Synchronized CSI on single RX chain devices

Abstract

A user client device having a single receive (RX) chain, a first antenna and a second antenna, and a processor that causes the user client device to couple the single RX chain to the first antenna to receive a first data packet on a first channel (406) and determine a first channel state information (CSI) block for the first channel based on one or more fields in the first data packet (406), decouple the first antenna from the single RX chain and couple the second antenna to the single RX chain to continue receiving the first data packet on a second channel (408), determine a second CSI block for the second channel based on one or more of a portion of the first plurality of fields (408), aggregate the first CSI block with the second CSI block (410), and generate a CSI matrix based on aggregating the first CSI block with the second CSI block (410).

Description

BACKGROUND

[0001] Wireless signals (e.g., frames) transmitted in a network travel along multiple paths from a transmitter (e.g., an access point (AP)) to a receiver (e.g., a user client device / node). In wireless communications, channel state information (CSI) represents how a wireless signal travels along multiple paths from a transmitter to a receiver at a specific carrier frequency via a specific radio frequency (RF) chain configuration. In an example, CSI represents the combined effects of scattering, fading, power decay with distance, delay spread, multipath characteristics of the channel, and the TX and RX RF chain configurations. A CSI matrix is a three-dimensional (3D) matrix of complex values representing the magnitude and phase shift of the transmitted wireless signal and channel. The CSI matrix includes a list of multiple two-dimensional (2D) values (also referred to as a CSI block) per receiver-transmitter pair in the RF chain configuration at a specific carrier frequency (e.g., multiple frequencies) and for one time period. The CSI matrix can be used for different sensing applications, such as, for example, for “positioning,” performance measurements, and for human presence detection. As used herein, positioning is identifying a location or position of a device in an environment, and its uses can include positioning a location of a car to enable keyless entry of the car, positioning an object (e.g., a person) in an indoor environment (e.g., a shopping mall) in order to navigate within the indoor environment, etc. As used herein, human presence detection is a process of identifying changes that have occurred in an environment and movement of objects (to, for example, detect a human fall, detect a location of an object, and object movement). The method of obtaining the CSI matrix is referred to as channel estimation (e.g., estimating a channel). SUMMARY

[0002] According to at least one example of the present disclosure, a user client device for channel estimation in a network includes a transceiver having a single RX chain, a first antenna coupled to the transceiver, a second antenna coupled to the transceiver; and a processor coupled to the transceiver, the first antenna, and the second antenna. The processor is configured to execute instructions that cause the user client device to couple the single RX chain to the first antenna to receive a first data packet on a first channel, wherein the first data packet comprises a first plurality of fields; determine a first CSI block for the first channel based on one or more of the first plurality of fields; decouple the first antenna from the single RX chain and couple the second antenna to the single RX chain to continue receiving the first data packet on a second channel, wherein the first data packet on the second channel comprises a portion of the first plurality of fields; determine a second CSI block for the second channel based on one or more of the portion of the first plurality of fields, aggregate the first CSI block with the second CSI block; and generate a CSI matrix based on aggregating the first CSI block with the second CSI block.

[0003] According to at least one example of the disclosure, a system for channel estimation in a network includes a transmission node configured to transmit a first data packet and a first user client node wirelessly coupled to the transmission node. The first user client node includes a transceiver having a single RX chain, a first antenna and a second antenna; and a processor coupled to the transceiver, the first antenna and the second antenna, and configured to execute instructions that cause the first user client node to couple the single RX chain to the first antenna; receive the first data packet from the first antenna, wherein the first data packet comprises a first physical layer (PHY) preamble, a first PHY header and a first medium access control (MAC) header; determine a first CSI block based on one or more of the first PHY preamble, the first PHY header and the first MAC header of the first data packet from the first antenna; decouple the first antenna from the single RX chain and couple the second antenna to the single RX chain; continue to receive the first data packet from the second antenna, wherein the second data packet comprises at least a portion of the first PHY preamble, the first PHY header and the first MAC header; determine a second CSI block based on the first data packet from the second antenna; aggregate the first CSI block with the second CSI block; and generate a CSI matrix based on aggregating the first CSI block with the second CSI block.

[0004] According to at least one example of the disclosure, a method for channel estimation in a network includes providing a user client device including a single RX chain transceiver, a first antenna and a second antenna; coupling the single RX chain transceiver to the first antenna; receiving, by the first antenna, a first data packet on a first channel, wherein the first data packet comprises a first plurality of fields; determining a first CSI block for the first channel based on one or more of the first plurality of fields; decoupling the first antenna from the single RX chain transceiver and coupling the second antenna to the single RX chain transceiver; receiving, by the second antenna, a second data packet on a second channel, wherein the second data packet comprises a second plurality of fields; determining a second CSI block for the second channel based on one or more of the second plurality of fields; aggregating the first CSI block with the second CSI block; and generating a CSI matrix based on aggregating the first CSI block with the second CSI block. BRIEF DESCRIPTION OF DRAWINGS

[0005] Detailed descriptions of various examples will now be presented with reference to the accompanying drawings, in which:

[0006] Figure 1 is a block diagram of a network environment in accordance with various examples;

[0007] Figure 2 is a block diagram of a computing device according to various examples;

[0008] Figure 3 is a block diagram of a computing device according to various examples;

[0009] Figure 4 A method for obtaining a CSI matrix for signal transmission on a single channel according to various examples;

[0010] Figure 5 A method for obtaining a CSI matrix for signal transmission on multiple channels according to various examples; and

[0011] Figure 6 is a block diagram of an electronic device according to various examples. DETAILED DESCRIPTION

[0012] A user client device may include a single receive (RX) chain radio or multiple RX chain radios. An RX chain radio (also referred to as an RX chain) includes a radio and all its supporting infrastructure, including mixers, amplifiers, and analog-to-digital converters. Multiple RX chains include several RX chain radios. A user client device with multiple RX chains improves its channel estimation compared to a user client device with a single RX chain because the CSI matrix includes multiple CSI blocks for multiple frequencies, multiple receivers, and transmitters, and obtained over multiple time periods. Transmission nodes / network nodes (e.g., WIFI access points, WIFI routers, or user client devices) in a wireless local area network (WLAN, also commonly referred to as WIFI) typically use multiple-input, multiple-output (MIMO) technology with orthogonal frequency division multiplexing (OFDM) to wirelessly transmit and receive signals to and from other network devices within their operating bandwidth (e.g., 80 megahertz (MHz) bandwidth, 160 MHz bandwidth, or 320 MHz bandwidth). These transmission nodes have multiple RX chain radios. Each RX chain radio (hereinafter referred to as an RX chain) includes multiple antennas to simultaneously transmit and receive data in the WLAN. Each RX chain provides a matrix of CSI values ​​for antennas and subcarrier frequencies. The CSI matrix obtained from multiple RX chains provides channel estimates spatially and across several channels and can provide enhanced positioning, sensing, and performance measurements compared to the CSI matrix from a single RX chain.

[0013] Internet of Things (IoT) devices are commonly used in homes (e.g., thermostats or doorbell cameras) or carried on the body (e.g., heart rate trackers) to provide a connected environment. These IoT devices may be low-cost devices using commercial Wi-Fi transceivers with a single RX chain and a single antenna. Furthermore, these low-cost IoT devices operate on relatively low channel bandwidths (e.g., 20 MHz channel bandwidth based on the Institute of Electrical and Electronics Engineers (IEEE) 802.11 20 MHz Station (STA) Only operating profile). Consequently, the CSI of these low-cost IoT devices is a CSI block, which limits positioning accuracy, sensing sensitivity, and performance. Furthermore, the limited positioning, sensing, and performance of the CSI block of IoT devices hinders their deployment in positioning and sensing applications.

