A shipboard communication device

Abstract

This invention discloses a shipborne communication device, comprising: an omnidirectional antenna; a customer premises equipment (CPE) for communicating with a coastal base station via the omnidirectional antenna, and a user terminal communicating with the CPE; wherein the coastal base station is a base station installed on the coast, and the user terminal is a terminal device located in the nearshore waters of the coast; a radio frequency transmission link connected between the omnidirectional antenna and the CPE; the radio frequency transmission link includes a final stage power amplifier and a distortion adjuster; the final stage power amplifier is connected to the omnidirectional antenna; the distortion adjuster is used to adjust at least one of the input signal corresponding to the final stage power amplifier and the power supply voltage of the final stage power amplifier, so that the final stage power amplifier linearly amplifies the input signal.

Description

Technical Field

[0001] This invention relates to the field of communication technology, and in particular to a shipborne communication device. Background Technology

[0002] In recent years, the construction of new information infrastructure at sea in my country has been in full swing. With the advent of the 5G era, the marine economy is ushering in new opportunities for large-scale development. Basic telecommunications companies are accelerating 5G coverage in distant waters, extending 5G capabilities to the ocean and integrating it into the construction of "smart oceans." N41 (B41), as the main frequency band promoted by major operators, will become increasingly important in future near-shore deployments.

[0003] Traditional maritime communication mainly falls into two categories: one relies on satellite transmission, which requires specialized equipment and is extremely expensive, making it difficult to support the needs of ordinary customers; the other relies on the existing 4G network coverage along the coast, but the coverage distance is short and cannot meet the needs of maritime customers. Currently, a relatively innovative solution is to use B28+B41 coastal base stations for ultra-long-range coverage combined with ferry cabin repeaters to enhance coverage. However, because repeaters use omnidirectional antennas, their radiation efficiency is low, and their large size makes them inconvenient to install; furthermore, repeaters amplify wireless information, requiring the user terminal to have a 5G module, which places high demands on user equipment, and in situations with many ships, they are prone to self-oscillation, severely affecting the internet experience. Summary of the Invention

[0004] This invention provides a shipborne communication device to solve the aforementioned technical problems existing in the prior art.

[0005] In a first aspect, to solve the above-mentioned technical problems, embodiments of the present invention provide a shipborne communication device, comprising:

[0006] Omnidirectional antenna;

[0007] A customer premises equipment (CPE) is used to communicate with a coastal base station via the omnidirectional antenna, and a user terminal communicates with the CPE; wherein, the coastal base station is a base station installed on the coast, and the user terminal is a terminal device located in the near-shore waters of the coast.

[0008] A radio frequency transmission link is connected between the omnidirectional antenna and the CPE; the radio frequency transmission link includes a final stage power amplifier and a distortion adjuster; the final stage power amplifier is connected to the omnidirectional antenna;

[0009] The distortion adjuster is used to adjust at least one of the input signal corresponding to the final stage power amplifier and the power supply voltage of the final stage power amplifier, so that the final stage power amplifier linearly amplifies the input signal.

[0010] In one possible implementation, the radio frequency transmission link further includes a first coupler connected between the final stage power amplifier and the omnidirectional antenna;

[0011] The distortion adjuster is a digital predistorter. The output of the digital predistorter is connected to the input of the final stage power amplifier. One input of the digital predistorter is used to receive the input signal, and the other input of the digital predistorter is connected to one output of the first coupler.

[0012] The digital predistorter is used to measure the output signal of the final stage power amplifier in real time, compare the output signal with the input signal, determine the nonlinear characteristics of the final stage power amplifier, and generate and output a compensation signal corresponding to the nonlinear characteristics. The compensation signal is superimposed on the input signal to become the predistortion signal. The predistortion signal cancels the nonlinear characteristics of the final stage power amplifier, so that the final stage power amplifier can linearly amplify the input signal even when it is operating in the nonlinear region.

[0013] In one possible implementation, the radio frequency transmission link further includes a first coupler, the input of which is used to receive the input signal, and one output of which is connected to the final stage power amplifier.

[0014] The distortion adjuster is an envelope tracker. The input terminal of the envelope tracker is connected to the other output terminal of the first coupler, and the output terminal of the envelope tracker is connected to the power supply terminal of the final stage power amplifier. The envelope tracker is used to detect the envelope of the input signal in real time and adjust the power supply voltage provided to the final stage power amplifier in real time according to the envelope of the input signal, so that the final stage power amplifier operates in the linear region.

[0015] In one possible implementation, the radio frequency transmission link further includes a first coupler connected between the final stage power amplifier and the omnidirectional antenna;

[0016] The distortion adjuster is an enhanced adaptive power amplifier. One input terminal of the enhanced adaptive power amplifier is used to receive the input signal. The other input terminal of the enhanced adaptive power amplifier is connected to one output terminal of the first coupler. One output terminal of the enhanced adaptive power amplifier is connected to the input terminal of the final stage power amplifier. The other output terminal of the enhanced adaptive power amplifier is connected to the power supply terminal of the final stage power amplifier.

[0017] The enhanced adaptive power amplifier is used to measure the output signal of the final stage power amplifier in real time, compare the output signal with the input signal, determine the nonlinear characteristics of the final stage power amplifier, and generate and output a compensation signal corresponding to the nonlinear characteristics. Simultaneously, it adjusts the power supply voltage supplied to the final stage power amplifier in real time according to the envelope of the input signal, so that the final stage power amplifier operates in the linear region. The compensation signal is superimposed on the input signal to form a predistortion signal, which cancels the nonlinear characteristics of the final stage power amplifier, enabling the final stage power amplifier to linearly amplify the input signal even when operating in the nonlinear region.

[0018] One possible implementation of the enhanced adaptive power amplifier includes:

[0019] A second coupler, the input terminal of which is used to receive the input signal;

[0020] An adaptive module, one input terminal of which is connected to the first output terminal of the second coupler, and the other input terminal of which is connected to one output terminal of the first coupler; the adaptive module is used to compare the difference between the input signal and the output signal.

