TWI572173B - Master station and method for high-efficiency wi-fi (hew) communication with a minimum ofdma bandwidth unit - Google Patents

Description

For high performance with minimum orthogonal frequency division multiple access (OFDMA) bandwidth units Main station and method of WI-FI (HEW) communication Priority claim

The present application claims the benefit of priority to U.S. Patent Application Serial No. 14/447,254, filed on Jul. 30, 2014, which is hereby incorporated herein in No., dated November 19, 2013, serial number 61/973, 376, submitted on April 1, 2014, serial number 61/976,951, submitted on April 8, 2014, serial number 61/986, 256, Submitted on April 30, 2014, serial number 61/986, 250, submitted on April 30, 2014, serial number 61/991, 730, submitted on May 12, 2014, serial number 62/013, 869, 2014 Submitted on June 18, and Serial No. 62/024, 801, filed on Jul. 15, 2014, the entire disclosure of which is incorporated herein by reference.

Field of invention

Embodiments relate to wireless networks. Some embodiments relate to wireless local area networks (WLANs), Wi-Fi networks, and one of the IEEE 802.11 standards. Operating networks such as the IEEE 802.11ac standard or the IEEE 802.11ax SIG (referred to as DensiFi). Some embodiments relate to high performance wireless or high performance WLAN (HEW) communications.

Background of the invention

Wi-Fi communication has evolved towards increasing data rates (eg, from IEEE 802.11a/g to IEEE 802.11n to IEEE 802.11ac). The upcoming IEEE 802.11ax task group for HEW is an evolutionary standard for this standard. HEW intends to provide an increase in data capacity while maintaining compatibility with legacy systems. There is a general need to achieve an increase in data capacity while maintaining compatibility with legacy systems.

According to an embodiment of the present invention, a primary station is specifically provided, which includes a hardware processing circuit including a physical layer circuit and a medium access control layer circuit, and is configured to be combined in a Wi-Fi network. Medium communication, the hardware processing circuit is configured to perform the following actions: during an orthogonal frequency division multiple access (OFDMA) control period, including a frequency using one or more channels of multiple minimum OFDMA bandwidth units Widely communicating with the scheduling station, during the OFDMA control period, the primary station has dedicated control for a wireless medium, wherein each minimum OFDMA bandwidth unit includes a predetermined number of subcarriers, which does not include protection of the channel Subcarrier.

100‧‧‧HEW Network

102‧‧‧Main station

104‧‧‧HEW station/schedule station/high efficiency wireless (HEW) station

106‧‧‧Old station

202‧‧5MHz band allocation segment

202A~202D‧‧‧5MHz band allocation segment

204‧‧‧Protected subcarrier/band edge

401‧‧‧ bandwidth

402‧‧‧OFDMA bandwidth unit/minimum OFDMA bandwidth unit

404‧‧‧ Band edge

501‧‧‧Bandwidth/Broadband Bandwidth

504‧‧‧ Band edge

600‧‧‧HEW device

602‧‧‧Physical Layer (PHY) Circuit/PHY

604‧‧‧Media Access Control Layer Circuit (MAC)/MAC

606‧‧‧Processing Circuit

608‧‧‧ memory

Figure 1 illustrates an HEW network in accordance with some embodiments; 2 illustrates a subcarrier configuration of a 20 MHz channel grouped with a 5 MHz subchannel; FIG. 3 illustrates a subcarrier configuration for 20 MHz, 40 MHz, 80 MHz, and 160 MHz channels; FIG. 4 illustrates a minimum OFDMA configuration for a group according to some embodiments. 20 MHz channel of the bandwidth unit subchannel; FIG. 5 illustrates a wideband channel grouped with an OFDMA minimum bandwidth unit subchannel in accordance with some embodiments; and FIG. 6 illustrates a HEW communication device in accordance with some embodiments.

Detailed description of the preferred embodiment

The description and drawings are to be considered as illustrative of the embodiments Other embodiments may incorporate structural changes, logic changes, electrical changes, process variations, and other changes. Portions and features of some embodiments may be included in, or substituted for, other parts and features of other embodiments. The embodiments set forth in the scope of the patent application cover all available equivalents of the scope of the claims.

FIG. 1 illustrates a HEW network in accordance with some embodiments. The HEW network 100 can include a primary station (STA) 102, a plurality of HEW stations 104 (i.e., HEW devices), and a plurality of legacy stations 106 (legacy devices). The primary station 102 can be arranged to communicate with the HEW station 104 and the legacy station 106 in accordance with one or more of the IEEE 802.11 standards. In some embodiments, the primary station 102 can be arranged to communicate with the HEW station 104 in accordance with the IEEE 802.11ax standard for HEW. In some embodiments, the primary station 102 can be an access point (AP), although the scope of the embodiments in this aspect is not limit.

According to an embodiment, the primary station 102 can include a physical layer (PHY) and medium access control layer (MAC) circuitry that can be arranged to compete for wireless media (eg, during a contention period) to receive dedicated control duration HEW control of the media Cycle (ie, Transmission Opportunity (TXOP)). The primary station 102 can transmit the HEW primary synchronization transmission at the beginning of the HEW control period. During the HEW control period, the HEW station 104 can communicate with the primary station 102 in accordance with a non-contention based scheduling multiple access technique. This is different from conventional Wi-Fi communication, in which devices communicate according to contention-based communication technologies rather than non-contention multiple access technologies. The legacy station 106 avoids communication during the HEW control period. In some embodiments, the primary synchronous transmission may be referred to as HEW control and scheduled transmission.

