Signal compensating system and method for radio over fiber communication

Abstract

A signal compensation system for RoF (RoFi) communication includes a first device, a first optical fiber, and a second device. The first device receives radio frequency (RF) signals emitted by a base station and includes a first signal transmitter for transmitting RF signals at a preset signal strength. The first optical fiber transmits the RF signals. The second device includes a second signal receiver for receiving the RF signals, a signal measurement unit, a signal compensation unit, and a power amplifier. The signal measurement unit measures the current signal strength of the RF signals. The signal compensation unit generates a signal compensation value based on the preset signal strength and the current signal strength, and generates an adjusted signal strength based on the current signal strength and the signal compensation value. When the current signal strength is within a signal strength range, the power amplifier transmits the RF signals at the adjusted signal strength.

Description

Technical Field

[0001] This invention relates to the field of communications, and more particularly to a signal compensation system and method for fiber optic wireless (RoF) communications. Prior Technology

[0002] In recent years, with the increasing demands for quality of life and communication technology, people have higher and higher requirements for signal communication speed and quality, which traditional wireless communication technology can no longer meet. To meet the demand for high-speed, high-capacity wireless communication, technology developers have developed fiber optic radio frequency (RF over Fiber) technology, which combines fiber optic communication and radio frequency communication. Because fiber optic technology has advantages such as long transmission distance, wide bandwidth, and strong anti-interference capabilities, fiber optic link transmission is widely used in various communication systems. RF over Fiber technology, which combines fiber optic communication and radio frequency communication technologies, can utilize the low-loss and high-bandwidth characteristics of fiber optics to transmit radio frequency signals through fiber optics, thereby increasing the bandwidth of wireless access networks and providing users with high-speed, high-capacity wireless communication services.

[0003] In existing fiber optic communication systems, signal attenuation due to factors such as fiber length and bending can affect communication efficiency. Therefore, the system needs to perform signal attenuation testing to determine whether signal compensation is necessary. Generally, the traditional method for determining fiber optic signal attenuation involves the transmitter sending a pilot signal to the receiver, which then sends the pilot signal back. By comparing the transmitted and received pilot signal values, the attenuation value can be determined, allowing for gain compensation in the fiber optic RF transmission system. However, when using this signal test, the system must stop normal communication services and only transmit the pilot signal to detect the attenuation level. Furthermore, the transmission process requires the transmitter to send the pilot signal to the receiver, which then sends it back, interrupting service and requiring signal transmission time, thus reducing convenience and increasing testing costs. Furthermore, when the system encounters temporary signal instability (such as line collisions or pulling) or prolonged insufficient signal power, the system cannot detect signal attenuation in a timely manner, thus significantly reducing signal quality. Summary of the Invention

[0004] In view of this, one aspect of the present invention provides a signal compensation system for RoF (RoFi) communication. In one specific embodiment, the RoF communication signal compensation system includes a first device, a first optical fiber, and a second device. The first device is communicatively connected to a base station and is used to receive radio frequency (RF) signals emitted by the base station. The first device includes a first signal transmitter, which transmits RF signals with a preset signal strength. The first optical fiber is communicatively connected to the first signal transmitter and is used to transmit the RF signals. The second device further includes a second signal receiver, a signal measurement unit, a signal compensation unit, and a power amplifier. The second signal receiver is communicatively connected to the first optical fiber and is used to receive the RF signals. The signal measurement unit is connected to the second signal receiver and is used to measure a current signal strength of the RF signals. The signal compensation unit is connected to the signal measurement unit and stores the preset signal strength of the first signal transmitter. The signal compensation unit generates a signal compensation value based on the preset signal strength and the current signal strength, and generates an adjusted signal strength based on the current signal strength and the signal compensation value. The power amplifier is connected to the signal compensation unit and has a signal strength range value. The power amplifier is used to transmit radio frequency (RF) signals. Specifically, when the adjusted signal strength is within the signal strength range value, the power amplifier transmits RF signals with the adjusted signal strength.

[0005] The signal strength range includes an upper limit and a lower limit, with the lower limit being the upper limit multiplied by a safety factor.

[0006] Specifically, when the adjusted signal strength is greater than the upper limit of the signal strength, the signal compensation unit calculates the upper limit and lower limit of the signal strength to generate a signal strength difference, and generates an updated signal compensation value based on the signal compensation value and the signal strength difference.

