PD circuit and optical wireless communication receiving system

Abstract

The PD circuit comprises a first PD array, the first PD array comprises a first port and a second port, the second port is connected with a first transimpedance amplifier, the first port is in an open circuit state, or the first port is connected with a second transimpedance amplifier. One end of the two ports of the first PD array in the PD circuit is connected with the trans-impedance amplifier, and the other end of the two ports of the first PD array replaces a matched load resistor through open circuit design or the trans-impedance amplifier, so that photo-generated current in the PD array is fully utilized, and the system sensitivity of the receiver is improved. Besides, the equivalent impedance of the array unit in the PD array is designed to be low impedance, and the delay of the PD array unit can be reduced by reducing the inductance L, so that the influence of delay inequality on bandwidth performance when a plurality of photo-generated currents are combined can be reduced, and the complexity of a PD circuit is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of optical wireless communication, and more particularly to a PD circuit and an optical wireless communication receiving system. BACKGROUND

[0002] Optical wireless communication (OWC) technology is one of the key fields in wireless communication technology, and has advantages such as large available bandwidth, small transmitting antenna, and anti-electromagnetic interference. The industry and academia have corresponding system solutions in indoor short-distance and outdoor long-distance communication scenarios. Current high-speed optical wireless communication system solutions are mainly applied in single-user stationary point-to-point scenarios. The light source and photodetector in the existing system have adopted broadband devices, and the active area of the broadband photodetector is small.

[0003] Currently, the diameter of the light sensing surface of a single broadband photoelectric diode (PD) or avalanche photodiode (APD) device is about 40-16 um, and the light sensing area is small, which cannot be directly used in an OWC receiver, requires strict alignment, and does not support receiver mobility. A broadband PD array is the main technical path to solve the above problems, and expanding the light sensing area through array technology is beneficial to improving the mobility of the receiver and reducing the alignment requirements. However, the broadband PD array technology currently used in the industry has the problems of high complexity and reduced sensitivity caused by loss of photo-generated current, thereby affecting the complexity, cost and even communication effect of high-speed, alignment-free and large-field-of-view OWC receiver equipment. In order to jointly optimize the three indicators of the light sensing surface, complexity and sensitivity of the PD array, it is necessary to design a new broadband PD array technology solution. SUMMARY

[0004] The present application provides a PD circuit which can effectively expand the light sensing area while ensuring the communication bandwidth, and reduce the complexity of the circuit structure and the sensitivity reduction caused by the loss of photo-generated current.

[0005] In a first aspect, a PD circuit is provided, characterized in that it comprises: a first PD array, the first PD array comprising a first port and a second port, the second port being connected with a first transimpedance amplifier, and the first port being in an open circuit state, or the first port being connected with a second transimpedance amplifier.

[0006] In this technical solution, two ports of the first PD array in the PD circuit are connected with a transimpedance amplifier at one end, and the other end is designed by an open circuit or a transimpedance amplifier to replace a matching load resistor, so as to fully utilize the photo-generated current in the PD array and improve the sensitivity of the receiver system.

[0007] With reference to the first aspect, in some implementations of the first aspect, the first PD array includes N PD array units, an equivalent impedance Z of each of the PD array units is less than 50Ω, where N is a positive integer greater than or equal to 2.

[0008] In the technical solution, the equivalent impedance of the PD array unit is limited to Z less than 50Ω, and it should be understood that the time delay of the PD array unit is less than 1 ns. By reducing the inductance L, the time delay of the PD array unit can be reduced, so that the influence of the time delay difference on the bandwidth performance when the multiple photocurrents are combined can be reduced.

[0009] It can be understood that by reducing the inductance L to reduce the time delay of the PD array unit, the time delay alignment network such as an array external optical waveguide can be avoided, and the complexity of the PD circuit can be reduced.

[0010] With reference to the first aspect, in some implementations of the first aspect, each of the PD array units is configured to receive an optical signal and convert the optical signal into a current signal, and when the first port is in an open circuit state, the first transimpedance amplifier includes a first input port and a first output port, the second port is connected to the first input port, and the first transimpedance amplifier is configured to receive the current signal from the first input port, convert the current signal into a voltage signal, and output the voltage signal from the first output port.

[0011] With reference to the first aspect, in some implementations of the first aspect, when the first port is connected to the second transimpedance amplifier, the first transimpedance amplifier includes a first input port and a first output port, the second port is connected to the first input port, and the first transimpedance amplifier is configured to receive a first current signal from the first input port, convert the first current signal into a first voltage signal, and output the first voltage signal from the first output port, where the first current signal is a part of the current signal; the second transimpedance amplifier includes a second input port and a second output port, the first port is connected to the second input port, and the second transimpedance amplifier is configured to receive a second current signal from the second input port, convert the second current signal into a second voltage signal, and output the second voltage signal from the second output port, where the second current signal is a part of the current signal; and the first voltage signal and the second voltage signal are combined into a third voltage signal via a first combiner.

[0012] With reference to the first aspect, in some implementations of the first aspect, the first transimpedance amplifier or the second transimpedance amplifier is further configured to provide a bias voltage to the first PD array.

[0013] In the technical solution, the bias voltage of the PD can be integrated in the trans-impedance amplifier. The bias voltage is not provided by a separate bias voltage provider, and the complexity of the PD circuit is reduced.

[0014] With reference to the first aspect, in some implementations of the first aspect, the PD circuit further includes a first bias voltage provider configured to provide the bias voltage to the first PD array.

[0015] In the technical solution, the first bias voltage provider can be used to provide the bias voltage to the first PD array.

[0016] With reference to the first aspect, in some implementations of the first aspect, when the first port is in an open circuit state, the PD circuit further includes a first equalizer configured to receive the voltage signal from the first output port, and perform compensation processing on the voltage signal, the compensation processing being configured to compensate for a high-frequency part of the voltage signal; when the first port is connected to the second trans-impedance amplifier, the PD circuit further includes a first equalizer and / or a second equalizer, the first equalizer being configured to receive the first voltage signal from the first output port, and perform compensation processing on the first voltage signal, the compensation processing being configured to compensate for a high-frequency part of the first voltage signal, and input the compensated first voltage signal to the first combiner; the second equalizer being configured to receive the second voltage signal from the second output port, and perform compensation processing on the second voltage signal, the compensation processing being configured to compensate for a high-frequency part of the second voltage signal, and input the compensated second voltage signal to the first combiner.

[0017] In the technical solution, the compensation processing refers to compensating for the high-frequency part of the voltage signal, so as to offset the different time delays of the multiple photo-generated current signals generated by the multiple PD array units. Based on the solution, the influence of the transmission time delay of the current signals output by the PD array units in the PD array circuit on the bandwidth performance can be reduced, and the performance of the receiver system is improved.

[0018] With reference to the first aspect, in some implementations of the first aspect, the equivalent impedance Z of each PD array unit is greater than or equal to 10 Ω and less than or equal to 30 Ω.

[0019] The solution provides an equivalent impedance of the PD array unit.