According to an embodiment, the primary synchronization transmission may include a multi-device HEW preamble arranged to signal and identify the data fields of the plurality of programming HEW stations 104. The primary station 102 can be further arranged to transmit (in the downlink direction) and/or receive (in the uplink direction) one or more of the data fields to/from the scheduled HEW station 104 during the HEW control period. In such embodiments, the primary station 102 can include training fields in the multi-device HEW preamble to allow for synchronization and initial channel estimation for each of the scheduled HEW stations 104.

According to some embodiments, the HEW station 104 may be a Wi-Fi or IEEE 802.11 group of stations (STAs) that are further assembled for HEW operation (eg, according to IEEE 802.11ax). The HEW station 104 can be configured to communicate with the primary station 102 in accordance with a non-contention-based multiple access technique, such as scheduled orthogonal frequency division multiple access (OFDMA) technology, during the HEW control period, and can be configured to interface Receive and decode the HEW pre-multiple device of the HEW frame. The HEW station 104 can also be configured to decode the indicated data fields received by the primary station 102 during the HEW control period.

According to some embodiments, the primary station 102 can be configured to communicate with the scheduling station 104 during the OFDMA control period, including the bandwidth using one or more of the plurality of minimum OFDMA bandwidth units, during the OFDMA control period. During this time, the primary station 102 has dedicated control of the wireless medium. In these embodiments, each minimum OFDMA bandwidth unit includes a predetermined number of subcarriers that do not include the guard subcarriers of the channel. In such embodiments, the guard subcarriers are provided at the edge of the band of the bandwidth and have guard subcarriers in addition to the subcarriers of each of the smallest OFDMA bandwidth units. In such embodiments, there is no need to provide guard subcarriers between the smallest OFDMA bandwidth units of the channel. These embodiments are described in more detail below.

The embodiments disclosed herein provide an OFDMA design for HEW that is backward compatible and can coexist with legacy Wi-Fi. These embodiments are used for the oldest channelization to the greatest extent possible. These embodiments provide a minimum OFDMA bandwidth unit that is sufficiently aligned with legacy OFDM structures. In addition to the novel OFDMA allocations discussed in more detail below, the embodiments disclosed herein further provide for coexistence with legacy IEEE 802.11 standards including the legacy IEEE 802.11ac standard. The High Efficiency WLAN Research Group (HEW SG) (now the IEEE 802.11ax Mission Group) has evolved Wi-Fi from the 802.11ac/ah Recommendation. As one of the target usage scenarios, this research group has high-density deployment scenarios such as sports fields, hotspots, and cellular offloading. One of the main uses of this new group is for dense deployment and cellular offloading. This article reveals The illustrated minimum OFDMA bandwidth unit allocation provides symmetric sub-channelization and can improve overall system spectrum utilization, thereby improving overall system performance, especially in such use cases.

Because one of the primary use cases in HEW is for dense deployment with many devices that attempt to access media at medium data rates, methods that allow for more simultaneous access may be needed. The current IEEE 802.11ac specification allows for bandwidths up to 160 MHz and eight simultaneous MIMO streams. The focus on HEW is the use of fat pipes (wide bandwidth) to provide access to many devices using OFDMA. According to some embodiments, a minimum ODFMA bandwidth unit is defined that is aligned with the old channelization. Prior to 802.11 HEW, OFDMA was not used as an access mechanism in Wi-Fi. The embodiments disclosed herein attempt to reuse as much as possible the basic physical layer blocks used to implement previous releases of the IEEE 802.11 Wi-Fi standard.

According to an embodiment, the minimum OFDMA bandwidth units are assembled to allow efficient and scalable OFDMA configuration. In some embodiments, a minimum bandwidth size of 4.375 MHz is provided. In such embodiments, the allocation of bandwidth can be done in a manner that also allows for backward compatibility with legacy devices, as the waveforms for the disclosed subchannels will allow for use in legacy devices (eg, symbol time can be CCA detection is performed in the mid-range of the OFDMA transmission. Therefore, a protection mechanism is provided which makes this method more attractive than other methods.

To date, these other approaches have not resolved the asymmetry in the band edges, where guard tones are provided to avoid adjacent interference and to limit spectral masking. The minimum OFDMA bandwidth unit defined for subchannelization disclosed herein The embodiments are more efficient and provide symmetric distribution of the spectrum, as well as providing alignment with 11n/ac channelization and backward compatibility with legacy systems.

Figure 2 illustrates a subcarrier configuration of a 20 MHz channel with a 5 MHz subchannel. As illustrated in FIG. 2, the total number of subcarriers is 56, of which 52 are data subcarriers and 4 are pilots. For a 20 MHz channel, the pilot subcarriers can be located at positions -21, -7, 7, and 21 of the DC subcarrier relative to the center of the band. As shown, there are vacancies at the four guard subcarriers 204 (left side) and vacancies at the three guard subcarriers 204 (right side) to provide a guard band. These guard bands are used for legacy communications to limit the interference level of adjacent channels and provide sufficient margin for power amplifier back-off and filtering. As shown in FIG. 2, dividing the 20 MHz channel into 5 MHz band allocation segments 202 causes asymmetry because the available bandwidth at either edge is less than the intermediate band (ie, not all subcarriers of each 5 MHz allocation segment are available). ).

Figure 3 illustrates a subcarrier configuration for 20MHz, 40MHz, 80MHz, and 160MHz channels. As illustrated in Figure 3, similar asymmetry exists in the 40, 80, and 160 MHz channels as described with respect to the 5 MHz allocation segment of Figure 2. For 40MHz, 80MHz, and 160MHz channels, the guard band can be wide (eg, there are 6 and 5 subcarrier allocation segments on each edge).