[0007] Specifically, when the adjusted signal strength is less than the lower limit of the signal strength, the signal compensation unit increases the signal compensation value by a specific compensation value every certain time interval to generate an updated signal compensation value.

[0008] The signal compensation unit pre-stores a threshold number of occurrences. When the adjusted signal strength is less than the lower limit, the power amplifier generates an abnormal signal, and the signal compensation unit records the number of abnormal occurrences. When the number of abnormal occurrences is greater than or equal to the threshold number, the signal compensation unit increases the signal compensation value by a specific compensation value.

[0009] Another aspect of the present invention provides a signal compensation method for RoF (RoFi) communication. In one specific embodiment, the signal compensation method for RoF communication includes the following steps: a first signal transmitter of a first device transmits a radio frequency (RF) signal emitted by a base station at a preset signal strength; a first optical fiber transmits the RF signal; a second signal receiver of a second device receives the RF signal; a signal measurement unit of the second device measures the current signal strength of the RF signal; a signal compensation unit of the second device generates a signal compensation value based on the preset signal strength and the current signal strength, and generates an adjusted signal strength based on the current signal strength and the signal compensation value; and when the adjusted signal strength is within a signal strength range, a power amplifier transmits the RF signal at the adjusted signal strength.

[0010] The signal compensation method for RoF (RoFi) communication further includes the following steps: when the adjusted signal strength is greater than the upper limit of the signal strength, the signal compensation unit calculates the upper limit and lower limit of the signal strength to generate a signal strength difference; the signal compensation unit generates an updated signal compensation value based on the signal compensation value and the signal strength difference, and generates an updated adjusted signal strength based on the current signal strength and the updated signal compensation value; and the power amplifier transmits a radio frequency signal with the updated adjusted signal strength.

[0011] The signal compensation method for Fiber Optic Wireless (RoF) communication further includes the following steps: when the adjusted signal strength is less than the lower limit of the signal strength, the signal compensation unit increases a specific compensation value to the signal compensation value at regular intervals to generate an updated signal compensation value, and generates an updated adjusted signal strength based on the current signal strength and the updated signal compensation value; and the power amplifier transmits radio frequency signals with the updated adjusted signal strength.

[0012] The step of having the signal compensation unit add a specific compensation value to the signal compensation value at regular intervals when the adjusted signal strength is less than the lower limit of the signal strength to generate an updated signal compensation value, and generating an updated adjusted signal strength based on the current signal strength and the updated signal compensation value, further includes the following steps: when the adjusted signal strength is less than the lower limit of the signal strength, the power amplifier generates an abnormal signal; the signal compensation unit records the number of abnormalities of the abnormal signal; and when the number of abnormalities is greater than or equal to a threshold, the signal compensation unit adds a specific compensation value to the signal compensation value at regular intervals to generate an updated signal compensation value, and generates an updated adjusted signal strength based on the current signal strength and the updated signal compensation value.

[0013] Prior to the step of transmitting the radio frequency signal emitted by the base station to the first signal transmitter of the first device with a preset signal strength, the method further includes the following step: the first device transmits the preset signal strength to the second device.

[0014] In summary, the signal compensation system for RoF (Radio over Fiber) communication of the present invention can measure the current signal strength of the radio frequency signal in real time through the signal measurement unit, and can immediately compensate for signal attenuation caused by lines or hardware components through the signal compensation unit, without the need for signal attenuation testing through additional test signals, thereby improving convenience and maintaining signal transmission quality. Furthermore, the signal compensation system for RoF communication of the present invention can also detect in real time whether the compensated signal strength is within the normal operating signal strength range through the power amplifier, and can detect temporary or long-term abnormal signal strength conditions. The compensation value can then be adjusted under different conditions through the signal compensation unit to achieve a "fast decrease, slow increase" signal strength control mechanism, thereby improving signal transmission efficiency and signal quality. Simple Explanation of the Diagram

[0015]

[0016] Figure 1 is a functional block diagram illustrating a signal compensation system for fiber optic wireless (RoF) communication according to a specific embodiment of the present invention.

[0017] Figure 2 is a graph illustrating the adjustment of the signal strength of a radio frequency signal according to a specific embodiment of the present invention.

[0018] Figure 3 is a functional block diagram illustrating a signal compensation system for fiber optic wireless (RoF) communication according to a specific embodiment of the present invention.

[0019] Figure 4 is a flowchart illustrating the steps of a signal compensation method for fiber optic wireless (RoF) communication according to a specific embodiment of the present invention.

