HK40021320B

HK40021320B - Wireless personal area network transmit beamforming

Info

Publication number: HK40021320B
Application number: HK62020011217.0A
Authority: HK
Inventors: L‧卢昂; A‧哈韦里宁; Y‧福冈; P‧登伯尔; H‧登伯尔; J‧林斯基; T‧卡吉尔
Original assignee: 高通股份有限公司
Priority date: 2017-06-30
Filing date: 2018-05-25
Publication date: 2021-11-12

Description

Wireless personal area network transmit beamforming

Technical Field

Various aspects and embodiments described herein relate generally to wireless communications, and more specifically to signaling that may enable transmit (Tx) beamforming in a Wireless Personal Area Network (WPAN).

Background

In a multi-antenna communication system, a plurality of (N)_TMultiple) transmitting antennas and one or more (N)_RMultiple) receive antennas are typically used for data transmission. N is a radical of_TThe multiple transmit antennas may be used to increase system throughput by transmitting different data from the antennas or to improve reliability by transmitting data redundantly. In a multi-antenna communication system, a propagation path exists between each pair of transmit and receive antennas. In N_TA transmitting antenna and N_RN is formed between the receiving antennas_T·N_RA different propagation path. These propagation paths may experience different channel conditions (e.g., different fading, multipath, and interference effects) and may achieve different signal-to-interference-plus-noise ratios (SNRs). Thus, N_T·N_RThe channel response of the individual propagation paths may vary from path to path, and may also vary in time for time-varying wireless channels, and across frequency for dispersive wireless channels. The varying nature of the propagation path makes it challenging to transmit data in an efficient and reliable manner.

Therefore, one approach to improving the reliability of data transmission is to employ transmit diversity with a beamforming sender (beamformer), which can potentially increase the link budget by more than three decibels (3 dB). For example, transmit diversity generally refers to redundant transmission of data across space, frequency, time, or a combination thereof. In addition to this, transmit diversity may be used to maximize diversity for data transmission across as many dimensions as possible to achieve robust performance and simplify processing of transmit diversity at both the transmitter and receiver. Another complementary technique that can be used to improve the performance of wireless transmissions is to employ beamforming to control the directionality of the transmitted signal. In a transmitting system or device, beamforming may be employed between a signal source and an antenna radiating element to "shape" the radiated field in three-dimensional space toward a receiving system or device. In order to steer the beam toward the receiving system or device, the transmitting system or device requires an estimate of the wireless channel. However, the prior art for obtaining a channel estimate for a particular link between two devices assumes that the channel is invariant and reciprocal, which is generally not guaranteed in Wireless Personal Area Networks (WPANs) where devices communicate using a frequency hopping scheme.

Disclosure of Invention

The following presents a simplified summary relating to one or more aspects and/or embodiments disclosed herein. Thus, the following summary should not be considered an extensive overview of all contemplated aspects and/or embodiments, nor should the following summary be considered to identify key or critical elements related to all contemplated aspects and/or embodiments, or to delineate the scope associated with any particular aspect and/or embodiment. Accordingly, the sole purpose of the following description is to present some concepts relating to one or more aspects and/or embodiments related to the mechanisms disclosed herein in a simplified form as a prelude to the detailed description presented below.

According to various aspects, techniques are provided for enabling implicit and/or explicit transmit (Tx) beamforming in a Wireless Personal Area Network (WPAN). In particular, the implicit transmit beamforming may be enabled during certain events, frames, and/or other conditions in which the channel between a beamforming sender device and a beamforming receiver (beamforming) device may be assumed or guaranteed to be reciprocal (i.e., packets are received and transmitted on the same frequency). In such a case, the beamforming sender device may estimate Channel State Information (CSI) based on packets received from the beamforming receiver device, and use the estimated CSI to steer a beam in a direction towards the beamforming receiver device. In a use case of implementing explicit transmit beamforming, the beamforming receiver device may estimate the CSI based on packets received from the beamforming sender device and provide the estimated CSI to the beamforming sender device, which may then use the estimated CSI received from the beamforming receiver device to steer a beam in a direction towards the beamforming receiver device.

According to various aspects, a method for beamforming a wireless transmission may comprise: in a WPAN implementing a frequency hopping system, establishing a wireless link with a beamforming receiver device at a beamforming sender device; receiving, at the beamforming sender device, a first packet from the beamforming receiver device, wherein the first packet may be received on a first frequency; estimating, at the beamforming sender device, channel state information associated with the wireless link based on the first packet received from the beamforming receiver device; and beamforming, by the beamforming sender device, a second packet to be sent to the beamforming receiver device on the first frequency such that the second packet is steered in a direction towards the beamforming receiver device.

According to various aspects, a beamforming sender device may comprise: a receiver configured to: on a WPAN implementing a frequency hopping system, receiving a first packet transmitted on a first frequency from a beamforming receiver device; one or more processors configured to: estimating channel state information associated with a wireless link between the beamforming sender device and the beamforming receiver device based on the first packet received from the beamforming receiver device; and a transmitter comprising a plurality of transmit antennas, the transmit antennas configured to: beamforming a second packet transmitted to the beamforming receiver device such that the second packet is steered in a direction towards the beamforming receiver device, wherein the second packet is transmitted on the first frequency.

According to various aspects, a beamforming sender device may comprise: means for receiving, from a beamforming receiver device, a first packet transmitted on a first frequency over a WPAN implementing a frequency hopping system; means for estimating channel state information associated with a wireless link between the beamforming sender device and the beamforming receiver device based on the first packet received from the beamforming receiver device; and means for beamforming a second packet transmitted to the beamforming receiver device such that the second packet is steered in a direction towards the beamforming receiver device, wherein the second packet is transmitted on the first frequency.

According to various aspects, a computer-readable storage medium may have computer-executable instructions recorded thereon, wherein the computer-executable instructions may be configured to cause a beamforming sender device having one or more processors to: on a WPAN implementing a frequency hopping system, receiving a first packet transmitted on a first frequency from a beamforming receiver device; estimating channel state information associated with a wireless link between the beamforming sender device and the beamforming receiver device based on the first packet received from the beamforming receiver device; and beamforming a second packet transmitted to the beamforming receiver device such that the second packet is steered in a direction towards the beamforming receiver device, wherein the second packet is transmitted on the first frequency.

According to various aspects, a method for beamforming a wireless transmission may comprise: in a WPAN implementing a frequency hopping system, establishing a wireless link with a beamforming receiver device at a beamforming sender device; at the beamforming sender device, configuring a first packet to request the beamforming receiver device to return a response packet that enables the beamforming sender device to obtain an estimate of channel state information associated with the wireless link; transmitting, by the beamforming sender device, the first packet to the beamforming receiver device; and beamforming, by the beamforming sender device, a second packet to be transmitted to the beamforming receiver device according to the frequency hopping system based on the response packet returned from the beamforming receiver device, wherein the beamforming sender device is configured to: beamforming the second packet to steer the second packet in a direction toward the beamformee device.