[0014] This document discloses an example of a channel estimation technique for estimating a CSI matrix using a user client device (e.g., a STA) with a single RX chain and at least two antennas when WLAN packets (e.g., Wi-Fi packets) are wirelessly transmitted from a transmitter node. The quality of the CSI matrix obtained by the STA is equivalent to that of a CSI matrix obtained by the STA from multiple RX chains (hereinafter referred to as an equivalent CSI matrix).

[0015] In an example, when a signal (e.g., a Wi-Fi signal) is transmitted from a transmitting node (e.g., an AP) to a STA over a 20 MHz channel bandwidth, a user client device performs channel estimation techniques by identifying opportunities to obtain CSI values. In this example, the signal is a predicted WLAN packet (also known as a repeated WLAN packet, such as, for example, an AP beacon frame transmission) or an unpredicted WLAN packet (also known as a random WLAN packet, such as an AP transmission to a STA). In this example, the STA receives a WLAN packet at a first antenna that includes OFDM symbols on different subcarrier frequencies ("subcarriers") or different center frequencies. The OFDM symbols may be transmitted in one or more fields of the WLAN packet. In this example, the OFDM symbols are received from an IEEE 802.11 PHY preamble field, an IEEE 802.11 PHY header field, an IEEE 802.11 MAC header field, or an IEEE 802.11 payload data field. The OFDM symbols may include a data subcarrier (e.g., frequency) component and a pilot subcarrier component. When receiving a WLAN packet at a first antenna (also referred to as a first CSI block antenna), the user client device may synchronize to fields of the WLAN packet and / or to the pilot subcarrier component of the WLAN packet and / or obtain information for channel estimation from the data subcarrier component. In an example, a STA receives a WLAN packet directed to (e.g., intended for) a neighboring STA. In an example, a STA receives a WLAN packet directed to (e.g., intended for) the STA. In an example, the PHY preamble field may include synchronization information, such as, for example, one or more short training fields (STFs), one or more long training fields (LTFs), and one or more signal (SIG) fields. In an example, the PHY header field may include fields that provide information about the packet configuration (e.g., format, data rate, etc.). In an example, the MAC header field includes an Internet Protocol (IP) address field, such as a destination or source. In an example, the payload data field includes a repeated data field, such as, for example, a packet extension (PE) field located at the end of the WLAN packet. The STA generates or determines the first CSI block using information determined from one or more of a PHY preamble field, a PHY header field, a MAC header field, or a data field.

[0016] In an example, a STA switches to a second antenna when receiving a signal using intra-WLAN packet antenna switching. In an example, the second antenna may also be referred to as a second CSI block antenna. In an example, a STA switches using intra-WLAN packet antenna switching to obtain information from WLAN packets during a transmission stream. In an example, intra-WLAN packet antenna switching from a first antenna to a second antenna occurs when a WLAN packet is received as a single WLAN packet on both the first and second antennas without gaps in the transmission of the WLAN packets. To illustrate, in a first period, the STA does not transmit or receive WLAN packets. In a second period, the STA receives a WLAN packet from a transmitter node at the first antenna and switches to the second antenna to continue receiving WLAN packets at the second antenna without gaps in the transmission from the transmitter node. In an example, the STA may also receive another WLAN packet at the second antenna. In an example, the STA receives (e.g., obtains) the WLAN packet at the second antenna via a multipath channel. In an example, a multipath channel represents multiple paths, including a direct path and additional paths that the WLAN packet travels when it reflects and / or refracts from obstacles as the WLAN packet wirelessly travels from the destination node to the STA. In an example, a WLAN packet experiences multipath effects (e.g., amplitude attenuation and / or phase shift from reflection and refraction) in a multipath channel. The STA generates a second CSI block based on intra-WLAN packet antenna switching from a first antenna to a second antenna using one or more fields (e.g., using the packet LTF received at the second antenna, for example), and combines the CSI blocks to obtain a dual-antenna equivalent CSI matrix. In another example, during inter-WLAN packet antenna switching during transmission streams of different time periods, the STA generates an equivalent combined CSI matrix over a 40 MHz channel using the first 20 MHz CSI block and the second 20 MHz CSI block by combining the first CSI block obtained over a 20 MHz channel bandwidth with the second CSI block obtained over a second 20 MHz channel bandwidth. In this example, the inter-WLAN packet antenna switching from the first antenna to the second antenna occurs when there is a gap in transmission or reception from the transmitter node. To illustrate, in a first period, the STA does not transmit or receive WLAN packets. In a second period, the STA receives WLAN packets from the transmitter node at the first antenna. The transmitter node stops transmitting (e.g., during a gap in transmission), whereupon the STA switches to the second antenna and uses the second antenna to receive another WLAN packet at the second antenna. The channel estimation technique enables deployment of a single RX chain device (e.g., a low-cost IoT device) for CSI-based positioning, sensing, and performance improvement, and overcomes issues with low-cost IoT devices with a single RX chain. For example, the low-cost IoT device emulates a high-cost network device with multiple RX chains and multiple antennas by providing an equivalent CSI matrix that can be used for CSI-based positioning, sensing, and performance improvement.Furthermore, the equivalent CSI matrix obtained by the low-cost IoT device is a CSI matrix compliant with the IEEE 802.11 standard for CSI-based applications.

[0017] Figure 1 FIG2 is a diagram of a network environment 100 according to various examples. In the example, the network environment 100 (e.g., a Wi-Fi type environment) includes a communication network 102, a transmission node 104, user client nodes / devices 106 and 108 (also referred to as STAs), a communication link 110, and communication networks 112 and 114.

[0018] In an example, the communication network 102 uses a wireless network communication protocol (e.g., IEEE), or other suitable protocols based on IEEE 802.11, 802.11 / WIFI, IEEE 802.16 / WiMAX (hereinafter referred to as WLAN), Bluetooth (BT), Bluetooth Low Energy (BLE), ZIGBEE, Ultra Wideband (UWB), and cellular communications under the Third Generation Partnership Project (3GPP) (e.g., 5G and 4G Long Term Evolution (LTE)).

[0019] In an example, the transmission node 104 is an AP, a router, a switch, or any other network device having multiple RX chains and multiple antennas. In an example, the STAs 106 and 108 are single RX chain devices (e.g., user clients) having at least two antennas. In an example, the STAs 106 and 108 and the transmission node 104 are configured to perform wireless communications in the communication network 102 using the communication link 110. In an example, the STAs 106, 108, and the transmission node 104 are associated in the communication network 102 as a basic service set (BSS), which includes a group of stations that form an association in the communication network 102. In an example, the transmission node 104 is configured to simultaneously transmit WLAN packets in the communication network 102.

[0020] In the example, STA 106 and STA 108 are low-cost IoT devices (e.g., mobile IoT devices or fixed IoT devices with a single RX chain) that communicate with transmission node 104 via communication link 110. In the example, STA 106 and STA 108 include a network access layer designed for low-power IoT applications that utilize short-lived connections to transmission node 104.

[0021] In an example, communication networks 112 and 114 are communicatively coupled to transmission node 104. In an example, communication networks 112 and 114 include any one of a combination of different types of suitable communication networks, such as, for example, a broadcast network, a wired network, a public network (e.g., the Internet), a private network, a wireless network, a cellular network, or any other suitable private and / or public network. In an example, either of communication networks 112 and 114 can have any suitable communication range associated therewith and include a global network (e.g., the Internet), a metropolitan area network (MAN), a wide area network (WAN), a local area network (LAN), or a personal area network (PAN). In an example, communication networks 112 and 114 include any type of media over which network traffic can be carried and, in an example, can include coaxial cable, twisted pair, optical fiber, hybrid fiber coaxial (HFC) media, microwave terrestrial transceivers, RF communication media, white space communication media, ultra-high frequency communication media, satellite communication media, or any combination thereof.