[0021] A predistorter, one input of which is connected to the second output of the second coupler, the other input of which is connected to the other output of the adaptive module, and the output of which is connected to the final stage power amplifier; the predistorter is used to determine the nonlinear characteristics of the final stage power amplifier based on the difference, and to generate and output the compensation signal;

[0022] An envelope detector is provided, with its input terminal connected to the third output terminal of the second coupler and its output terminal connected to the power supply terminal of the final stage power amplifier. The envelope tracker is used to detect the envelope of the input signal in real time and adjust the power supply voltage provided to the final stage power amplifier in real time according to the envelope of the input signal, so that the final stage power amplifier operates in the linear region.

[0023] One possible implementation of the envelope tracker includes:

[0024] The serially connected analog-to-digital converter module, envelope detection module, envelope shaping module, and envelope tracking power supply;

[0025] The analog-to-digital converter circuit is used to acquire the input signal and convert it into the corresponding baseband signal;

[0026] The envelope detection module is used to detect the amplitude of the baseband signal and extract the envelope signal that characterizes the instantaneous power level of the baseband signal.

[0027] The envelope shaping module is used to shape the envelope signal so that the shaped envelope signal meets the input requirements of the envelope tracking power supply.

[0028] The envelope tracking power supply is used to generate a power supply voltage that varies with the shaped envelope signal and is provided to the final stage power amplifier.

[0029] One possible implementation of the omnidirectional antenna includes:

[0030] A first omnidirectional antenna and a second omnidirectional antenna, wherein the first omnidirectional antenna is a horizontally polarized antenna in the low-frequency band and the second omnidirectional antenna is a vertically polarized antenna in the low-frequency band;

[0031] A third omnidirectional antenna and a fourth omnidirectional antenna, wherein the third omnidirectional antenna is a horizontally polarized antenna in the high-frequency band, and the fourth antenna is a vertically polarized antenna in the high-frequency band; wherein the low-frequency band communicates based on time-division duplex, and the high-frequency band communicates based on frequency-division duplex;

[0032] Each of the first omnidirectional antenna, the second omnidirectional antenna, the third omnidirectional antenna, and the fourth omnidirectional antenna corresponds to a radio frequency transmission link; the first omnidirectional antenna and the second omnidirectional antenna share one of the distortion adjusters, and the third omnidirectional antenna and the fourth omnidirectional antenna share another distortion adjuster.

[0033] In one possible implementation, the low-frequency band is the N41 band, and the high-frequency band is the N28 band;

[0034] The maximum transmit power of the final stage power amplifier is 43dBm.

[0035] In one possible implementation, the shipborne communication device further includes:

[0036] The connector has a common end connected to the omnidirectional antenna and a first end connected to the radio frequency transmission link; the connector also includes a second end for connecting either the first end or the second end of the connector to the common end of the connector.

[0037] The radio frequency receiving link is connected between the CPE and the second end of the connector.

[0038] In one possible implementation, the omnidirectional antenna corresponds to a time-division duplex communication mode, and the connector is a switch;

[0039] The omnidirectional antenna corresponds to the frequency division duplex communication mode, and the connector is a coupler. Attached Figure Description

[0040] Figure 1 This is a schematic diagram of the structure of a shipborne communication device;

[0041] Figure 2 This is a schematic diagram of the radio frequency link corresponding to the N28 band;

[0042] Figure 3 This is a schematic diagram of the radio frequency link corresponding to the N41 band;

[0043] Figure 4 This is a schematic diagram of the structure of a shipborne communication device provided in an embodiment of the present invention;

[0044] Figure 5 This is a schematic diagram of another shipborne communication device provided in an embodiment of the present invention;

[0045] Figure 6 This is a schematic diagram illustrating the linearization of a power amplifier.

[0046] Figure 7 This is a schematic diagram of the structure of a digital predistorter provided in an embodiment of the present invention;

[0047] Figure 8 This is a schematic diagram of another shipborne communication device provided in an embodiment of the present invention;

[0048] Figure 9 This is a schematic diagram of the structure of an envelope tracker provided in an embodiment of the present invention;

[0049] Figure 10 This is a schematic diagram of another shipborne communication device provided in an embodiment of the present invention;

[0050] Figure 11 This is a schematic diagram of an enhanced adaptive power amplifier provided in an embodiment of the present invention;

[0051] Figure 12 This is a schematic diagram of another shipborne communication device provided in an embodiment of the present invention;

[0052] Figures 13-15 This is a schematic diagram of the architecture of a shipborne communication device provided in an embodiment of the present invention.

[0053] Figure label:

[0054] 1. Omnidirectional antenna, 2. CPE, 3. RF transmission link, 31. Final stage power amplifier, 32. Distortion adjuster, 33. First coupler, 32a. Analog-to-digital conversion module, 32b. Envelope detection module, 32c. Envelope shaping module, 32d. Envelope tracking power supply, 34. Filter, 321. Second coupler, 322. Adaptive module, 323. Predistorter, 4. Connector, 5. RF receiving link. Detailed Implementation

[0055] This invention provides a shipborne communication device to solve the aforementioned problems existing in the prior art.

[0056] It should be understood that the specific structural and functional details disclosed in the embodiments of the present invention are merely representative and are intended to describe exemplary embodiments of this application. However, this application can be implemented in many alternative or combined forms and should not be construed as being limited solely to the embodiments set forth herein.

[0057] In the description of this application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this application, unless otherwise stated, "multiple" means two or more. Furthermore, the term "comprising" and any variations thereof are intended to cover non-exclusive inclusion.

[0058] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0059] The terminology used in this application is for the purpose of describing particular embodiments only and is not intended to limit exemplary embodiments. Unless the context clearly indicates otherwise, the singular forms “a” and “an” as used herein are also intended to include the plural. It should also be understood that the terms “comprising” and / or “including” as used herein specify the presence of the stated features, integers, steps, operations, units, and / or components, without excluding the presence or addition of one or more other features, integers, steps, operations, units, components, and / or combinations thereof.