4 illustrates a 20 MHz channel grouped with an OFDMA minimum bandwidth unit subchannel, in accordance with some embodiments. To avoid the asymmetry described with respect to Figures 2 and 3, the embodiments disclosed herein define OFDMA bandwidth unit 402 based on the number of subcarriers in each unit. In some embodiments, the most The small OFDMA bandwidth unit can be 14 subcarriers, which in some embodiments can be equal to 14 x 312.5 KHz = 4.375 MHz, using the same FFT size as defined in the legacy system. In particular, to allow legacy coexistence, the same FFT size can be used, and thus the symbol duration and guard interval will allow for CCA detection during any portion of the OFDMA transmission used for the legacy device 106 (FIG. 1). If the legacy device 106 wakes up during OFDMA transmission, this would allow the legacy device 106 to perform guard interval detection and delay the transmission of the same mechanism as those outlined in the old specification. Therefore, the legacy device 106 will correctly delay the achievement of the old coexistence.

In some embodiments, if it is decided to increase the FFT size and thereby increase the symbol duration and the guard interval change (eg, to support the outdoor channel), the number of subcarriers in the OFDMA bandwidth unit can be increased by the same ratio because the FFT size is obtained. Increasing the minimum band allocation segment of 4.375 MHz at the same time can be kept constant. For example, if the FFT size is increased from the old 64-point FFT to the 128-point FFT for 20 MHz operation, there may be 14 x 128/64 = 28 subcarriers with a reduced pair of 20 MHz/128 = 156.25 KHz. Carrier spacing, resulting in a minimum OFDMA unit with 28 x subcarrier spacing = 4.375 MHz.

Table 1 below summarizes the number and subcarrier design of OFDMA subchannels in each of the 20, 40, 80, and 160 MHz modes of operation in accordance with some embodiments. As described in more detail below, for 80 MHz and 160 MHz, the number of OFDMA subchannels is increased to 17 and 36, respectively (compared to 16 and 32 asymmetric subchannel allocations when used as the minimum OFDMA unit at 5 MHz (respectively For 80 and 160 MHz) relative ratio). Accordingly, the embodiments disclosed herein provide A symmetric OFDMA structure with the smallest OFDMA unit allows for simultaneous access by more users and thus allows for better utilization of the spectrum.

According to an embodiment, the mapping of the modulation and coding scheme (MCS) in each OFDMA subchannel is simplified because the OFDMA bandwidth units disclosed herein are symmetric. An asymmetrical structure such as that shown in Figures 2 and 3 may require different MCS mappings on either edge in the subchannel relative to the middle of the frequency band in the subchannel, since the subchannels will utilize different numbers of pairs. Carrier.

According to an embodiment, the primary station 102 can be configured to communicate with the scheduling station 104 within a bandwidth 401 comprising one or more channels using a plurality of minimum OFDMA bandwidth units 402 during an OFDMA control period, where the OFDMA control During the period, the primary station 102 has dedicated control over the wireless medium. Each minimum OFDMA bandwidth unit 402 can include a predetermined number of subcarriers that do not include the guard subcarriers of the channel. In such embodiments, the guard subcarriers are provided at the band edge 404 of the bandwidth 401. In addition to the subcarriers of each of the minimum OFDMA bandwidth units 402, guard subcarriers are provided, and the guard subcarriers need not be provided between the smallest OFDMA bandwidth units 402 of the channel.

In some embodiments, the additional null subcarriers identified by Table 1 may be used as guard subcarriers and may be provided between the minimum OFDMA bandwidth units, although the scope of the embodiments is not limited in this aspect. These embodiments will relax the requirement for frequency accuracy for each user assigned the smallest OFDMA bandwidth unit because frequency inaccuracy can cause inter-carrier interference ICI).

In some embodiments, for processing a signal having a 20-MHz channel with a 64-point FFT, the predetermined number of data and pilot subcarriers per minimum OFDMA bandwidth unit 402 is fourteen (14), with subcarriers The interval is 312.5 KHz, and each minimum OFDMA bandwidth unit 402 occupies a bandwidth of 4.375 MHz. In such embodiments, the primary station 102 can communicate with the scheduling station 104 using a plurality of 4.375 MHz sub-channels, with each 4.375 MHz sub-channel corresponding to the smallest OFDMA bandwidth unit 402.

In such embodiments, subcarrier spacing consistent with legacy IEEE 802.11 systems (e.g., 312.5 KHz) may be used. The use of fourteen data subcarriers for the minimum OFDMA bandwidth unit 402 provides symmetric frequency band allocation because the guard subcarriers are not included. This differs from the 5 MHz band allocation segment 202 illustrated in Figure 2 as an asymmetric allocation segment because the 5 MHz band allocation segments 202A and 202D at the band edge 204 would need to include guard subcarriers (will not be used). Thus, the 5 MHz band allocation segments 202A and 202D will utilize fewer subcarriers than the 5 MHz band allocation segments 202B and 202C near the center of the channel. Thus, the 5 MHz band allocation segments 202A and 202D at the band edge 204 can have a smaller data handling capacity (and a smaller MCS) than the 5 MHz band allocation segments 202B and 202C near the center of the channel. This asymmetry can result in increased real Line solution complexity and other shortcomings. According to such embodiments, symmetry is provided by the minimum OFDMA bandwidth unit 402 because the minimum OFDMA bandwidth units use the same predetermined number of subcarriers, and none of the subcarriers are guard subcarriers.

FIG. 5 illustrates a wideband channel grouped with an OFDMA minimum bandwidth unit subchannel, in accordance with some embodiments. In such embodiments, the primary station 102 (FIG. 1) can be configured to schedule and schedule stations within a bandwidth 501 that includes one or more channels using a plurality of minimum OFDMA bandwidth units 402 during an OFDMA control period. 104 communications, during which the primary station 102 has dedicated control of the wireless medium. Each minimum OFDMA bandwidth unit 402 includes a predetermined number of subcarriers that do not include the guard subcarriers of the channel. In these embodiments, each channel of the wideband channel can be a 20 MHz channel, and when the channel is a wideband channel 501 and contains two or more adjacent 20 MHz channels, in two or more adjacent 20 MHz channels No guard subcarriers are provided between at least some of the adjacent minimum OFDMA bandwidth units 402, although the scope of the embodiments is not limited in this aspect. In some other embodiments, guard subcarriers may be provided between each adjacent 20 MHz channel at band edge 404 (Fig. 4).