[0022] In operation, STA 106 and STA 108 are operable to perform intra-WLAN packet channel estimation techniques (e.g., channel estimation using a single WLAN packet) or inter-WLAN packet channel estimation techniques (e.g., channel estimation using multiple WLAN packets) in a WLAN network using a single RX chain. In an example, the channel estimation techniques are performed using WLAN packets received from a transmitting node 104 based on the IEEE 802.11 standard. In an example, the transmitting node 104 is configured to transmit WLAN packets using block-based modulation (e.g., OFDM), orthogonal frequency division multiplexing access (OFDMA), or other multi-carrier modulation methods. The term "block-based modulation" as used herein refers to operations performed in a WIFI-type environment. In an example, STA 106 and STA 108 listen for signal transmissions (e.g., WLAN / WIFI packets) from the transmitting node 104 over the communication link 110. In an example, the WLAN packet may include a physical layer protocol data unit (PPDU) frame having a preamble field, a header field, and a payload data field. Each WLAN packet is transmitted over a 20 MHz channel bandwidth and includes a preamble field, a header field, and OFDM symbols in a payload data field that can be used for intra-WLAN or inter-WLAN packet channel estimation. In the example where the WLAN packet is a legacy OFDM-based WLAN packet (e.g., a classic WIFI packet such as an IEEE 802.11a / g / p / j / n / ac / ah WLAN packet), the OFDM symbol includes 48 data subcarriers (e.g., with frequency indices of -26 to +26) and 4 pilot signals / tones (e.g., with frequency indices of ±21 and ±7). In the example where the WLAN packet is a WIFI-6 OFDMA-based WLAN packet (e.g., 802.11ax) or a WIFI-7 OFDMA-based WLAN packet (e.g., 802.11be), the WLAN packet includes resource units. A resource element represents a group of 78.125 kilohertz (kHz) bandwidth subcarriers, which may include 26, 52, 106, 242, 484, or 996 subcarriers and includes OFDM symbols with pilot signals located at fixed positions (e.g., fixed frequency indices). In an example, the pilot signals are subcarriers that include known signals at predetermined or predefined subcarriers or frequencies. In an example, for a 20 MHz channel bandwidth with a resource element size of 26 subcarriers or 52 subcarriers, the pilot signals are at frequency indices of ±10, ±22, ±36, ±48, ±62, ±76, ±90, ±102, and ±116, and for a resource element size of 106 subcarriers or 242 subcarriers, the pilot signals are at frequency indices of ±22, ±48, ±90, and ±116.In an example, STA 106 and STA 108 are operable to perform channel estimation techniques using pilot signals from WLAN packets transmitted over a higher channel bandwidth, such as 40 MHz, 80 MHz, 160 MHz, or 320 MHz, as disclosed in the IEEE 802.11ax and 802.11be standards, which are incorporated herein by reference. In an example, a transmitting node 104 transmits a WLAN packet intended for STA 106 or STA 108 within the communication network 102. In an example, STA 108 listens to a channel in the WLAN and receives one or more WLAN packets not intended for STA 108. In an example, STA 106 or STA 108 receives a WLAN packet not intended for STA 106 or STA 108 from the transmitting node 104.

[0023] In an example, each STA 106 and STA 108 is operable to switch its antenna to receive a single WLAN transmission stream from the transmitting node 104 in a 20 MHz channel bandwidth on a single RX chain. In an example, each STA 106 and STA 108 is operable to switch its antenna to receive multiple transmission streams in a wideband channel bandwidth (e.g., 80 MHz or 160 MHz). In an example, the STA 106 and STA 108 each have two antennas, which are alternately switched when a signal (e.g., a WLAN packet) is received from the transmitting node 104. In an example, the STA 106 or STA 108 listens on the WLAN channel for available transmissions from the transmitting node 104. The STA 106 or STA 108 passively scans the WLAN channels in the communication network 102 to detect and receive available transmissions from the transmitting node 104. In an example, the STA 106 or STA 108 waits to receive a WLAN packet from the transmitting node 104. In an example, the WLAN packet may be a predicted WLAN packet, such as a beacon frame that is periodically transmitted to stations in the BSS from the transmitting node 104. The WLAN packet contains information about the transmitting node 104 along with a timing reference.

[0024] In an example, STA 106 or STA 108 obtains (e.g., generates) a CSI matrix for a WLAN channel during a single WLAN transmission or for multiple WLAN transmissions using the first antenna and the second antenna (a "combined CSI matrix"). In an example, the combined CSI matrix is ​​obtained from information in a preamble of a layer 1 PHY layer, from information in a MAC header, from a payload field of a WLAN packet, or as described above in Figure 1, and the information in the other fields discussed in

[15] . In an example, a combined CSI matrix is ​​generated from a CSI block that is spliced ​​together (e.g., aggregated or combined) using multiple intra-WLAN and / or inter-WLAN group CSI blocks generated from signals received at the antennas. In the example of a STA 106 or STA 108 having two antennas, the antenna alternates between the first antenna and the second antenna to receive WLAN packets during a single WLAN transmission. In an example, the CSI matrix is ​​an equivalent CSI matrix that can be used for position sensing and other positioning applications. The channel estimation technique enables deployment of a single RX chain device (e.g., a low-cost IoT device) for CSI-based positioning, sensing, and performance improvement and overcomes the issues of low-cost IoT devices with a single RX chain. For example, a low-cost IoT device emulates a high-cost network device with multiple RX chains and multiple antennas by providing an equivalent CSI matrix that can be used for CSI-based positioning, sensing, and performance improvement. In addition, the equivalent CSI matrix obtained by the STA 106 or STA 108 is a CSI matrix that complies with the IEEE 802.11 standard for CSI-based applications. Thus, in effect, the channel estimation technique improves the performance of the communication network 102 and the STA 106 or STA 108 and the transmitting node 104 in the entire network, which enables the STA 106 or STA 108 to be deployed in CSI-based applications.

[0025] Figure 2 2 is a block diagram of STA 200 according to various examples. STA 200 is STA 106 or STA 108 ( Figure 1 2. STA 200 is an example of a STA (shown in FIG. 2). In the example, STA 200 includes an antenna switch 202, a transceiver 204, a communication circuit 206, a storage device 208, a controller 210, an antenna 212, an antenna 214, and a software application 216. Although STA 200 is shown with two antennas 212 and 214, in the example, STA 200 may include additional antennas that are generally similar to antennas 212 and 214. In the example, antenna switch 202 is electrically coupled to antennas 212 and 214. Transceiver 204 is coupled to antennas 212 and 214 and communication circuit 206. Communication circuit 206 is coupled to storage device 208 and controller 210. Storage device 208 stores software application 216 including executable instructions.

[0026] In an example, STA 200 is a single RX chain device having multiple antennas (e.g., antenna 212 and antenna 214). In an example, antenna 212 and antenna 214 are dipole antennas, monopole antennas, patch antennas, loop antennas, microstrip antennas, or other types of antennas suitable for transmitting RF signals. In an example, a single antenna with multiple apertures can be used instead of antenna 212 and antenna 214. In an example, each aperture can be considered a separate antenna. In an example, antennas 212 and 214 can be effectively separated to achieve spatial diversity and different channel characteristics that can be generated between each of antennas 212 and antenna 214 and the antenna of the transmitting station. In an example, antennas 212 and 214 can be operated to receive signals from a transmitting node (e.g., Figure 1 The RF transmitter at the transmitting node 104 shown in FIG. 1 receives a transmission stream in a 20 MHz channel bandwidth as an OFDM or OFDMA burst transmission or pulse type signal (e.g., a WLAN packet). In a WLAN operated by STA 200, multiple transmission streams may be transmitted over a 20 MHz channel bandwidth. In the example, the transmitting node is Figure 1 The transmission node 104 is shown in FIG.

