Rate and Antenna Selection Using a Single TXOP

Abstract

In one example, the method includes obtaining an XOP (Transmission Opportunity) on a Wi-Fi channel at a probing Wi-Fi device (100). The method includes transmitting a probe packet from the probing Wi-Fi device (100) to a receiving Wi-Fi device (116) during a TXOP using a first antenna (114.1), receiving a first feedback in response to transmitting the probe packet using the first antenna, transmitting a probe packet from the probing Wi-Fi device to the receiving Wi-Fi device during a TXOP using a second antenna (114.2), receiving a second feedback in response to transmitting the probe packet using the second antenna, and setting, by the probing Wi-Fi device, a set of transmission parameters and a selected antenna based at least in part on the first or second feedback.

Description

Technical Field

[0001] Wi-Fi is a term used to represent communications that use various ones of the Institute of Electrical and Electronics Engineers (IEEE) 802.11 family of wireless network protocols. Wi-Fi stations communicate by transmitting blocks (packets) of data to each other over a wireless link. Link adaptation refers to the matching of modulation, coding, and other signal and protocol parameters to the conditions on the wireless link. Link adaptation algorithms respond to channel conditions by changing the operating point of the wireless link in order to achieve performance criteria that may include the highest possible throughput and the lowest possible power consumption.

Summary of the Invention

[0002] In at least one example of this description, a method includes obtaining a TXOP (Transmission Opportunity) on a Wi-Fi channel in a probing Wi-Fi device. The method also includes transmitting a probe packet from the probing Wi-Fi device to a receiving Wi-Fi device during the TXOP using a first antenna. The method includes receiving a first feedback in response to transmitting the probe packet using the first antenna. The method also includes transmitting a probe packet from the probing Wi-Fi device to a receiving Wi-Fi device during the TXOP using a second antenna. The method includes receiving a second feedback in response to transmitting the probe packet using the second antenna. The method also includes setting a set of transmission parameters and a selected antenna by the probing Wi-Fi device based at least in part on the first feedback or the second feedback.

[0003] In at least one example described herein, a method includes obtaining a TXOP on a Wi-Fi channel at a probing Wi-Fi device. The method also includes transmitting, during the TXOP using a first antenna, a first probe packet from the probing Wi-Fi device to a receiving Wi-Fi device, the first probe packet being transmitted with a first set of transmission parameters. The method includes receiving a first feedback in response to transmitting the first probe packet using the first antenna. The method also includes transmitting, during the TXOP using the first antenna, a second probe packet from the probing Wi-Fi device to the receiving Wi-Fi device, the second probe packet being transmitted with a second set of transmission parameters. The method includes receiving a second feedback in response to transmitting the second probe packet using the first antenna. The method also includes transmitting, during the TXOP using a second antenna, a second probe packet from the probing Wi-Fi device to the receiving Wi-Fi device, the second probe packet being transmitted with the second set of transmission parameters. The method includes receiving a third feedback in response to transmitting the second probe packet using the second antenna. The method also includes setting, by the probing Wi-Fi device, one or more transmission parameters within the set of transmission parameters, based at least in part on the first feedback, the second feedback, or the third feedback.

[0004] In at least one example described herein, the system includes a memory that stores instructions within a probing Wi-Fi device. The system includes a processor coupled to a Wi-Fi transmitter and a Wi-Fi receiver in the probing Wi-Fi device, and the Wi-Fi transmitter and the Wi-Fi receiver are configured to communicate via a Wi-Fi channel. The processor is configured to execute instructions stored in the memory. The instructions are executed to obtain a TXOP on the Wi-Fi channel. The instructions are also executed by the Wi-Fi transmitter to transmit a probe packet to a receiving Wi-Fi device using a first antenna during the TXOP, and the probe packet is transmitted with transmission parameters within a set of transmission parameters. The instructions are executed to receive a first feedback in the Wi-Fi receiver in response to transmitting the probe packet using the first antenna. The instructions are also executed by the Wi-Fi transmitter to transmit a probe packet to a receiving Wi-Fi device using a second antenna during the TXOP, and the probe packet is transmitted with transmission parameters within a set of transmission parameters. The instructions are executed to receive a second feedback in the Wi-Fi receiver in response to transmitting the probe packet using the second antenna. The instructions are executed by the probing Wi-Fi device to set transmission parameters and a selected antenna within a set of transmission parameters based at least in part on the first feedback or the second feedback.

Brief Description of the Drawings

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[0012] The same reference number or other reference indicators are used in the drawings to indicate the same or similar (functional and / or structural) features.

DETAILED DESCRIPTION OF THE INVENTION

[0013] Link adaptation in 802.11 protocol technology involves the use of algorithms that change the link device operating point in response to channel conditions. Some common degrees of freedom driven by link adaptation algorithms are options for modulation and coding schemes and transmission power. In the case of a multiple-input multiple-output (MIMO) system, there are more degrees of freedom. For example, the number of spatial streams and the specific antenna elements that can be used for those streams are also options that can be evaluated by link adaptation algorithms.

[0014] TXOP (Transmission Opportunity) is a Quality of Service (QoS) feature of the IEEE 802.11 protocol that provides contention-free channel access to Wi-Fi devices for a limited time period. Wi-Fi devices must obtain air access to a specific channel (using the 802.11 Extended Distributed Channel Access (EDCA) procedure) during the duration of the TXOP. After the TXOP is completed, the Wi-Fi device may have to re-acquire air access and issue the next available TXOP before transmitting again. In some systems, Wi-Fi devices determine their transmission characteristics or operating profiles by assessing the channel conditions before transmitting data packets over the channel. Wi-Fi devices can assess channel conditions such as throughput (e.g., bit rate), power consumption (e.g., transmitter power), modulation coding scheme (MCS), or other transmitter and channel characteristics. Wi-Fi devices may attempt to meet performance criteria based on these channel characteristic estimates, which may include the highest available bit rate and / or the lowest transmitter power.