[0020] In a second aspect, an optical wireless communication receiving system is provided, comprising a lens and a first PD circuit, the first PD circuit being the PD circuit of any one of claims 1-8, the lens being configured to receive an incident optical signal, the incident optical signal converging through the lens to form a spot on at least one PD array unit of the first PD circuit, the spot being configured to be used by the PD array unit to obtain an optical signal, wherein the N PD array units of the first PD circuit are connected in a non-linear connection manner.

[0021] The non-linear connection manner can be understood as that the N PD array units are distributed or wired in a non-linear manner, for example, the N PD array units are wired in the shape of at least one polygon (for example, a rectangle, a triangle), and for another example, the N PD array units are wired in the shape of at least one circle. It should be understood that the polygon and the circle here are both open shapes. It can be understood that the first PD array unit and the last PD array unit are connected to two ports of the first PD array respectively.

[0022] In a possible implementation, the N array units in the first PD circuit are connected in the connection manner of at least two "rectangles" or at least two "triangles". Alternatively, it can also be referred to as "serpentine" connection.

[0023] In a third aspect, an optical wireless communication receiving system is provided, comprising a first PD circuit and a second PD circuit, the first PD circuit and the second PD circuit being the PD circuit of any one of claims 1-9, and a second combiner, wherein a voltage signal output by the first PD circuit and a voltage signal output by the second PD circuit are combined via the second combiner to output a combined voltage signal.

[0024] In this scheme, the two kinds of PD circuits can be spliced and combined, and the voltage signal output by the first PD circuit and the voltage signal output by the second PD circuit are superimposed and output, which is equivalent to the superposition of the light sensing areas of the first PD circuit and the second PD circuit.

[0025] In a fourth aspect, an optical wireless communication receiving system is provided, comprising a first PD circuit and a second PD circuit, the first PD circuit and the second PD circuit being the PD circuit of any one of claims 1-9, wherein the transimpedance amplifiers in the first PD circuit and the second PD circuit are in differential mode, and a voltage signal output by the first PD circuit and a voltage signal output by the second PD circuit are respectively output in differential mode.

[0026] In this scheme, the two kinds of PD circuits can be spliced and combined, and the voltage signal output by the first PD circuit and the voltage signal output by the second PD circuit are obtained in differential mode, and the light sensing areas are superimposed, which is equivalent to the superposition of the light sensing areas of the first PD circuit and the second PD circuit. Figure 8The OWC receiving system shown in the figure has higher TIA integration.

[0027] In a fifth aspect, a signal processing method is provided, which is applied to an optical receiver, the optical receiver comprising a first PD array, wherein the first PD array comprises a first port and a second port, the second port being connected with a first trans-impedance amplifier, the first port being in an open circuit state, the first PD array further comprising N PD array units, the method comprising: the optical receiver generating a current signal through the partial or all PD array units, the first PD array causing all the current signals generated by the partial or all PD array units to enter the first trans-impedance amplifier; and the optical receiver converting the all current signals into a voltage signal through the first trans-impedance amplifier.

[0028] In the technical solution, the optical receiver can transmit all the generated photo-generated current signals to the first trans-impedance amplifier to convert into a voltage signal, thereby avoiding loss of photo-generated current and ensuring sensitivity of the optical receiver.

[0029] In a sixth aspect, a signal processing method is provided, which is applied to an optical receiver, the optical receiver comprising a first PD array, wherein the first PD array comprises a first port and a second port, the second port being connected with a first trans-impedance amplifier, the first port being connected with a second trans-impedance amplifier, the first PD array further comprising N PD array units, the method comprising: the optical receiver generating a current signal through the partial or all PD array units, the first PD array causing a first current signal to enter the first trans-impedance amplifier, the first PD array causing a second current signal to enter the second trans-impedance amplifier, the sum of the first current signal and the second current signal being all the current signals generated by the partial or all PD array units; and the optical receiver converting the all current signals into a voltage signal through the first trans-impedance amplifier and the second trans-impedance amplifier.

[0030] In the technical solution, the optical receiver can transmit all the generated photo-generated current signals to the first trans-impedance amplifier and the second trans-impedance amplifier to convert into a voltage signal, thereby avoiding loss of photo-generated current and ensuring sensitivity of the optical receiver.

[0031] In a seventh aspect, a computer readable storage medium is provided, the computer readable medium storing program code for execution by an apparatus, the program code comprising code for performing the method provided in the fifth aspect or the sixth aspect.

[0032] In an eighth aspect, a computer program product containing instructions, which, when the computer program product is run on a computer, cause the computer to execute the method provided in the fifth aspect or the sixth aspect. BRIEF DESCRIPTION OF DRAWINGS

[0033] Figure 1 A schematic diagram of a PD circuit is shown.

[0034] Figure 2 A schematic diagram of a PD circuit is shown.

[0035] Figure 3 A schematic diagram of a PD circuit is shown.

[0036] Figure 4 A schematic diagram of a PD circuit is shown.

[0037] Figure 5 A schematic diagram of a PD circuit is shown.

[0038] Figure 6 A schematic diagram of a PD circuit is shown.

[0039] Figure 7 A schematic diagram of a light OWC receiving system is shown.

[0040] Figure 8 A schematic diagram of a light OWC receiving system is shown.

[0041] Figure 9 A schematic diagram of a light OWC receiving system is shown. DETAILED DESCRIPTION

[0042] The technical solutions in the present application will be described below with reference to the drawings.

[0043] The embodiments described in the present application are only partial embodiments, rather than all embodiments. Based on the content described in the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the embodiments claimed by the present application.

[0044] The present application can be applied to various communication systems, for example: a global system for mobile communication (GSM) system, a code division multiple access (CDMA) system, a wideband code division multiple access (WCDMA) system, a general packet radio service (GPRS), a long term evolution (LTE) system, an LTE frequency division duplex (FDD) system, an LTE time division duplex (TDD), a universal mobile telecommunication system (UMTS), a worldwide interoperability for microwave access (WiMAX) communication system, a 5th generation (5G) system or new radio (NR), a future 6th generation (6G) system, inter-satellite communication, and satellite communication, and the like. The antenna and / or antenna system described in the embodiments of the present application can also be applied to other communication systems, which will not be described in detail herein.

[0045] Optical wireless communication technology is one of the key fields in wireless communication technology. Unlike wireless communication systems in the 5-6 GHz, 60 GHz, and THz frequency bands, optical wireless communication technology has advantages such as large available bandwidth, small transmitting antenna, and resistance to electromagnetic interference. The industry and academia have corresponding system solutions for indoor short-range and outdoor long-range communication scenarios.

[0046] In the present application, the optical wireless communication system solution is mainly applied to a single-user stationary point-to-point scenario. For example, network devices, terminal devices, or network devices and terminal devices can all perform point-to-point communication.

[0047] Among them, the network device can be referred to as a (wireless) access network ((radio) access network, (R)AN) device, which can provide access to a communication network for authorized users in a specific area, and can specifically include a wireless network device in a 3rd generation partnership project (3rd generation partnership project, 3GPP) network. It can also include an access point in a non-3GPP (non-3GPP) network. The following is for convenience. AN device is represented.