[0027] In an example, antenna switch 202 is operable to switch between antenna 212 and antenna 214 when receiving a transmission stream, such that antenna 212 and antenna 214 are alternately coupled to transceiver 204. Switching between antenna 212 and antenna 214 results in receiving the transmission stream at antenna 212 and antenna 214 at different time periods. In an example, antennas 212 and 214 can be tuned to the frequency of the transmission stream such that subcarriers in the transmission stream are received by antennas 212 and 214. In an example, each antenna 212 and 214 can switch to receive subcarriers during a transmission stream (e.g., an intra-WLAN packet) and / or switch at different transmission time periods (e.g., to obtain an inter-WLAN packet). Each antenna 212 and 214 is connected to a transmitting node (e.g., Figure 1 The transmitting node 104 shown in FIG. 1 may be tuned to a frequency of a 20 MHz channel bandwidth transmission stream over a wide bandwidth of the transmitting node 104.

[0028] In an example, transceiver 204 includes a transmitter, a receiver, and other RF circuitry that provides an RX chain. Transceiver 204 amplifies transmission streams received from antennas 212 and 214 and outputs them to communication circuitry 206. Transmission streams for transmission on antennas 212 and 214 are received from communication circuitry 206 and sent to antennas 212 and 214. Communication circuitry 206 is operable to implement modulation and framing of WLAN packets in the transmission streams according to an applicable communication protocol or standard (e.g., IEEE 802.11) under the control of controller 210.

[0029] In an example, the communication circuit 206 receives an RF transmitter (eg, Figure 1 204 and the communication circuit 206. The ADC and the DAC are located between the outputs of the transceiver 204 and the communication circuit 206, within the communication circuit 206, or within the transceiver 204. The ADC demodulates the transmission stream from the transceiver 204, while the DAC modulates the transmission stream for transmission via antennas 212 and 214. In an example, the communication circuit 206 may be arranged to contend for a wireless medium (e.g., a WLAN) and configure the transmission stream for transmission over the wireless medium. The communication circuit 206 may be arranged to transmit and receive signals. The communication circuit 206 may also include circuitry for modulation / demodulation, upconversion / downconversion, filtering, amplification, and the like.

[0030] In an example, transceiver 204 and communication circuitry 206 transmit and receive transmission streams to and from other communication stations using one or more antennas 212 and 214. In an example, communication circuitry 206 includes circuitry operable to control access to a wireless medium for PHY communication and / or IEEE 802.11 MAC communication and / or any other communication layer for transmitting and receiving signals. STA 200 may also include a controller 210 having processing circuitry and memory 208 arranged to perform the operations described herein.

[0031] In some examples, storage device 208 includes any type of memory for storing information in a machine (e.g., computer) readable form, including non-transitory memory. For example, storage device 208 may include computer-readable storage devices, read-only memory (ROM), random access memory (RAM), magnetic disk storage media, optical storage media, flash memory devices, and other storage devices and media. In an example, storage device 208 stores one or more software applications 216 (e.g., embedded applications) for performing the channel estimation techniques described herein. In an example, storage device 208 stores information for configuring controller 210 to perform channel estimation techniques using transmission streams received by STA 200. When executed by controller 210, one or more software applications 216 (e.g., embedded applications) perform the functions associated with STA 200 described herein. Specific examples may be implemented in one or a combination of hardware, firmware, and software. Other examples may also be implemented as instructions stored on a computer-readable storage device, which may be read and executed by at least one processor to perform the operations described herein. A computer-readable storage device may include any non-transitory memory mechanism for storing information in a form readable by a machine (e.g., a computer). For example, a computer-readable storage device may include ROM, RAM, magnetic disk storage media, optical storage media, flash memory devices, and other storage devices and media.

[0032] In an example, the controller 210 includes one or more processors and may be configured with instructions stored on a computer-readable storage device memory. The controller 210 includes logic for performing the channel estimation described herein. The logic may be encoded in one or more tangible media (e.g., storage device 208) for execution by a processor in the controller 210. For example, the processor may execute computer-readable instructions stored in a non-transitory computer-readable medium such as storage device 208. For example, the logic may be in the form of software executed by the processor, digital signal processor (DSP) instructions, or in the form of fixed logic such as in an integrated circuit.

[0033] In one example, STA 200 may be part of an IoT device, such as a personal digital assistant (PDA), a laptop or portable computer with wireless communication capabilities, a web tablet, a wireless phone, a smartphone, a wireless headset, a pager, an instant messaging device, a digital camera, an access point (AP), a television, a medical device (e.g., a heart rate monitor, a blood pressure monitor, etc.), a wearable computer device, or another device that can wirelessly receive and / or transmit information. In one example, STA 200 may include a keyboard, a display, a non-volatile memory port, multiple antennas, a graphics processor, an application processor, a speaker, and other mobile device components. The display may be a liquid crystal display (LCD) screen including a touch screen.

[0034] Although STA 200 is described as having several separate functional elements, two or more functional elements may be combined and implemented through a combination of software-configured elements, such as a processing element including a DSP and / or other hardware elements. For example, some elements may include one or more microprocessors, DSPs, field programmable gate arrays (FPGAs), application-specific integrated circuits (ASICs), radio frequency integrated circuits (RFICs), and a combination of various hardware and logic circuit systems for performing at least the functions described herein. In some embodiments, the functional elements of STA 200 may refer to one or more processes operating on one or more processing elements. The channel estimation technology performed by STA 200 enables STA 200 to be deployed for CSI-based positioning, sensing, and performance improvement, and overcomes the problems of low-cost IoT devices with a single RX chain. For example, STA 200 emulates a high-cost network device with multiple RX chains and multiple antennas by providing an equivalent CSI matrix that can be used for CSI-based positioning, sensing, and performance improvement. In addition, the equivalent CSI matrix obtained by STA 200 is a CSI matrix that complies with the IEEE 802.11 standard for CSI-based applications. Thus, in effect, the channel estimation technique improves the performance of a user client device having a single RX chain coupled to a communication network and transmit nodes throughout the network, which enables the user client device having a single RX chain to be deployed in CSI-based applications.

[0035] Figure 3 is a block diagram of a transmission node 300 according to various examples. In the example, the transmission node 300 is Figure 1 304 and STA 306. In the example, the transmission node 300 includes STA 302, STA 304, and antennas 306, 308, 310, and 312. In the example, STA 302 is a user client device / node having a single RX chain with antennas 306 and 308, and STA 304 is a user client device / node having a single RX chain with antennas 310 and 312. In the example, each STA 302 and STA 304 is STA 200. In the example, the transmission node 300 having two radios (e.g., STA 302 and STA 304) represents a multi-RX chain device. In operation, the transmission node 300 is operable to transmit data over a WLAN (e.g., Figure 1transmitting WLAN packets in a communication network (e.g., the communication network 102 shown in Figure 1 a STA (e.g., the STA 106 or the STA 108 shown in Figure 1 a STA (e.g., the STA 106 or the STA 108 shown in

[0036] Figure 4 is a method implemented by a user client device in a WLAN according to various examples. In an example, the user client device is Figure 1 a STA (e.g., the STA 106 or the STA 108 shown in Figure 4 The method of uses a user client device with a single RX chain to implement a channel estimation technique to obtain an equivalent CSI matrix during signal transmission of a WLAN packet. Figure 4 The method of includes the following steps.