[0060] To make the above-mentioned objects, features, and advantages of the present invention more apparent and understandable, the present invention will be further described below in conjunction with the accompanying drawings and embodiments. However, the exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided to make the present invention more comprehensive and complete, and to fully convey the concept of the exemplary embodiments to those skilled in the art. The same reference numerals in the figures denote the same or similar structures, and therefore repeated descriptions of them will be omitted. Terms describing position and direction in the present invention are illustrative based on the accompanying drawings, but changes can be made as needed, and all such changes are included within the scope of protection of the present invention. The accompanying drawings of the present invention are for illustrative purposes only and do not represent actual proportions.

[0061] It should be noted that specific details are set forth in the following description to provide a full understanding of the invention. However, the invention can be practiced in many ways other than those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below. The following description is a preferred embodiment for carrying out the present application; however, the description is for the purpose of illustrating the general principles of the application and is not intended to limit the scope of the application. The scope of protection of this application shall be determined by the appended claims.

[0062] Please refer to Figure 1 This is a schematic diagram of the structure of a shipborne communication device, which includes:

[0063] Two antenna groups, each corresponding to two orthogonal polarization directions; each antenna group includes directional antenna 1 to directional antenna 6, each corresponding to a different sector area, and directional antenna 1 to directional antenna 6 together form an omnidirectional coverage area (i.e., a 360° coverage area); each antenna group corresponds to one radio frequency transmission link, each omnidirectional antenna corresponds to one radio frequency reception link, and every two radio frequency reception links form a pair (one is the main set, and the other is the diversity set) as a radio frequency reception path, thus forming 6 radio frequency reception paths;

[0064] The intelligent station tracking module is connected to directional antennas 1 to 6 in each antenna group. The intelligent station tracking module is used to detect the power corresponding to the main set in each radio frequency receiving path and use it as the received power of the corresponding radio frequency receiving path. The module selects the one with the largest received power from the 6 radio frequency receiving paths as the main signal path for signal transmission.

[0065] The 5G Customer Premise Equipment (CPE) connects to the smart base station tracking module. The 5G CPE connects to the largest RF receiving path selected by the smart base station tracking module. The 5G CPE converts the signals received from the base station through this connected RF receiving path into mobile hotspot (Wi-Fi) signals or wired signals. Simultaneously, it also transmits signals sent by the user terminal to the base station via an RF transmission connection. The user terminal can access the mobile network via Wi-Fi using the 5G CPE, or it can connect to a wireless router via a wired (Ethernet) connection, allowing the user terminal to access the mobile network through the wireless router.

[0066] Shipborne communication equipment can support a frequency band, such as the N28 or N41 band, or other frequency bands. Figure 1 The diagram shows a shipborne communication device supporting one frequency band. The device can also support multiple frequency bands; for example, it can simultaneously support both the N28 and N41 bands, in which case each band corresponds to one frequency band. Figure 1 The structure shown is sufficient.

[0067] Please refer to Figure 2 and Figure 3 , Figure 2 This is a schematic diagram of the radio frequency link corresponding to the N28 band. Figure 3 This is a schematic diagram of the radio frequency link corresponding to the N41 band.

[0068] The N28 band corresponds to RF links including 2 RF transmit links, 6 RF receive paths (consisting of 12 RF transmit links), and coupling links; among which, such as Figure 2 As shown, the RF transmission link includes: a fixed attenuator 2, a final stage amplifier, and directional antennas 1 to 6 share a single RF transmission link. One of the directional antennas is selected via switches 1 to 3. The RF reception link includes: a low-noise amplifier (LNA) 1, a bandpass filter, a coupler, a switch 4, and an LNA 2, where LNA 1 has a bypass function. The coupling link includes: a coupler, a switch 5, an LNA 3, a fixed attenuator 3, and a switch 6. The RF transmission and reception links share a fixed attenuator 1, a duplexer 1, and a duplexer connected to the directional antenna (e.g., ...). Figure 2 (The duplexer 2 is connected to the directional antenna 1).

[0069] The radio frequency links corresponding to the N41 band also include 2 radio frequency transmit links, 6 radio frequency receive paths (consisting of 12 radio frequency transmit links), and coupling links; among them, such as Figure 3As shown, the RF transmission link includes: a fixed attenuator 2, a reserved amplifier, a final stage amplifier, and a bandpass filter. Directional antennas 1 to 6 share a single RF transmission link, with one of the directional antennas selected via switches 1 to 3. The RF reception link includes: a surface acoustic wave (SAW) filter, LNA1, a coupler, switch 4, and LNA2, where LNA1 has a bypass function. The coupling link includes: a coupler, switch 5, LNA3, fixed attenuator 3, and switch 6. The RF transmission and reception links share a transmit / receive switch and a switch connected to the directional antenna (e.g., ...). Figure 3 Switch 7 is connected to directional antenna 1.

[0070] It should be noted that, Figure 2 and Figure 3 Only the directional antenna 1 corresponding to one node in switch 2, one node in switch 4, and one node in switch 5 is shown in the diagram. In reality... Figure 2 and Figure 3 The remaining five nodes of switches 2 and 3 that are not connected correspond to directional antennas 2 through 6, respectively. The remaining five nodes of switches 4 and 5 that are not connected are connected to the couplers in the RF receiving links corresponding to directional antennas 2 through 6, respectively. This is for ease of observation. Figure 2 The remaining directional antennas and their corresponding RF receiving links and coupling links are not shown, but they can be referenced. Figure 2 or Figure 3 The setup and connection methods of the RF receiving link and coupling link corresponding to the directional antenna 1 are not described here.

[0071] The biggest advantage of the shipborne communication device obtained by adopting the above scheme is that the communication performance is relatively good, but the cost is relatively high. The transmission power of the transmission link in the above communication device is 30dBm, and the actual transmission distance can reach 110KM, which can solve the problem of the short communication distance of the repeater station in the ferry cabin in the existing technology.