[0015] In some assessment processes, a Wi-Fi device sets its transmitter channel characterization based on bitrate and / or transmitter power and transmits a probe packet to a receiving Wi-Fi device during a first TXOP. The transmitting device receives a response packet (e.g., an acknowledgment (ACK) or other feedback metric) from the receiving device, and the transmitting device may interpret this as an indication that the trial setting was effective for reliable transmission of the probe packet. The Wi-Fi device may then send one or more such additional probe packets sent in different trial settings to assess the channel conditions during a second or subsequent TXOP. After the Wi-Fi device has assessed the channel conditions, it transmits its data packet using a selected transmitter setting based on the assessed channel conditions. However, since the Wi-Fi device must reacquire air access for the next available TXOP in the system, transmitting each probe packet in a different TXOP can take a significant amount of time. Also, in a system with multiple antennas, using a separate TXOP for each antenna can increase the duration of the link assessment process with the number of antennas. In a system with multiple antennas that send multiple probes for each antenna, the time to complete the link assessment process can increase significantly.

[0016] In some examples herein, a single TXOP is used in the link assessment process. During a single TXOP, along with antenna selection, efficient and optimal transmission parameter settings are determined. The collection of transmission parameters can be referred to herein as a set of transmission parameters. A single receive chain transmitter generates one sequence of probes within a single TXOP. The probes can be, in some examples, physical layer convergence protocol (PLCP) protocol data units (PPDUs). In some examples, the probe packets are null packets, but the probing Wi-Fi device selects these packets to cause the receiving Wi-Fi device to send a response. Each PPDU corresponds to a different set of transmission parameters via a different antenna. The probes are sent to the receiving device, and the receiving device can send feedback to the transmitter if a PPDU is received. The transmitter selects the next set of transmission and antenna parameters in response to the PPDU, based on the feedback or the absence of feedback. The next PPDU can have lower or higher power, lower or higher complexity power, modulation, and coding schemes, different antennas, etc. The transmitter can receive feedback again and then send another probing PPDU. The Wi-Fi device can be configured to repeat the process until an appropriate or optimal antenna with an appropriate or optimal set of transmission parameters within the set of transmission parameters corresponding to the communication medium is selected. In some examples, after the probing Wi-Fi device selects an antenna and transmission parameters, data exchange can occur between Wi-Fi devices during a single TXOP.

[0017] Figure 1 is a block diagram of a Wi-Fi device 100 in various examples of this specification. The Wi-Fi device 100 includes a processor 102 and a memory 104. The memory 104 stores instructions or logic 106 that cause the processor 102 to perform various functionalities described herein when executed by the processor 102. The memory 104 is an example of a non-transitory computer-readable medium. The components in the Wi-Fi device 100 can be coupled via a bus 108 or in any other suitable manner. In FIG. 1, an example where the components are coupled via the bus 108 is shown.

[0018] The Wi-Fi device 100 also includes a transmitter 110 and a receiver 112. The Wi-Fi device 100 can be a single receive chain device in one example. The Wi-Fi device 100 can include any number of antennas, such as antennas 114.1, 114.2, up to antennas 114.N (collectively antennas 114). The Wi-Fi device 100 can communicate with another Wi-Fi device 116 via a link 118. In some examples, the Wi-Fi device 100 is called a probing Wi-Fi device and the Wi-Fi device 116 is called a receiving Wi-Fi device.

[0019] The processor 102 is configured to read and execute computer-readable instructions. For example, the processor 102 is configured to call and execute instructions in a program stored in the memory 104, including the logic 106. In some examples, the logic 106 includes one or more link adaptation algorithms. The processor 102 drives or controls the transmitter 110 to perform transmission in response to the processor 102 transmitting data. Also, the processor 102 drives or controls the receiver 112 to perform reception in response to the processor 102 receiving data. Thus, the processor 102 can be regarded as a control center for performing data transmission or reception, and the transmitter 110 and the receiver 112 are executors for performing transmission operations and reception operations.

[0020] This description is considered to be the result of the functionality of Wi-Fi device 100, processor 102, and logic 106. Wi-Fi device 100, processor 102, and logic 106 may include processing circuit elements such as one or more processors (e.g., one or more processing cores). Wi-Fi device 100, processor 102, and logic 106 may include any combination of integrated circuit elements, discrete logic circuit elements, and analog circuit elements such as one or more microprocessors, microcontrollers, digital signal processors, application specific integrated circuits, central processing units, field programmable gate arrays, and / or any other processing resources. The techniques described in this description may also be embodied or encoded in a manufactured product that includes a non-transitory computer-readable storage medium such as memory 104. Although processor 102 is described as a single processor, processor 102 may include multiple components such as the processing resources listed above, as well as any combination of other discrete or integrated logic circuit elements and / or analog circuit elements.

[0021] In some examples, memory 104 is coupled to processor 102 via bus 108. In other examples, memory 104 is integrated with processor 102. Memory 104 is configured to store multiple groups of various software programs and / or instructions, including logic 106. Memory 104 may include one or more storage devices. For example, memory 104 may include high-speed random access memory and / or may include non-volatile memory such as one or more disk storage devices, flash memory, another non-volatile solid-state storage device, or pseudo-static random access memory (PSRAM). Memory 104 may store an operating system such as ANDROID, IOS, WINDOWS, or LINUX. Memory 104 may further store a network communication program. The network communication program is useful for communicating with one or more attached devices, one or more user devices, or one or more network devices. Memory 104 may further store a user interface program. The user interface program displays the content of an application via a graphical interface and receives data or actions performed by a user on the application via input controls such as a menu, a dialog box, or a physical input device (not shown). Memory 104 is configured to store instructions or logic 106 for implementing the various methods and processes provided in the various examples of this description.

[0022] The Wi-Fi device 100 may also include other communication components such as a Global Positioning System (GPS) module, a cellular module, a Bluetooth or Bluetooth Low Energy (BLE) module, a ZigBee module, Long Term Evolution (LTE), LTE Machine Type Communication (LTE-M), Narrowband LTE (NB-LTE), Sub-Gigahertz communication (Sub-1G), or a Wireless Fidelity (Wi-Fi) module. The Wi-Fi device 100 may also support other wireless communication signals such as satellite signals or shortwave signals. The Wi-Fi device 100 may be provided with a wired network interface or a Local Area Network (LAN) interface to support wired communication.