[0037] At step 402, the user client device receives a request for a CSI matrix. In an example, the user client device receives the request from a positioning engine via a transmission node. In an example, the transmission node is Figure 1 the transmission node 104 shown in In an example, the positioning engine requests the CSI matrix for positioning or performance measurement of a channel connected to the user client device.

[0038] At step 404, the user client device identifies a detection opportunity. In an example, the user client device identifies a WLAN packet transmission opportunity from a WLAN (e.g., the communication network 102 shown in Figure 1WLAN packets in signals transmitted on a communication channel by a transmitting node in a communication network 102 (e.g., in a communication network 102). In an example, the WLAN packets are directed to (e.g., intended for) adjacent user client devices that are neighbors of the user client device, which avoids collisions when signals directed to the user client devices also arrive at approximately the same time period. In an example, when the user client device is in a BSS containing the WLAN of the transmitting node, the user client device is operable to receive WLAN packets intended for the adjacent user client devices from the transmitting node. In an example, each WLAN packet is periodically transmitted over a 20 MHz channel bandwidth over an 80 MHz operating channel bandwidth of the transmitting node. Each WLAN packet represents an opportunity to obtain information in the time domain for channel estimation.

[0039] In an example, each WLAN packet may include a PPDU frame having a preamble field, a SIG field, and a payload data field with OFDM symbols. In examples where the WLAN packet is a classic WLAN or legacy OFDM-based WLAN packet, the payload data field includes an OFDM symbol having 48 data subcarriers (e.g., with frequency indices of -26 to +26) and 4 pilot subcarriers / tones (e.g., with frequency indices of ±21 and ±7). In examples where the WLAN packet is a WIFI-6 OFDMA-based WLAN packet (e.g., an IEEE 802.11ax WLAN packet), the WLAN packet includes resource units having OFDM symbols that may include 26, 52, 106, 242, 484, or 996 subcarriers. The OFDM symbols include predefined pilot subcarrier signals at fixed frequency indices (e.g., predefined frequency indices). User client devices identify the predefined OFDM symbols in the WLAN packet based on their unique waveforms. In an example, the user client device identifies a predetermined / predefined OFDM symbol of a pilot signal in one or more fields of a WLAN packet. In an example of a beacon frame, the user client device listens to the beacon frame using the beacon time schedule in the beacon interval field. In an example, the user client device uses the beacon frame to perform channel estimation.

[0040] In step 406, the user client device receives a WLAN packet at a first antenna during a first time period. In an example, the user client device receives the WLAN packet transmitted from a transmitting node in the WLAN (e.g., by a transmitter in the transmitting node). In an example, the user client device may switch to the first antenna to receive the WLAN packet in a 20 MHz channel bandwidth at the first antenna. In an example, the user client device stores field information from the WLAN packet, including predefined OFDM symbols that may be obtained from one or more fields of a PHY preamble, a PHY header, and / or a data field. The OFDM symbols may include data subcarriers and pilot subcarriers. In an example, the first antenna transmits the information obtained from the WLAN packet to a processor for channel estimation. In an example, the user client device generates a first CSI block for the 20 MHz channel bandwidth using the field information from the WLAN packet. In an example, the user client device generates the first CSI block from OFDM symbols in the LTF of the first WLAN packet.

[0041] In step 408, the user client device switches from the first antenna to the second antenna to receive a signal at the second antenna. In an example, the user client device receives (e.g., obtains) a signal including a WLAN packet at the second antenna during a second time period. In an example, the WLAN packet is a second WLAN packet based on the first WLAN packet that has a multipath effect because it experienced collisions or reflections during transmission from the transmitting node when it reached the second antenna. In another example, the second WLAN packet is a 20 MHz channel bandwidth WLAN packet transmitted by the transmitting node at a different center frequency than the 20 MHz channel bandwidth of the first WLAN packet. As used herein, multipath effect of a WLAN packet includes amplitude attenuation and phase shift of OFDM symbols in the WLAN packet due to reflections or collisions in the wireless channel when the WLAN packet reaches the antenna via two or more paths. In an example, the user client device receives the second WLAN packet that includes a predetermined / predefined field. In an example, during the switching period when the user client device switches from the first antenna to the second antenna to receive a signal, the user client device may receive unreliable information in the wireless channel, which is ignored. The user client device stores field information from the received WLAN packet for processing at the user client device. In an example, the user client device uses OFDM symbols from a field in a WLAN packet to generate a second CSI block for a 20 MHz channel bandwidth. In an example, the user client device generates the second CSI block from OFDM symbols in the LTF of the second WLAN packet. In an example, the user client device may switch from the second antenna back to the first antenna to receive additional WLAN packets over a multipath channel and store the PHY preamble, PHY header (e.g., MAC header), and / or data field from the received additional WLAN packets. In an example, the user client device may use information from the WLAN packet to generate another CSI block for a 20 MHz channel bandwidth. In an example, the user client device may switch back and forth between the first and second antennas to obtain additional CSI blocks at each antenna after switching.

[0042] In step 410, the user client device generates an equivalent CSI matrix using information from one or more fields in the WLAN packet. In an example, the user client device generates a CSI block from a field located in the PHY preamble, generates a CSI block from a field located in the PHY or MAC header, generates a CSI block based on a known synchronization sequence field transmitted in the WLAN packet, or generates a CSI block based on a known repetitive signal of the WLAN packet (e.g., a pilot symbol or PE field of the WLAN packet) in WLAN packets received at the first antenna and the second antenna. In an example, as described above, the user client device generates a first CSI block from first LTF information in the PHY preamble obtained using the first antenna, and generates a second CSI block from subsequent LTF information in the PHY preamble obtained using the second antenna. In an example, the user client device generates the first CSI block using a first 20 MHz channel bandwidth WLAN packet, and generates the second CSI block using a second 20 MHz WLAN packet transmitted from the same transmitter at a different center frequency. In an example, the user client device aggregates the first CSI block with the second CSI block to obtain an equivalent 40MHz CSI matrix from two 20MHz channel bandwidth CSI blocks. In an example, the user client device performs RF chain CSI block combination (e.g., performs frequency domain CSI block combination) by combining the first CSI block with the second CSI block. The channel estimation technology enables a transmission node (e.g., a low-cost IoT device) to generate an equivalent CSI matrix that simulates the CSI matrix of a multi-RX chain network device and is deployed for CSI-based positioning, sensing, and performance improvement. In addition, the equivalent CSI matrix is ​​a CSI matrix that complies with the IEEE 802.11 standard for CSI-based applications such as CSI-based positioning, sensing, and performance improvement. Therefore, in practice, the channel estimation technology improves the performance of user client devices with a single RX chain and transmission node in the WLAN and the entire network, which enables user client devices with a single RX chain to be deployed in CSI-based applications.

[0043] Figure 5 The present invention is a method implemented by a user client device in a WLAN according to various embodiments. In the embodiment, the user client device is Figure 1 STA 106 or STA 108 in. In the example, Figure 5 The method implements a channel estimation technique on a user client device having a single RX chain when receiving multiple transmissions of a WLAN packet by a STA. The channel estimation technique provides an equivalent CSI matrix for a communication link between a transmitting node and the user client device. Figure 5 The method comprises the following steps.

[0044] In step 502, a user client device receives a request for a CSI matrix. In an example, the request for the CSI matrix is ​​sent from a positioning engine coupled to a transmitting node in a WLAN. In an example, the transmitting node is Figure 1 The transmission node 104 is shown in FIG.