[0020] Figure 5 is a flowchart illustrating the steps of a signal compensation method for fiber optic wireless (RoF) communication according to a specific embodiment of the present invention. Implementation

[0021] To make the advantages, spirit, and features of the present invention easier and clearer to understand, detailed descriptions and discussions will follow with reference to specific embodiments and the accompanying drawings. It is important to note that these specific embodiments are merely representative examples of the present invention, and the specific methods, apparatus, conditions, materials, etc., exemplified are not intended to limit the present invention or the corresponding specific embodiments.

[0022] The indefinite articles “a,” “an,” and “an” preceding the apparatus or element of this invention do not impose a limit on the quantity (i.e., the number of times) of the apparatus or element. Therefore, “a” should be interpreted as including one or at least one, and the singular form of apparatus or element also includes the plural form, unless the quantity clearly refers to the singular form.

[0023] Please refer to Figure 1. Figure 1 is a functional block diagram illustrating a signal compensation system S for fiber optic wireless (RoF) communication according to a specific embodiment of the present invention. As shown in Figure 1, in this specific embodiment, the signal compensation system S for fiber optic wireless (RoF) communication includes a first device 1, a first optical fiber 31, and a second device 2. The first device 1 is communicatively connected to a base station BS and the first optical fiber 31, and the first optical fiber 31 is communicatively connected to the second device 2. In practice, the base station BS can be a fixed high-power bidirectional transmitter and can emit radio frequency (RF) signals.

[0024] In this specific embodiment, the first device 1 is used to receive radio frequency signals from the base station BS. In practice, the first device 1 may be a main signal processing device and may include a communication interface (not shown). The base station BS can connect to the communication interface via a cable to communicate with the first device 11 and transmit radio frequency signals, and the first device 1 can generate downlink signals based on the radio frequency signals.

[0025] In this specific embodiment, the first device 1 includes a first signal transmitter 11 communicatively connected to a first optical fiber 31 and used to transmit radio frequency signals (i.e., downlink signals) to the first optical fiber 31. In practice, the first signal transmitter 11 can be an Analog Laser Transmitting Optical Sub-Assembly (TOSA). The first signal transmitter 11 can convert the electrical signal of the downlink signal into an optical signal and transmit the signal through the first optical fiber 31. Further, the first signal transmitter 11 can transmit radio frequency signals with a preset signal strength. In practice, the preset signal strength can be a device characteristic value of the first signal transmitter 11. Specifically, the preset signal strength can be a fixed correspondence between the current and the signal light intensity that the first signal transmitter 11 can emit (i.e., factory default value), for example: a signal with a current value of 1.5A can correspond to a signal strength of 20.0dBm. The first signal transmitter 11 may have a current-signal intensity correspondence table, and this correspondence table contains a complex set of factory values. In practical applications, since the quality of different signal transmitters is not entirely the same, each signal transmitter may have a different current-signal intensity correspondence table. The first signal transmitter 11 will select a set of factory values ​​from the current-signal intensity correspondence table as the preset signal intensity to transmit the radio frequency signal.

[0026] In this specific embodiment, the second device 2 includes a second signal receiver 22, a signal measurement unit 23, a signal compensation unit 24, a power amplifier 25, and an antenna 26. The second signal receiver 22 is communicatively connected to the first optical fiber 31 and to the signal measurement unit 23. The signal compensation unit 24 is connected to the signal measurement unit 23 and the power amplifier 25, and the antenna 26 is connected to the power amplifier 25. The second signal receiver 22 is used to receive the radio frequency signal transmitted by the first optical fiber 31. In practice, the second signal receiver 22 can be an Analog Laser Receiving Optical Sub-Assembly (ROSA) module. The second signal receiver 22 can convert the optical signal of the radio frequency signal into an electrical signal.

[0027] In this specific embodiment, the signal measurement unit 23 is used to measure the current signal strength of the radio frequency (RF) signal received by the second signal receiver 22. In practice, the signal measurement unit 23 can be a signal measurement chip. After the second signal receiver 22 converts the optical signal of the RF signal into an electrical signal, the signal measurement unit 23 can measure the electrical signal to generate the current signal strength of the RF signal. The electrical signal can be a current value, and the signal measurement unit 23 can convert the current value into a signal strength value as the current signal strength of the RF signal. In practical applications, the signal measurement unit 23 can periodically measure the current signal strength of the RF signal, for example, measuring and generating the current signal strength every second, but is not limited to this. The periodic measurement time of the signal measurement unit 23 can also be determined according to requirements or design.