[0023] In various examples, the Wi-Fi device 100 may further include an input / output interface (not shown) to enable communication between the Wi-Fi device 100 and one or more input / output devices (not shown). Examples of input / output devices include audio input / output devices, key input devices, displays, etc. The input / output devices are configured to implement an interaction between the Wi-Fi device 100 and the user or the external environment. The input / output devices may further include a camera, a touch screen, sensors, etc. The input / output devices communicate with the processor 102 via the user interface.

[0024] The Wi-Fi device 100 shown in FIG. 1 is an example of a Wi-Fi system or device. During actual application, the Wi-Fi device 100 may include more or fewer components. The Wi-Fi device 100 may connect to other Wi-Fi devices such as the Wi-Fi device 116 during operation.

[0025] In one exemplary operation, the Wi-Fi device 100 performs a transmission rate and antenna selection process that includes subsequent phases in a single TXOP. First, the Wi-Fi device 100 executes an initial transmission rate selection phase at an initial antenna. Second, the Wi-Fi device 100 performs a probing phase at an alternative antenna and then makes an antenna selection. Third, the Wi-Fi device 100 may perform an optional final rate selection phase. Fourth, the Wi-Fi device 100 may perform a data exchange phase with another Wi-Fi device.

[0026] In an example herein, the Wi-Fi device 100 may be able to alternate antenna element and transmission parameter optimization during a single TXOP channel sounding probing phase. During a TXOP, the channel used is not available to other devices or users. Thus, other users do not interfere with the link sounding procedure performed by the Wi-Fi device 100, and the Wi-Fi device 100 can complete the link sounding procedure in a timely manner. This becomes more important as the number of antennas increases and may require longer link sounding procedures to find the optimal antenna. If the Wi-Fi device 100 uses multiple TXOPs, the Wi-Fi device 100 has to compete with other devices for each TXOP, and if the Wi-Fi device 100 loses the competition for a TXOP, it has to wait until the channel is cleared again. By using a single TXOP, the Wi-Fi device 100 can select an appropriate or optimal antenna with an appropriate or optimal set of transmission parameters within the set of transmission parameters corresponding to the communication medium without waiting for an additional TXOP to become available.

[0027] In the operation of one example, the Wi-Fi device 100 generates a sequence of multi-antenna probing PPDUs transmitted during a single TXOP. This sequence can be referred to as a PPDU burst. The PPDU can be a short probing transmission that does not include any data payloads, such as a QoS (Quality of Service) Null frame. In one example, each PPDU within the burst can correspond to a different transmit antenna 114. The transmitter 110 starts transmitting the PPDU burst at an initial antenna, such as antenna 114.1.

[0028] The Wi-Fi device 100 then receives feedback regarding the transmitted PPDU. The feedback can be, in one example, an acknowledgment or ACK. If the Wi-Fi device 100 receives an ACK, the transmission parameters used for that PPDU were good enough to successfully complete the transmission for that channel and that receiving device. If the Wi-Fi device 100 does not receive an acknowledgment, a NACK results (either not an acknowledgment or a negative acknowledgment). When a NACK occurs, this means that the transmission parameters and / or the antenna did not complete the transmission. Another type of feedback that can be received by the Wi-Fi device 100 can be the packet error rate. Another type of feedback can be the channel state information (CSI). The Wi-Fi device 100 can transmit a probe, which results in the Wi-Fi device 100 receiving some type of CSI in the reply.

[0029] After the Wi-Fi device 100 receives feedback in response to the PPDU, the Wi-Fi device 100 analyzes the feedback. Based on the feedback, the Wi-Fi device 100 can assess and evaluate the channel conditions. If the result of the PPDU is an ACK, the Wi-Fi device 100 can proceed to transmit data using the same set of antennas and transmission parameters as the successful PPDU. The Wi-Fi device 100 can send another PPDU using the same antennas with a different set of transmission parameters. The Wi-Fi device 100 can send another PPDU using different antennas with the same set of transmission parameters as the first PPDU or with a different set of transmission parameters. The Wi-Fi device 100 can be configured to perform all of these actions during the same TXOP. Since the TXOP can continue as long as required, the Wi-Fi device 100 can request sufficient time to perform a potential PPDU burst for antenna 114.

[0030] In another exemplary operation, the Wi-Fi device 100 can prepare a PPDU burst corresponding to different sets of transmission parameters, such as antennas, bitrates, transmitter power, modulation, and coding schemes. Using this option, the Wi-Fi device 100 can select the optimal antenna along with transmission parameters that match the communication medium on which the system operates. Thus, the Wi-Fi device 100 can be configured to perform antenna selection and optimization of the transmission parameter set in the same TXOP.

[0031] In another exemplary operation, the Wi-Fi device 100 can combine probing and data exchange. The PPDU burst can include data exchange after a probing sequence. The multi-antenna selection method system described herein enables setting the configuration of subsequent transmissions to an optimal or appropriate state based on the results of the link assessment process. Thus, the Wi-Fi device 100 can perform antenna selection, transmission parameter set optimization, and data exchange in the same TXOP.

[0032] Figure 2 is a timing diagram 200 of antenna selection using a PPDU burst in various examples of this specification. The timing diagram 200 shows a TXOP 202 in which a Wi-Fi device performs antenna selection using a continuous multi-antenna probing PPDU burst. In the timing diagram 200, the Wi-Fi device selects an antenna to be used for the next transmission.