[0048] The AN device can use different wireless access technologies. There are two types of current wireless access technologies: 3GPP access technology (for example, wireless access technology used in third generation (3rd generation, 3G), fourth generation (4th generation, 4G) or 5G system) and non-3GPP (non-3GPP) access technology. 3GPP access technology refers to access technology that conforms to 3GPP standard specifications, for example, access network equipment in a 5G system is called a next generation Node Base station (next generation Node Base station, gNB) or RAN device. Non-3GPP access technology can include air interface technologies represented by access points (access points, APs) in wireless fidelity (wireless fidelity, WiFi), worldwide interoperability for microwave access (worldwide interoperability for microwave access, WiMAX), code division multiple access (code division multiple access, CDMA) and the like. AN device can allow terminal devices and 3GPP core networks to interconnect and interwork using non-3GPP technology.

[0049] The AN device can be responsible for wireless resource management on the air interface side, quality of service (quality of service, QoS) management, data compression and encryption, and other functions. The AN device provides access services for terminal devices, and then completes the forwarding of control signals and user data between terminal devices and core networks.

[0050] An AN device can include, but is not limited to, a macro base station, a micro base station (also known as a small cell), a radio network controller (RNC), a Node B (NB), a base station controller (BSC), a base transceiver station (BTS), a home base station (e.g., home evolved NodeB, or home Node B, HNB), a baseband unit (BBU), an AP in a WiFi system, a wireless relay node, a wireless backhaul node, a transmission point (TP), or a transmission and reception point (TRP), etc., and can also be a gNB or a transmission point (TRP or TP) in a 5G (e.g., NR) system, one or a group of (including multiple antenna panels) antenna panels of a base station in a 5G system, or a network node constituting a gNB or a transmission point, such as a distributed unit (DU), or a base station in a next-generation communication 6G system, etc. The embodiments of the present application do not limit the specific technology and specific device form adopted by the AN device

[0051] A terminal device can be an access terminal, a subscriber unit, a subscriber station, a mobile station, a mobile, a remote station, a remote terminal, a mobile device, a user terminal, a terminal, a wireless communication device, a user agent, or a user device.

[0052] The terminal device can be a device providing voice / data to a user, for example, a handheld device with wireless connection function, a vehicle-mounted device, etc. At present, some examples of terminals are: mobile phone, tablet computer, notebook computer, palm computer, mobile internet device (MID), wearable device, virtual reality (VR) device, augmented reality (AR) device, wireless terminal in industrial control, wireless terminal in self driving, wireless terminal in remote medical surgery, wireless terminal in smart grid, wireless terminal in transportation safety, wireless terminal in smart city, wireless terminal in smart home, cellular phone, cordless phone, session initiation protocol (SIP) phone, wireless local loop (WLL) station, personal digital assistant (PDA), handheld device with wireless communication function, computing device or other processing device connected to a wireless modem, wearable device, terminal device in a 5G network, or terminal device in a future evolved public land mobile network (PLMN), etc. The embodiments of the present application are not limited thereto.

[0053] By way of example and not limitation, in the embodiments of the present application, the terminal device can also be a wearable device. The wearable device can also be referred to as a wearable smart device, which is a general term for devices that are designed and developed by applying wearable technology to daily wear, such as glasses, gloves, watches, clothing, and shoes. The wearable device is a portable device that is directly worn on the body or integrated into the user's clothes or accessories. The wearable device is not only a hardware device, but also a device that realizes powerful functions through software support and data interaction and cloud interaction. The general wearable smart device includes devices with full functions, large size, and the ability to realize complete or partial functions without relying on a smart phone, such as smart watches or smart glasses, and devices that focus on a certain application function and need to be used in cooperation with other devices, such as smart phones, such as various smart wristbands and smart jewelry for monitoring vital signs.

[0054] In addition, in the embodiments of the present application, the terminal device can also be a terminal device in an IoT system. IoT is an important part of future information technology development, and its main technical feature is to connect objects through communication technology and network, so as to realize the intelligent network of man-machine interconnection and object-object interconnection.

[0055] It should be noted that the terminal device and the access network device can communicate with each other by using a certain air interface technology (such as NR or LTE technology, etc.). The terminal device and the terminal device can also communicate with each other by using a certain air interface technology (such as NR or LTE technology, etc.).

[0056] In the embodiments of the present application, the device for implementing the function of the terminal device can be a terminal device, or a device capable of supporting the terminal device to implement the function, such as a chip system or a chip, which can be installed in the terminal device. In the embodiments of the present application, the chip system can be composed of a chip, or can include a chip and other discrete devices.

[0057] It should be noted that the light source and the photodetector in the optical wireless communication system have adopted a wideband device, in which the active area of the wideband photodetector is small, with a diameter of um order of magnitude. For example, the photodiode (PD) or APD single device has a light sensing surface diameter of about 40-16 um, which cannot be directly used in the OWC receiver, requires strict alignment, and does not support receiver mobility. The PD array is the main technical path to solve the above problems. Expanding the light sensing area by using array technology is beneficial to improve the mobile characteristics of the receiver and reduce the alignment requirements.

[0058] Figure 1 A schematic diagram of a PD circuit is shown.

[0059] As shown in Figure 1 , the PD circuit includes a plurality of wideband PD basic units (PD1, PD2, …, PD N , wherein each wideband PD basic unit is composed of a PD and an equivalent inductive circuit, one end of each PD is grounded, and the other end is connected through the equivalent inductive circuit to form a traveling wave structure wideband PD array. Each wideband PD basic unit forms a 50Ω impedance. The PD generates a current signal after being irradiated, part of the current signal is output through the inductor arranged on the left, and the other part is output through the inductor arranged on the right after being provided with a bias voltage by the biasing device.

[0060] Among them, the 50Ω resistor arranged on the left and the RF load 50Ω load arranged on the right are matched, which ensures that the current will not be reflected in the transmission process.

[0061] The PD circuit can also provide a bias voltage vbias .

[0062] The PD circuit also includes an optical fiber network arranged at the periphery of the PD array.

[0063] It should be understood that the distance of current transmission to the RF load is different for each PD, and therefore, the time difference in which the current generated by different PDs reaches the RF load. The optical fiber network at the periphery can be used to offset the time delay to achieve optimal merging gain of the telecommunication signal and ensure bandwidth improvement.

[0064] In this scheme, on the one hand, the current generated by each PD is transmitted in two directions, left and right. The current in the left direction is transmitted through a 50Ω load, and the current in the right direction is output, resulting in a loss of at least half of the photo-generated current and a decrease in sensitivity.

[0065] On the other hand, although the use of optical fibers or optical waveguiders of different lengths can achieve different time delays and offset the time delay difference of photo-generated currents of different PDs, the coupling efficiency of spatial optical signals into the optical fiber is low, which is not suitable for wireless optical communication scenarios. At the same time, the arrangement of the optical fiber network at the periphery of the PD array also increases the complexity of the OWC receiver device.