[0072] To address the issue of high cost in the aforementioned solutions, this invention provides further improvements. The following description, in conjunction with the accompanying drawings, details an embodiment of a shipborne communication device provided by this invention.

[0073] Please refer to Figure 4 This is a schematic diagram of a shipborne communication device provided in an embodiment of the present invention. The shipborne communication device includes:

[0074] Omnidirectional antenna 1; Omnidirectional antenna 1 is an antenna capable of achieving 360° signal coverage on a single plane. Omnidirectional antenna 1 can be a single-polarized omnidirectional antenna 1, such as a horizontally polarized omnidirectional antenna 1 or a vertically polarized omnidirectional antenna 1; Omnidirectional antenna 1 can also be a dual-polarized omnidirectional antenna 1, that is, capable of both horizontal and vertical polarization, without any specific restrictions. One frequency band can correspond to one horizontally polarized omnidirectional antenna 1 and one vertically polarized omnidirectional antenna 1, or one frequency band can correspond to one dual-polarized omnidirectional antenna 1.

[0075] Customer Premises Equipment (CPE2) communicates with the coastal base station via omnidirectional antenna 1, and with the user terminal via CPE2. The coastal base station is a base station installed on the coast, and the user terminal is a terminal device located in the nearshore waters. CPE2 acts as a baseband and transceiver, communicating with the coastal base station via omnidirectional antenna 1 and with the user terminal via Wi-Fi. CPE2 also provides a Local Area Network (LAN) interface, allowing the user terminal to connect to the CPE2 via a network cable and access the mobile network. Nearshore waters refer to the sea area within 100 km of the coastline.

[0076] The radio frequency transmission link 3 is connected between the omnidirectional antenna 1 and the CPE2; the radio frequency transmission link 3 includes a final stage power amplifier 31 and a distortion adjuster 32; the final stage power amplifier 31 is connected to the omnidirectional antenna 1;

[0077] The distortion adjuster 32 is used to adjust at least one of the input signal corresponding to the final stage power amplifier 31 and the power supply voltage of the final stage power amplifier 31, so that the final stage power amplifier 31 linearly amplifies the input signal.

[0078] It should be noted that, Figure 4 For radio frequency links employing Frequency Division Duplexing (FDD), radio frequency transmission link 3 also includes, for example, Figure 2 The fixed attenuator 2 is shown; for RF links employing Time Division Duplexing (TDD), the RF transmit link 3 also includes, as shown in the figure. Figure 3 The fixed attenuator 2, reserved amplifier, and bandpass filter are shown in the diagram.

[0079] In some embodiments, the maximum transmit power of the final stage power amplifier 31 is 43dBm, so that the omnidirectional antenna 1 can cover 100KM of near-sea area regardless of whether the N41 band or the N28 band is used.

[0080] In the embodiments provided by the present invention, since the omnidirectional antenna 1 is sampled, it is not necessary to set up multiple directional antennas to achieve omnidirectional signal coverage, thereby effectively reducing the number of antennas and the corresponding radio frequency receiving link 5, and also eliminating the need to set up an intelligent station tracking module, thus effectively reducing the cost of the shipborne communication device; and a distortion regulator is set up for the final stage power amplifier 31 in the radio frequency transmitting link 3, and the distortion regulator is used to adjust at least one of the input signal and the power supply voltage of the final stage power amplifier 31, so that the final stage power amplifier 31 linearly amplifies the input signal, thereby improving the power efficiency of the final stage power amplifier 31, and enabling the omnidirectional antenna 1 to cover the near-sea area.

[0081] Please refer to Figure 5 This is a schematic diagram of another shipborne communication device provided in an embodiment of the present invention. The radio frequency transmission link further includes a first coupler 33, connected between the final stage power amplifier 31 and the omnidirectional antenna 1;

[0082] The distortion adjuster 32 is a digital pre-distortion (DPD) 323. The output of the digital pre-distortion 323 is connected to the input of the final stage power amplifier 31. One input of the digital pre-distortion 323 is used to receive the input signal, and the other input of the digital pre-distortion 323 is connected to one output of the first coupler 33.

[0083] The digital predistorter 323 is used to measure the output signal of the final stage power amplifier 31 in real time, compare the output signal with the input signal, determine the nonlinear characteristics of the final stage power amplifier 31, and generate and output a compensation signal corresponding to the nonlinear characteristics. The compensation signal is superimposed with the input signal to become the predistortion signal. The predistortion signal cancels the nonlinear characteristics of the final stage power amplifier 31, so that the final stage power amplifier 31 can linearly amplify the input signal even when it is operating in the nonlinear region.

[0084] The working principle of DPD technology is to pre-distort the input signal in the digital domain to generate a distorted signal (referred to as the compensation signal in this invention) that is opposite to the nonlinear characteristics of the power amplifier. When this input signal is combined with the distorted signal, the overall distortion is greatly reduced, thereby improving the linearity of the amplifier. This method can not only improve the linearity of the signal, but also expand the linear range of the power amplifier and improve its efficiency without changing its characteristics. Figure 6The diagram illustrates the linearization of a power amplifier. The input signal becomes nonlinear as the gain increases. When the input signal A1 is amplified by the power amplifier, the amplifier will saturate due to excessive power, causing the output signal P1 to become nonlinear. Therefore, the input signal A2 is introduced to compensate for the nonlinearity of the P1 signal. The input signal A2 directly passes through the output signal P2 of the power amplifier, finally forming a straight line P1 + P2 = K(A1 + A2) (the straight line with input signal A3 and output signal P3, where K is a coefficient), thus making the input and output signals completely linearized.