According to various aspects, a beamforming sender device may comprise: one or more processors configured to: in a WPAN implementing a frequency hopping system, establishing a wireless link with a beamforming receiver device and configuring a first packet to request the beamforming receiver device to return a response packet to enable the beamforming sender device to obtain an estimate of channel state information associated with the wireless link; and a transmitter configured to: transmitting the first packet to the beamforming receiver device, and transmitting a second packet to the beamforming receiver device according to the frequency hopping system based on the response packet returned from the beamforming receiver device, wherein the transmitter may include a plurality of transmit antennas configured to: beamforming at least the second packet such that the second packet is steered in a direction toward the beamformed receiver device.

According to various aspects, a beamforming sender device may comprise: means for establishing a wireless link with a beamforming receiver device in a WPAN implementing a frequency hopping system; means for configuring a first packet to request the beamforming receiver device to return a response packet to enable the beamforming sender device to obtain an estimate of channel state information associated with the wireless link; means for transmitting the first packet to the beamforming receiver device; and means for transmitting a second packet to the beamformee device according to the frequency hopping system based on the response packet returned from the beamformee device, wherein at least the second packet is beamformed such that the second packet is steered in a direction towards the beamformee device.

According to various aspects, a computer-readable storage medium may have computer-executable instructions recorded thereon, wherein the computer-executable instructions may be configured to cause a beamforming sender device to: in a WPAN implementing a frequency hopping system, establishing a wireless link with a beam forming receiver device; configuring a first packet to request the beamforming receiver device to return a response packet to enable the beamforming sender device to obtain an estimate of channel state information associated with the wireless link; transmitting the first packet to the beamforming receiver device; and transmitting a second packet to the beamformee device in accordance with the frequency hopping system based on the response packet returned from the beamformee device, wherein at least the second packet is beamformed such that the second packet is steered in a direction towards the beamformee device.

Other objects and advantages associated with the aspects and embodiments disclosed herein will be apparent to those skilled in the art based on the drawings and detailed description.

Drawings

A more complete understanding of the various aspects and embodiments described herein, as well as many of the attendant advantages thereof, will be readily obtained as the same becomes better understood by reference to the following detailed description when considered in connection with the accompanying drawings, which are given by way of illustration and not of limitation, and wherein:

fig. 1 illustrates a relationship between a bluetooth protocol stack and an Open Systems Interconnection (OSI) seven-layer model in accordance with various aspects.

Fig. 2 illustrates an implementation that supports one or more logical connections using a bluetooth protocol stack, in accordance with various aspects.

Fig. 3 illustrates an example Wireless Personal Area Network (WPAN) in accordance with various aspects and embodiments described herein.

Fig. 4 illustrates an exemplary radiation pattern that may be optimized using transmit beamforming in accordance with various aspects.

Fig. 5 illustrates an example signaling flow for implicitly enabling transmit beamforming at a Wireless Personal Area Network (WPAN) slave device in communication with a WPAN master device in accordance with various aspects.

Fig. 6A and 6B illustrate example signaling flows for implicitly and/or explicitly enabling transmit beamforming at a Wireless Personal Area Network (WPAN) master device in communication with a WPAN slave device in accordance with various aspects.

Fig. 7 illustrates an exemplary wireless device in which various aspects and embodiments described herein may be implemented.

Detailed Description

Various aspects and embodiments are disclosed in the following description and related drawings to illustrate specific examples related to the exemplary aspects and embodiments. Alternative aspects and embodiments will be apparent to persons skilled in the relevant art(s) upon reading this disclosure, and may be constructed and implemented without departing from the scope or spirit of the present disclosure. Additionally, well-known elements will not be described in detail or may be omitted so as not to obscure the relevant details of the aspects and embodiments disclosed herein.

The word "exemplary" is used herein to mean "serving as an example, instance, or illustration. Any embodiment described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments. Likewise, the term "embodiments" does not require that all embodiments include the discussed feature, advantage or mode of operation.

The terminology used herein describes particular embodiments only and should not be construed as limiting any embodiments disclosed herein. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood by those within the art that the terms "comprises," "comprising," "includes" and/or "including," when used herein, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof.

Further, various aspects and/or embodiments are described in terms of sequences of actions to be performed by, for example, elements of a computing device. Those skilled in the art will recognize that various actions described herein can be performed by specific circuits (e.g., Application Specific Integrated Circuits (ASICs)), by program instructions being executed by one or more processors, or by a combination of both. Additionally, these sequence of actions described herein can be considered to be embodied entirely within any form of non-transitory computer readable medium having stored thereon a corresponding set of computer instructions that when executed would cause an associated processor to perform the functions described herein. Thus, the various aspects disclosed herein may be embodied in a number of different forms, all of which are contemplated to be within the scope of the claimed subject matter. Additionally, for each of the aspects described herein, the respective form of any such aspect may be described herein as, for example, "logic configured to" perform the described action and/or other structural components configured to perform the described action.

As used herein, the term "wireless personal area network" or "WPAN" may generally refer to a computer network used for data transfer between personal wireless devices (e.g., cellular phones, laptop computers, tablet computers, Personal Digital Assistants (PDAs), etc.). In general, WPANs may be used to enable communication between personal wireless devices themselves (interpersonal communication) or to connect to higher level networks and the internet (uplink), where one "master" device acts as an internet router. WPANs typically utilize short-range wireless network protocols such as, for example,(for example,low Energy (BLE),Is classic,Long distance (BLR)), (BLR),A wireless USB,And the like. Thus, while much of the description provided herein relates to implementations based on bluetooth technology, those skilled in the art will recognize that the various aspects and embodiments described herein may be suitably applied to other suitable WPANs and/or WPANs that utilize other suitable technologies.

According to various aspects, fig. 1 illustrates the relationship between the bluetooth protocol stack 130 and seven layers in the Open Systems Interconnection (OSI) model 110, where the OSI model 110 is established to standardize information transfer between points over the internet or other wired and/or wireless networks. In particular, the OSI model 110 generally separates the communications process between two points in a network into seven stacked layers, with each layer adding certain functionality. Each device processes messages such that downstream flow through each layer occurs at the sending endpoint and upstream flow through the layers occurs at the receiving endpoint. The programming and/or hardware to provide the seven layers in the OSI model 110 is typically a combination of: device operating systems, application software, TCP/IP and/or other transport and network protocols, and other software and hardware.

More specifically, referring to fig. 1, the OSI model 110 includes a physical layer 112(OSI layer 1) for transmitting a bitstream over a network at a physical level. The Institute of Electrical and Electronics Engineers (IEEE) subdivides the physical layer 112 into a PLCP (physical layer convergence procedure) sublayer and a PMD (physical medium dependent) sublayer. The data link layer 114(OSI layer 2) provides physical level synchronization, performs bit stuffing, and provisions transport protocol knowledge and management, among other things. The IEEE subdivides the data link layer 114 into two additional sub-layers, which include: a Medium Access Control (MAC) sublayer for controlling data transmission to and from the physical layer; and a Logical Link Control (LLC) sublayer to interface with the network layer 116(OSI layer 3), interpret commands, and perform error recovery.