Some alternative embodiments may use different FFT sizes and may provide smaller minimum OFDMA bandwidth units. For example, for processing with a 20 MHz channel having a 256-point FFT, the predetermined number of data and pilot subcarriers for each minimum OFDMA bandwidth unit 402 can be fourteen. In such embodiments, each minimum OFDMA bandwidth unit can occupy a bandwidth of 1.09375 MHz. In these embodiments, sixteen minimum OFDMA bandwidths The element can occupy a 20 MHz channel instead of the four illustrated in Figure 4. In such embodiments that use a larger FFT size (eg, 128, 256, or 512 for a 20 MHz channel), the subcarriers can occupy a smaller bandwidth (ie, the bandwidth can be scaled down by FFT). The ratio of size (ie 128/64 for a 128-point FFT, 256/64 for a 256-point FFT and 512/64 for a 512-point FFT). For example, for a 256-point FFT The subcarrier can occupy 4.375/(256/64)=1.09375MHz. Different FFT sizes can also be used for the wideband channel.

In some embodiments, a larger minimum OFDMA bandwidth unit may be provided. For example, for a signal processing a 20 MHz channel with a 64-point FFT, the predetermined number of data and pilot subcarriers per minimum OFDMA bandwidth unit is twenty-eight (28), with a subcarrier spacing of 312.5 kHz. . In these embodiments, each minimum OFDMA bandwidth unit can occupy a bandwidth of 8.75 MHz. In these embodiments, the two smallest OFDMA bandwidth units can occupy 20 MHz channels instead of the four illustrated in the figure.

In some embodiments, for processing a signal of a 20 MHz channel having a 128-point FFT, the predetermined number of data and pilot subcarriers per minimum OFDMA bandwidth unit may be twenty eight (28), with The carrier spacing is 156.25 KHz. In such embodiments, each minimum OFDMA bandwidth unit can occupy a bandwidth of 4.375 MHz. In this exemplary embodiment, four minimum OFDMA bandwidth units with 28 subcarriers may each occupy a 20 MHz channel. Such embodiments may be used, for example, to support outdoor passages, although the scope of the embodiments in this aspect is not limited.

In some embodiments, each channel can be a 20 MHz channel. It includes four minimum OFDMA bandwidth units 402, and the channels utilized by the primary station 102 to communicate with the scheduling station 104 during the OFDMA control period include one or more adjacent 20 MHz channels. In some embodiments, a single 20 MHz channel can provide four minimum OFDMA bandwidth units for communicating with the scheduling station 104 using a channel comprising a single 20 MHz channel during the OFDMA control period (ie, having a 20 MHz bandwidth). 402, a total of 56 data subcarriers in addition to one DC subcarrier and seven guard subcarriers at band edge 404 (see Table 1). In the example illustrated in FIG. 4, one band edge may have three guard subcarriers and the other band edge may have four guard subcarriers. In the example illustrated in FIG. 4, no guard subcarriers are provided between the smallest OFDMA bandwidth units 402 of the channel.

In some embodiments, communication with the scheduling station 104 is used for wideband channels (ie, bandwidths for 40 MHz, 80 MHz, and 160 MHz) that include two or more adjacent 20 MHz channels during the OFDMA control period. In this regard, the primary station 102 can allocate a minimum OFDMA bandwidth unit 402 having two or more adjacent 20 MHz channels with no guard subcarriers therebetween, although in this aspect the scope of the embodiments is not limited because The guard subcarriers can be provided between each 20 MHz channel at the band edge 404. In some such embodiments, due to the spectral alignment inherent in OFDMA communication (ie, the OFDMA signal can be aligned in power, frequency, and time), there may be no need to have two or more adjacent 20 MHz channels. A guard subcarrier is provided between the minimum OFDMA bandwidth units 402. This is different from legacy IEEE 802.11 communication in every 20 MHz channel. In such embodiments, subcarriers in the adjacent channel that were previously guard subcarriers may be used to convey the data.

In some embodiments, for communicating with the scheduling station 104 using a wideband bandwidth 501 (eg, a wideband channel) comprising two connected or adjacent 20 MHz channels for a bandwidth of 40 MHz during an OFDMA control period, the primary Station 102 can allocate up to eight minimum OFDMA bandwidth units 402 each having fourteen (14) subcarriers, a total of 112 data and pilot subcarriers, one DC subcarrier, and seven at band edge 504 (7) Protective subcarriers (see Table 1). These embodiments may use a 64-point FFT. When a 256-point FFT is used, the number of allocations can be scaled at least 256/64 proportionally. In the example illustrated in FIG. 5, one band edge of the wideband bandwidth 501 may have three guard subcarriers and the other band edge may have four guard subcarriers. In such 40 MHz embodiments, when no guard subcarriers are provided between adjacent 20 MHz channels of a 40 MHz wideband channel, there may be several (eg, eight) additional or empty subcarriers that may remain unused. In some embodiments, additional or null subcarriers may be used as guard subcarriers between the smallest OFDMA bandwidth units to relax hardware implementations, such as local oscillator accuracy in each user device.

In some embodiments, additional null subcarriers may be added to guard subcarriers at two band edges of 40 MHz, specified between two 20 MHz subchannels, specified between minimum OFDMA units, and/or designated around DC (For example, to relax the requirement for DC offset).