[0085] Please refer to Figure 7 This is a schematic diagram of a digital predistorter provided in an embodiment of the present invention. The digital predistorter includes: a second coupler, a predistorter, and an adaptive adjustment module. The input terminal of the second coupler is used to receive the input signal corresponding to the power amplifier. One output terminal of the second coupler is connected to one input terminal of the predistorter, and the other output terminal of the second coupler is connected to one input terminal of the adaptive module. The output terminal of the predistorter is connected to the input terminal of the power amplifier, the other input terminal of the predistorter is connected to the output terminal of the adaptive module, and the other input terminal of the adaptive module is connected to one output terminal of the first coupler.

[0086] In some embodiments, the radio frequency transmission link further includes a filter connected between the output of the first coupler and the antenna.

[0087] To achieve a stable linear system P1+P2=K(A1+A2), the following technical decomposition is required. The input signal corresponding to the final stage power amplifier 31 (denoted as A, A=D+E) is, since the coupler does not change the characteristics of the signal, but only changes the amplitude of the signal, so D=K1×E, where K1 is a coefficient. The adaptive module 322 can know the function curves of the signals A and D by detecting the E signal. Similarly, the signal G enters the second coupler. The signal G is the output of the power amplifier and has a linear relationship with the signal B, G=K2×B, where K2 is a coefficient. After the automatic detection module receives the B signal, it knows the function of the output of G. By comparing the difference between the B and E signals, it can know the difference between D and G. Compensation is performed through C to generate the signal F. F enters the power amplifier to generate G. After passing through the power amplifier, G=K3×F, where K3 is a coefficient. By continuously iterating, when the signal G meets the maximum power condition and is linear, G passes through the first coupler and filter, and the signal is output to the antenna. The antenna then transmits the signal.

[0088] Furthermore, in practical applications, DPD technology needs to consider various factors, including the amplifier's memory effect, hardware defects, and non-ideal conditions. The amplifier's memory effect means that its output is a function of the current input signal and its past historical signals, which needs to be considered in the DPD model. Moreover, since the input signal is analog, factors such as gain and phase slope unevenness in the analog signal's forward and feedback paths, local oscillator phase noise, direct conversion gain and phase imbalance, carrier leakage, amplifier gain fluctuations, and control loop timing variations all degrade DPD performance.

[0089] In practical applications, to achieve a practical and effective DPD solution, it is necessary to model and then correct the dynamic nonlinear behavior of the power amplifier. This typically involves complex mathematical models, such as Volterra series and Generalized Memory Polynomial (GMP) methods. These models can help capture the nonlinear characteristics of the power amplifier and enable predistortion processing in the digital domain.

[0090] In the embodiments provided by the present invention, the nonlinear distortion of the final stage power amplifier 31 is compensated by using a digital predistorter 323 to predistort the input signal corresponding to the final stage power amplifier 31, thereby effectively improving the quality and efficiency of signal transmission and achieving linearity under the condition of 20W (43dBm) transmission power. This keeps the error vector magnitude (EVM) of the shipborne communication device at a reasonable level (deterioration not exceeding 1%), thus meeting the requirements of high-speed long-distance transmission.

[0091] Please refer to Figure 8 This is a schematic diagram of another shipborne communication device provided in an embodiment of the present invention. The radio frequency transmission link further includes a first coupler 33. The input end of the first coupler 33 is used to receive input signals, and one output end of the first coupler 33 is connected to the final stage power amplifier 31.

[0092] The distortion adjuster 32 is an envelope tracker (ET). The input terminal of the envelope tracker is connected to the other output terminal of the first coupler 33, and the output terminal of the envelope tracker is connected to the power supply terminal of the final stage power amplifier 31. The envelope tracker is used to detect the envelope of the input signal in real time and adjust the power supply voltage supplied to the final stage power amplifier 31 in real time according to the envelope of the input signal, so that the final stage power amplifier 31 operates in the linear region.

[0093] Envelope tracking technology (ET) employed by envelope trackers dynamically adjusts the power amplifier's supply voltage to match the envelope of the input signal, thereby reducing energy loss. The core of ET technology lies in real-time monitoring of the input signal envelope and adjusting the power supply voltage to the amplifier based on changes in the envelope. When the input signal amplitude is small, the supply voltage decreases accordingly, reducing unnecessary energy consumption; conversely, when the input signal amplitude is large, the supply voltage increases to ensure the amplifier can provide sufficient output power.

[0094] The core of ET technology is the ET power modulator, which must be able to output a voltage that matches the envelope of the input signal to ensure that the power amplifier amplifies the signal without distortion (i.e., always operates in the linear region). The output voltage of the ET power supply must have high bandwidth and high efficiency to meet the requirements of mobile communication technology development for input signal envelope bandwidth and peak-to-average power ratio (PAPR).

[0095] By setting the distortion adjuster 32 as an envelope tracker, the envelope of the input signal is detected in real time, and the power supply voltage provided to the final stage power amplifier 31 is adjusted in real time according to the envelope of the input signal. This ensures that the power supply voltage provided by the error tracker closely matches the final stage power amplifier 31, so that the final stage power amplifier 31 always operates in the linear region regardless of the type of input signal envelope it receives. This improves the power amplifier efficiency of the final stage power amplifier 31, enables high-power transmission, and allows the omnidirectional antenna 1 to cover the near-sea area.

[0096] Please refer to Figure 9 This is a schematic diagram of an envelope tracker provided in an embodiment of the present invention, showing an analog-to-digital conversion module 32a, an envelope detection module 32b, an envelope shaping module 32c, and an envelope tracking power supply 32d connected in series.

[0097] The analog-to-digital converter circuit is used to acquire the input signal from the output of the first coupler 33 and convert it into the corresponding baseband signal;

[0098] The envelope detection module 32b is used to detect the amplitude of the baseband signal and extract the envelope signal that characterizes the instantaneous power level of the baseband signal;

[0099] The envelope shaping module 32c is used to shape the envelope signal so that the shaped envelope signal meets the input requirements of the envelope tracking power supply 32d;

[0100] Envelope tracking power supply 32d is used to generate a power supply voltage that varies with the shaped envelope signal and is supplied to the final stage power amplifier 31.