According to various aspects, still referring to fig. 1, network layer 116(OSI layer 3) handles data transport (e.g., routing and forwarding) across a network in a manner that is independent of any medium and specific network topology, transport layer 118(OSI layer 4) manages end-to-end control and error checking according to application-level reliability requirements to multiplex data transport across the network, and session layer 120(OSI layer 5) establishes, coordinates, and terminates sessions, exchanges, and dialogs between applications to provide management and data flow control services.

According to various aspects, still referring to fig. 1, the presentation layer 122(OSI layer 6) converts incoming and outgoing data from one presentation format to another presentation format, which may include adding a service structure to the data unit according to the common representation to provide the data to the application layer 124(OSI layer 7), while at the application layer 124, identifying communication partners, identifying quality of service (QoS), considering user authentication and privacy, identifying constraints on the data syntax, and managing any other functions related to managing communications between host applications.

Turning now to the bluetooth protocol stack 130, a Radio Frequency (RF) layer 132 generally corresponds to the physical layer 112 in the OSI model 110, a baseband layer 134 and a link manager protocol layer 136 generally correspond to the data link layer 114, and a Host Controller Interface (HCI)138 separates the RF layer 132, the baseband layer 134 and the link manager protocol layer 136 from upper layers. For example, the physical layer 112 in the OSI model 110 manages the electrical interface to the communication medium (which includes modulation and channel coding) and thus covers the bluetooth radio in the RF layer 132 (and possibly a portion of the baseband layer 134), while the data link layer 114 manages the transmission, framing, and error control over a particular link, which overlaps with the tasks (e.g., error checking and correction) performed in the link manager protocol layer 136 and the control end of the baseband layer 134.

Above the HCI 138, logical link control and adaptation protocol (L2CAP)140, RF communication (RFCOMM) channel 142, Telephony Control Specification (TCS)144, Service Discovery Protocol (SDP)146, audio/video distribution transport protocol (AVDTP)148, Synchronous Connection Oriented (SCO) audio 150, object exchange (OBEX)152, and TCP/IP 154 functions correspond to the network layer 116, transport layer 118, and session layer 120. The application layer 156 includes a bluetooth profile (e.g., Hands Free Profile (HFP) for voice, advanced audio distribution profile (A2DP) for high quality audio streams, Video Distribution Profile (VDP) for video streams, etc.) and corresponds to the presentation layer 122 and the application layer 124 in the OSI model 110. Thus, a bluetooth profile may generally be considered synonymous with "app" in OSI model 110. With respect to bluetooth HFP, the RFCOMM channel 142 includes a communication channel (not shown) named "service level connection" ("SLC") that emulates a serial port for additional communication between an Audio Gateway (AG) device and a hands-free (HF) device. For voice audio connections, for example, in bluetooth HFP, a separate baseband link called a Synchronous Connection Oriented (SCO) channel carries voice data, which is represented as audio (SCO)150 in fig. 1. For A2DP, the audio data (unidirectional high quality audio content, which may be in a mono record or stereo box) passes over the AVDTP 148, which in turn passes over the L2CAP 140. At the radio level, all L2CAP 140 data flows over the logical link.

According to various aspects, bluetooth wireless technology systems typically come in two forms, including Basic Rate (BR) and Low Energy (LE), where the former also includes optional Enhanced Data Rate (EDR) alternate Medium Access Control (MAC) and Physical (PHY) layer extensions. Both bluetooth BR systems and bluetooth LE systems include device discovery, connection establishment and connection mechanisms. However, bluetooth LE systems include features designed to implement products that require lower current consumption, lower complexity, and lower cost than BR/EDR, and have designs that support use cases and applications with lower data rates and lower duty cycles. In general, one system including any optional components may be preferred over the other depending on the user or application. Further, devices implementing both systems may communicate with other devices implementing both systems as well as devices implementing either system. However, some profiles and use cases may only be supported in one system or the other, and thus, the device implementing both systems has the capability to support most use cases. Referring to fig. 1, a bluetooth core system generally includes a host, which is a logical entity defined as all layers below an application layer 156 (in which a bluetooth profile is implemented) and above the HCI 138, and one or more controllers, which are logical entities defined as all layers below the HCI 138. According to various aspects, a bluetooth enabled device typically has one master controller, which may be a BR/EDR controller that includes an RF layer 132, a baseband layer 134, a link manager protocol layer 136, and optionally an HCI 138. Alternatively, the master controller may be a Low Energy (LE) controller that includes an LE PHY, a link manager protocol layer 136, and optionally an HCI 138. In a further alternative, the master controller may merge the BR/EDR portion and the LE controller portion into a single controller, in which case the controller configuration has only one bluetooth device address shared between the merged BR/EDR and LE controller portions.

According to various aspects, fig. 2 illustrates an implementation that supports one or more logical connections using a bluetooth protocol stack 220. For example, File Transfer Protocol (FTP)202 provides a method for transferring files that may include all file types, including binary and ASCII text, without data loss, Basic Imaging Profile (BIP)204 establishes the basic requirements for implementing negotiation of size and encoding of image-related data, Serial Port Profile (SPP)206 defines how to establish a virtual serial port and connect two bluetooth-enabled devices, and RFCOMM220 is a protocol that has been adopted for bluetooth based on the standard for serial port emulation. Further, as mentioned above, the bluetooth protocol stack 200 includes a L2CAP layer 228 that provides Multiplexing (MUX) and Demultiplexing (DEMUX) capabilities in the bluetooth protocol stack 200. For example, the L2CAP layer 228 may establish a Channel Id (CID) link to the MUX/DEMUX sublayer 238, where CID refers to a logical connection on the L2CAP layer 228 between two devices serving a single application or higher layer protocol. The MUX/DEMUX sublayer 238 may operate on logical links provided by baseband layer protocols. Host Controller Interface (HCI)240, upon receiving data over a logical link, transfers lower layer protocols to a host device (e.g., a bluetooth enabled laptop computer or mobile phone). Thus, HCI 240 represents a command interface to a baseband controller and provides unified access to baseband capabilities for controlling bluetooth radio unit 244.

According to various aspects, in Bluetooth BR/EDR and Bluetooth LE implementations, Bluetooth radio 244 operates in the unlicensed 2.4GHz ISM band. In a bluetooth LE implementation, a frequency hopping transceiver is employed to combat interference and fading, and provides a number of Frequency Hopping Spread Spectrum (FHSS) carriers. In bluetooth LE, Frequency Division Multiple Access (FDMA) and/or Time Division Multiple Access (TDMA) schemes may be employed, and the physical channel is subdivided into time units (or "events") in which packets may be placed to transmit data between bluetooth LE devices. Generally, there are two types of time, which include an announce event and a connect event. A device that transmits an announcement packet on the announcement PHY channel is called an announcer, and a device that receives an announcement on the announcement channel without the intention of connecting to the announcement device is called a scanner. Transmissions on the announcement PHY channel occur in announcement events, where at the beginning of each announcement event, the announcer sends an announcement packet corresponding to the announcement event type. Depending on the advertising packet type, the scanner may make a request to the advertiser on the same advertising PHY channel, and a response from the advertiser on the same advertising PHY channel may follow the request. On top of the physical channels, the links, channels and associated control protocols are arranged in a hierarchical structure based on physical channels, physical links, logical transport, logical links and L2CAP channels.