In some embodiments, the master station 102 can be allocated up to seventeen (17) for communicating with the scheduling station 104 using a wide frequency channel comprising four connected 20 MHz channels for an 80 MHz bandwidth during the OFDMA control period. Minimum OFDMA bandwidth units each having fourteen (14) subcarriers, total A total of 238 data and pilot subcarriers, one DC subcarrier, and seven (7) guard subcarriers at band edge 504 (see Table 1). These embodiments may use a 64-point FFT. When a 256-point FFT is used, the number of allocations can be scaled at least 256/64 proportionally. In such 80 MHz embodiments that provide up to 17 minimum OFDMA bandwidth units 502, when no guard subcarriers are provided between adjacent 20 MHz channels of an 80 MHz wideband channel, there may be several (eg, ten) that may remain un Additional or empty subcarriers used. In some embodiments, additional or null subcarriers may be used as guard subcarriers between the smallest OFDMA bandwidth units. In these 80 MHz embodiments, another minimum OFDMA bandwidth unit can be allocated by eliminating guard subcarriers between adjacent 20 MHz channels (ie, 17 minimum OFDMA bandwidth units each having 14 subcarriers) 16 minimum OFDMA bandwidth units). Note that eliminating 7 guard subcarriers between each 20 MHz will result in 3x7 = 21 additional null subcarriers. The 80 MHz channel has 6 and 5 guard segments at the edge of each band instead of 4 and 3 for 20 MHz, and has 3 at DC and around DC. The change in the structure of these vacancies may provide another minimum OFDMA unit plus additional vacancies, as described in Table 1.

In some embodiments, the primary station 102 can be allocated up to thirty for communicating with the scheduling station 104 using a wide frequency channel having a bandwidth of eight connected 20 MHz channels during the OFDMA control period for a bandwidth of 160 MHz. Six (36) minimum OFDMA bandwidth units each having fourteen (14) subcarriers, for a total of 504 data and pilot subcarriers, one DC subcarrier, and seven (7) guards at band edge 504 Subcarrier. These embodiments may use a 64-point FFT. When using a 256-point FFT, the number of allocations can be at least The example expands the ratio of 256/64. In these 160 MHz embodiments, most or all of the guard subcarriers will conventionally be provided between adjacent 20 MHz channels available for communication. In such 160 MHz embodiments, by eliminating guard subcarriers between adjacent 20 MHz channels, a number (e.g., up to four) of additional minimum OFDMA bandwidth units can be allocated (i.e., up to 36 each having 14) The minimum OFDMA bandwidth unit of the subcarrier replaces the 32 minimum OFDMA bandwidth units).

In some embodiments, the primary station 102 can be configured to use a wide frequency channel comprising two non-contiguous 80 MHz wideband channels (ie, 80+80 MHz channels) for the 160 MHz bandwidth during the OFDMA control period. Station 104 communication. For each 80 MHz wideband channel with 80+80 MHz channels, the primary station 102 can allocate up to seventeen (17) minimum OFDMA bandwidth units each having fourteen (14) subcarriers for a total of 238 data and Pilot subcarriers, one DC subcarrier, and seven (7) guard subcarriers at band edge 504. In such an embodiment using a wide frequency channel having a bandwidth of 160 MHz comprising two non-contiguous 80 MHz wide frequency channels (i.e., 80 + 80 bandwidth channels), each 80 MHz channel may include four connected 20 MHz channels. In such embodiments, null subcarriers may be specified on the band edges of each 80 MHz channel. Therefore, a 160 MHz connected bandwidth channel of less than 36 allocation segments can be allocated. For example, subcarriers of at least one of the 36 allocation segments may be vacated for guard bands and null subcarriers. In some embodiments utilizing a 160 MHz bandwidth, thirty-five (35) minimum OFDMA bandwidth units may be used, and additional null subcarriers (which may be used for another minimum OFDMA bandwidth unit) may be used for the minimum OFDMA bandwidth. Empty subcarriers between cells.

In some embodiments, the primary station may allocate a bandwidth to the scheduling station 104 based on the minimum OFDMA bandwidth unit 402 for communicating with the primary station during the control period. The scheduling station 104 can be a high performance wireless (HEW) station 104 (i.e., IEEE 802.11ax), and the primary station 102 can be an access point that is configured for HEW communication with the HEW station 104 and is configured Used for legacy communication with legacy stations 106 (eg, IEEE 802.11ac). In such embodiments, during an OFDMA control period, the primary station 102 may use a minimum OFDMA bandwidth unit based on a non-contention based multiple access technique such as scheduled OFDMA and/or partition multiple access (SDMA) techniques. Communicate with the scheduled HEW station 104. Outside the OFDMA control cycle, the primary station can be configured to communicate with stations including legacy stations 106 in accordance with contention-based communication techniques (known IEEE 802.11, CSMA/CA).

In some embodiments, the minimum OFDMA bandwidth unit 402 can be configured to time multiplex transmission and frequency multiplex transmission during the control period. During the control period, the packet may be received from the scheduling station 104 in accordance with an uplink SDMA technique using OFDMA, or the packet may be transmitted to the scheduling station 104 in accordance with the downlink multiplex transmission technique using OFDMA. In some embodiments, during the control period, the packet may be received from the scheduling station 104 in accordance with an uplink SDMA technique using OFDMA, although the scope of the embodiments is not limited in this aspect.

In some embodiments, the primary station 102 can transmit primary synchronization transmissions during an initial portion of the control cycle, including multi-device preambles arranged to signal and identify data fields for the plurality of scheduling stations 104. The primary synchronization transmission can identify the parameters of the minimum OFDMA bandwidth unit 402, which are used by the scheduling station. 104 is used to communicate with the primary station 102 during the control period. Communication during the control period uses a minimum OFDMA bandwidth unit 402. In some embodiments, the scheduling station 104 can allocate more than one minimum OFDMA bandwidth unit 402 because the minimum OFDMA bandwidth unit 402 is the smallest amount of bandwidth that can be allocated.