[0033] The example of the timing diagram 200 includes two antennas, a first antenna 114.1 and a second antenna 114.2. The TXOP 202 in this example includes an antenna selection phase 204 and a data exchange phase 206. At the start of the antenna selection phase 204, the first antenna 114.1 transmits a first probe packet 208A to a receiving Wi-Fi device such as the Wi-Fi device 116. The Wi-Fi device 100 transmits the first probe packet 208A together with a set of transmission parameters. For example, the first probe packet 208A may have a certain transmission power, a certain bit rate, a certain MCS, etc. The MCS may be binary phase shift keying (BPSK), quadrature phase shift keying (QPSK), quadrature amplitude modulation (QAM), or any other suitable modulation coding scheme. The first probe packet 208A may also include other transmission parameters. Since the Wi-Fi device 100 may be configured to store transmission parameters in a memory such as the memory 104, the Wi-Fi device 100 can evaluate the channel conditions and track the performance of probe packets with different transmission parameters to find a suitable or optimal antenna and a suitable or optimal set of transmission parameters corresponding to the communication medium.

[0034] After the Wi-Fi device 100 transmits the first probe packet 208A, the first antenna 114.1 may receive feedback 210. The feedback 210 may be in the form of an ACK from the receiving Wi-Fi device. The feedback 210 may be a packet including CSI regarding the channel. The feedback 210 may include any other type of data providing information regarding the channel. Also, in some examples, the Wi-Fi device 100 may not receive a response from the receiving Wi-Fi device. This negative response, or NACK, is also a form of feedback that the Wi-Fi device 100 may receive. The Wi-Fi device 100 may store the feedback 210, for example, in the memory 104. The Wi-Fi device 100 may be configured to set transmission parameters based at least in part on the feedback 210 and other feedback.

[0035] In the example of FIG. 2, after the Wi-Fi device 100 receives the feedback 210, the Wi-Fi device 100 transmits the second probe packet 208B to the receiving Wi-Fi device using the second antenna 114.2. In this example, the first probe packet 208A and the second probe packet 208B have the same transmission parameters except that they are transmitted by different antennas. For example, if the first probe packet 208A has a first transmission power and a first bit rate, the second probe packet 208B also has the first transmission power and the first bit rate.

[0036] After the Wi-Fi device 100 transmits the second probe packet 208B, the second antenna 114.2 may receive feedback 212. The feedback 212 can be of any type of the feedback described above with respect to the feedback 210. In this example, the Wi-Fi device 100 analyzes the feedback 210 and 212 and determines that the second antenna 114.2, along with the transmission parameters of the second probe packet 208B, provides an appropriate or optimal communication medium using those specific transmission parameters. For example, the first antenna 114.1 may receive a NACK for the feedback 210, while the second antenna 114.2 receives an ACK for the feedback 212. The Wi-Fi device may then use the second antenna 114.2 and the transmission parameters of the probe packet 208B to transmit data during the data exchange phase 206 of the TXOP 202. This data transmission is shown as PPDU transmission 214 in FIG. 2. After the Wi-Fi device 100 transmits the PPDU transmission 214 to the receiving Wi-Fi device, the second antenna 114.2 may receive feedback 216 from the receiving Wi-Fi device. The Wi-Fi device 100 may be configured to store and / or use this feedback 216 for subsequent transmissions.

[0037] As shown in FIG. 2, a Wi-Fi device can use a single TXOP 202 for antenna selection using a multi-antenna probing PPDU burst. Although two antennas are shown in FIG. 2, in other examples, a Wi-Fi device may use any number of antennas. For example, Wi-Fi device 100 can transmit a probe packet such as a second probe packet 208A from more than two antennas, along with feedback from each probe packet used to select an optimal antenna and transmission parameters. After Wi-Fi device 100 selects an antenna and transmission parameters, Wi-Fi device 100 can transmit data to a receiving Wi-Fi device. Wi-Fi device 100 can be configured to perform the entire process including data transmission during a single TXOP 202. By using a single TXOP, Wi-Fi device 100 does not need to compete with other devices for the TXOP of each antenna, but may require a large amount of time if Wi-Fi device 100 has, for example, eight antennas.

[0038] FIG. 3 is a timing diagram 300 of antenna and rate selection using a PPDU burst in various examples of this specification. The timing diagram 300 shows a TXOP 302 in which a Wi-Fi device performs antenna and rate selection and optimization using consecutive multi-antenna probing PPDU bursts. In the timing diagram 300, the Wi-Fi device selects the antenna to be used for the next transmission and optimizes the transmission parameters according to the communication channel.

[0039] The example of the timing diagram 300 includes two antennas, the first antenna 114.1 and the second antenna 114.2. The TXOP 302 in this example includes an antenna selection and transmission parameter tuning phase 304 and a data exchange phase 306. At the start of the tuning phase 304, the first antenna 114.1 transmits a first probe packet 308A to a receiving Wi-Fi device such as the Wi-Fi device 116. The Wi-Fi device 100 transmits the first probe packet 308A together with a set of transmission parameters. For example, the first probe packet 308A may have a certain transmission power, a certain bit rate, a certain MCS, a certain format, etc. Since the Wi-Fi device 100 can store the transmission parameters in a memory such as the memory 104, the Wi-Fi device 100 can evaluate the channel conditions and track the performance of probe packets with different transmission parameters to find an appropriate or optimal antenna and an appropriate or optimal set of transmission parameters corresponding to the communication medium.

[0040] After the Wi-Fi device 100 transmits the first probe packet 308A, the first antenna 114.1 may receive feedback 310. The feedback 310 may be in the form of an ACK, NACK, CSI, etc. from the receiving Wi-Fi device as described above. The Wi-Fi device 100 may be configured to store the feedback 310 in, for example, the memory 104. The Wi-Fi device 100 may be configured to set the antenna selection and transmission parameters based at least in part on the feedback 310 and other feedbacks.

[0041] In the example of FIG. 3, after the Wi-Fi device 100 receives the feedback 310, the Wi-Fi device 100 transmits the second probe packet 308B to the receiving Wi-Fi device using the second antenna 114.2. In this example, the first probe packet 308A and the second probe packet 308B have the same transmission parameters except that they are transmitted by different antennas. For example, if the first probe packet 308A has a first transmission power and a first bit rate, the second probe packet 308B also has the first transmission power and the first bit rate.