Referring to fig. 2, in bluetooth BR/EDR and bluetooth LE implementations, the L2CAP layer 228 provides channel-based abstraction to applications and services, where the L2CAP layer 228 segments (fragment) and de-segments (de-fragment) the application data and multiplexes/demultiplexes multiple channels on a shared logical link. However, in a bluetooth LE implementation, two additional protocol layers are provided above the L2CAP layer 228. Specifically, as shown in fig. 2, a Security Manager Protocol (SMP)216 uses a fixed L2CAP channel to implement security functions between devices, and an attribute protocol (ATT)214 provides a method for transferring small amounts of data over the fixed L2CAP channel. The device also uses the ATT protocol 214 to determine services and capabilities associated with other devices. The ATT protocol 214 also depends on a Generic Access Profile (GAP)210, which provides a basis for all other profiles and defines how two bluetooth enabled devices discover each other and establish a connection with each other. Generic Attributes (GATT) profiles 212 are built on the ATT protocol 214 and define a service framework for using the ATT protocol 214 according to procedures, formats, and characteristics associated with certain services (e.g., discovery, read, write, notification, and indication characteristics, configuration broadcast characteristics, etc.). In general, the GAP 210, GATT profile 212, and ATT protocol 214 are not transport specific and may be used in Bluetooth BR/EDR and Bluetooth LE implementations. However, to implement the GATT profile 212 and ATT protocol 214, a bluetooth LE implementation is required, since the GATT profile 212 is used to discover services in bluetooth LE.

In accordance with various aspects, fig. 3 illustrates an exemplary Wireless Personal Area Network (WPAN)300 that includes a WPAN device 310 that communicates over a physical communication interface or layer (shown in fig. 3 as air interface 308). In general, those skilled in the art will recognize that the WPAN device 310 and 318 shown in fig. 3 may be bluetooth classic devices and/or bluetooth LE devices capable of implementing the bluetooth protocol stack 130 shown in fig. 1 and/or the bluetooth protocol stack 200 shown in fig. 2 to communicate with each other. Those skilled in the art will also recognize, however, that other suitable Radio Access Technologies (RATs) may be used to enable communication within the WPAN 300 and/or between the various WPAN devices 310 and 318 (e.g.,a wireless USB,Etc.). In general, the WPAN devices 310 and 318 may communicate point-to-point (unicast) or point-to-multipoint (multicast or broadcast). In either case, performance associated with wireless communication in WPAN 300 may be improved by using transmit diversity with a beamformed sender.

Transmit beamforming generally refers to a technique that may be implemented to improve range and/or data rate at a given transmitting device having multiple individual antennas based on the following principles: signals transmitted via multiple antennas may be manipulated to "steer" the transmitted signal toward a particular recipient. This principle is illustrated, for example, in fig. 4, which shows an exemplary antenna radiation pattern 400 that may be optimized using transmit beamforming. More specifically, the antenna radiation pattern 400 may originate from the transmitting WPAN device 310, with the transmitting WPAN device 310 depicted at the origin of the antenna radiation pattern 400 in fig. 4. As shown in fig. 4, the antenna radiation pattern 400 may have a main lobe 412 that exhibits a maximum field strength, contains a maximum power, and covers a maximum area. In general, the direction of the main lobe 412 indicates the directivity of the antenna or overall antenna radiation pattern 400. Furthermore, as shown in fig. 4, antenna radiation pattern 400 includes various side lobes 414 and a back lobe 416 in the opposite direction of main lobe 412, where side lobes 414 generally represent unwanted radiation in an undesired direction. Thus, as specified in the IEEE 802.11n specification, transmit beamforming utilizes multiple transmit antennas that may be available in a multiple-input multiple-output (MIMO) system (e.g., WPAN device 310 and 318) to steer beams toward a receiver based on knowledge of the channel between the transmitter and the receiver.

For example, practical implementations typically involve computing a steering matrix in which transmitter weights are applied to transmitted signals and used to steer the signals in a direction toward a particular client. Then, weights are derived from Channel State Information (CSI). In general, and as used in the following description, a device that applies a steering matrix to transmitted signals is referred to as a beamforming sender (or BF sender), while a device toward which signals are steered is referred to as a beamforming receiver (or BF receiver). As previously mentioned, there are generally two ways for the BF sender to obtain the channel estimates needed to steer the beam towards the BF recipient efficiently, for example, when WPAN device 310 transmits towards WPAN device 312 and steers the beam.

A first approach involves implicit feedback, where a first device sends a packet (normal or sounding) to a second device. The second device then estimates the CSI and uses the estimated CSI to steer the beam for the next packet to be transmitted to the first device. However, implicit feedback methods typically assume that the channel being estimated is invariant and reciprocal, which therefore limits the application to frequency hopping systems such as bluetooth classic and bluetooth LE. Furthermore, a second method for estimating CSI involves explicit feedback, where the first device may estimate CSI from a normal or sounding packet received from the second device. The first device may then transmit the estimated CSI to the second device, which may use the received CSI to steer beams for a next packet transmitted to the first device. However, the explicit feedback method also assumes that the channel being estimated is invariant, which similarly limits the application to frequency hopping systems such as bluetooth classic and bluetooth LE.

However, there are some limited cases under which the bluetooth channel may be constant and reciprocal. More specifically, the bluetooth channel may be generally constant when transmitting and receiving on the same frequency, which can be guaranteed during certain bluetooth events, e.g., bluetooth LE connection events and when Adaptive Frequency Hopping (AFH) is enabled in classical bluetooth. Accordingly, fig. 5 illustrates an exemplary signaling flow 500 for implicitly enabling transmit beamforming at a slave Wireless Personal Area Network (WPAN) device 510 in communication with a master WPAN device 512. In general, the signaling flow 500 may be applied in a bluetooth LE and/or classic bluetooth use case, where unicast data or audio is sent from the WPAN device 510 to the master WPAN device 512.

In various embodiments, during connection establishment at block 522, the master WPAN device 512 and the slave WPAN device 510 may discover beamforming capabilities associated with each other. For example, a basic case for implementing transmit beamforming requires two or more antennas at the transmitting device. Further, in the classic bluetooth use case, the master WPAN device 512 and the slave WPAN device 510 may enable Adaptive Frequency Hopping (AFH) at block 522.