[0045] At step 504, the user client device identifies and detects the WLAN (e.g., Figure 1 WLAN packets in a communication network 102 (e.g., a WLAN client device) are used for channel state estimation. In this example, a user client device listens for WLAN packets transmitted from a transmitting node (e.g., an AP) on a communication channel in the WLAN. In this example, the WLAN packets are directed to the user client device's neighbors ("neighboring user client devices"), which are not intended to be received by the user client device. In this example, the transmitting node transmits the WLAN packets over an 80 MHz channel bandwidth. Each WLAN packet represents an opportunity to identify information for channel state estimation.

[0046] At step 506, the user client device receives a first WLAN packet from a transmitting node at a first antenna within a first time period. In an example, the user client device receives a WLAN packet having OFDM symbols transmitted over a 20 MHz channel bandwidth in a PHY preamble field, a PHY MAC header field, and / or a payload data field of the WLAN packet. For example, the PHY preamble field includes one or more of an STF, an LTF, and a SIG field, the PHY MAC header field includes an IP address in a MAC header, and the payload data field includes a PE field. In an example, the user client device stores the OFDM symbols from the fields in the WLAN packet. Each OFDM symbol includes predefined subcarriers (e.g., a predefined center frequency of the subcarriers), which may include predefined pilot subcarriers. In an example, the WLAN packet may be a legacy OFDM-based WLAN packet (e.g., classic WIFI packet of IEEE 802.11a / g / p / j / n / ac / ah WLAN packet) or a WIFI-6 OFDMA-based WLAN packet (e.g., IEEE 802.11ax WLAN packet).

[0047] In an example, a user client device identifies a predefined subcarrier with a predefined subcarrier index from one or more LTFs in the preamble of a 20 MHz channel bandwidth WLAN packet. In an example, the LTF with its predefined subcarrier index can be identified a priori before receiving the WLAN packet and can be used for transmitter synchronization. In an example, the STA processes the subcarriers in the LTF to obtain the first CSI block of the 20 MHz channel bandwidth of the WLAN, which can be used to estimate the equivalent CSI matrix. In an example, the CSI matrix can be obtained according to the equation Ri = Xi * Hi ANT1 Determine the first CSI block, where Xi is a vector of complex numbers (i+jq) representing constellation points in the input data at the transmitter, which are mapped onto N orthogonal subcarriers representing the mapped constellation points of the OFDM symbol, Hi ANT1 is the multipath channel response of the i subcarriers using the first antenna, the multipath channel response representing a vector of channel responses for a 20 MHz channel bandwidth in the frequency domain, and Ri is a vector of complex numbers of the receiver for the i subcarriers received after performing a Fast Fourier Transform (FFT) on the OFDM symbol to recover the constellation points of the input data. Since the LTFs in Xi are known a priori to the user client device, Hi is used by the user client device ANT1 =Ri / Xi to estimate Hi ANT1 Assume that the multipath channel Hi ANT1 The ideal channel estimate is Equal to Hi ANT1 During reception at the first antenna, Yi is equal to the transmitted Xi and is obtained according to Equation 1, where Yi is the vector of constellation points of the input data.

[0048]

[0049] Yi = (Xi * Hi ANT1 ) / Hi ANT1 (2)

[0050] Yi = Xi (3)

[0051] As shown in Equation 3, Yi is equal to the transmitted Xi. ANT1 The first CSI block is delivered to the user client device as a 20 MHz channel bandwidth obtained using the first antenna.

[0052] In step 508, the user client device switches to the second antenna to receive (e.g., obtain) a second WLAN packet during a second time period. In this example, the second WLAN packet is the same first WLAN packet that has experienced multipath effects during transmission. In this example, the second WLAN packet is a 20 MHz WLAN packet transmitted from a transmitter at a transmitting node at a different center frequency. In this example, the second WLAN packet includes constellation points of input data mapped onto N orthogonal subcarriers representing a mapped constellation point of an OFDM symbol. In this example, the OFDM symbol includes pilot subcarriers with a known data sequence. The pilot subcarriers can be used for synchronization between the transmitter at the transmitting node and the receiver at the user client device. In this example, the pilot subcarriers (e.g., subcarrier bins) in each 20 MHz channel bandwidth are assumed to be continuous in frequency and do not vary in the frequency domain. In this example, the STA stores a pilot subcarrier index i of the pilot subcarrier in a pilot subcarrier bin of the second WLAN packet. In this example, each pilot subcarrier is equivalent to a pilot subcarrier bin.

[0053] At step 510, the user client device determines a channel estimate Hi for a pilot subcarrier i in the pilot subcarrier band of the second WLAN packet using a priori knowledge of the predefined symbols at the predefined pilot subcarriers transmitted in the WLAN packet. ANT2 In an example, during reception at the second antenna, the user client device determines the multipath channel response Hi of the i subcarriers at the second antenna. ANT2 For each pilot subcarrier index i, a channel estimate Hi of the pilot subcarrier with pilot subcarrier index i is generated. ANT2 Channel estimation Hi ANT2 Depicts the multipath channel effect in the frequency domain and varies depending on the multipath channel, cyclic shift diversity, and beamforming. In this example, Hi ANT2 Is plural. If Ri is available, then Hi can be used ANT2 =Ri / Xi to calculate the Hi of the pilot frequency band ANT2 , because the Xi of the pilot subcarrier band is known to the user client device. In the instance where only Yi is available, channel compensation uses Hi ANT1 In this example, Yi is not equal to Xi, but equal to Xi*(Hi ANT2 / Hi ANT1 ). In the pilot subcarrier frequency band, Xi is known to the user client device, and Hi ANT2 Can be calculated as Hi ANT2 =(Yi*Hi ANT1 In this example, the Hi of each pilot subcarrier frequency band is calculated using step 510. ANT2 .

[0054] At step 512, the user client device determines the channel response Hj of the adjacent subcarrier Xj with subcarrier index j. ANT2 In an example, as used herein, a neighboring subcarrier Xj is a subcarrier that is immediately adjacent to a pilot subcarrier without intervening subcarriers between the pilot subcarrier Xi and the neighboring subcarrier Xj on either side of the pilot subcarrier Xi. In an example, the subcarrier index j of the neighboring subcarrier Xj that is adjacent to the pilot subcarrier Xj with the pilot subcarrier index i is obtained. For example, for each pilot subcarrier index i, the neighboring subcarrier index j is i+1 or i-1. Using the channel continuity assumption that the subcarriers in the 20 MHz channel bandwidth are continuous, the user client device uses the channel estimate Hi of all pilot subcarriers with the pilot subcarrier index i ANT2 A coarse channel estimate Hj of the adjacent subcarrier Xj in the subcarrier index j of the 20 MHz channel bandwidth adjacent to the pilot subcarrier Xi with the pilot subcarrier index i ANT2 In this example, a coarse channel estimate Hj of the neighboring subcarrier Xj with subcarrier index j in the channel is used. ANT2 To compensate for the channel effect in the adjacent subcarrier Xj with adjacent subcarrier index j. The compensated adjacent subcarrier X'j is stored in the compensated adjacent subcarrier frequency band. In the example, Hj is determined for subcarrier index j=i+1 or j=i-1. ANT2 , which represents the channel response of the frequency bands adjacent to the pilot subcarrier frequency band. In this example, the user client device does not know Xj a priori and uses decision feedback to determine Xj. The user client device assumes a continuous channel response of the subcarriers in a 20 MHz channel bandwidth, which does not change rapidly between adjacent frequency bands of the pilot subcarrier frequency band. Using the channel continuity assumption:

[0055] Hj ANT2 Equal to Hi ANT2 , and Rj ANT2 / Hi ANT2 Approximately equal to Rj ANT2 / Hj ANT2 .

