Channel state information measurement method and associated wireless communication chip and electronic device

This application claims the priority of US Provisional Application No. 63/118,614 (filed on Nov. 25, 2020), which is included herein by reference in its entirety.

In wireless communications, channel state information (CSI) refers to known channel properties of a communication link. The CSI describes how a signal propagates from a transmitter to a receiver and represents the combined effect of, for example, scattering, fading, and power decay with distance. Recently, some applications use CSI to do the sensing detection, for example, the CSI variation can be detected to perform user behavior recognition.

In Wi-Fi scenario, the CSI is obtained by using a pair device, that is a first device serves as the transmitter to send a packet, and a second device serves as the receiver to receive the packet to estimate the CSI. However, this means that the CSI can be estimated only when there are two devices, which will cause inconvenience to the user. In addition, the CSI variation will be changed due to the environment setup, that is changes in the surrounding environment will increase a difficulty of sensing detection.

It is therefore an objective of the present invention to provide a CSI measurement method, which can use a single electronic device to obtain the CSI for the sensing detection, to solve the above-mentioned problems.

According to one embodiment of the present invention, an electronic device comprising a first antenna, a second antenna and a wireless communication chip is disclosed. The wireless communication chip is configured to control the first antenna to broadcast a packet, control the second antenna to receive the packet broadcasted from the first antenna, and determine channel state information according to the packet received by the second antenna.

According to another embodiment of the present invention, a wireless communication chip comprising a transmitting circuit, a receiving circuit and a processing circuit is disclosed. The transmitting circuit is arranged to couple to a first antenna external to the wireless communication chip. The receiving circuit is arranged to couple to a second antenna external to the wireless communication chip. The processing circuit is configured to control the transmitting circuit to broadcast a packet via the first antenna, control the receiving circuit to receive the packet via the second antenna, and determine channel state information according to the packet received by the receiving circuit.

According to another embodiment of the present invention, a channel state information measurement method comprises the steps of: controlling a first antenna within an electronic device to broadcast a packet; controlling a second antenna within the electronic device to receive the packet; and determining channel state information according to the packet received by the second antenna.

These and other objectives of the present invention will no doubt become obvious to those of ordinary skill in the art after reading the following detailed description of the preferred embodiment that is illustrated in the various figures and drawings.

FIG. 1 is a diagram illustrating an electronic device according to one embodiment of the present invention.

FIG. 2 shows arrangements of the antennas according to one embodiment of the present invention.

FIG. 3 shows arrangements of the antennas according to another embodiment of the present invention.

FIG. 4 shows arrangements of the antennas according to another embodiment of the present invention.

Certain terms are used throughout the following description and claims to refer to particular system components. As one skilled in the art will appreciate, manufacturers may refer to a component by different names. This document does not intend to distinguish between components that differ in name but not function. In the following discussion and in the claims, the terms “including” and “comprising” are used in an open-ended fashion, and thus should be interpreted to mean “including, but not limited to . . . ”. The terms “couple” and “couples” are intended to mean either an indirect or a direct electrical connection. Thus, if a first device couples to a second device, that connection may be through a direct electrical connection, or through an indirect electrical connection via other devices and connections.

FIG. 1 is a diagram illustrating an electronic device 100 according to one embodiment of the present invention. As shown in FIG. 1 , the electronic device 100 comprises a wireless communication chip (in this embodiment, a Wi-Fi chip 110 serve as the wireless communication chip), a processor 120 and at least two antennas 102 and 104 , wherein the Wi-Fi chip 110 comprises a processing circuit 112 , a transmitting circuit 114 and a receiving circuit 116 , the transmitting circuit 114 is coupled to the antenna 102 , and the receiving circuit 116 is coupled to the antenna 104 . In this embodiment, the electronic device 100 can be an access point, a router, a computer, a television or any other electronic device capable of wirelessly communicating with other devices.

In this embodiment, the Wi-Fi chip 110 is configured to continuously use two antennas 102 and 104 within the electronic device to obtain the CSI, for the Wi-Fi chip 110 or the processor 120 to do the sensing detection (e.g., user behavior recognition). Specifically, the processing circuit 112 controls the transmitting circuit 114 to broadcast packets through the antenna 102 , and the receiving circuit 116 receives these packets from the antenna 104 . Then, the processing circuit 112 calculates the CSI based on data of the broadcasted packets and data of the received packets. In detail, the relationship between the broadcasted data and the received data can be expressed as y=H*x+n, wherein ‘x’ represents the data of the broadcasted packet, ‘y’ represents the data of the received packet, ‘n’ represents noise, and ‘H’ represents the CSI. In addition, the CSI have amplitude components (i.e. read part) and phase components (i.e., imaginary part), and the CSI can be represented as a matrix.

When the transmitting circuit 114 broadcasts one packet, the receiving circuit 116 may receive the packet via multiple paths, for example, a light-of-sight (LOS) propagation path and many reflection paths, and the CSI determined by the processing circuit 112 is based on signal strengths of these paths. Therefore, when the electronic device 100 is located in a stable environment, the processing circuit 112 may always determine the similar CSI (i.e., the CSI changes slightly); and if the environment changes, for example a person enters a room, the processing circuit 112 may determine a different CSI, so the Wi-Fi chip 110 or the processor 120 can detect the environment variation based on the difference between the CSIs.