[0042] After the Wi-Fi device 100 transmits the second probe packet 308B, the second antenna 114.2 may receive feedback 312. The feedback 312 may be of any type of the feedback described above with respect to the feedback 310. Next, the Wi-Fi device 100 transmits a third probe packet 314A by the first antenna 114.1. The third probe packet 314A in this example includes a set of transmission parameters different from those of the first probe packet 308A or the second probe packet 308B. In this example, the Wi-Fi device 100 transmits probe packets with different transmission parameters on different antennas in order to optimize both antenna selection and transmission parameters. For example, the Wi-Fi device 100 may be configured to transmit the first probe packet 308A and the second probe packet 308B at a first transmission power, while the Wi-Fi device 100 may be configured to transmit the third probe packet 314A at a second transmission power different from the first transmission power. Alternatively, the third probe packet 314A may have different MCS or other transmission parameters compared to the first probe packet 308A and the second probe packet 308B. The Wi-Fi device 100 may be configured to select the transmission parameters of the third probe packet 314A based at least in part on the feedback 310 and / or the feedback 312 in some examples. In other examples, the memory 104 may store pre-set transmission parameters for various probe packets.

[0043] After the Wi-Fi device 100 transmits the third probe packet 314A by the first antenna 114.1, the Wi-Fi device 100 may receive feedback 316. The feedback 316 may be of any type of the feedback described above with respect to the feedback 310. After the Wi-Fi device 100 receives the feedback 316, the second antenna 114.2 may transmit the fourth probe packet 314B. In this example, the fourth probe packet 314B has the same transmission parameters as the third probe packet 314A, except that it is transmitted by a different antenna. For example, if the third probe packet 314A has a second transmission power and a second bit rate, the fourth probe packet 314B also has the second transmission power and the second bit rate.

[0044] After the Wi-Fi device 100 transmits the fourth probe packet 314B, the second antenna 114.2 may receive feedback 318. The feedback 318 may be of any type of the feedback described above with respect to the feedback 310. Next, the Wi-Fi device 100 transmits the fifth probe packet 320 by the first antenna 114.1. In this example, the Wi-Fi device 100 may be configured to transmit the fifth probe packet 320 with a set of transmission parameters different from those of the first probe packet 308A, the second probe packet 308B, the third probe packet 314A, or the fourth probe packet 314B. After the Wi-Fi device 100 transmits the fifth probe packet 320 by the first antenna 114.1, the Wi-Fi device 100 may receive feedback 322. The feedback 322 may be of any type of the feedback described above with respect to the feedback 310.

[0045] In this example, after the Wi-Fi device 100 receives the feedback 322, the Wi-Fi device 100 selects the first antenna 114.1 and the transmission parameters associated with the fifth probe packet 320. Next, the process moves to the data exchange phase 306 of the TXOP 302. In the data exchange phase 306, the PPDU transmission 324 uses the first antenna 114.1 and the transmission parameters of the fifth probe packet 320 to transmit data from the Wi-Fi device 100 to the receiving Wi-Fi device. The first antenna 114.1 can then receive the feedback 326 from the receiving Wi-Fi device. As shown in FIG. 3, the Wi-Fi device 100 can be configured to perform all of the antenna selection and transmission parameter tuning phase 304 and the data exchange phase 306 in a single TXOP.

[0046] In other examples, the Wi-Fi device 100 may use more than two antennas, and the Wi-Fi device 100 may transmit any number of probe packets to tune the transmission parameters. The Wi-Fi device 100 can receive feedback from the probe packets and is used to select the best antenna and transmission parameters for the communication medium.

[0047] FIG. 4 is a timing diagram 400 of antenna and rate selection using PPDU bursts in various examples of this specification. Although timing diagrams 200, 300, and 400 are shown as separate processes, the probing Wi-Fi device may be configured to implement any combination of the techniques described with respect to timing diagrams 200, 300, and 400. Timing diagram 400 shows a TXOP 402 in which the probing Wi-Fi device performs antenna and rate selection and optimization using a continuous multi-antenna probing PPDU burst. In timing diagram 400, Wi-Fi device 100 selects the antenna to be used for the next transmission and optimizes the transmission parameters according to the communication channel. In this example, Wi-Fi device 100 optimizes the first antenna using a plurality of probe packets. After the process is completed, Wi-Fi device 100 can use the optimized parameters as a starting point for the second antenna. The same process can be continued for any number of antennas. This iterative process can reduce the amount of probe packets used during the selection and optimization process compared to other examples.

[0048] The example of the timing diagram 400 includes two antennas, the first antenna 114.1 and the second antenna 114.2. The TXOP 402 in this example includes an antenna selection and transmission parameter tuning phase 404 and a data exchange phase 406. At the start of phase 404, the first antenna 114.1 transmits a first probe packet 408 to a receiving Wi-Fi device such as the Wi-Fi device 116. The Wi-Fi device 100 transmits the first probe packet 408 along with a set of transmission parameters. For example, the first probe packet 408 may have a certain transmission power, a certain bit rate, a certain MCS, a certain format, etc. Since the Wi-Fi device 100 may store the transmission parameters in a memory such as the memory 104, the Wi-Fi device 100 can evaluate the channel conditions and track the performance of probe packets with different transmission parameters to find an appropriate or optimal antenna and an appropriate or optimal set of transmission parameters corresponding to the communication medium.

[0049] After the Wi-Fi device 100 transmits the first probe packet 408, the first antenna 114.1 may receive feedback 410. The feedback 410 may be in the form of an ACK, NACK, CSI, etc. from the receiving Wi-Fi device as described above. The Wi-Fi device 100 may store the feedback 410 in, for example, the memory 104. The Wi-Fi device 100 may be configured to set the antenna selection and transmission parameters based at least in part on the feedback 410 and other feedback.