[0066] In summary, the broadband PD array structure currently used in the industry is complex, and the receiver sensitivity is low, which affects the complexity, cost, and even communication effect of high-speed, alignment-free, and mobile OWC receiver devices. For the joint optimization of the three indicators of the PD array photosensitive surface, complexity, and sensitivity, it is necessary to adopt a new broadband PD array technical solution.

[0067] The broadband OWC system needs to use a receiver based on the PD array technology to expand the effective photosensitive surface. The current technical solution has the problems of high complexity and low sensitivity due to the loss of photo-generated current.

[0068] The present application proposes a low-impedance traveling wave structure PD array to expand the effective photosensitive surface area, uses an open circuit or a double-TIA structure, avoids the use of an additional matching load circuit, reduces the loss of photo-generated current, and at the same time guarantees the communication bandwidth.

[0069] The present application can be applied to indoor and outdoor wireless optical communication scenarios, including but not limited to indoor short-distance high-speed data transmission and inter-satellite optical communication. It is embodied in the receiver system. In addition, scenarios that require tolerance to large assembly tolerances and large alignment errors can also use this technology, such as inter-board and intra-board high-speed optical communication and inter-chip communication.

[0070] The present application can be applied to a wireless optical communication receiver device, and the specific product form can be a terminal, a tablet, a portable machine, etc. At the same time, the receiver system based on optical fibers in the existing network can also use the present technology, which changes the scheme of combining the PD in the traditional optical module with the trans-impedance amplifier (TIA) to the present application.

[0071] In the present application, the PD can be an avalanche photodiode (APD), a PIN photodiode (PIN-PD), etc. The present application embodiment does not limit this.

[0072] First, the functional elements that can be used in the PD circuit proposed in the present application are introduced.

[0073] 1. Trans-impedance amplifier (TIA)

[0074] The TIA is a current-voltage converter. For example, an operational amplifier can convert an input current into a proportional output voltage. The TIA is mainly used to convert the output current of a photomultiplier tube, a Geiger-Muller tube, and a photodetector into a functional voltage.

[0075] A simple TIA mainly includes a large value feedback resistor, for example, R f The resistor. This R f The resistor is used to set the gain of the TIA, because the TIA is connected in a negative feedback configuration. The TIA provides simple linear signal processing to consume current through the operational amplifier and the resistor.

[0076] 2. Bias tee

[0077] The bias tee can provide a bias voltage. The high-frequency feeding circuit of the broadband amplifier is affected by the parasitic capacitance parameter, and the performance decreases sharply, so the feeding needs to use the bias tee. The bias tee is composed of a high-frequency inductor and a capacitor with ultra-wideband, close to idealization, and no resonance point. Among them, the capacitor is used to isolate direct current and prevent direct voltage from leaking to the subsequent circuit or test instrument; the high-frequency inductor is used to isolate alternating current information and prevent high-frequency signals from leaking to the power supply system.

[0078] The bias voltage is usually the voltage applied in electronic devices or circuits to make them work normally. This voltage is used to ensure that the device or circuit works in the appropriate working area to achieve the required performance. In electronic devices such as amplifiers, transistors, integrated circuits, etc., by applying a proper bias voltage, the device can work in its linear region, so as to realize stable and controllable operation.

[0079] The following is a detailed description of a PD circuit provided in an embodiment of the present application.

[0080] See also Figure 2 , as an example, Figure 2 A structural schematic diagram of a PD circuit provided in an embodiment of the present application is shown.

[0081] like Figure 2 As shown, the PD circuit includes a first PD array.

[0082] The following describes this structure in detail.

[0083] First PD array:

[0084] The first PD array includes N PD array units, where N is a positive integer greater than or equal to 2.

[0085] The N PD array units are connected to each other to form a traveling wave structure PD array.

[0086] Each PD array unit includes a first PD and a first equivalent inductance circuit.

[0087] As an example, the first equivalent inductance circuit may be implemented by a winding inductor, for example Figure 2 In the PD array unit shown in the figure, the equivalent inductance circuit is realized by two inductors with an inductance of L / 2. The equivalent inductance circuit can also be realized by microstrip lines or gold bonding wires. The specific implementation does not limit the protection scope of this application.

[0088] As an example, the first PD may include a PD, such as Figure 2 As shown in , multiple PDs may also be included, which is not limited in the embodiments of the present application.

[0089] It should be understood that one end of the PD of each PD array unit is grounded, and the other end is connected to the equivalent inductor circuit.

[0090] It should be noted that in the PD array unit, the equivalent circuit of the PD is a capacitor C, the inductive reactance of each inductor is L / 2, and the equivalent impedance Z of the PD array unit is

[0091] In a possible implementation, the equivalent impedance Z is a low impedance.

[0092] It will be appreciated that by reducing the inductance L, the impedance Z can be reduced.

[0093] In one possible implementation, the low impedance Z can be understood as being close to the input impedance of the TIA.

[0094] One possible understanding is that low impedance refers to an equivalent impedance value lower than that commonly used.

[0095] For example, Z is less than 50Ω.

[0096] For example, Z is 10Ω-30Ω.

[0097] It should be noted that in the PD array unit, the time delay of the PD array unit is By reducing the inductance L, the time delay of the PD array unit can be reduced, so that the influence of the time delay difference on the bandwidth performance when the plurality of photo-generated currents are combined can be reduced.

[0098] It can be understood that by reducing the inductance L to reduce the time delay of the PD array unit, the time delay alignment network such as an array external optical waveguide can be avoided, so that the structure of the PD circuit can be simplified, and the complexity of the optical receiver can be reduced.

[0099] Each PD array unit is configured to receive an optical signal and convert the optical signal into an electrical signal.

[0100] For example, the PD is irradiated by a light spot to generate an optical signal, and the optical signal is converted into a current signal (which can also be referred to as a photo-generated current signal), and the current signal is output through an equivalent inductance circuit.

[0101] The first PD array includes a first port 111 and a second port 112, wherein the first port 111 is in an open circuit state, and the second port 112 is connected to the first transimpedance amplifier.

[0102] The current signal is output through the PD array unit, and part of the current is transmitted to the first port 111, and another part of the current is transmitted to the second port 112. Because the first port 111 is in an open circuit state, the part of the current is reflected back to the second port 112, so that the two parts of the current signal enter the first input port 121 through the first input port 121 to realize voltage conversion.

[0103] This method can avoid the loss of the photo-generated current signal converted by the first PD, and is beneficial to improve the sensitivity of the optical receiver system.

[0104] The first transimpedance amplifier includes a first input port 121 and a first output port 122, and the first transimpedance amplifier receives the current signal from the first input port 121 and converts it into a voltage signal, and outputs the voltage signal from the first output port 122.

[0105] It should be understood that the first transimpedance amplifier further includes R f The resistor and the operational amplifier can refer to the term explanation in the foregoing, and will not be repeated here.

[0106] In one possible implementation, the first transimpedance amplifier is further configured to provide a bias voltage.

[0107] It can be understood that the first trans-impedance amplifier can be integrated as a PD to provide a bias voltage. A separate bias voltage generator is not required to provide the bias voltage, reducing the complexity of the PD circuit.