In some such embodiments, a small amount of additional power amplifier (PA) back-off and filtering can help define a guard band of 1250 KHz across band edges 404 (Fig. 4) and 504 (Fig. 5) consistently across all bandwidths. (4 null subcarriers on the left and 3 null subcarriers on the right). In some alternative embodiments, additional null subcarriers may be allocated to provide an additional guard band similar to the legacy allocation shown in FIG. Some embodiments may use: for an 80 MHz channel, only 16 of the 17 possible sub-channels (or only 35 of the 36 possible sub-channels), or for a 160 MHz channel, 36 possible sub-- Only 35 of the channels are used to release one OFDMA unit for use as 14 additional null subcarriers. The availability of additional null subcarriers in the 40, 80 and 160 MHz wideband channels provides design flexibility. As mentioned earlier, additional null subcarriers may be allocated as guard segments or may be allocated around the DC to relax the requirement for DC offset cancellation. Additional null subcarriers may also be allocated between the OFDMA units to relax the oscillator accuracy requirements.

FIG. 6 illustrates a HEW communication device in accordance with some embodiments. The HEW device 600 can be an HEW compliant device that can be arranged to communicate with one or more other HEW devices, such as the HEW station 104 (FIG. 1) or the primary station 102 (FIG. 1), and with legacy devices. HEW device 600 may be adapted to operate as primary station 102 (FIG. 1) or HEW station 104 (FIG. 1). According to an embodiment, the HEW device 600 may particularly include a hardware processing circuit that may include a physical layer (PHY) circuit 602 and medium access control layer circuit (MAC) 604. PHY 602 and MAC 604 may be HEW compliant layers and may also conform to one or more legacy IEEE 802.11 standards. The PHY 602 can be arranged to transmit HEW frames, such as HEW frames (Fig. 4). The HEW device 600 can also include other processing circuits 606 and memory 608 that are assembled to perform the various operations described herein.

According to some embodiments, the MAC 604 may be arranged to contend for the wireless medium during the contention period to receive a control over the media HEW control period and to group the HEW frames. The PHY 602 can be arranged to transmit HEW frames as discussed above. The PHY 602 can also be arranged to receive HEW frames from the HEW station. The MAC 604 can also be arranged to transmit and receive operations via the PHY 602. PHY 602 may include circuitry for modulation/demodulation, upconversion/down conversion, filtering, amplification, and the like. In some embodiments, processing circuit 606 can include one or more processors. In some embodiments, two or more antennas may be coupled to a physical layer circuit that is arranged to transmit and receive signals, including transmitting HEW frames. Memory 608 can store information for assembly processing circuitry 606 for performing operations for assembling and transmitting HEW frames and performing the various operations described herein.

In some embodiments, HEW device 600 can be configured to communicate over a multi-carrier communication channel using OFDM communication signals. In some embodiments, HEW device 600 can be configured to receive signals in accordance with a particular communication standard, such as the Institute of Electrical and Electronics Engineers (IEEE) standards, including IEEE 802.11-2012, 802.11n-2009, and/or 802.11ac- 2013 standard, and/or recommended specifications for WLAN including the proposed HEW standard, although in this aspect the scope of the invention is not limited as it may also be suitable Transmit and/or receive communications in accordance with other technologies and standards. In some other embodiments, HEW device 600 can be configured to receive signals transmitted using one or more other modulation techniques, such as spread spectrum modulation (eg, direct sequence code division multiple access (DS-CDMA) And/or frequency hopping code division multiple access (FH-CDMA), time division multiplexing (TDM) modulation and/or frequency division multiplexing (FDM) modulation, although in this aspect the scope of the embodiment Unlimited.

In some embodiments, the HEW device 600 can be part of a portable wireless communication device, such as a personal digital assistant (PDA), a laptop or portable computer with wireless communication capabilities, a web tablet, a wireless telephone. Or smart phones, wireless headsets, pagers, instant messaging devices, digital cameras, access points, televisions, medical devices (eg heart rate monitors, blood pressure monitors, etc.) or other devices that can receive and/or transmit information wirelessly Device. In some embodiments, HEW device 600 can include one or more of the following: a keyboard, a display, a non-electric memory cartridge, a plurality of antennas, a graphics processor, an application processor, a speaker, and other mobile device components. The display can be an LCD screen including a touch screen.

The antenna of HEW device 600 may include one or more directional or omnidirectional antennas including, for example, dipole antennas, monopole antennas, block antennas, loop antennas, microstrip antennas, or other types of antennas suitable for transmission of RF signals. In some multiple input multiple output (MIMO) embodiments, the antennas can be effectively separated to take advantage of the spatial diversity and different channel characteristics that can occur between each of the antennas and the antennas of the transmitting stations.

Although the HEW device 600 is illustrated as having a number of individual functional elements, one or more of the functional elements may be combined and may be assembled by a software. A combination of components, such as processing elements including a digital signal processor (DSP), and/or other hardware components is implemented. For example, some components may include one or more microprocessors, DSPs, field programmable gate arrays (FPGAs), application specific collective circuits (ASICs), radio frequency collective circuits (RFICs), and at least for performing the functions described herein. A combination of various hardware and logic circuits. In some embodiments, the functional elements of HEW device 600 may involve operating one or more processes on one or more processing elements.

Embodiments can be implemented in one or a combination of hardware, firmware, and software. Embodiments can also be implemented as instructions stored on a computer readable storage device, which can be read and executed by at least one processor for performing the operations described herein. The computer readable storage device can include any non-transitory mechanism for storing information in a form readable by a machine (eg, a computer). For example, computer readable storage devices may include read only memory (ROM), random access memory (RAM), disk storage media, optical storage media, flash memory devices, and other storage devices and media. Some embodiments may include one or more processors and may be stored in an instruction stored on a computer readable storage device.