[0101] like Figure 9As shown, after the input signal corresponding to the final stage power amplifier 31 passes through the first coupler 33, a portion of the signal enters the analog-to-digital conversion module 32a to sample the input signal and generate the baseband signal (i.e., IQ data). Then, it enters the envelope detection module 32b to generate a specific envelope signal. Due to the randomness of the envelope signal, a peak-to-average power ratio (PAPR) signal will be generated. At this time, the envelope shaping module 32c is needed to perform envelope shaping, assign the shaped waveform to the envelope tracking power supply 32d (ETPS), so that the envelope tracker can capture the peak and trough of the input signal and then dynamically adjust the output of the envelope tracking power supply 32d according to this information to keep it consistent with the envelope of the input signal.

[0102] Furthermore, to ensure that the peaks and troughs of the input signal are synchronized with the voltage waveform applied to the final stage power amplifier 31, the envelope tracker also needs to perform delay balancing and synchronization. This involves matching the delays occurring in different signal paths during envelope tracking to avoid mismatches when delivering the required voltage to the final stage power amplifier 31, which would lead to increased power consumption, reduced efficiency, and increased distortion.

[0103] The envelope tracking power supply 32d (ETPS) uses the envelope shaping module 32c to generate a variable supply voltage (VPA) and provides it to the final stage power amplifier 31. The ETPS must possess the dynamic performance characteristics associated with conventional power amplifiers, such as bandwidth, noise, gain, and accuracy. The ETPS must have sufficient bandwidth to keep up with the modulation rate, meaning its bandwidth is approximately two to three times the modulation bandwidth. Long Term Evolution (LTE) channel bandwidth is as high as 20MHz, requiring 50MHz in the ETPS bandwidth. With increasing throughput, for example, in the N41 band (100MHz bandwidth), a higher 300MHz bandwidth is needed in 5G channels, and the ETPS bandwidth can be 2 to 3 times that of the N41 band. To maintain overall system power efficiency, the ETPS needs to have higher power efficiency.

[0104] Please continue reading Figure 9 The radio frequency transmission link 3 also includes a filter 34, which is connected between the final stage power amplifier 31 and the omnidirectional antenna 1.

[0105] Please refer to Figure 10 This is a schematic diagram of another shipborne communication device provided in an embodiment of the present invention. The radio frequency transmission link also includes a first coupler 33, which is connected between the final stage power amplifier 31 and the omnidirectional antenna 1.

[0106] The distortion adjuster 32 is an enhanced adaptive power amplifier. One input terminal of the enhanced adaptive power amplifier is used to receive the input signal. The other input terminal of the enhanced adaptive power amplifier is connected to one output terminal of the first coupler 33. One output terminal of the enhanced adaptive power amplifier is connected to the input terminal of the final stage power amplifier 31. The other output terminal of the enhanced adaptive power amplifier is connected to the power supply terminal of the final stage power amplifier 31.

[0107] The Enhanced Power Tracking (EPT) amplifier is used to measure the output signal of the final stage power amplifier 31 in real time, compare the output signal with the input signal, determine the nonlinear characteristics of the final stage power amplifier 31, and generate and output a compensation signal corresponding to the nonlinear characteristics. At the same time, it also adjusts the power supply voltage supplied to the final stage power amplifier 31 in real time according to the envelope of the input signal, so that the final stage power amplifier 31 operates in the linear region. The compensation signal is superimposed with the input signal to become a predistortion signal. The predistortion signal cancels the nonlinear characteristics of the final stage power amplifier 31, so that the final stage power amplifier 31 can linearly amplify the input signal even when operating in the nonlinear region.

[0108] EPT (Electronic Power Tracking) combines Average Power Tracking (APT) and Digital Power Distribution (DPD) technologies. DPD compensates for the nonlinear distortion of the power amplifier by adding predistortion during baseband signal processing, allowing the amplifier to operate at higher efficiency. EPT combines the advantages of APT and DPD, providing higher efficiency and better linearity. Furthermore, EPT optimizes the amplifier's performance by dynamically adjusting the power supply voltage. The core of EPT technology lies in adjusting the power amplifier's supply voltage in real time based on the power level of the input signal, thereby improving efficiency while maintaining linearity.

[0109] EPT technology can also be combined with envelope tracking (ET) technology for finer power control. ET technology dynamically adjusts the power amplifier's supply voltage by more accurately tracking the envelope of the input signal, resulting in higher efficiency and better linearity. This technology is particularly effective when processing signals with a high peak-to-average power ratio (PAPR) because it reduces energy loss and improves the amplifier's efficiency.

[0110] Please see Figure 11 This is a schematic diagram of an enhanced adaptive power amplifier provided in an embodiment of the present invention. The enhanced adaptive power amplifier includes:

[0111] The second coupler 321 has its input terminal used to receive the input signal;

[0112] An adaptive module 322 is provided, with one input terminal connected to the first output terminal of the second coupler 321 and the other input terminal connected to one output terminal of the first coupler 33; the adaptive module 322 is used to compare the difference between the input signal and the output signal.

[0113] A predistorter 323 is provided, with one input connected to the second output of the second coupler 321, the other input connected to the other output of the adaptive module 322, and the output connected to the final stage power amplifier 31. The predistorter 323 is used to determine the nonlinear characteristics of the final stage power amplifier 31 based on the difference, and to generate and output the compensation signal.

[0114] An envelope tracker 324 is provided, the input of which is connected to the third output of the second coupler 321, and the output of which is connected to the power supply of the final stage power amplifier 31. The envelope tracker is used to detect the envelope of the input signal in real time and adjust the power supply voltage provided to the final stage power amplifier 31 in real time according to the envelope of the input signal, so that the final stage power amplifier 31 operates in the linear region.

[0115] The structure of envelope tracker 324 can be referred to the structure of the aforementioned envelope tracker, and will not be repeated here.