[0108] In another possible implementation, the PD circuit further includes a first bias generator configured to provide the bias voltage.

[0109] The first bias generator can refer to the foregoing description and will not be repeated here.

[0110] Referring to Figure 3 , as an example, Figure 3 a schematic structural diagram of another PD circuit is shown.

[0111] Figure 3 The PD circuit shown in Figure 2 includes a first PD array, a first trans-impedance amplifier, and a first bias generator. The first trans-impedance amplifier and the first PD array are the same as those shown in , and will not be repeated here. Only the first bias generator will be described in detail below.

[0112] Figure 3 As shown in , the first bias generator includes three ports. The upper port 1 is connected to a power supply for providing a direct current voltage. The port 2 is an input end of an alternating current signal, and the port 3 is an output end of the alternating current signal. The direct current voltage provided by the power supply enters the first PD array through the port 2, thereby providing a bias voltage v bias for the PD array unit.

[0113] It can be understood that the photo-generated current signal can enter through the port 2 and pass through the capacitor to be output from the port 3 to enter the first trans-impedance amplifier.

[0114] It should be understood that the photo-generated current signal can be a radio frequency signal, a high frequency signal, or a wideband signal, and the like, and the embodiments of the present application do not limit this.

[0115] Figure 3 The structure of the first bias generator shown is only an example and does not cause any limitation to the embodiments of the present application.

[0116] Based on the above embodiment, in the broadband PD array circuit, N PD array units are interconnected to form a PD array, which can increase the photosensitive area and reduce the alignment requirements; and, one port of the PD array remains open, eliminating the matching resistor, which can fully utilize the photocurrent in the PD array, avoid photocurrent loss, and improve the sensitivity of the receiver system; in addition, the equivalent impedance of each PD array unit is low impedance, for example, limited to Z less than 50Ω, which reduces the delay of the PD array unit and avoids the reduction of broadband signal bandwidth caused by delay misalignment, thereby helping to simplify the structure of the PD array circuit. In summary, the PD circuit proposed in the above embodiment can effectively expand the photosensitive area while reducing the complexity of the PD array circuit and improving the sensitivity of the receiver system.

[0117] Optionally, the PD circuit may further include a first equalizer.

[0118] See also Figure 4 , as an example, Figure 4 Another structural schematic diagram of the PD circuit provided in an embodiment of the present application is shown.

[0119] Figure 4 The PD circuit shown in FIG includes a first PD array, a first transimpedance amplifier, and a first equalizer. The first transimpedance amplifier and the first PD array are connected to Figure 2 The structures shown are the same and will not be described in detail. Only the first equalizer will be described in detail below.

[0120] like Figure 4 As shown, the first equalizer is used to receive a voltage signal from the first output port 122 of the first transresistor and perform compensation processing on the voltage signal.

[0121] The compensation process refers to compensating the high-frequency portion of the voltage signal, thereby reducing the impact of different time delay differences of multiple photocurrent signals generated by multiple PD array units on bandwidth performance.

[0122] Based on this solution, the impact of the transmission delay of the current signal output by each PD array unit in the PD array circuit on the bandwidth performance can be reduced, thereby improving the performance of the receiver system.

[0123] It is understandable that the above Figure 4 In the PD circuit shown in FIG, the first transimpedance amplifier can provide a bias voltage. Optionally, the PD circuit may further include a first polarizer, and the bias voltage is provided by the first polarizer. The first transimpedance amplifier may or may not have the function of providing a bias voltage, and this embodiment of the application is not limited to this.

[0124] In summary, the above embodiments provide a PD circuit, which improves the sensitivity of the receiver system through the design of the open port, reduces the time delay difference introduced when the light spot irradiates multiple PD array units through the low impedance design, realizes the simplification of the structure, and guarantees the communication bandwidth.

[0125] On the basis of the above embodiments, in order to provide better broadband performance, the following design of the PD circuit is provided.

[0126] Referring to Figure 5 , as an example, Figure 5 another structural schematic diagram of the PD circuit provided by the embodiments of the present application is shown.

[0127] As Figure 5 shown, the PD circuit includes a first PD array.

[0128] The first PD array includes a first port and a second port, the second port is connected with a first transimpedance amplifier, and the first port is connected with a second transimpedance amplifier.

[0129] Among them, the specific structure of the first PD array structure, the first transimpedance amplifier and the second transimpedance amplifier can refer to the description in the foregoing Figure 2 , and will not be repeated here.

[0130] In this embodiment, the current output by the first PD array is divided into two parts: a first current signal and a second current signal, the first current signal is amplified by the first transimpedance amplifier to obtain a first voltage signal, and the second current signal is amplified by the second transimpedance amplifier to obtain a second voltage signal, and the first voltage signal and the second voltage signal are combined by a combiner to output a third voltage signal.

[0131] As Figure 5 shown, the first PD array includes a first port 111 and a second port 112, wherein the first port 111 is connected with a second transimpedance amplifier, and the second port 112 is connected with a first transimpedance amplifier.

[0132] The first transimpedance amplifier includes a first input port 121 and a first output port 122, and the first transimpedance amplifier receives a first current signal from the first input port 121 and converts it into a first voltage signal, and outputs the first voltage signal from the first output port 122.

[0133] The second transimpedance amplifier includes a second input port 131 and a second output port 132, and the second transimpedance amplifier receives a second current signal from the first input port 131 and converts it into a second voltage signal, and outputs the second voltage signal from the second output port 132.

[0134] The first voltage signal and the second voltage signal enter the first combiner, and a third voltage signal is output after the first combiner combines the first voltage signal and the second voltage signal.

[0135] In the PD circuit provided in the embodiment, the photo-generated current signal generated by the PD array unit can be amplified by the first transimpedance amplifier and the second transimpedance amplifier, ensuring that the photo-generated current signal has no reflection and improving the bandwidth performance.

[0136] In a possible implementation, the first transimpedance amplifier or the second transimpedance amplifier is further configured to provide the bias voltage.

[0137] It can be understood that the first transimpedance amplifier and / or the second transimpedance amplifier can be integrated internally to provide the function of providing the bias voltage for the PD array unit. An independent biasing device is not required to provide the bias voltage, and the complexity of the PD circuit is reduced.

[0138] In another possible implementation, the PD circuit further includes a first biasing device, configured to provide the bias voltage.

[0139] The first biasing device can refer to the foregoing description and will not be described herein again.

[0140] The deployment of the first biasing device can refer to the foregoing description Figure 3 and will not be described herein again.

[0141] It should be noted that the first biasing device can be deployed at the second port of the first PD array, as shown in Figure 3 The first biasing device can also be deployed at the first port of the first PD array, that is, the first biasing device provides the bias voltage to the PD array unit through the first port. The embodiments of the present application do not limit this.

[0142] It can be understood that when the first biasing device is deployed at the first port of the first PD array, the capacitance of the first biasing device should be arranged on the side of the second input port 131, so that the direct current voltage generated by the power supply can enter the first PD array, and the photo-generated current signal can enter the second transimpedance amplifier.