[0028] In this specific embodiment, the signal compensation unit 24 stores the preset signal strength of the first signal transmitter 11 and generates a signal compensation value based on the preset signal strength and the current signal strength. In practice, the signal compensation unit 24 can be a signal compensation calculation chip and can pre-store the current-signal intensity correspondence table of the first signal transmitter 11. The first device 1 can pre-transmit the current-signal intensity correspondence table of the first signal transmitter 11 to the second device 2. The signal compensation unit 24 can calculate the signal attenuation value of the radio frequency signal transmitted from the first device 1 to the second device 2 based on the current signal strength measured by the signal measurement unit 23 and the preset signal strength in the current-signal intensity correspondence table, and the signal compensation unit 24 generates a signal compensation value based on the signal attenuation value, wherein the signal attenuation value is the signal compensation value and can be the signal attenuation caused by the circuit / hardware components. For example, when the preset signal strength is 18dBm and the current signal strength is 15dBm, the signal compensation value (i.e., the signal attenuation value) generated by the signal compensation unit 24 is 3dBm.

[0029] Furthermore, the signal compensation unit 24 is used to adjust the signal strength based on the current signal strength and the signal compensation value. In practice, after the signal compensation unit 24 calculates the signal compensation value, it can compensate the current signal strength of the radio frequency signal received by the second signal receiver 22 to the signal strength before attenuation. That is, in this specific embodiment, the signal compensation unit 24 can compensate the radio frequency signal gain to the signal strength when the first device 1 transmits the radio frequency signal, so that the radio frequency signal is not affected by the line length or hardware components, thereby maintaining the signal quality and signal strength.

[0030] In this specific embodiment, the power amplifier 25 is used to transmit radio frequency signals through the antenna 26. In practice, after the signal compensation unit 24 compensates the signal strength of the radio frequency signal to the adjusted signal strength, the power amplifier 25 then transmits the radio frequency signal with the adjusted signal strength to the third device 3 through the antenna 26. The third device 3 can be a mobile device (such as a smartphone) or other device with communication functions. In this specific embodiment, the power amplifier 25 has a signal strength range value, which includes an upper limit value and a lower limit value. The power amplifier 25 is used to detect whether the adjusted signal strength is within the signal strength range value. In practice, the signal strength range value can be the operating signal strength range within which the power amplifier 25 can operate normally. The upper limit value can be the saturation value of the power amplifier 25, and the lower limit value can be the tolerance value of the power amplifier 25. Further, in this specific embodiment, the lower limit value is the upper limit value multiplied by a safety factor. In practice, the safety factor can be determined based on the design or requirements, or based on the range of radio frequency signal strength emitted by the base station (BS).

[0031] Please refer to Figures 1 and 2 together. Figure 2 is a graph illustrating the adjusted signal strength of a radio frequency signal according to a specific embodiment of the present invention, where the horizontal axis represents time, the vertical axis represents signal strength, Smax is the upper limit of signal strength (i.e., saturation value), and Smin is the lower limit of signal strength (i.e., tolerance value). As shown in Figures 1 and 2, in this specific embodiment, when the adjusted signal strength of the radio frequency signal generated by the signal compensation unit 24 is within the signal strength range (point A in Figure 2), that is, when the adjusted signal strength is between the saturation value and the tolerance value, it indicates that the signal strength of the compensated radio frequency signal (i.e., the adjusted signal strength) is within the normal operating range of the power amplifier 25. At this time, the power amplifier 25 can directly transmit the radio frequency signal with the adjusted signal strength.

[0032] When the adjusted signal strength of the RF signal generated by the signal compensation unit 24 exceeds the upper limit of the signal strength (point B in Figure 2), it indicates that the signal strength of the compensated RF signal has exceeded the saturation value of the power amplifier 25, and the power amplifier 25 may be damaged due to signal strength overload. At this time, the signal compensation unit 24 calculates the upper limit of the signal strength Smax and the lower limit of the signal strength Smin to generate a signal strength difference, and generates an updated signal compensation value based on the signal compensation value and the signal strength difference. In practice, the signal strength difference is the difference between the upper limit of the signal strength and the lower limit of the signal strength, and the signal compensation unit 24 subtracts the signal strength difference from the signal compensation value to calculate the updated signal compensation value. Then, the signal compensation unit 24 generates an updated adjusted signal strength based on the current signal strength of the RF signal received by the second signal receiver 22 and the updated signal compensation value to ensure that the updated adjusted signal strength is within the normal operating range of the power amplifier 25. It is worth noting that while the signal compensation unit 24 is calculating and updating the signal compensation value, the power amplifier 25 will also first send an RF signal with the signal strength of the upper limit of the signal strength. After the signal compensation unit 24 compensates and generates an updated and adjusted signal strength, it will then send an RF signal with the updated and adjusted signal strength.