[0116] In the embodiments provided by the present invention, by using an enhanced adaptive power regulator, the operating state of the final stage power amplifier 31 can be dynamically adjusted according to the characteristics of the input signal to improve efficiency and linearity. Furthermore, it can more precisely control the power amplification in the nonlinear region of the final stage power amplifier, resulting in lower EMV and faster transmission rate in the shipborne communication system.

[0117] Please refer to Figure 12 This is a schematic diagram of another shipborne communication device provided in an embodiment of the present invention. The shipborne communication device further includes:

[0118] Connector 4, the common end of connector 4 is connected to omnidirectional antenna 1, and the first end of connector 4 is connected to radio frequency transmission link 3; connector 4 also includes a second end, which is used to connect the first end or the second end of connector 4 to the common end of connector 4.

[0119] RF receiving link 5 is connected between CPE2 and the second end of connector 4.

[0120] If the shipborne communication device uses TDD communication, then connector 4 is a switch; if the shipborne communication device uses FDD communication, then connector 4 is a duplexer. The structure of the RF receiving link 5 can be referenced based on the communication mode it adopts. Figure 2 or Figure 3 The structure of the RF receiver link 5 will not be described in detail here.

[0121] Please refer to Figures 13-15 This is a schematic diagram of the architecture of a shipborne communication device provided in an embodiment of the present invention, including an omnidirectional antenna:

[0122] The first omnidirectional antenna is a horizontally polarized antenna in the low-frequency band, and the second omnidirectional antenna is a vertically polarized antenna in the low-frequency band.

[0123] The third omnidirectional antenna and the fourth omnidirectional antenna are used. The third omnidirectional antenna is a horizontally polarized antenna in the high-frequency band, and the fourth antenna is a vertically polarized antenna in the high-frequency band. Communication in the low-frequency band is based on time-division duplex, and communication in the high-frequency band is based on frequency-division duplex.

[0124] The first omnidirectional antenna, the second omnidirectional antenna, the third omnidirectional antenna, and the fourth omnidirectional antenna each correspond to a radio frequency transmission link; the first omnidirectional antenna and the second omnidirectional antenna share a distortion adjuster, and the third omnidirectional antenna and the fourth omnidirectional antenna share another distortion adjuster.

[0125] like Figures 12-14 The shipborne communication device shown supports the N28 and N41 frequency bands. The N28 frequency band uses frequency division duplex (FDD) mode communication, and the N41 frequency band uses time division duplex (TDD) mode communication.

[0126] like Figure 12 As shown, the distortion adjuster is a DPD, and the RF links supporting the N28 band include RF receiving link C and RF receiving link D, as well as two RF transmitting links consisting of final stage power amplifiers C and D, negative feedback network C and negative feedback network D, and DPD-B; the RF links supporting the N41 band include RF receiving link A and RF receiving link B, as well as two RF transmitting links consisting of final stage power amplifiers A and B, negative feedback network A and negative feedback network B, and DPD-A.

[0127] like Figure 13As shown, the distortion adjuster is ET, and the RF links supporting the N28 band include RF receiving links C and D, as well as two RF transmitting links consisting of final stage power amplifiers C and D, first couplers C and D, and ET-B; the RF links supporting the N41 band include RF receiving links A and B, as well as two RF transmitting links consisting of final stage power amplifiers A and B, first couplers A and B, and ET-A.

[0128] Shipborne communication devices can also support a frequency band, such as Figure 14 As shown, the distortion adjuster is EPT, and the radio frequency links supporting the N41 band include radio frequency receiving link A and radio frequency receiving link B, as well as two radio frequency transmitting links consisting of final stage power amplifier A and final stage power amplifier B, negative feedback network A and negative feedback network B, and EPT-A.

[0129] Please continue reading Figure 14 The CPE can provide an enable signal EN to the EPT to control whether the EPT is working. For RF links using TDD mode, the EPT can use an internal buffer to split the enable signal EN into two sub-enable signals, en1 and en2, and provide them to the final stage power amplifier A and final stage power amplifier B respectively. This accommodates the switching between transmit and receive modes in two TDD modes (i.e., transmit is off when receiving, and the receive link is grounded when transmitting), thus preventing equipment damage. For RF links using FDD mode, it is only necessary to ensure that the transmit power of the final stage power amplifier reaches its maximum value and maintains good linearity.

[0130] Similarly, Figure 12 and Figure 13 The CPE in the system can control whether the distortion adjuster is working by providing enable signals to different distortion adjusters (DPD or ET). For RF links using TDD mode, the distortion adjuster can provide enable signals (en1, en2) to different final stage power amplifiers to switch between transmit and receive.

[0131] Although preferred embodiments of the invention have been described, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including both the preferred embodiments and all changes and modifications falling within the scope of the invention.

[0132] Obviously, those skilled in the art can make various modifications and variations to this invention without departing from its spirit and scope. Therefore, if these modifications and variations fall within the scope of the claims of this invention and their equivalents, this invention also intends to include these modifications and variations.

Claims

1. A shipborne communication device, characterized in that, include: Omnidirectional antenna; A customer premises equipment (CPE) is used to communicate with a coastal base station via the omnidirectional antenna, and a user terminal communicates with the CPE; wherein, the coastal base station is a base station installed on the coast, and the user terminal is a terminal device located in the near-shore waters of the coast. A radio frequency transmission link is connected between the omnidirectional antenna and the CPE; the radio frequency transmission link includes a final stage power amplifier and a distortion adjuster; the final stage power amplifier is connected to the omnidirectional antenna; The distortion adjuster is used to adjust at least one of the input signal corresponding to the final stage power amplifier and the power supply voltage of the final stage power amplifier, so that the final stage power amplifier linearly amplifies the input signal.