[0143] Based on the above embodiment, in the broadband PD array circuit, the N PD array units are connected with each other to form a PD array, so that the light receiving area can be increased and the alignment requirement can be reduced. In addition, the two ports of the PD array are connected with the two trans-impedance amplifiers respectively, and the voltage signals output by the two trans-impedance amplifiers are combined and output, so that the photo-generated current in the PD array can be fully utilized, the loss of the photo-generated current can be avoided, the sensitivity of the receiver system can be improved, and the system bandwidth can be further improved. In addition, the equivalent impedance of each PD array unit is low impedance, for example, limited to less than 50Ω, so that the time delay of the PD array unit can be reduced, the reduction of the broadband signal bandwidth caused by the misalignment of the time delay can be avoided, and the structure of the PD array circuit can be simplified. In summary, the PD circuit provided in the above embodiment can effectively increase the light receiving area, reduce the complexity of the PD array circuit, improve the sensitivity of the receiver system, and improve the system bandwidth.

[0144] Optionally, the PD circuit can further include a first equalizer.

[0145] Referring to Figure 6 , as an example, Figure 6 another structure of the PD circuit provided in the embodiment of the present application is shown.

[0146] Figure 6 The PD circuit shown in the above embodiment includes a first PD array, a first trans-impedance amplifier, a second trans-impedance amplifier, a first equalizer, and a second equalizer. The structures of the first PD array, the first trans-impedance amplifier, the second trans-impedance amplifier, the first equalizer, and the second equalizer can be referred to the description of the structures shown in Figure 2 , and will not be described herein again.

[0147] As shown in Figure 6 , the first equalizer is configured to receive the first voltage signal from the first output port 122 of the first trans-impedance amplifier, compensate the first voltage signal, and input the compensated voltage signal into the first combiner.

[0148] The second equalizer is configured to receive the second voltage signal from the second output port 132 of the second trans-impedance amplifier, compensate the second voltage signal, and input the compensated voltage signal into the first combiner.

[0149] The first combiner combines the two compensated voltage signals and outputs a fourth voltage signal.

[0150] The compensation process can be referred to the description in the foregoing description, and will not be described herein again.

[0151] Based on the above scheme, the influence of the transmission time delay of the current signals output by the PD array units in the PD array circuit on the bandwidth performance can be reduced, and the performance of the receiver system can be improved.

[0152] It can be understood that the aboveFigure 6 In the PD circuit shown in the above embodiment, the first transimpedance amplifier or the second transimpedance amplifier can provide the bias voltage. Alternatively, the PD circuit can further include a first polarizer, and the bias voltage is provided by the first polarizer. The first transimpedance amplifier or the second transimpedance amplifier can have the function of providing the bias voltage, or can not have the function of providing the bias voltage, which is not limited in the embodiments of the present application.

[0153] In summary, the above embodiment provides a PD circuit, which fully utilizes the photo-generated current signal through the design of two TIAs, further improves the sensitivity and bandwidth of the receiver system, and offsets the time delay difference of multiple PD array units through the low-impedance design, thereby facilitating the simplification of the structure of the PD array circuit.

[0154] Based on the above PD circuit, the embodiments of the present application further provide an optical wireless communication receiving system.

[0155] The system includes a lens and a first PD circuit. The first PD circuit includes N PD array units.

[0156] The lens is configured to receive an incident light signal. The incident light signal is converged on some or all of the PD array units in the first PD circuit through the lens, and forms a light spot on some or all of the PD array units.

[0157] For example, the lens can be a condenser lens, an imaging lens, a Fresnel lens, a metasurface lens, a condenser metasurface lens, a convex lens, a fisheye lens, a lens group, etc., which is not limited in the embodiments of the present application.

[0158] The first PD circuit can be any one of the PD circuits provided in the above embodiments. For example, the first PD circuit can be any one of the PD circuits shown in the above embodiments. The description of the first PD circuit can refer to the description of the above embodiments, which is not described herein. Figures 2 to 6

[0159] In the present application, the PD array unit covered by the light spot can be one or multiple.

[0160] It should be understood that the light spot covers the PD array unit, which actually means that the light spot irradiates the PD photosensitive area in the PD array unit, or in other words, the light spot irradiates (or covers) the complete photosensitive area of a PD, or in other words, the light spot irradiates (or covers) part of the photosensitive area in a PD. The embodiments of the present application are not limited in this regard.

[0161] In one possible line of sight, the N array units in the first PD circuit are connected in a non-linear connection manner.

[0162] ​The nonlinear connection mode can be understood as that the N PD array units are distributed or wired in a nonlinear manner, for example, the N PD array units are wired in at least one polygonal (for example, rectangular, triangular) shape, for another example, the N PD array units are wired in at least one circular shape. It should be understood that the polygon and the circle here are both open shapes, and it can be understood that the first PD array unit and the last PD array unit are connected to two ports of the first PD array respectively.

[0163] In a possible implementation, the number of the PD array units receiving the light spot irradiation is less than or equal to 4.

[0164] It should be understood that the less the PD array units irradiated by one light spot, the more concentrated the light spot energy is.

[0165] It should be noted that the less the number of the PD array units irradiated by one light spot, the smaller the time delay difference between the photoelectric current signals generated by the PD array units, so that the bandwidth and other performances can be kept consistent when the light spot moves.

[0166] It should be understood that when the light spot irradiates one PD array unit, the equalizer in the PD circuit can be replaced by an adjustable time delay device.

[0167] In a possible implementation, the N array units in the first PD circuit are connected in at least two "rectangular" or at least two "triangular" shapes. Alternatively, it can also be referred to as "serpentine" connection.

[0168] Referring to Figure 7 , for example, Figure 7 a structure diagram of an optical OWC receiving system is shown.

[0169] As Figure 7 shown, the OWC receiving system includes a lens and a first array circuit, wherein Figure 7 the first array circuit in Figure 6 the array circuit shown.

[0170] The first array circuit includes a first PD array including N PD array units.

[0171] As Figure 7 shown, for example, N is equal to 8.

[0172] The wiring mode of the 8 PD array units can include a plurality of modes, for example Figure 7 the 3 "rectangular" wiring modes shown in

[0173] It can be understood that in this case, the same light spot irradiates any consecutive n PD array units when the light spot moves in the PD circuit, and the time delay difference between the photo-generated current signals generated by the n PD array units is the same, that is, the time delay difference is constant when the light spot moves within a certain range, thereby ensuring consistent bandwidth performance.

[0174] The 8 PD array units can also be arranged in a "triangle", "circle", or the like. The embodiments of the present application do not limit this.

[0175] The wiring manner refers to the arrangement manner of the N PD array units in the first PD array, and can also be understood as the distribution manner of the N PDs.

[0176] In the present application, in order to expand the photosensitive area of the PD array, not only the number of PD array units can be increased, but also at least two optical wireless communication receiving systems in the above embodiments can be combined and spliced, or at least two PD circuits can be spliced.

[0177] In the following embodiments, the combination of two optical wireless communication receiving systems is taken as an example for description.

[0178] In a possible implementation, the optical wireless communication system includes a lens, a first PD circuit, and a second PD circuit.