[0056] Since Rj ANT2 / Hj ANT2 =Xj, so Rj ANT2 / Hi ANT2 Approximately equal to Xj.

[0057] At step 514, the user client device inputs the compensated adjacent subcarrier frequency segment X'j with the compensated adjacent subcarrier index j into the data slicer. In this example, X'j is a constellation point and is not equal to any value, but is part of a predefined constellation point set known to the user client device. The user client device may ANT2 / Hi ANT2 Incorporate "Hard Slicer" above.

[0058] At step 516, the user client device obtains decision feedback regarding the slicing performed on the compensated adjacent subcarrier segment X'j. In an example, the user client device may estimate the constellation points of the compensated adjacent subcarrier segment in order to obtain a decision regarding the compensated adjacent subcarrier segment X'j. In an example, the decision feedback regarding slicing is used to obtain an estimate Hj of the channel response for the adjacent subcarrier with subcarrier index j. ANT2 In an example, when there is no slicing error, the data slicer generates a slicing decision for the adjacent subcarrier Xj with subcarrier index j in the compensated adjacent subcarrier band with good probability. The slicing decision is used to obtain an estimated channel response Hj for the adjacent subcarrier Xj with subcarrier index j. ANT2 In an example, the user client device can be based on Hj ANT2＝ Rj ANT2 / Xj uses adjacent subcarriers Xj to calculate Hj ANT2 .

[0059] In step 518, the user client device obtains a second subcarrier segment with an additional subcarrier with subcarrier index k. The additional subcarrier is not a pilot subcarrier with pilot subcarrier index i or a neighboring subcarrier with neighboring subcarrier index j. In an example, the user client device performs channel estimation on the remaining subcarriers by determining the signal-to-noise ratio (SNR) in the second subcarrier segment. In an example, when the SNR of the new subcarrier with subcarrier index k does not include a multipath null and has constellation points spaced apart with a large radius (a "wide" location), steps 510 to 518 are iteratively repeated until all data subcarriers in the 20 MHz channel bandwidth are estimated (e.g., a CSI matrix for all subcarriers is obtained). In an example, a multipath null is a zero amplitude subcarrier that occurs when a second WLAN packet arrives completely out of phase with a first WLAN packet and cancels out the first WLAN packet. In an example, the user client device uses Hj for neighboring subcarriers with subcarrier index j where j=i+1 and j=i-1. ANT2 The previous steps 510 to 518 may be repeated for the pilot subcarrier with pilot subcarrier index k. Pilot k is a neighbor of the adjacent subcarrier with subcarrier index j. In the example, Hk is used ANT2 Hi ANT2 Similar assumptions are made, and the previous steps are repeated for k=i+2 and k=i-2. In this example, steps 510 to 518 are repeated iteratively until Hk is determined or calculated. ANT2 All frequency bands. ANT2The user client device aggregates the first CSI block with the second CSI block to generate an equivalent CSI matrix for the channel between the transmitting node and the user client device.

[0060] At step 520 , the user client device switches to the first antenna and receives another WLAN data packet, and step 506 is repeated.

[0061] In step 522, the user client device obtains a channel estimate for the second channel. In this example, the user client device switches to the second antenna and performs steps 508 to 518 until all signals are received over the wideband bandwidth of the WLAN and each channel is estimated. The equivalent CSI matrix has the same quality as the equivalent CSI matrix obtained using the LTF in step 506. The channel estimation technique enables the user client device to simulate a higher-cost network device and is deployed for CSI-based positioning, sensing, and performance improvement. In addition, the equivalent CSI matrix is ​​a CSI matrix that complies with the IEEE 802.11 standard for CSI-based applications such as CSI-based positioning, sensing, and performance improvement. Therefore, in practice, the channel estimation technique improves the performance of user client devices with a single RX chain and transmit node in the WLAN and the entire network, which enables user client devices with a single RX chain to be deployed in CSI-based applications.

[0062] Figure 6 is a block diagram of an electronic device 602 according to various examples. In examples, the electronic device 602 is, or is incorporated into, or coupled (e.g., connected) to an electronic system 600, such as a computer, an electronic control "box" or display, a communication device (including a transmitter or receiver), or any type of electronic system operable to process information.

[0063] In some examples, electronic device 602 includes a megacell or system on a chip (SoC) including control logic, and station 604, power supply 606, input-output (I / O) ports 608, central processing unit (CPU) 610, and storage device 612 (e.g., RAM). In an example, electronic device 602 is coupled to a networking device 616. In an example, station 604 is STA 200 ( Figure 2 In the example, the networked device 616 is Figure 36. The example of a transmission node 300 (e.g., a network node) shown in FIG. CPU 610 is a CISC-type (Complex Instruction Set Computer) CPU, a RISC-type CPU (Reduced Instruction Set Computer), an MCU-type (Microcontroller Unit), or a DSP. CPU 610 includes one or more processors. The one or more processors are arranged to execute code for converting the one or more processors into a special-purpose machine or for improving the functionality of other components in electronic device 602 to provide a desired output, without performing operations similar to the one or more processors. CPU 610 includes memory and logic for storing information frequently accessed from storage device 612.

[0064] In some examples, the storage device 612 is a memory, such as an on-processor cache, an off-processor cache, RAM, flash memory, or a disk storage device, for storing one or more software applications 614 (e.g., embedded applications). When executed by the CPU 610, the one or more software applications 614 (e.g., embedded applications) perform the functions associated with the electronic device 602 described herein.

[0065] In an example, the networking device 616 controls the electronic device 602 with instructions for performing the channel estimation techniques described herein. In an example, the storage device 612 stores a software application 614 (e.g., an embedded application) for performing the channel estimation techniques using a transmission stream received by the electronic device 602 or multiple transmission streams received by the electronic device 602.

[0066] CPU 610 and power supply 606 are coupled to I / O port 608. In an example, I / O port 608 provides an interface configured to receive input from (and / or provide output to) networking device 616. Networking device 616 may include any device (including test equipment) capable of peer-to-peer and / or networked communication with electronic device 602. In an example, electronic device 602 is coupled to peripherals and / or other computing devices, including tangible, non-transitory media (e.g., flash memory) and / or wired or wireless media. These and other input and output devices are selectively coupled to electronic device 602 through external devices using wireless or wired connections. Storage device 612, for example, can be accessed by networking device 616. Power supply 606, CPU 610, and storage device 612 are also optionally coupled to an external power source (not shown) configured to receive power from a power source (e.g., a battery, a solar cell, a "live" power line, an inductive field, a fuel cell, a capacitor, and the like).

[0067] In an example, the power supply 606 is in the same physical assembly as the electronic device 602 or is coupled to the electronic device 602. Figure 6Although not shown, power supply 606 includes power generation components. The power generation components include one or more power switches. Each switch is independently controlled to generate power to power various components of electronic device 602 at various input voltages. Electronic device 602 operates in various power saving modes, where the power switches provide (and / or shut down) individual voltages depending on the selected power saving mode and the arrangement of various components within a particular power domain.

[0068] The term "coupled" is used throughout this specification. The term encompasses any connection, communication, or signal path that enables a functional relationship consistent with this description. For example, if device A generates a signal that controls device B to perform an action, then in the first instance, device A is coupled to device B. Alternatively, in the second instance, if intermediary component C does not substantially alter the functional relationship between devices A and B, such that device B is controlled by device A via control signals generated by device A, then device A is coupled to device B through intermediary component C.