[0050] In the example of FIG. 4, after the Wi-Fi device 100 receives the feedback 410, the Wi-Fi device 100 transmits a second probe packet 412A to the receiving Wi-Fi device using the first antenna 114.1. After the Wi-Fi device 100 transmits the second probe packet 412A, the first antenna 114.1 may receive a feedback 414. The feedback 414 may be any type of the feedback described above with respect to the feedback 410. As described above, the Wi-Fi device 100 may be configured to transmit several probe packets from the first antenna 114.1 in order to optimize the transmission parameters for the first antenna 114.1. After the first antenna 114.1 transmits a probe packet and the Wi-Fi device 100 optimizes the transmission parameters, the process moves to the second antenna and uses the optimized transmission parameters as a starting point for the second antenna. The Wi-Fi device 100 may be configured to repeat the process for any number of antennas using any number of probe packets until the Wi-Fi device 100 finds the optimal antenna and the optimal transmission parameters. The Wi-Fi device 100 may be configured to perform these processes in a single TXOP as described herein.

[0051] In the timing diagram 400, after the Wi-Fi device 100 receives the feedback 414, the optimization of the transmission parameters for the first antenna 114.1 is completed. Then the process moves to the second antenna 114.2, which transmits a third probe packet 412B in this example. The third probe packet 412B has the same transmission parameters as the second probe packet 412A. The second probe packet 412A includes the optimized transmission parameters for the first antenna 114.1, and the Wi-Fi device 100 can use these transmission parameters as a starting point for the second antenna 114.2.

[0052] After the Wi-Fi device 100 transmits the third probe packet 412B, the second antenna 114.2 receives feedback 416 from the Wi-Fi receiving device. Then the second antenna 114.2 transmits a fourth probe packet 418. The fourth probe packet 418 has transmission parameters different from those of the first probe packet 408, the second probe packet 412A, or the third probe packet 412B. After the Wi-Fi device 100 transmits the fourth probe packet 418, the Wi-Fi device 100 receives feedback 420. The feedback 420 can be any type of the feedback described above with respect to the feedback 410.

[0053] In this example, the Wi-Fi device 100 determines that the second antenna 114.2 using the transmission parameters of the fourth probe packet 418 is optimal for the communication medium. Accordingly, the antenna selection and transmission parameter tuning phase 404 ends and the data exchange phase 406 begins. In the data exchange phase 406, PPDU transmission 422 uses the second antenna 114.2 and the transmission parameters of the fourth probe packet 418 to transmit data from the Wi-Fi device 100 to the receiving Wi-Fi device. Then, the second antenna 114.2 may receive feedback 424 from the receiving Wi-Fi device. As shown in FIG. 4, the Wi-Fi device 100 may be configured to perform all of the antenna selection and transmission parameter tuning phase 404 and the data exchange phase 406 in a single TXOP 402.

[0054] In the examples herein, a probing Wi-Fi device may be configured to find optimal transmission parameters using any number of probe packets. A trade-off may be made between immediately selecting appropriate transmission parameters or using a longer process to select the best or optimal parameters. The probing Wi-Fi device may use a composite algorithm that utilizes transmission power, bit rate, MCS, packet size, format, and other transmission parameters to optimize communication. Wi-Fi device 100 may select the next best probe packet for transmission from among any number of potential probe packets based on feedback from previous probe packets. Also, or alternatively, Wi-Fi device 100 may be configured to determine whether to issue another probing PPDU based on the results of the evaluation. Wi-Fi device 100 may store the results in memory 104 in some examples.

[0055] Figure 5 is a flowchart of a method 500 for antenna selection in various examples herein. The steps of method 500 may be performed in any suitable order. The hardware components described above with respect to FIG. 1 may perform method 500 in some examples. Any suitable hardware or digital logic may perform method 500 in some examples.

[0056] Method 500 begins at 510, where a probing Wi-Fi device, such as Wi-Fi device 100, acquires air access and obtains a TXOP on a Wi-Fi channel. The steps described in method 500 are performed within a single TXOP.

[0057] Method 500 continues at 520, where the probing Wi-Fi device transmits a probe packet with transmission parameter settings to a receiving Wi-Fi device using a first antenna during the TXOP. The probe packet may be a packet such as probe packet 208A described above. The probe packet may include any number of transmission parameter settings in various examples.

[0058] Method 500 continues at 530, where the probing Wi-Fi device receives a first feedback in response to transmitting a probe packet using the first antenna. The first feedback may be a feedback such as feedback 210 described above.

[0059] Method 500 continues at 540, where the probing Wi-Fi device transmits a probe packet from the probing Wi-Fi device to the receiving Wi-Fi device with transmission parameter settings during a TXOP using the second antenna. In this example, the probe packet may be a probe packet such as probe packet 208B and has transmission parameters similar to those of probe packet 208A.

[0060] Method 500 continues at 550, where the probing Wi-Fi device receives a second feedback in response to transmitting a probe packet using the second antenna. The second feedback may be a feedback such as feedback 212 described above.

[0061] Method 500 continues at 560, where the probing Wi-Fi device sets a set of transmission parameters and a selected antenna based at least in part on the first feedback or the second feedback. The set of transmission parameters may include any number or type of transmission parameters. As an example, in FIG. 2, the probing Wi-Fi device 100 transmits a PPDU transmission 214 to the receiving Wi-Fi device using a set of transmission parameters of the probe packet 208B. In that example, the probing Wi-Fi device 100 uses the second antenna 114.2 for the PPDU transmission 214, although the probing Wi-Fi device 100 may use a different antenna in another example. In other examples, the probing Wi-Fi device 100 may use any number of antennas and may transmit any number of probe packets before selecting the transmission parameters.

[0062] Figure 6 is a flowchart of method 600 for antenna and rate selection in various examples of this specification. The steps of method 600 can be performed in any suitable order. The hardware components described above with respect to FIG. 1 can implement method 600 in some examples. In some examples, any suitable hardware or digital logic can implement method 600.

[0063] Method 600 begins at 610, where a probing Wi-Fi device acquires air access and obtains a TXOP on the Wi-Fi channel. The steps described in method 600 are performed with a single TXOP.

[0064] Method 600 continues at 620, where the probing Wi-Fi device transmits a first probe packet to the receiving Wi-Fi device along with a first set of transmission parameters using the first antenna during the TXOP. As an example, the Wi-Fi device transmits the first probe packet 408 during TXOP 402 in FIG. 4.