[0179] The description of the lens can refer to the description in the foregoing embodiments and will not be repeated.

[0180] The first PD circuit and the second PD circuit can be the PD circuits provided in the above embodiments. For example, the first PD circuit can be any one of the PD circuits shown in Figures 2 to 6 The description of the first PD circuit and the second PD circuit can refer to the description in the above embodiments and will not be repeated.

[0181] Referring to Figure 8 , as an example, Figure 8 a structure schematic diagram of another OWC receiving system provided in an embodiment of the present application is shown.

[0182] As shown in Figure 8 , the OWC receiving system includes a first PD circuit and a second PD circuit.

[0183] In a possible implementation, the OWC receiving system further includes a lens.

[0184] The voltage signal output by the first PD circuit is input to the third combiner through the first combiner, the voltage signal output by the second PD circuit is input to the third combiner through the second combiner, and the combined voltage signal is output after being combined by the third combiner.

[0185] It should be understood that the first PD circuit and the second PD circuit can each include an equalizer, for example, the first equalizer and the second equalizer shown in the figure. The specific description can refer to Figure 8 , and will not be described here. Figure 6

[0186] It should be understood that the voltage signal output by the first PD circuit and the voltage signal output by the second PD circuit are superimposed and output, which is equivalent to the superposition of the light receiving areas of the first PD circuit and the second PD circuit, so that the array size and the light receiving area can be further improved.

[0187] It should be understood that the first PD circuit and the second PD circuit in Figure 8 are taken as examples, and any PD circuit shown in Figure 6 may also be used for splicing, and the embodiments of the present application are not limited thereto. Figures 2 to 5

[0188] It can be understood that the first PD circuit and the second PD circuit in Figure 8 may include a plurality of wiring modes, for example, the plurality of "rectangular" wiring modes shown in the figure, or the plurality of "triangular" wiring modes, and the embodiments of the present application are not limited thereto. Figure 7

[0189] Referring to Figure 9 , as an example, Figure 9 shows a structure schematic diagram of another OWC receiving system provided by the embodiments of the present application.

[0190] As shown in the figure, the OWC receiving system includes a first PD circuit and a second PD circuit. Figure 9

[0191] In a possible implementation, the OWC receiving system further includes a lens.

[0192] Among them, the first PD circuit and the second PD circuit realize the combination of the two PD circuits through two differential mode transimpedance amplifiers.

[0193] Among them, the voltage signal output by the first PD circuit is output through a first combiner, and the voltage signal output by the second PD circuit is output through a second combiner.

[0194] It should be understood that the first PD circuit and the second PD circuit can each include an equalizer, for example, the first equalizer and the second equalizer shown in the figure. The specific description can refer to Figure 6 , and will not be described here.

[0195] It should be understood that the bias voltage in the first PD circuit and the bias voltage in the second PD circuit are opposite. For example, Figure 9 ​​​​Bias tees shown in FIG. 1.

[0196] It should be understood that the voltage signals output by the first PD circuit and the voltage signals output by the second PD circuit are in differential mode, which is different from Figure 8 The OWC receiving system shown in FIG. 1 has higher TIA integration, so that the array size and light receiving area can be further improved.

[0197] It should be understood that Figure 9 The first PD circuit and the second PD circuit in FIG. 1 can be connected in Figure 6 The PD circuit shown in FIG. 1 can also be spliced using any PD circuit shown in FIG. 1, and the embodiments of the present application do not limit this. Figures 2 to 5 The PD circuit shown in FIG. 1 can also be spliced using any PD circuit shown in FIG. 1, and the embodiments of the present application do not limit this.

[0198] It can be understood that Figure 9 In the first PD circuit and the second PD circuit in FIG. 1, the wiring mode of the PD array unit can include multiple modes, for example, Figure 7 The wiring mode of the multiple "rectangles" shown in FIG. 1 can also be the wiring mode of the multiple "triangles", and the embodiments of the present application do not limit this.

[0199] The present application also provides a signal processing method, which is applied to an optical receiver.

[0200] The optical receiver includes a first PD array. The first PD array can refer to any PD array shown in the foregoing, and will not be repeated here.

[0201] In one possible implementation, the first PD array includes a first port and a second port, the second port is connected with the first transimpedance amplifier, the first port is in an open circuit state, the optical receiver generates a current signal through part or all of the PD array units, and the first PD array causes all the current signals generated by the part or all of the PD array units to enter the first transimpedance amplifier; and the optical receiver converts all the current signals into voltage signals through the first transimpedance amplifier.

[0202] It can be understood that the above-mentioned PD circuit can be any one of Figures 2-4 In the above-mentioned PD circuit, the photo-generated current signals generated by the PD array units all enter the first transimpedance amplifier for amplification and output, so that the current loss caused by the matching resistor is avoided, and the sensitivity of the optical receiver is improved.

[0203] In another possible implementation, the first PD array includes a first port and a second port, the second port is connected with the first trans-impedance amplifier, and the first port is connected with the second trans-impedance amplifier. The optical receiver generates a current signal through part or all of the PD array units. The first PD array causes a first current signal to enter the first trans-impedance amplifier, and the first PD array causes a second current signal to enter the second trans-impedance amplifier. The sum of the first current signal and the second current signal is the total current signal generated by the part or all of the PD array units. The optical receiver converts the total current signal into a voltage signal through the first trans-impedance amplifier and the second trans-impedance amplifier.

[0204] It can be understood that the above PD circuit can be Figure 5 or Figure 6 The PD circuit shown in the figure is that part of the photo-generated current signal generated by the PD array unit enters the first trans-impedance amplifier for amplification and output, and part of the photo-generated current signal enters the second trans-impedance amplifier for amplification and output. Therefore, the current loss caused by the matching resistor is avoided, and the sensitivity of the optical receiver is improved.

[0205] Based on the above technical solutions, in the embodiments of the present application, the array structure is used to improve the wideband PD photosensitive surface, expand the photosensitive surface of the OWC receiver, and reduce the alignment requirement. A low-impedance network is designed to reduce the array structure delay, reduce the wideband signal bandwidth caused by the misalignment of the delay, and make the circuit structure simple. The matching load resistor is replaced by an open circuit design or a TIA to fully utilize the current in the PD array and improve the sensitivity of the receiver system. In addition, the splicing and merging of multiple PD circuits can further improve the PD photosensitive area.

[0206] Those skilled in the art can understand that the units and algorithm steps of the examples described in combination with the embodiments disclosed herein can be realized by electronic hardware or a combination of computer software and electronic hardware. Whether the functions are realized in hardware or software depends on the specific application and design constraints of the technical solutions. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the present application.

[0207] Those skilled in the art can clearly understand that, for the convenience and brevity of description, the specific working process of the system, device and unit described above can refer to the corresponding process in the foregoing method embodiments, which will not be described here.

[0208] In several embodiments provided in the present application, it should be understood that the disclosed system, device and method can be implemented in other manners. For example, the described device embodiments are merely schematic. The division of the units is merely logical function division. There can be other division manners in actual implementation. For example, a plurality of units or components can be combined or integrated into another system, or some features can be ignored or not executed. In addition, the displayed or discussed mutual couplings or direct couplings or communication connections can be indirect couplings or communication connections through some interfaces, devices or units, and can be in electrical, mechanical or other forms.