[0069] A device "configured to" perform a task or function may be configured (e.g., programmed and / or hardwired) by the manufacturer at the time of manufacture to perform the function and / or may be configurable (or reconfigured) by a user after manufacture to perform the function and / or other additional or alternative functions. Configuration may be through firmware and / or software programming of the device, through the construction and / or layout of the device's hardware components and interconnections, or a combination thereof.

[0070] Circuits or devices described herein as including specific components may instead be adapted to be coupled to such components to form the described circuit systems or devices. For example, a structure described as including one or more semiconductor elements (e.g., transistors), one or more passive elements (e.g., resistors, capacitors, and / or inductors), and / or one or more sources (e.g., voltage and / or current sources) may instead include only semiconductor elements within a single physical device (e.g., a semiconductor die and / or an integrated circuit (IC) package) and may be adapted to be coupled to at least some of the passive elements and / or sources to form the described structure during or after manufacturing, for example, by an end user and / or a third party.

[0071] Although specific components may be described herein as components of a particular process technology, these components may be exchanged for components of other process technologies. The circuits described herein may be reconfigured to include replacement components to provide functionality at least partially similar to the functionality available before the component replacement. Unless otherwise stated, components shown as resistors generally represent any one or more elements coupled in series and / or parallel to provide the impedance represented by the resistor shown. Modifications are possible in the described examples, and other examples are possible within the scope of the claims.

Claims

1. A user client device for channel estimation in a network, comprising: a transceiver comprising a single receive (RX) chain; a first antenna coupled to the transceiver; a second antenna coupled to the transceiver; and a processor coupled to the transceiver, the first antenna, and the second antenna, and configured to execute instructions that cause the user client device to: coupling the single RX chain to the first antenna to receive a first data packet on a first channel, wherein the first data packet on the first channel includes a first plurality of fields; determining a first channel state information (CSI) block for the first channel based on one or more of the first plurality of fields; decoupling the first antenna from the single RX chain and coupling the second antenna to the single RX chain to continue receiving the first data packet on a second channel, wherein the first data packet on the second channel includes a portion of the first plurality of fields; determining a second CSI block for the second channel based on one or more of the portions of the first plurality of fields; Aggregating the first CSI block and the second CSI block; and A CSI matrix is ​​generated based on aggregating the first CSI block and the second CSI block.

2. The user client device of claim 1 , wherein the first data packet is a wireless local area network (WLAN) packet, wherein the first plurality of fields includes a first physical layer (PHY) preamble, a first PHY header, and a first medium access control (MAC) header, and wherein the processor is configured to generate the first CSI block based on first subcarrier information in any field of the first PHY preamble, the first PHY header, and the first MAC header.

3. The user client device of claim 1, wherein the processor is further configured to receive, with the second antenna, a second data packet comprising a second plurality of fields.

4. The user client device of claim 3 , wherein the second data packet is a WLAN packet, wherein the second plurality of fields includes a second PHY preamble, a second PHY header, and a second MAC header, and wherein the processor is configured to generate the second CSI block based on second subcarrier information in any fields of the second PHY preamble, the second PHY header, and the second MAC header.

5. The user client device of claim 4, wherein the second plurality of fields comprises a payload field, and wherein the processor is further configured to generate the second CSI block based on pilot subcarrier information in the payload field.

6. The user client device of claim 4, wherein the first plurality of fields and the second plurality of fields comprise one or more long training fields (LTFs), and wherein the processor is configured to generate the second CSI block based on any LTF of the one or more LTFs.

7. The user client device of claim 1, wherein the first data packet is directed to a second user client device that is a neighbor of the user client device.

8. The user client device of claim 1, wherein the first data packet is directed to the user client device.

9. The user client device of claim 1, wherein the first plurality of fields includes a payload field, and wherein the processor is further configured to generate the first CSI block based on pilot subcarrier information in the payload field.

10. A system for channel estimation in a network, comprising: a transmitting node configured to transmit a first data packet; and a first user client node wirelessly coupled to the transmission node, wherein the first user client node comprises: a transceiver comprising a single receive (RX) chain, a first antenna, and a second antenna; and a processor coupled to the transceiver, the first antenna, and the second antenna and configured to execute instructions that cause the first user client node to: coupling the single RX chain to the first antenna; receiving the first data packet from the first antenna, wherein the first data packet from the first antenna includes a first physical layer (PHY) preamble, a first PHY header, and a first medium access control (MAC) header; determining a first channel state information (CSI) block based on one or more of the first PHY preamble, the first PHY header, and the first MAC header of the first data packet from the first antenna; decoupling the first antenna from the single RX chain and coupling the second antenna to the single RX chain; continuing to receive the first data packet from the second antenna, wherein the first data packet from the second antenna includes the first PHY preamble, the first PHY header, and at least a portion of the first MAC header; determining a second CSI block based on the first data packet from the second antenna; Aggregating the first CSI block with the second CSI block; and A CSI matrix is ​​generated based on aggregating the first CSI block and the second CSI block.

11. The system of claim 10, wherein the first PHY preamble comprises one or more long training fields (LTFs), and wherein the instructions cause the first user client node to generate the first CSI block based on any one of the one or more LTFs.

12. The system of claim 10, wherein the first data packet is a wireless local area network (WLAN) packet comprising the first PHY preamble, the first PHY header, and a first plurality of orthogonal frequency division multiplexing (OFDM) symbols in the first MAC header, and wherein the instructions cause the first user client node to generate the first CSI block based on the first plurality of OFDM symbols.

13. The system of claim 10 , wherein the instructions cause the first user client node to receive a second data packet comprising a second plurality of fields from the second antenna, wherein the second data packet is a multipath WLAN packet comprising a second PHY preamble, a second PHY header, and a second plurality of OFDM symbols in a second MAC header, and wherein the instructions cause the first user client node to generate the second CSI block based on the second plurality of OFDM symbols.

14. The system of claim 13, wherein the second PHY preamble comprises one or more LTFs, and wherein the instructions cause the first user client node to generate the second CSI block based on any one of the one or more LTFs.

15. The system of claim 10 , wherein the system further comprises a second user client node wirelessly coupled to the transmitting node and being a neighbor of the first user client node, and wherein the instructions cause the first user client node to generate the first CSI block based on the first data packet directed to the second user client node.

16. The system of claim 10, wherein the instructions cause the first user client node to generate the first CSI block based on the first data packet directed to the first user client node.

17. The system of claim 10, wherein the first data packet is a WLAN packet including a payload field, and wherein the instructions further cause the first user client node to generate the first CSI block based on pilot subcarrier information in the payload field.

18. A method for channel estimation in a network, comprising: Providing a user client device comprising a single receive (RX) chain transceiver, a first antenna, and a second antenna; coupling the single RX chain transceiver to the first antenna; receiving, by the first antenna, a first data packet on a first channel, wherein the first data packet on the first channel comprises a first plurality of fields; determining a first channel state information (CSI) block for the first channel based on one or more of the first plurality of fields; decoupling the first antenna from the single RX chain transceiver and coupling the second antenna to the single RX chain transceiver; continuing to receive the first data packet on a second channel by the second antenna, wherein the first data packet on the second channel includes at least a portion of the first plurality of fields; determining a second CSI block for the second channel based on receiving the first data packet on the second channel; Aggregating the first CSI block and the second CSI block; and A CSI matrix is ​​generated based on aggregating the first CSI block and the second CSI block.

19. The method of claim 18, further comprising generating the first CSI block based on the first data packet directed to a second user client device that is a neighbor of the user client device.

20. The method of claim 18, further comprising generating the first CSI block based on the first data packet directed to the user client device.

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