The Abstract is provided to comply with 37 C.F.R. Section 1.72(b), which requires the reader to determine an abstract of the nature and gist of the present disclosure. It should be understood that the abstract will not be used to limit or clarify the scope or meaning of the scope of the claims. The scope of the following patent application is hereby incorporated by reference in its entirety in its entirety in its entirety in its entirety herein

402‧‧‧OFDMA bandwidth unit/minimum OFDMA bandwidth unit

501‧‧‧Bandwidth/Broadband Bandwidth

504‧‧‧ Band edge

Claims (23)

A primary station includes a hardware processing circuit including a physical layer circuit and a medium access control layer circuit, and is configured to communicate in a wireless local area network (WLAN), the hardware processing circuit group Configuring to perform communication with a scheduled station within a bandwidth including one or more of the plurality of minimum OFDMA bandwidth units during an orthogonal frequency division multiple access (OFDMA) control period, During the OFDMA control period, the primary station has dedicated control for a wireless medium, wherein each minimum OFDMA bandwidth unit includes a predetermined number of subcarriers with a subcarrier spacing of 78.125 KHz, which does not include the channel a guard subcarrier, wherein the bandwidth is divided into a maximum number of one of the minimum OFDMA bandwidth units, and wherein each of the maximum number of the minimum OFDMA bandwidth units is scheduled to a separate scheduled station. The primary station of claim 1, wherein the guard subcarriers are provided at a frequency band edge of the bandwidth, in addition to the subcarriers of each of the minimum OFDMA bandwidth units Subcarriers, and wherein no guard subcarriers are provided between the minimum OFDMA bandwidth units of a channel. The primary station of claim 1, wherein each channel is a 20 MHz channel, and wherein the channel is a broadband channel and includes two or two When an adjacent 20 MHz channel is upstream, no guard subcarriers are provided between adjacent minimum OFDMA bandwidth units of the two or more adjacent 20 MHz channels. The primary station of claim 3, wherein for processing a signal having a 20 MHz channel of a 64-point FFT, the predetermined number of data and pilot subcarriers for each of the minimum OFDMA bandwidth units is fourteen (14) A subcarrier with a subcarrier spacing of 312.5 kHz, and each of the smallest OFDMA bandwidth units occupies a bandwidth of 4.375 MHz. The primary station of claim 3, wherein for processing a 20 MHz channel having a 256-point FFT, the predetermined number of data and pilot subcarriers for each of the smallest OFDMA bandwidth units is fourteen (14) And each of the minimum OFDMA bandwidth units occupies one of the bandwidths of 1.09375 MHz. The primary station of claim 4, wherein each channel is a 20 MHz channel comprising one of four minimum OFDMA bandwidth units, wherein the channel communicated with the scheduling stations by the primary station during the OFDMA control period Included in one or more adjacent 20 MHz channels, wherein the single 20 MHz channel is configured to provide four minimum OFDMAs for communicating with the scheduled station using one channel comprising a single 20 MHz channel during the OFDMA control period The bandwidth unit has a total of 56 data subcarriers in addition to one DC subcarrier and seven (7) guard subcarriers at the edges of the bands. The primary station of claim 6, wherein the primary station is configured to configure the broadband station with one or more adjacent 20 MHz channels for communication with the scheduled station during the OFDMA control period The minimum OFDMA bandwidth units of two or more adjacent 20 MHz channels with no guard subcarriers therebetween. The primary station of claim 7, wherein the primary station is configured to communicate with the scheduled station using one of the two connected 20 MHz channels for one bandwidth of 40 MHz during the OFDMA control period. To allocate up to eight minimum OFDMA bandwidth units each having fourteen (14) subcarriers, a total of 112 data and pilot subcarriers, one DC subcarrier, and seven (7) guards at the edges of the bands Subcarrier. The primary station of claim 8, wherein the primary station is configured to communicate with the scheduled station using one of four connected 20 MHz channels for one bandwidth of 80 MHz during the OFDMA control period Allocating up to seventeen (17) minimum OFDMA bandwidth units each having fourteen (14) subcarriers, for a total of 238 data and pilot subcarriers, one DC subcarrier, and seven at the edge of the bands ( 7) protective subcarriers. The primary station of claim 9, wherein the primary station communicates with the scheduled station for a bandwidth of one of the eight connected 20 MHz channels for one of the 160 MHz bandwidths during the OFDMA control period The system is configured to allocate up to thirty-six (36) minimum OFDMA bandwidth units each having fourteen (14) subcarriers, for a total of 504 data and leads. Frequency subcarrier, one DC subcarrier, and seven (7) guard subcarriers at the edge of the band. The primary station of claim 9, wherein for one of the 160 MHz bandwidths, one of the two non-contiguous 80 MHz wideband channels is used for communication with the scheduled station during the OFDMA control period, wherein each of the 80 MHz In the case of a wideband channel, the primary station is configured to allocate up to seventeen (17) minimum OFDMA bandwidth units each having fourteen (14) subcarriers, for a total of 238 data and pilot subcarriers, one DC Subcarriers and seven (7) guard subcarriers at the edges of the bands. The primary station of claim 2, wherein the primary station is configured to allocate a bandwidth to the scheduled stations based on the minimum OFDMA bandwidth unit for communicating with the primary station during the control period, wherein the primary station The station is a high-performance wireless (HEW) station, and the primary station is an access point, which is configured to perform HEW communication with the HEW station, and is configured to perform legacy communication with the legacy station, where The equal minimum OFDMA bandwidth unit can be configured to time multiplex transmission and frequency multiplex transmission during the control period, and wherein during the control period: the packet is received from the uplink SDMA technique using one of OFDMA The scheduling station, or packet, is transmitted