In various embodiments, assuming that the master WPAN device 512 learns that the slave WPAN device 510 has beamforming capability (i.e., is capable of operating as a BF sender), the master WPAN device 512 may poll for data from the slave WPAN device 510 using robust packet types and low throughput modulation, as depicted at 524. For example, in a bluetooth LE use case, the master WPAN device 512 may transmit packets to poll for data from the slave WPAN device 510 at each connection event. Alternatively, in the classic bluetooth use case, the master WPAN device 512 may transmit a packet to poll for data from the slave WPAN device 510 at each bluetooth frame in which the master WPAN device 512 transmits. In any case, at block 526, the slave WPAN device 510 may estimate the CSI using the polling packet received from the master WPAN device 512. Subsequently, at block 528, the slave WPAN device 510 may make a beamforming decision and send an appropriate response to the master WPAN device 512 with or without beamforming, as depicted at 530. For example, in various embodiments, the slave WPAN device 510 may make beamforming decisions based on Received Signal Strength Indication (RSSI) associated with polling packets, channel assessment information, retransmission and/or lost packet rates, quality of service (QoS) requirements for the links, and/or other suitable criteria. Further, although not explicitly shown in fig. 5, the slave WPAN device 510 combines the beamforming decision at block 528 with a transmit power control decision made each time the slave WPAN device 510 transmits to the master WPAN device 512. Accordingly, because the poll packet received at 524 is received on the same frequency used to send the slave response at 530, the bluetooth channel can be guaranteed to be unchanged during this time. Thus, the slave WPAN device 510 can estimate CSI from the poll packet received at 524 and beamform the response packet sent to the master WPAN device 512 at 530.

According to various aspects, as discussed above, the signaling flow 500 shown in fig. 5 may enable the slave WPAN device 510 to operate as a beamforming sender (BF sender) during a connection event in a bluetooth LE use case and/or when AFH is enabled in a classic bluetooth use case. However, because the classic bluetooth and bluetooth LE use cases are typically implemented such that the master is the first entity to transmit during each connection event, and subsequent transmissions are on different frequencies due to the frequency hopping scheme, the signaling flow 500 shown in fig. 5 can only be used to provide the slave WPAN device 510 with CSI close enough for beam steering.

Accordingly, fig. 6A and 6B illustrate exemplary signaling flows 600A, 600B that may be used to implicitly and/or explicitly enable transmit beamforming at the master WPAN device 612 such that the master WPAN device 612 may operate as a beamforming sender (BF sender) and the slave WPAN device 610 may operate as a beamforming receiver (BF receiver). Furthermore, those skilled in the art will recognize that transmit beamforming is typically implemented for each packet at the baseband level, and thus the signaling flow 500 shown in fig. 5 and the signaling flows 600A, 600B shown in fig. 6A and 6B may be used in combination to implement bi-directional beamforming communication in a WPAN. Further, as will be described in greater detail herein, the signaling flows 600A, 600B illustrated in fig. 6A and 6B may support certain aspects in which sounding packets are used to enable the master WPAN device 612 to beamform packets to be transmitted to the slave WPAN device 610. Thus, the signaling flows 600A, 600B illustrated in fig. 6A and 6B may be implemented at least in part on top of a bluetooth use case because current bluetooth implementations do not support sounding packets for the purpose of estimating general Channel State Information (CSI) and/or do not support explicit transmit beamforming processes.

According to various aspects, during connection establishment at block 622, the master WPAN device 612 and the slave WPAN device 610 may discover beamforming capabilities associated with each other in a manner similar to that described above. In various embodiments, the master WPAN device 612 may determine the quality of a link with the slave WPAN device 610 at each connection event (e.g., based on a Received Signal Strength Indication (RSSI) associated with packets received from the slave WPAN device 610, channel assessment information, retransmission and/or lost packet rates, QoS requirements for the link, and/or other suitable criteria). When conditions on the link between the master WPAN device 612 and the slave WPAN device 610 are normal, the master WPAN device 612 may simply transmit to the slave WPAN device 610 using normal data packets and modulation, and the slave WPAN device 610 may respond in a normal manner (with or without beamforming (e.g., based on the signaling flow 500 as shown in fig. 5)). However, when the master WPAN device 612 detects poor link quality or bad link quality at block 624, the master WPAN device 612 may take action to initiate the process of: beamforming is implicitly enabled with respect to transmissions to the slave WPAN device 610, as shown in fig. 6A, as described herein.

Specifically, at 626, the master WPAN device 612 may configure the packet to enable the slave WPAN device 610 to estimate the CSI. For example, in various embodiments, the configured packets may be of the normal bluetooth LE packet type that is transmitted with low bit rate modulation when link quality is poor. Thus, the master WPAN device 612 may utilize low bit rate modulation to transmit bluetooth LE packet types to the slave WPAN device 610, as depicted at 628. The packet may contain information requesting a response from the WPAN device 610 with a probe packet. At block 630, the slave WPAN device 610 may then estimate CSI between the master WPAN device 612 and the slave WPAN device 610 using the packet transmitted at 628. Subsequently, the slave WPAN device 610 can transmit a sounding packet to the master WPAN device 612 as depicted at 632 (e.g., a special packet that facilitates CSI estimation). Thus, in various embodiments, the master WPAN device 612 may then estimate CSI based on the sounding packets and appropriately beamform subsequent packets transmitted to the slave WPAN device 610 based on the estimated CSI, as depicted at 636. For example, in various embodiments, the beamformed packet transmitted at 636 to the slave WPAN device 610 may be the first packet in a sequence of connection events, and the slave WPAN device 610 may then make a decision regarding: whether to beamform a response to the packet transmitted at 636 in the same manner as described with respect to fig. 5. Further, as described above, both the master WPAN device 612 and the slave WPAN device 610 can combine their respective beamforming decisions with transmit power control decisions made each time a transmission is sent to the other device.

According to various aspects, returning to block 626, the configured packet may be a special sounding packet, which may be a Null Data Packet (NDP), a packet containing robust and easy to capture synchronization words, or another suitably configured packet that allows the slave WPAN device 610 to estimate the CSI for transmissions from the master WPAN device 612 to the slave WPAN device 610.

According to various aspects, the signaling flow 500 shown in fig. 5 and the signaling 600A shown in fig. 6A have been described above with respect to a method for implicitly enabling transmit (Tx) beamforming in a WPAN. More specifically, implicit transmit beamforming (with or without sounding packets) may generally refer to an implementation that: among other things, the beamforming sender or "BF sender" (e.g., slave WPAN device 510 in fig. 5, master WPAN device 612 in fig. 6A) estimates CSI and assumes that the channels are reciprocal, enabling the BF sender to use the locally computed CSI estimates to properly form and steer a beam toward the beamforming or "BF receiver". In implicit transmit beamforming methods, the BF receiver typically does not send any estimated CSI to the beamforming sender. However, the signaling flow 600A as shown in fig. 6A may be adapted to explicitly enable transmit beamforming for transmissions sent between the master WPAN device 612 and the slave WPAN device 610 as shown in fig. 6B.

In particular, the explicit transmit beamforming method illustrated in fig. 6B may be implemented with or without sounding packets, wherein a BF receiver may estimate CSI and send the estimated CSI to a BF sender, which then uses the estimated CSI received from the BF receiver to form beams. For example, when the master WPAN device 612 detects poor link quality, the packet configured at block 626 and sent to the slave WPAN device 610 at 628 may include a generic Protocol Data Unit (PDU) that also includes an explicit request for the slave WPAN device 610 to return CSI estimated at block 630. Accordingly, as depicted at 634, the slave response includes the estimated CSI such that the master packet transmitted at 636 is an explicit beamforming packet based on the estimated CSI received from the slave WPAN device 610. The subsequent packets may then use low or high bit modulation, use beamforming, and include CSI to enable beamforming for subsequent packets. Further, when the master WPAN device 612 detects poor link quality, the slave response as sent at 634 can be an implicit beamforming packet (i.e., based on the CSI estimated by the slave WPAN device 610 at block 630). The subsequent packets may then continue in substantially the same manner as described above with respect to the bad link condition.