[0065] Method 600 continues at 630, where the probing Wi-Fi device receives a first feedback in response to transmitting the first probe packet using the first antenna. The first feedback can be, for example, feedback 410 in one example.

[0066] Method 600 continues at 640, where the probing Wi-Fi device transmits a second probe packet to the receiving Wi-Fi device along with a second set of transmission parameters using the first antenna during the TXOP. The second probe packet can be, for example, the second probe packet 412A in one example.

[0067] Method 600 continues at 650, where the probing Wi-Fi device receives a second feedback in response to transmitting a second probe packet using the first antenna. The second feedback can be, in one example, feedback 414.

[0068] Method 600 continues at 660, where the probing Wi-Fi device transmits a second probe packet along with a second set of transmission parameters to the receiving Wi-Fi device during a TXOP using the second antenna. As an example, the probing Wi-Fi device transmits a second probe packet 412B using the second antenna 114.2.

[0069] Method 600 continues at 670, where the probing Wi-Fi device receives a third feedback in response to transmitting a second probe packet using the second antenna. The third feedback can be, in one example, feedback 416.

[0070] Method 600 continues at 680, where the probing Wi-Fi device sets one or more transmission parameters within a set of transmission parameters based at least in part on the first feedback, the second feedback, or the third feedback. As an example, in FIG. 4, the probing Wi-Fi device transmits a PPDU transmission 422 to the receiving Wi-Fi device using the transmission parameters of the probe packet 418. In that example, Wi-Fi device 100 uses the second antenna 114.2 for the PPDU transmission 422, although Wi-Fi device 100 may use a different antenna in another example. In other examples, Wi-Fi device 100 may use any number of antennas and may transmit any number of probe packets before selecting the transmission parameters.

[0071] FIG. 7 is a flowchart of a method 700 for antenna and rate selection in various examples of this specification. The steps of method 700 may be performed in any suitable order. The hardware components described above with respect to FIG. 1 may perform method 700 in some examples. In some examples, any suitable hardware or digital logic may perform method 700.

[0072] Method 700 describes a memory, such as memory 104, that stores instructions for a probing Wi-Fi device, such as Wi-Fi device 100. Wi-Fi device 100 includes a processor 102 that is coupled to a Wi-Fi transmitter 110 and a Wi-Fi receiver 112 in the probing Wi-Fi device 100. The Wi-Fi transmitter 110 and the Wi-Fi receiver 112 are configured to communicate via a Wi-Fi channel, such as link 118. The processor 102 is configured to execute instructions or logic 106 stored in the memory 104 to perform the steps of method 700.

[0073] Method 700 begins at 710, where instructions cause the Wi-Fi device 100 to acquire a TXOP on the Wi-Fi channel. The steps described in method 700 are performed with a single TXOP.

[0074] Method 700 continues at 720, where instructions cause the Wi-Fi device 100 to transmit a probe packet to a receiving Wi-Fi device via the Wi-Fi transmitter 110 using the first antenna during the TXOP, and the Wi-Fi transmitter 110 transmits the probe packet with a transmission parameter within a set of transmission parameters. As an example, the first antenna 114.1 may be configured to transmit the probe packet 208A in FIG. 2.

[0075] Method 700 continues at 730, where instructions cause the Wi-Fi device 100 to receive a first feedback at the Wi-Fi receiver 112 in response to transmitting the probe packet using the first antenna. The first feedback may be, for example, feedback 210 in one example.

[0076] Method 700 continues at 740, where the instruction causes a Wi-Fi receiving device to receive a probe packet from the Wi-Fi transmitter 110 during the TXOP using the second antenna and transmit it to the Wi-Fi transmitting device 110, and the Wi-Fi transmitter 110 transmits the probe packet along with the transmission parameters within the set of transmission parameters. In this example, the second antenna 114.2 transmits the probe packet 208B to the Wi-Fi receiving device.

[0077] Method 700 continues at 750, where the instruction causes the Wi-Fi device 100 to receive second feedback at the Wi-Fi receiver 112 in response to transmitting the probe packet using the second antenna. The second feedback can be, for example, feedback 212 in one example.

[0078] Method 700 continues at 760, where the instruction causes a probing Wi-Fi device such as the Wi-Fi device 100 to set the transmission parameters and the selected antenna within the set of transmission parameters based at least in part on the first feedback or the second feedback.

[0079] In the examples of this specification, a single probing TXOP is implemented, and the probing Wi-Fi device generates feedback for multiple antennas from consecutive probing PPDUs during a single TXOP. Since the Wi-Fi device does not need to repeatedly compete with other devices for RXOP, the antenna selection time is faster than in other examples due to performing antenna selection during a single TXOP. Also, the Wi-Fi device 100 can be configured to combine antenna selection and data transmission in a single TXOP rather than applying the discovered transmission parameters to data transmission during the next TXOP. This process provides more efficient data transmission.

[0080] Also, in some examples, Wi-Fi devices perform antenna selection and probing for transmission parameters in a single TXOP. Instead of waiting for the next TXOP, the Wi-Fi device 100 can be configured to change the antenna used for transmission during the TXOP. Also, the Wi-Fi device 100 can optimize multiple antennas during a single TXOP.

[0081] The term "coupled" is used throughout this specification. This term can include a connection, communication, or signal path that enables a functional relationship consistent with this specification. For example, when device A generates a signal for controlling device B to perform a certain action, in a first example, device A is coupled to device B, or, in a second example, when an intervening component C does not substantially change the functional relationship between device A and device B, device A is coupled to device B via the intervening component C, and device B will be controlled by device A via the control signal generated by device A.

[0082] A device "configured to" perform a certain task or function can be configured (e.g., programmed and / or hardwired) by the manufacturer to perform that function at the time of manufacture, and / or can be configured (or reconfigured) by the user after manufacture to perform that function and / or other additional or alternative functions. Such configuration can be via programming of the device's firmware and / or software, via the structure and / or layout of the device's hardware components and interconnections, or via a combination thereof. Modifications within the scope of the claims are possible in the examples described, and other examples are also possible.

