidth units, and
 wherein no guard subcarriers are provided between the minimum OFDMA bandwidth units within a 20 MHz channel. 
 
     
     
         20 . The non-transitory computer-readable storage medium of  claim 19  wherein for processing signals of a 20 MHz channel with a 64-point FFT, the predetermined number of data and pilot subcarriers for each minimum OFDMA bandwidth unit is fourteen (14) with a subcarrier spacing of 312.5 KHz, and
 wherein each minimum OFDMA bandwidth unit occupies a bandwidth of 4.375 MHz. 
 
     
     
         21 . A master station comprising:
 one or more radios;   a memory;   physical-layer circuitry and medium-access control layer circuitry and configured for communicating in a Wi-Fi network in accordance with a high-efficiency Wi-Fi (HEW) technique, the circuitry configured to:   communicate with scheduled stations using the antennas within a bandwidth comprising one or more 20 MHz Wi-Fi channels using a plurality of minimum orthogonal frequency division multiple access (OFDMA) bandwidth units during an OFDMA control period during which the master station has exclusive control of a wireless medium,   wherein each minimum OFDMA bandwidth unit comprises a predetermined number of subcarriers that do not include guard subcarriers of the channel wherein the guard subcarriers are provided at band edges of the bandwidth, the guard subcarriers being in addition to the subcarriers of each of the minimum OFDMA bandwidth units,   wherein no guard subcarriers are provided between the minimum OFDMA bandwidth units within a 20 MHz channel,   wherein for processing signals of each 20 MHz channel with a 64-point FFT, the predetermined number of data and pilot subcarriers for each minimum OFDMA bandwidth unit is fourteen (14) with a subcarrier spacing of 312.5 KHz, and   wherein each minimum OFDMA bandwidth unit occupies a bandwidth of 4.375 MHz.   
     
     
         22 . The master station of  claim 21  wherein for communicating with scheduled stations during the OFDMA control period using a wideband channel comprising two or more adjacent 20 MHz channels, the master station is configured to allocate the minimum OFDMA bandwidth units of the two or more adjacent 20 MHz channels without guard subcarriers therebetween. 
     
     
         23 . The master station of  claim 22  further comprising one or more antennas coupled to the one or more radios.