According to various aspects, fig. 7 illustrates an example wireless device 700 in which various aspects and embodiments described herein may be implemented. For example, in various embodiments, the wireless device 700 shown in fig. 7 may correspond to a master device and/or a slave device capable of transmitting beamformed packets in accordance with various aspects and embodiments described herein.

In various embodiments, the wireless device 700 may include a processor 704, a memory 706, a housing 708, a transmitter 710, a receiver 712, one or more antennas 716, a signal detector 718, a Digital Signal Processor (DSP)720, a user interface 722, and a bus 724. Alternatively, functionality associated with the transmitter 710 and receiver 712 may be incorporated into the transceiver 714. Wireless device 700 may be configured to communicate in a wireless network including, for example, base stations, access points, and the like.

In various embodiments, the processor 704 may be configured to control operations associated with the wireless device 700, where the processor 704 may also be referred to as a Central Processing Unit (CPU). A memory 706 may be coupled to the processor 704, may be in communication with the processor 704, and may provide instructions and data to the processor 704. The processor 704 may perform logical and arithmetic operations based on program instructions stored in the memory 706. The instructions in the memory 706 are executable to perform one or more of the methods and processes described herein. Further, in various embodiments, processor 704 may include or be a component in a processing system implemented using one or more processors. The one or more processors may be implemented using any one or more of the following: general purpose microprocessors, microcontrollers, Digital Signal Processors (DSPs), Field Programmable Gate Arrays (FPGAs), Programmable Logic Devices (PLDs), controllers, state machines, gated logic, discrete hardware components, dedicated hardware finite state machines, combinations thereof, and/or any other suitable entity that can perform calculations and/or manipulate information. In various embodiments, the processing system may also include a machine-readable medium configured to store software that should be broadly interpreted to include any suitable instructions, whether referred to as software, firmware, middleware, microcode, hardware description language, or other terminology. The instructions may include code in a source code format, a binary code format, an executable code format, and/or any other suitable format. The instructions, when executed by one or more processors, may cause the processing system to perform one or more of the functions described herein.

In various embodiments, memory 706 may include Read Only Memory (ROM), Random Access Memory (RAM), and/or any suitable combination thereof. The memory 706 may also include non-volatile random access memory (NVRAM).

In various embodiments, the transmitter 710 and receiver 712 (or transceiver 714) may transmit and receive data between the wireless device 700 and a remote location. An antenna 716 may be attached to the housing 708 and electrically coupled to the transceiver 714. In some implementations, the wireless device 700 may also include multiple transmitters, multiple receivers, multiple transceivers and/or multiple antennas (not shown). In various embodiments, the signal detector 718 may be used to detect and quantify levels associated with one or more signals received at the transceiver 714. The signal detector 718 may detect the signal in terms of total energy, energy per subcarrier per symbol, power spectral density, and/or other means. In various embodiments, the DSP 720 may be used to process signals, where the DSP 720 may be configured to generate packets to be transmitted via the transmitter 710 and/or the transceiver 714. In various embodiments, the packet may comprise a physical layer protocol data unit (PPDU).

In various embodiments, user interface 722 may include, for example, a keypad, a microphone, a speaker, a display, and/or other suitable interfaces. User interface 722 may include any element or component that conveys information to a user associated with wireless device 700 and/or receives input from the user.

In various embodiments, various components associated with the wireless device 700 may be coupled together via a bus 724, which bus 724 may include a data bus, as well as a power bus, a control signal bus, and/or a status signal bus in addition to the data bus.

In various embodiments, wireless device 700 may also include other components or elements not shown in fig. 7. One or more components associated with wireless device 700 may communicate with other one or more components associated with wireless device 700 via such a unit: the unit may comprise a further communication channel (not shown) for providing e.g. an input signal to other components.

In various embodiments, while separate components are shown in FIG. 7, one or more of the components shown therein may be combined or collectively implemented. For example, the processor 704 and the memory 706 may be embodied on a single chip. Additionally or alternatively, the processor 704 may include memory, such as processor registers. Similarly, one or more of the functional blocks, or portions thereof, may be embodied on a single chip. Alternatively, the functionality associated with a particular block may be implemented on two or more chips. For example, the processor 704 may be used to implement not only the functions described above with respect to the processor 704, but also the functions described above with respect to the signal detector 718 and/or the DSP 20.

Those of skill in the art would understand that information and signals may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or particles, optical fields or particles, or any combination thereof.

Furthermore, those of skill in the art will appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the aspects disclosed herein may be implemented as electronic hardware, computer software, or combinations of both. To clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the various aspects and embodiments described herein.

The various illustrative logical blocks, modules, and circuits described in connection with the aspects disclosed herein may be implemented or performed with a general purpose processor, a Digital Signal Processor (DSP), an Application Specific Integrated Circuit (ASIC), a Field Programmable Gate Array (FPGA) or other programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. A processor may also be implemented as a combination of computing devices (e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, etc.).

The methods, sequences and/or algorithms described in connection with the aspects disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of the two. A software module may reside in RAM, flash memory, ROM, EPROM, EEPROM, registers, hard disk, a removable disk, a CD-ROM, or any other form of non-transitory computer-readable medium known in the art. An exemplary non-transitory computer readable medium is coupled to the processor such that the processor can read information from, and write information to, the non-transitory computer readable medium. In the alternative, the non-transitory computer readable medium may be integrated into the processor. The processor and the non-transitory computer readable medium may reside in an ASIC. The ASIC may be located in an IoT device. In the alternative, the processor and the non-transitory computer-readable medium may be discrete components in a user terminal.

In one or more exemplary aspects, the functions described herein may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software, the functions may be stored on or transmitted over as one or more instructions or code in a non-transitory computer-readable medium. Computer-readable media may include storage media and/or communication media including any non-transitory media that facilitates transfer of a computer program from one place to another. A storage media may be any available media that can be accessed by a computer. By way of example, and not limitation, such computer-readable media can comprise RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and that can be accessed by a computer. Also, any connection is properly termed a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using a coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of medium. The terms disk and optical disk (which may be used interchangeably herein) include CD, laser optical disk, DVD, floppy disk and blu-ray disk that usually reproduce data magnetically and/or optically with a laser. Combinations of the above should also be included within the scope of computer-readable media.

While the foregoing disclosure shows illustrative aspects and embodiments, those skilled in the art will recognize that various changes and modifications can be made herein without departing from the scope of the disclosure as defined by the appended claims. Furthermore, in light of the various illustrative aspects and embodiments described herein, those of skill in the art will recognize that the functions, steps, and/or actions recited in any of the methods described above and/or in any of the method claims that follow do not need to be performed in a particular order. Furthermore, to the extent that any element is described above in the singular or recited in the appended claims, those skilled in the art will recognize that the singular is also intended to be plural unless limitation to the singular is explicitly stated.