2. The shipborne communication device as described in claim 1, characterized in that, The radio frequency transmission link also includes a first coupler connected between the final stage power amplifier and the omnidirectional antenna; The distortion adjuster is a digital predistorter. The output of the digital predistorter is connected to the input of the final stage power amplifier. One input of the digital predistorter is used to receive the input signal, and the other input of the digital predistorter is connected to one output of the first coupler. The digital predistorter is used to measure the output signal of the final stage power amplifier in real time, compare the output signal with the input signal, determine the nonlinear characteristics of the final stage power amplifier, and generate and output a compensation signal corresponding to the nonlinear characteristics. The compensation signal is superimposed on the input signal to become the predistortion signal. The predistortion signal cancels the nonlinear characteristics of the final stage power amplifier, so that the final stage power amplifier can linearly amplify the input signal even when it is operating in the nonlinear region.

3. The shipborne communication device as described in claim 1, characterized in that, The radio frequency transmission link further includes a first coupler, the input of which is used to receive the input signal, and one output of which is connected to the final stage power amplifier. The distortion adjuster is an envelope tracker. The input terminal of the envelope tracker is connected to the other output terminal of the first coupler, and the output terminal of the envelope tracker is connected to the power supply terminal of the final stage power amplifier. The envelope tracker is used to detect the envelope of the input signal in real time and adjust the power supply voltage provided to the final stage power amplifier in real time according to the envelope of the input signal, so that the final stage power amplifier operates in the linear region.

4. The shipborne communication device as described in claim 1, characterized in that, The radio frequency transmission link also includes a first coupler connected between the final stage power amplifier and the omnidirectional antenna; The distortion adjuster is an enhanced adaptive power amplifier. One input terminal of the enhanced adaptive power amplifier is used to receive the input signal. The other input terminal of the enhanced adaptive power amplifier is connected to one output terminal of the first coupler. One output terminal of the enhanced adaptive power amplifier is connected to the input terminal of the final stage power amplifier. The other output terminal of the enhanced adaptive power amplifier is connected to the power supply terminal of the final stage power amplifier. The enhanced adaptive power amplifier is used to measure the output signal of the final stage power amplifier in real time, compare the output signal with the input signal, determine the nonlinear characteristics of the final stage power amplifier, and generate and output a compensation signal corresponding to the nonlinear characteristics. Simultaneously, it adjusts the power supply voltage supplied to the final stage power amplifier in real time according to the envelope of the input signal, so that the final stage power amplifier operates in the linear region. The compensation signal is superimposed on the input signal to form a predistortion signal, which cancels the nonlinear characteristics of the final stage power amplifier, enabling the final stage power amplifier to linearly amplify the input signal even when operating in the nonlinear region.

5. The shipborne communication device as described in claim 4, characterized in that, The enhanced adaptive power amplifier includes: A second coupler, the input terminal of which is used to receive the input signal; An adaptive module, one input terminal of which is connected to the first output terminal of the second coupler, and the other input terminal of which is connected to one output terminal of the first coupler; the adaptive module is used to compare the difference between the input signal and the output signal. A predistorter, one input of which is connected to the second output of the second coupler, the other input of which is connected to the other output of the adaptive module, and the output of which is connected to the final stage power amplifier; the predistorter is used to determine the nonlinear characteristics of the final stage power amplifier based on the difference, and to generate and output the compensation signal; An envelope detector is provided, with its input terminal connected to the third output terminal of the second coupler and its output terminal connected to the power supply terminal of the final stage power amplifier. The envelope tracker is used to detect the envelope of the input signal in real time and adjust the power supply voltage provided to the final stage power amplifier in real time according to the envelope of the input signal, so that the final stage power amplifier operates in the linear region.

6. The shipborne communication device as described in claim 3 or 5, characterized in that, The envelope tracker includes: The serially connected analog-to-digital converter module, envelope detection module, envelope shaping module, and envelope tracking power supply; The analog-to-digital converter circuit is used to acquire the input signal and convert it into the corresponding baseband signal; The envelope detection module is used to detect the amplitude of the baseband signal and extract the envelope signal that characterizes the instantaneous power level of the baseband signal. The envelope shaping module is used to shape the envelope signal so that the shaped envelope signal meets the input requirements of the envelope tracking power supply. The envelope tracking power supply is used to generate a power supply voltage that varies with the shaped envelope signal and is provided to the final stage power amplifier.

7. The shipborne communication device according to any one of claims 1-5, characterized in that, The omnidirectional antenna includes: A first omnidirectional antenna and a second omnidirectional antenna, wherein the first omnidirectional antenna is a horizontally polarized antenna in the low-frequency band and the second omnidirectional antenna is a vertically polarized antenna in the low-frequency band; A third omnidirectional antenna and a fourth omnidirectional antenna, wherein the third omnidirectional antenna is a horizontally polarized antenna in the high-frequency band, and the fourth antenna is a vertically polarized antenna in the high-frequency band; wherein the low-frequency band communicates based on time-division duplex, and the high-frequency band communicates based on frequency-division duplex; Each of the first omnidirectional antenna, the second omnidirectional antenna, the third omnidirectional antenna, and the fourth omnidirectional antenna corresponds to a radio frequency transmission link; the first omnidirectional antenna and the second omnidirectional antenna share one of the distortion adjusters, and the third omnidirectional antenna and the fourth omnidirectional antenna share another distortion adjuster.

8. The shipborne communication device as described in claim 7, characterized in that, The low-frequency band is the N41 band, and the high-frequency band is the N28 band; The maximum transmit power of the final stage power amplifier is 43dBm.

9. The shipborne communication device according to any one of claims 1-5, characterized in that, The shipborne communication device also includes: The connector has a common end connected to the omnidirectional antenna and a first end connected to the radio frequency transmission link; the connector also includes a second end for connecting either the first end or the second end of the connector to the common end of the connector. The radio frequency receiving link is connected between the CPE and the second end of the connector.

10. The shipborne communication device as claimed in claim 7, characterized in that, The omnidirectional antenna corresponds to a time-division duplex communication mode, and the connector is a switch. The omnidirectional antenna corresponds to the frequency division duplex communication mode, and the connector is a coupler.

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