[0209] The units described as separate components can or can not be physically separate, and the components shown as units can or can not be physical units, i.e., can be located in one place, or can be distributed on a plurality of network units. Some or all of the units can be selected according to actual needs to achieve the purpose of the embodiment.

[0210] In addition, each functional unit in the various embodiments of the present application can be integrated into a processing unit, or each unit can be a physically separate unit, or two or more units can be integrated into one unit.

[0211] If the functions are realized in the form of software function units and sold or used as independent products, they can be stored in a computer readable storage medium. Based on this understanding, the technical solutions of the present application can be embodied in the form of a software product, and the computer software product is stored in a storage medium, and includes a number of instructions for causing a computer device (which can be a personal computer, a server, or a network device, etc.) to execute all or part of the steps of the methods described in the various embodiments of the present application. The aforementioned storage medium includes: a U disk, a mobile hard disk, a read-only memory (ROM), a random access memory (RAM), a magnetic disk or an optical disk, and various media that can store program codes.

[0212] The above description is merely a specific implementation of the present application, but the protection scope of the present application is not limited thereto. Any person skilled in the art can easily think of changes or replacements within the technical scope disclosed in the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. A photodiode (PD) circuit, characterized by comprising: The PD circuit comprises: a first PD array, the first PD array comprises a first port and a second port, the second port is connected with a first trans-impedance amplifier, and the first port is in an open circuit state, or the first port is connected with a second trans-impedance amplifier.

2. The PD circuit of claim 1, wherein, The first PD array comprises N PD array units, and an equivalent impedance Z of each PD array unit is less than 50 Ω, where N is a positive integer greater than or equal to 2.

3. The PD circuit of claim 2, wherein, Each PD array unit is configured to receive an optical signal and convert the optical signal into a current signal, and when the first port is in the open circuit state, the first trans-impedance amplifier comprises a first input port and a first output port, the second port is connected with the first input port, the first trans-impedance amplifier is configured to receive the current signal from the first input port, convert the current signal into a voltage signal, and output the voltage signal from the first output port.

4. The PD circuit according to claim 2, wherein each PD array unit is configured to receive an optical signal and convert the optical signal into a current signal, and when the first port is connected with the second trans-impedance amplifier, The first transimpedance amplifier includes a first input port and a first output port, the second port is connected with the first input port, the first transimpedance amplifier is used for receiving a first current signal from the first input port, converting the first current signal into a first voltage signal, and outputting the first voltage signal from the first output port, wherein, the first current signal is a part of the current signal; the second trans-impedance amplifier comprises a second input port and a second output port, the first port is connected with the second input port, the second trans-impedance amplifier is configured to receive a second current signal from the second input port, convert the second current signal into a second voltage signal, and output the second voltage signal from the second output port, where the second current signal is a part of the current signal; wherein the first voltage signal and the second voltage signal are combined into a third voltage signal through a first combiner.

5. The PD circuit of any one of claims 1-4, wherein, The first trans-impedance amplifier or the second trans-impedance amplifier is further configured to provide a bias voltage to the first PD array.

6. The PD circuit of any one of claims 1-4, wherein, The PD circuit further comprises a first biaser configured to provide a bias voltage to the first PD array.

7. The PD circuit according to any one of claims 1-6, wherein when the first port is in the open circuit state, the PD circuit further comprises a first equalizer, the first equalizer is configured to receive the voltage signal from the first output port, and perform compensation processing on the voltage signal, the compensation processing being configured to compensate a high-frequency part of the voltage signal; when the first port is connected with the second trans-impedance amplifier, the PD circuit further comprises a first equalizer and / or a second equalizer, the first equalizer is configured to receive the first voltage signal from the first output port, perform compensation processing on the first voltage signal, the compensation processing being configured to compensate a high-frequency part of the first voltage signal, and input the compensated first voltage signal into the first combiner; the second equalizer is configured to receive the second voltage signal from the second output port, perform compensation processing on the second voltage signal, the compensation processing being configured to compensate a high-frequency part of the second voltage signal, and input the compensated second voltage signal into the first combiner.

8. The PD circuit of any one of claims 1-7, wherein, The equivalent impedance Z of each PD array unit is greater than or equal to 10Ω and less than or equal to 30Ω.

9. An optical wireless communication receiving system, characterized by Comprise: a lens and a first PD circuit, the first PD circuit is the PD circuit in any one of claims 1-8, the lens is used for receiving an incident light signal, the incident light signal through the lens converges on at least one PD array unit of the first PD circuit to form a light spot, and the light spot is used for the PD array unit to obtain a light signal, wherein the N PD array units of the first PD circuit are connected in at least two "rectangular" or at least two "triangular" connection modes.

10. An optical wireless communication receiving system, characterized by Comprise: a first PD circuit and a second PD circuit, the first PD circuit and the second PD circuit are the PD circuit in any one of claims 1-8, the voltage signal output by the first PD circuit and the voltage signal output by the second PD circuit output a combined voltage signal through a third combiner.

11. An optical wireless communication receiving system, characterized by Comprise: a first PD circuit and a second PD circuit, the first PD circuit and the second PD circuit are the PD circuit in any one of claims 1-8, wherein the transimpedance amplifiers in the first PD circuit and the second PD circuit are in differential mode, and the voltage signal output by the first PD circuit and the voltage signal output by the second PD circuit are respectively differentially output.

12. A signal processing method characterized by, The method is applied to an optical receiver, and the optical receiver comprises a first PD array, wherein the first PD array comprises a first port and a second port, the second port is connected with a first transimpedance amplifier, the first port is in an open circuit state, the first PD array further comprises N PD array units, and the method comprises: The optical receiver generates a current signal through the part or all of the PD array units, and the first PD array causes all the current signals generated by the part or all of the PD array units to enter the first transimpedance amplifier. The optical receiver converts the all current signals into a voltage signal through the first transimpedance amplifier.

13. A signal processing method, characterized by, The method is applied to an optical receiver, and the optical receiver comprises a first PD array, wherein the first PD array comprises a first port and a second port, the second port is connected with a first transimpedance amplifier, the first port is connected with a second transimpedance amplifier, the first PD array further comprises N PD array units, and the method comprises: The optical receiver generates a current signal through the part or all of the PD array units, and the first PD array causes a first current signal to enter the first transimpedance amplifier, and causes a second current signal to enter the second transimpedance amplifier, wherein the sum of the first current signal and the second current signal is all the current signals generated by the part or all of the PD array units. The optical receiver converts the all current signals into a voltage signal through the first transimpedance amplifier and the second transimpedance amplifier.

14. A computer-readable storage medium, characterized in that, The computer program or instructions are stored on a computer-readable storage medium, and when the computer program or instructions run on a communication device, the communication device executes the method as claimed in claim 12 or 13.

15. A computer program product, characterised in that, The computer program product comprises computer programs or instructions for executing the method as claimed in claim 12 or 13.

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