Claims

1. A method for beamforming wireless transmissions, comprising:

in a bluetooth wireless network implementing a frequency hopping system, establishing a bluetooth wireless link with a beamforming receiver device at a beamforming sender device;

transmitting, from the beamforming sender device to the beamforming receiver device, a first beamforming capability packet during connection establishment of the Bluetooth wireless link, the first beamforming capability packet configured to indicate beamforming capabilities of the beamforming sender device;

receiving a second beamforming capability packet from the beamforming receiver device, the second beamforming capability packet configured to indicate beamforming capabilities of the beamforming receiver device;

receiving, at the beamforming sender device, a first packet from the beamforming receiver device, wherein the first packet is received on a first frequency;

estimating, at the beamforming sender device, channel state information associated with the Bluetooth wireless link based on the first packet received from the beamforming receiver device; and

beamforming, by the beamforming sender device, a second packet to be transmitted to the beamforming receiver device to steer the second packet in a direction towards the beamforming receiver device, wherein the second packet is transmitted on the first frequency.

2. The method of claim 1, further comprising: deciding, at the beamforming sender device, whether to beamform the second packet based on one or more of: channel assessment information, a Received Signal Strength Indication (RSSI) associated with the first packet, a retransmission or lost packet rate, or a quality of service (QoS) requirement for the Bluetooth wireless link.

3. The method of claim 2, wherein the beamforming transmitter device decides whether to beamform the second packet in conjunction with a transmit power control decision for the second packet.

4. The method of claim 1, wherein the first packet is received during a bluetooth connection event and the second packet is transmitted during the bluetooth connection event.

5. The method of claim 1, wherein the first packet is received in a Bluetooth frame allocated for transmission from the beamforming receiver device when adaptive frequency hopping is enabled for the Bluetooth wireless link.

6. The method of claim 1, wherein the first packet received from the beamforming receiver device has a predetermined packet type and modulation to poll for data from the beamforming sender device.

7. The method of claim 1, further comprising: discovering, at the beamforming sender device, beamforming capabilities associated with the beamforming receiver device during a connection establishment procedure.

8. The method of claim 1, wherein the Bluetooth wireless link is established to implement a Bluetooth use case in which the beamforming sender device transmits unicast data or audio to the beamforming receiver device.

9. The method of claim 1, wherein the beamforming sender device and the beamforming receiver device implement a bluetooth use case in which the beamforming sender device acts as a slave and the beamforming receiver device acts as a master.

10. A beamforming sender device, comprising:

a receiver configured to: receiving, from a beamforming receiver device, a first packet transmitted on a first frequency over a Bluetooth wireless network implementing a frequency hopping system; wherein the receiver is configured to: receiving a second beamforming capability packet from the beamforming receiver device, the second beamforming capability packet configured to indicate beamforming capabilities of the beamforming receiver device;

one or more processors configured to: estimating channel state information associated with a Bluetooth wireless link between the beamforming sender device and the beamforming receiver device based on the first packet received from the beamforming receiver device; and

a transmitter configured to: transmitting, from the beamforming sender device to the beamforming receiver device, a first beamforming capability packet during connection establishment of the Bluetooth wireless link, the first beamforming capability packet configured to indicate beamforming capabilities of the beamforming sender device; the transmitter includes a plurality of transmit antennas configured to: beamforming a second packet transmitted to the beamforming receiver device such that the second packet is steered in a direction towards the beamforming receiver device, wherein the second packet is transmitted on the first frequency.

11. The beamforming sender device of claim 10, wherein the one or more processors are further configured to: deciding whether to beamform the second packet based on one or more of: channel assessment information, a Received Signal Strength Indication (RSSI) associated with the first packet, a retransmission or lost packet rate, or a quality of service (QoS) requirement for the Bluetooth wireless link.

12. The beamforming sender device of claim 11, wherein the one or more processors are configured to: deciding whether to beamform the second packet in conjunction with a transmit power control decision for the second packet.

13. The beamforming sender device of claim 10, wherein the first packet is received during a bluetooth connection event and the second packet is transmitted during the bluetooth connection event.

14. The beamforming sender device of claim 10, wherein the first packet is received in a bluetooth frame allocated for transmission from the beamforming receiver device when adaptive frequency hopping is enabled for the bluetooth wireless link.

15. The beamforming sender device according to claim 10, wherein the first packet received from the beamforming receiver device has a predetermined packet type and modulation to poll for data from the beamforming sender device.

16. The beamforming sender device of claim 10, wherein the one or more processors are further configured to: discovering a beamforming capability associated with the beamforming receiver device during a connection establishment procedure.

17. The beamforming sender device of claim 10, wherein the bluetooth wireless link is established to implement a bluetooth use case in which the beamforming sender device is configured to transmit unicast data or audio to the beamforming receiver device.

18. The beamforming sender device according to claim 10, wherein the beamforming sender device and the beamforming receiver device implement a bluetooth use case in which the beamforming sender device is configured to act as a slave role and the beamforming receiver device is configured to act as a master role.

19. A beamforming sender device, comprising:

means for receiving a first packet transmitted on a first frequency from a beamforming receiver device on a Bluetooth wireless network implementing a frequency hopping system; wherein the means for receiving is configured to: receiving a second beamforming capability packet from the beamforming receiver device, the second beamforming capability packet configured to indicate beamforming capabilities of the beamforming receiver device;

means for estimating channel state information associated with a Bluetooth wireless link between the beamforming sender device and the beamforming receiver device based on the first packet received from the beamforming receiver device; and

means for beamforming configured to: transmitting, from the beamforming sender device to the beamforming receiver device, a first beamforming capability packet during connection establishment of the Bluetooth wireless link, the first beamforming capability packet configured to indicate beamforming capabilities of the beamforming sender device; the means for beamforming is configured to: transmitting a second packet to the beamforming receiver device such that the second packet is steered in a direction towards the beamforming receiver device, wherein the second packet is transmitted on the first frequency.

20. A computer-readable storage medium having computer-executable instructions recorded thereon configured to cause a beamforming sender device having one or more processors to:

receiving, from a beamforming receiver device, a first packet transmitted on a first frequency over a Bluetooth wireless network implementing a frequency hopping system;

transmitting, during connection establishment, a first beamforming capability packet from a beamforming sender device to the beamforming receiver device, the first beamforming capability packet configured to indicate beamforming capabilities of the beamforming sender device;

receiving, at the beamforming sender device, a second beamforming capability packet from the beamforming receiver device, the second beamforming capability packet configured to indicate beamforming capabilities of the beamforming receiver device;

estimating channel state information associated with a Bluetooth wireless link between the beamforming sender device and the beamforming receiver device based on the first packet received from the beamforming receiver device; and

beamforming a second packet transmitted to the beamforming receiver device such that the second packet is steered in a direction towards the beamforming receiver device, wherein the second packet is transmitted on the first frequency.