to the scheduling stations in accordance with the use of downlink multiplex transmission techniques under OFDMA, wherein the primary stations are further configured to: Transmitting a primary synchronization transmission during an initial portion of the control period, comprising a multi-device preamble arranged to signal and identify data fields for the plurality of scheduling stations, wherein the primary synchronization transmission identifies such A parameter of a minimum OFDMA bandwidth unit, the parameters being used by the scheduling station to communicate with the primary station during the control period, and wherein the communication during the control period uses the minimum OFDMA bandwidth unit. The primary station of claim 1, wherein the guard subcarriers are provided at a frequency band edge of the bandwidth, in addition to the subcarriers of each of the minimum OFDMA bandwidth units Subcarriers, and wherein additional subcarriers are provided between the minimum OFDMA bandwidth units of a channel. A method for communication by a primary station in a wireless local area network (WLAN), the method comprising: using a plurality of minimums during an orthogonal frequency division multiple access (OFDMA) control period The one or more channels of the OFDMA bandwidth unit communicate with the scheduling station within a bandwidth during which the primary station has dedicated control over a wireless medium, wherein each minimum OFDMA bandwidth unit includes a band a predetermined number of subcarriers having a subcarrier spacing of 78.125 KHz, which does not include guard subcarriers of the channel, wherein the bandwidth is divided into a maximum number of one of the minimum OFDMA bandwidth units, and wherein the minimum OFDMA The maximum number of bandwidth units can be scheduled to one point each Opened scheduled station. The method of claim 14, wherein the guard subcarriers are provided at a frequency band edge of the bandwidth, in addition to the subcarriers of each of the minimum OFDMA bandwidth units. Carrier, and wherein no guard subcarriers are provided between the minimum OFDMA bandwidth units of a channel. The method of claim 14, wherein each channel is a 20 MHz channel, and wherein the channel is a broadband channel and comprises two or more adjacent 20 MHz channels, in the two or more adjacent 20 MHz No guard subcarriers are provided between adjacent minimum OFDMA bandwidth units of the channel. The method of claim 16, wherein for processing a signal having a 20 MHz channel of a 64-point FFT, the predetermined number of data and pilot subcarriers for each of the minimum OFDMA bandwidth units is fourteen (14) One of the subcarrier spacings is 312.5 kHz, and each of the smallest OFDMA bandwidth units occupies one of the 4.375 MHz bandwidths. A non-transitory computer readable storage medium storing instructions for execution by one or more processors for performing communication operations by a primary station in a wireless local area network (WLAN), The operations are grouped with the primary station to perform the following actions: during an orthogonal frequency division multiple access (OFDMA) control period, including one or more channels using a plurality of minimum OFDMA bandwidth units Communicating with the scheduling station within a bandwidth, during the OFDMA control period, the primary station has dedicated control for a wireless medium, wherein each minimum OFDMA bandwidth unit includes a predetermined one of the subcarrier spacings of 78.125 KHz a quantity of subcarriers that does not include guard subcarriers of the channel, wherein the bandwidth is divided into a maximum number of one of the minimum OFDMA bandwidth units, and wherein each of the maximum number of the minimum OFDMA bandwidth units The system can be scheduled to a separate scheduled station. The non-transitory computer readable storage medium of claim 18, wherein the guard subcarriers are provided at a frequency band edge of the bandwidth, except for the subcarriers of each of the minimum OFDMA bandwidth units The guard subcarriers are additionally provided, and no guard subcarriers are provided between the minimum OFDMA bandwidth units within a 20 MHz channel. The non-transitory computer readable storage medium of claim 19, wherein for processing a signal having a 20 MHz channel of a 64-point FFT, the data for each of the minimum OFDMA bandwidth units and the pilot subcarriers The predetermined number is fourteen (14) subcarriers with a subcarrier spacing of 312.5 kHz, and each of the smallest OFDMA bandwidth units occupies one of the 4.375 MHz bandwidths. A primary station comprising: one or more radios; a memory; The physical layer circuit and the medium access control layer circuit are configured to communicate in a wireless local area network (WLAN) according to a high performance (HE) technology, and the circuit is assembled to perform the following actions: During the frequency multiple access (OFDMA) control period, the antennas are used to communicate with the scheduling station within a bandwidth comprising one or more 20 MHz Wi-Fi channels using a plurality of minimum OFDMA bandwidth units, in the OFDMA control During the period, the primary station has dedicated control over a wireless medium, wherein each minimum OFDMA bandwidth unit includes a predetermined number of subcarriers that do not include guard subcarriers for the channel; wherein the guard subcarriers are provided At the edge of the bandwidth of the bandwidth, the guard subcarriers are provided in addition to the subcarriers of each of the minimum OFDMA bandwidth units, wherein the minimum OFDMA bandwidth units in a 20 MHz channel No guard subcarriers are provided, wherein for each signal of a 20 MHz channel having a 256-point FFT and a subcarrier spacing of 78.125 KHz, each minimum OFDMA bandwidth unit occupies a bandwidth of 4.375 MHz, where Bandwidth is divided The maximum number of one of the minimum OFDMA bandwidth units, and wherein each of the maximum number of the minimum OFDMA bandwidth units can be scheduled to a separate scheduled station. The primary station of claim 21, wherein for communicating with the scheduled station using one of two or more adjacent 20 MHz channels during the OFDMA control period, the primary station is configured to configure the Two The minimum OFDMA bandwidth units of one or more adjacent 20 MHz channels with no guard subcarriers therebetween. The primary station of claim 22, further comprising one or more antennas coupled to the one or more radios.