In light of above, the embodiment shown in FIG. 1 uses only one electronic device 100 , instead of two devices, to obtain the CSI to detect the environment variation. Therefore, it is easy for the user to use the electronic device 100 do the sensing detection.

FIG. 2 shows arrangements of the antennas 102 and 104 according to one embodiment of the present invention. As shown in FIG. 2 , the electronic device 100 can be implemented by a television, and the antenna 102 is located in the upper left corner of the television, and the antenna 104 is located in the upper right corner of the television. The signals received by the antenna 104 may comprise a LOS propagation path and at least one reflection path, and/or diffraction paths and/or refracted paths, and the processing circuit 112 can use the signals corresponding to the LOS propagation path and the other paths to determine the CSI.

In the embodiment shown in FIG. 2 , because the LOS propagation path indicates that the signal travels in a direct path from the antenna 102 to the antenna 104 , the LOS propagation path corresponds to highest power. For the detection of the CSI variation, the LOS propagation path may increase the complexity of determining the CSI variation. To solve this problem, the electronic device 100 is further designed to lower the energy of the LOS propagation path, as shown in FIG. 3 and FIG. 4 .

FIG. 3 shows arrangements of the antennas 102 and 104 according to another embodiment of the present invention. As shown in FIG. 3 , the electronic device 100 can be implemented by a television, and the antenna 102 is located in the upper left corner of the television, the antenna 104 is located in the lower right corner of the television. In this embodiment, there is no LOS propagation path for the antennas 102 and 104 , so the signals received by the antenna 104 may only correspond to reflection paths, diffraction paths and/or refracted paths, and the processing circuit 112 can use the signals corresponding to the paths without the LOS propagation path to determine the CSI. Because none of the signals received by the antenna 104 is from the LOS propagation path with high power, the energy of each subcarrier received by the antenna 104 is clearer for the processing circuit 112 , and it is convenient to determine the CSI variation.

It is noted that the arrangements of the antennas 102 and 104 shown in FIG. 3 is for illustrative only. In other embodiments of the present invention, as long as the signal received by the antenna 104 do not correspond to the LOS propagation path, the antennas 102 and 104 can be set anywhere in the television. For example, the antenna 102 can be located in the lower right corner of the television while the antenna 104 is located in the upper left corner of the television; or the antenna 102 can be located in the lower left corner of the television while the antenna 104 is located in the upper right corner of the television; or the antenna 102 can be located in the upper right corner of the television while the antenna 104 is located in the lower left corner of the television; or the antenna 102 is located in the upper left corner of the television, and the antenna 104 is located on the right side or lower side of the television; or the antenna 102 is located in the upper right corner of the television, and the antenna 104 is located on the left side or lower side of the television; or the antenna 102 is located in the lower left corner of the television, and the antenna 104 is located on the right side or upper side of the television; or the antenna 102 is located in the lower right corner of the television, and the antenna 104 is located on the left side or the lower side of the television; or the antenna 102 is located on one of the upper side and lower side of the television, and the antenna 104 is located on the other one of the upper side and lower side of the television; or the antenna 102 is located on one of the right side and left side of the television, and the antenna 104 is located on the other one of the right side and left side of the television.

FIG. 4 shows arrangements of the antennas 102 and 104 according to another embodiment of the present invention. As shown in FIG. 4 , the electronic device 100 can be implemented by a television, and the antenna 102 is located in the upper left corner of the television, the antenna 104 is located in the upper right corner of the television, and a barrier 410 such as an iron sheet is positioned on the LOS propagation path between the antennas 102 and 104 . In this embodiment, because of the barrier 410 positioned on the LOS propagation path, it can be considered that there is no LOS propagation path for the antennas 102 and 104 , so the signals received by the antenna 104 may only correspond to reflection paths, diffraction paths and/or refracted paths, and the processing circuit 112 can use the signals corresponding to the paths without the LOS propagation path to determine the CSI. Because none of the signals received by the antenna 104 is from the LOS propagation path with high power, the energy of each subcarrier received by the antenna 104 is clearer for the processing circuit 112 , and it is convenient to determine the CSI variation.

In another embodiment of the present invention, the energy of the signal corresponding to the LOS propagation path can be lowered by controlling the antennas 102 and 104 . For example, the Wi-Fi chip 110 may change the antenna isolation by controlling the polarization direction of the directional antenna, or the Wi-Fi chip 110 may use digital compensation to lower the energy of the signal corresponding to the LOS propagation path.

Briefly summarized, in the CSI measurement method of the present invention, by controlling one antenna of the electronic device to broadcast packets and controlling another antenna of the electronic device to receive the packets to calculate the CSI, the user can easily use only one electronic device to do the sensing detection. In one embodiment, by designing the electronic device to lower the energy of signal corresponding to the LOS propagation path, the energy of each subcarrier received by the antenna is clearer, and it is convenient to determine the CSI variation.

Those skilled in the art will readily observe that numerous modifications and alterations of the device and method may be made while retaining the teachings of the invention. Accordingly, the above disclosure should be construed as limited only by the metes and bounds of the appended claims.