21. A method for beamforming wireless transmissions, comprising:

at the beamforming sender device, configuring a first packet to request the beamforming receiver device to return a response packet that enables the beamforming sender device to obtain an estimate of channel state information associated with the bluetooth wireless link from the beamforming receiver device;

transmitting, by the beamforming sender device, the first packet to the beamforming receiver device;

and beamforming, by the beamforming sender device, a second packet to be transmitted to the beamforming receiver device according to the frequency hopping system based on the response packet returned from the beamforming receiver device, wherein the beamforming sender device is configured to: beamforming the second packet to steer the second packet in a direction toward the beamformee device.

22. The method of claim 21, wherein the first packet is configured to: requesting the beamforming receiver device to return a sounding packet as the response packet.

23. The method of claim 22, further comprising:

receiving the sounding packet from the beamforming receiver device; and

estimating, at the beamforming sender device, the channel state information based on the sounding packet received from the beamforming receiver device.

24. The method of claim 21, wherein the first packet is configured to: requesting the beamforming receiver device to estimate the channel state information, and returning the estimated channel state information to the beamforming sender device.

25. The method of claim 24, further comprising:

receiving the response packet from the beamforming receiver device, wherein the response packet includes the channel state information estimated at the beamforming receiver device; and

beamforming, at the beamforming sender device, the second packet transmitted to the beamforming receiver device using the channel state information estimated at the beamforming receiver device.

26. The method of claim 21, wherein the beamforming sender device configures the first packet to request the beamforming receiver device to return the response packet, the response packet enabling the beamforming sender device to obtain the estimated channel state information in response to the bluetooth wireless link having poor quality or poor quality.

27. The method of claim 21, further comprising: deciding, at the beamforming sender device, whether to beamform the second packet based on one or more of: channel assessment information, a Received Signal Strength Indication (RSSI) associated with the response packet, a retransmission or lost packet rate, or a quality of service (QoS) requirement for the Bluetooth wireless link.

28. The method of claim 27, wherein the beamforming sender device decides whether to beamform the second packet in conjunction with a transmit power control decision for the second packet.

29. The method of claim 21, wherein the first packet is configured as a bluetooth packet type.

30. The method of claim 21, wherein the response packet is an implicit beamforming packet containing the estimated channel state information.

31. The method of claim 21, wherein the beamforming sender device and the beamforming receiver device implement a bluetooth use case in which the beamforming sender device acts as a master and the beamforming receiver device acts as a slave.

32. A beamforming sender device, comprising:

one or more processors configured to: in a bluetooth wireless network implementing a frequency hopping system, establishing a bluetooth wireless link with a beamforming receiver device and configuring a first packet to request the beamforming receiver device to return a response packet to enable the beamforming sender device to obtain an estimate of channel state information associated with the bluetooth wireless link from the beamforming receiver device;

a receiver configured to: receiving a second beamforming capability packet from the beamforming receiver device, the second beamforming capability packet configured to indicate beamforming capabilities of the beamforming receiver device; and

a transmitter configured to: transmitting, from the beamforming sender device to the beamforming receiver device, a first beamforming capability packet during connection establishment of the Bluetooth wireless link, the first beamforming capability packet configured to indicate beamforming capabilities of the beamforming sender device; wherein the transmitter is configured to: transmitting the first packet to the beamforming receiver device, and transmitting a second packet to the beamforming receiver device according to the frequency hopping system based on the response packet returned from the beamforming receiver device, wherein the transmitter comprises a plurality of transmit antennas configured to: beamforming the second packet such that the second packet is steered in a direction toward the beamformee receiver device.

33. The beamforming sender device of claim 32, wherein the first packet is configured to: requesting the beamforming receiver device to return a sounding packet as the response packet.

34. The beamforming sender device of claim 33, wherein the receiver is further configured to: receive the sounding packet from the beamforming receiver device, and wherein the one or more processors are further configured to: estimating the channel state information based on the sounding packet received from the beamforming receiver device.

35. The beamforming sender device of claim 32, wherein the first packet is configured to: requesting the beamforming receiver device to estimate the channel state information, and returning the estimated channel state information to the beamforming sender device.

36. The beamforming sender device of claim 35, wherein the receiver is further configured to: receiving the response packet from the beamforming receiver device, the response packet comprising the channel state information estimated at the beamforming receiver device, and wherein the transmitter is further configured to: beamforming the second packet transmitted to the beamforming receiver device using the channel state information estimated at the beamforming receiver device.

37. The beamforming sender device of claim 32, wherein the first packet is configured to: requesting the beamforming receiver device to return the response packet to enable the beamforming sender device to obtain the estimated channel state information in response to the Bluetooth wireless link having poor or poor quality.

38. The beamforming sender device of claim 32, wherein the one or more processors are further configured to: deciding whether to beamform the second packet based on one or more of: channel assessment information, a Received Signal Strength Indication (RSSI) associated with the response packet, a retransmission or lost packet rate, or a quality of service (QoS) requirement for the Bluetooth wireless link.

39. The beamforming sender device of claim 38, wherein the one or more processors are configured to: deciding whether to beamform the second packet in conjunction with a transmit power control decision for the second packet.

40. The beamforming sender device of claim 32, wherein the first packet is configured as a bluetooth packet type.

41. The beamformee sender device of claim 32, wherein the response packet is an implicit beamforming packet containing the estimated channel state information.

42. The beamforming sender device according to claim 32, wherein the beamforming sender device and the beamforming receiver device implement a bluetooth use case in which the beamforming sender device is configured to act as a master role and the beamforming receiver device is configured to act as a slave role.

43. A beamforming sender device, comprising:

means for establishing a wireless link with a beamforming receiver device in a Bluetooth wireless network implementing a frequency hopping system;

means for transmitting a first beamforming capability packet from the beamforming sender device to the beamforming receiver device during connection establishment of the Bluetooth wireless link, the first beamforming capability packet configured to indicate beamforming capabilities of the beamforming sender device;

means for receiving a second beamforming capability packet from the beamforming receiver device, the second beamforming capability packet configured to indicate beamforming capabilities of the beamforming receiver device;

means for configuring a first packet to request the beamforming receiver device to return a response packet to enable the beamforming sender device to obtain an estimate of channel state information associated with the Bluetooth wireless link from the beamforming receiver device;

means for transmitting the first packet to the beamforming receiver device; and

means for transmitting a second packet to the beamformee device according to the frequency hopping system based on the response packet returned from the beamformee device, wherein the second packet is beamformed such that the second packet is steered in a direction toward the beamformee device.

44. A computer-readable storage medium having computer-executable instructions recorded thereon configured to cause a beamforming sender device having one or more processors to:

in a Bluetooth wireless network implementing a frequency hopping system, establishing a Bluetooth wireless link with a beamforming receiver device;

configuring a first packet to request the beamforming receiver device to return a response packet to enable the beamforming sender device to obtain an estimate of channel state information associated with the Bluetooth wireless link from the beamforming receiver device;

transmitting the first packet to the beamforming receiver device; and

transmitting a second packet to the beamforming receiver device in accordance with the frequency hopping system based on the response packet returned from the beamforming receiver device, wherein the second packet is beamformed such that the second packet is steered in a direction toward the beamforming receiver device.