[0033] For example, the power amplifier 25 has an upper limit signal strength of 20 dBm, a lower limit signal strength of 10 dBm, a signal strength difference of 10 dBm, and a signal compensation value of 8 dBm. When the current signal strength of the RF signal received by the second signal receiver 22 is 15 dBm, the signal compensation unit 24 adjusts the signal strength to 23 dBm based on the current signal strength and the signal compensation value. Since the adjusted signal strength is greater than the upper limit signal strength, the updated signal compensation value generated by the signal compensation unit 24 based on the signal compensation value and the signal strength difference is -2 dBm. Next, the signal compensation unit 24 updates the adjusted signal strength to 13 dBm based on the current signal strength and the updated signal compensation value. Finally, the power amplifier 25 transmits the RF signal through the antenna 26 with the updated adjusted signal strength.

[0034] When the adjusted signal strength of the RF signal generated by the signal compensation unit 24 is less than the lower limit of the signal strength (point C in Figure 2), it indicates that the signal strength of the compensated RF signal is still insufficient, which may lead to excessive signal noise or signal loss and significantly degrade signal quality. In this case, the signal compensation unit 24 will increase a specific compensation value to the signal compensation value at regular intervals to generate an updated signal compensation value. In practice, the interval can be 1 second, and the specific compensation value can be 1 dBm, but is not limited to these. The interval and the specific compensation value can also be determined according to design or requirements. Therefore, when the adjusted signal strength is insufficient, the signal compensation unit 24 can gradually gain the compensated RF signal strength to the normal operating range of the power amplifier 25 to ensure that the RF signal can be transmitted normally and maintain a certain signal quality.

[0035] The signal compensation unit can gradually increase the signal strength of the radio frequency signal in ways other than those described above. In one specific embodiment, the signal compensation unit 24 pre-stores a threshold number, and the power amplifier 25 can generate an abnormal signal when the adjusted signal strength is lower than the lower limit of the signal strength. The signal compensation unit 24 is used to record the number of abnormal signals. When the number of abnormal signals is greater than or equal to the threshold number, the signal compensation unit 24 increases the signal compensation value by a specific compensation value at regular intervals to generate an updated signal compensation value. In practice, the threshold number can be determined according to design or requirements, and the signal compensation unit 24 can also perform signal compensation only when the number of abnormal signals within a specific time period is greater than or equal to the threshold number. When the number of abnormal signals within a specific time period is less than the threshold number, it indicates a brief signal instability of the base station BS or an occasional situation caused by line contact. In this case, the signal compensation unit 24 will not perform signal compensation. When the number of anomalies within a specific time period is greater than or equal to the threshold, it indicates that the base station (BS) signal is unstable or the signal strength of the signal source is insufficient. At this time, the signal compensation unit 24 will perform signal compensation.

[0036] Therefore, the signal compensation system for RoF (Radio over Fiber) communication of the present invention can measure the current signal strength of the radio frequency signal in real time through the signal measurement unit, and can compensate for signal attenuation caused by lines or hardware components through the signal compensation unit to maintain signal quality. Furthermore, the signal compensation system for RoF communication of the present invention can also detect in real time whether the compensated signal strength is within the normal operating signal strength range through the power amplifier, and can further adjust the compensation value under different conditions through the signal compensation unit to improve signal transmission efficiency and signal quality.

[0037] The signal compensation system for RoF (RoF) communication of the present invention can compensate for both downlink and uplink signal strength. Please refer to Figure 3. Figure 3 is a functional block diagram illustrating a RoF signal compensation system S according to a specific embodiment of the present invention. As shown in Figure 3, in this specific embodiment, the RoF signal compensation system S further includes a second optical fiber 32, the first device 1 further includes a first signal receiver 12, and the second device 2 further includes a second signal transmitter 21. The second optical fiber 32 is communicatively connected to the first signal receiver 12 and the second signal transmitter 21. Similarly, the second signal transmitter 21 may also have a current-signal intensity correspondence table, and the second device 2 may also transmit the current-signal intensity correspondence table corresponding to the second signal transmitter 21 to the first device 1. Furthermore, the first device 1 may also include a signal measurement unit and a signal compensation unit (not shown).