Claims

1. It is a method, During a single TXOP (Transmission Opportunity), a probing Wi-Fi device transmits a first probe packet containing a first set of transmission parameters over a Wi-Fi channel via a first antenna to a receiving Wi-Fi device, Receiving a first feedback in response to transmitting a first probe packet via the first antenna, During the single TXOP, the first probe packet is transmitted from the probing Wi-Fi device to the receiving Wi-Fi device via the second antenna, Receiving a second feedback in response to transmitting the first probe packet via the second antenna, Transmitting a second probe packet from the probing Wi-Fi device to the receiving Wi-Fi device via the first antenna during the single TXOP, wherein the first and second transmit parameters differ by at least one transmit parameter, Receiving a third feedback in response to transmitting a second probe packet via the first antenna, The probing Wi-Fi device sets a set of operation parameters for transmission and selects one of the first and second antennas based at least in part on the first feedback, the second feedback, or the third feedback. Methods that include...

2. The method according to claim 1, A method further comprising, after setting a set of operation for the transmission parameters, having the probing Wi-Fi device send data packets to the receiving Wi-Fi device during the single TXOP.

3. The method according to claim 1, A method wherein the first probe packet is a Physical Layer Convergence Protocol (PLCP) protocol data unit (PPDU).

4. The method according to claim 1, A method wherein at least one of the first and second sets of transmission parameters is a transmission power.

5. The method according to claim 1, A method wherein the first feedback includes channel status information (CSI).

6. The method according to claim 1, A method wherein at least one of the first and second sets of transmission parameters is a modulation coding scheme (MCS).

7. The method according to claim 1, The first type of feedback described above is an affirmative response (ACK). Method.

8. The method according to claim 1, A method wherein the first feedback is a negative response (NACK).

9. The method according to claim 1, During the single TXOP, the probing Wi-Fi device transmits the second probe packet to the receiving Wi-Fi device via the second antenna, Receiving a fourth feedback in response to transmitting the second probe packet via the second antenna, The probing Wi-Fi device sets the set of operation of the transmission parameters based at least partially on the first feedback, the second feedback, the third feedback, or the fourth feedback, Methods that further include the above.

10. It is a method, Transmitting a first probe packet from a probing Wi-Fi device to a receiving Wi-Fi device via a first antenna during a single TXOP (Transmission Opportunity), wherein the first probe packet includes a first set of transmission parameters, Receiving a first feedback in response to transmitting a first probe packet via the first antenna, Transmitting a second probe packet from the probing Wi-Fi device to the receiving Wi-Fi device via the first antenna during the single TXOP, wherein the second probe packet includes a second set of transmission parameters. Receiving a second feedback in response to transmitting a second probe packet via the first antenna, During the single TXOP, the probing Wi-Fi device transmits the second probe packet to the receiving Wi-Fi device via the second antenna, Receiving a third feedback in response to transmitting the second probe packet via the second antenna, The probing Wi-Fi device sets one or more transmission parameters of the first and second sets of transmission parameters based at least partially on the first feedback, the second feedback, or the third feedback, Methods that include...

11. The method according to claim 10, A method further comprising, after setting one or more transmission parameters from the first and second sets of transmission parameters, having the proving Wi-Fi device send data packets to the receiving Wi-Fi device during the single TXOP.

12. The method according to claim 10, A method wherein the first probe packet is a Physical Layer Convergence Protocol (PLCP) protocol data unit (PPDU).

13. The method according to claim 10, A method wherein one of the first and second sets of transmission parameters is the transmission power.

14. The method according to claim 10, A method wherein one of the first and second sets of transmission parameters is a modulation coding scheme (MCS).

15. The method according to claim 10, A method wherein the first feedback includes channel status information (CSI).

16. The method according to claim 10, Before setting one or more transmit parameters of the first and second sets of transmit parameters, during a single TXOP, the probing Wi-Fi device transmits a third probe packet to the receiving Wi-Fi device via the second antenna, wherein the third probe packet includes a third transmit parameter of the third set of transmit parameters. Receiving a fourth feedback in response to transmitting the third probe packet via the second antenna, The probing Wi-Fi device sets one or more transmission parameters from the first, second, and third sets of transmission parameters based at least partially on the first feedback, the second feedback, the third feedback, or the fourth feedback, Methods that further include the above.

17. It is a system, In a probing Wi-Fi device, there is a memory for storing instructions, A processor coupled to a Wi-Fi transmitter and a Wi-Fi receiver configured to communicate via a Wi-Fi channel in the aforementioned probing Wi-Fi device, The Wi-Fi transmitter transmits a first probe packet containing first transmission parameters to a receiving Wi-Fi device via a first antenna during a single TXOP (Transmission Opportunity). In response to transmitting the first probe packet via the first antenna, the Wi-Fi receiver receives the first feedback. The Wi-Fi transmitter transmits the first probe packet to the receiving Wi-Fi device via the second antenna during the single TXOP. In response to transmitting the first probe packet via the second antenna, the Wi-Fi receiver receives a second feedback, The Wi-Fi transmitter transmits a second probe packet containing a second transmission parameter different from the first transmission parameter to the receiving Wi-Fi device via one of the first and second antennas during the single TXOP. In response to transmitting a second probe packet through one of the first and second antennas, the Wi-Fi receiver receives a third feedback, The probing Wi-Fi device sets at least one of the first and second transmission parameters and selects one of the first and second antennas based at least in part on the first feedback, the second feedback, or the third feedback. Therefore, the processor is configured to execute instructions stored in the memory, A system that includes this.

18. The system according to claim 17, The aforementioned processor, After setting at least one of the first and second transmission parameters, the Wi-Fi transmitter transmits data packets to the receiving Wi-Fi device during the single TXOP. A system further configured to execute the instructions stored in the memory.

19. The system according to claim 17, A system in which the first probe packet is a Physical Layer Convergence Protocol (PLCP) protocol data unit (PPDU).

20. The system according to claim 17, A system in which one of the first and second transmission parameters is the transmission power.

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