[0038] In practice, after the second device 2 receives the radio frequency (RF) signal transmitted by the third device 3 through the antenna 26, the second device 2 can generate an uplink signal based on the RF signal. The second signal transmitter 21 can convert the electrical signal of the uplink signal into an optical signal and transmit it to the first signal receiver 12 through the second optical fiber 32. After the first signal receiver 12 converts the optical signal of the RF signal into an electrical signal, the signal measurement unit of the first device 1 can measure the electrical signal to generate the current signal strength of the RF signal. Then, the signal compensation unit of the first device 1 can generate a signal compensation value for the RF signal transmitted from the second device 2 to the first device 1 based on the current signal strength measured by the signal measurement unit and the corresponding current-signal-optical intensity correspondence table of the second signal transmitter 21. The signal compensation unit can then generate an adjustment signal strength for the uplink signal based on the current signal strength and the signal compensation value. Finally, the first device 1 transmits the uplink signal to the base station (BS) with the adjusted signal strength.

[0039] Please refer to Figure 4. Figure 4 is a flowchart illustrating the steps of a signal compensation method for RoF (RoFi) communication according to a specific embodiment of the present invention. The steps in Figure 4 can be achieved using the RoF communication signal compensation system of Figure 1. As shown in Figure 4, in this specific embodiment, the signal compensation method for fiber optic wireless (RoF) communication includes the following steps: Step S1: The first signal transmitter 11 of the first device 1 transmits the radio frequency signal emitted by the base station BS with a preset signal strength; Step S2: The first optical fiber 31 transmits the radio frequency signal; Step S3: The second signal receiver 22 of the second device 2 receives the radio frequency signal; Step S4: The signal measurement unit 23 of the second device 2 measures the current signal strength of the radio frequency signal; Step S5: The signal compensation unit 24 of the second device 2 generates a signal compensation value based on the preset signal strength and the current signal strength, and generates an adjusted signal strength based on the current signal strength and the signal compensation value; Step S6: The power amplifier 25 of the second device 2 determines whether the adjusted signal strength is within the signal strength range; and Step S7: When the adjusted signal strength is within the signal strength range, the power amplifier 25 transmits the radio frequency signal with the adjusted signal strength. Before performing step S1, the signal compensation method for fiber optic wireless (RoF) communication can also perform the following steps: Step S8: The first device 1 sends a preset signal strength to the second device 2.

[0040] Furthermore, the signal compensation method for RoF (RoFi) communication further includes the following steps: Step S711: When the adjusted signal strength is greater than the upper limit of the signal strength, the signal compensation unit 24 calculates the upper limit and lower limit of the signal strength to generate a signal strength difference; Step S712: The signal compensation unit 24 generates an updated signal compensation value based on the signal compensation value and the signal strength difference, and generates an updated adjusted signal strength based on the current signal strength and the updated signal compensation value; and Step S713: The power amplifier 25 transmits an radio frequency signal with the updated adjusted signal strength. Step S72: When the adjusted signal strength is less than the lower limit of the signal strength, the signal compensation unit 24 increases a specific compensation value to the signal compensation value at regular intervals to generate an updated signal compensation value, and generates an updated adjusted signal strength based on the current signal strength and the updated signal compensation value; and Step S73: The power amplifier 25 transmits an radio frequency signal with the updated adjusted signal strength.

[0041] Please refer to Figure 5. Figure 5 is a flowchart illustrating the steps of a signal compensation method for fiber optic wireless (RoF) communication according to a specific embodiment of the present invention. The steps in Figure 5 can be achieved through the signal compensation system for fiber optic wireless (RoF) communication of Figure 1, and Figure 5 is a further step of step S72 of Figure 4. As shown in Figure 5, in this specific embodiment, the signal compensation method for fiber optic wireless (RoF) communication includes the following steps: Step S721: When the adjusted signal strength is less than the lower limit of the signal strength, the power amplifier 25 generates an abnormal signal; Step S722: The signal compensation unit 24 records the number of abnormal signals; and Step S723: When the number of abnormal signals is greater than or equal to the number threshold, the signal compensation unit 24 increases a specific compensation value to the signal compensation value every such time interval to generate an updated signal compensation value, and generates an updated adjusted signal strength based on the current signal strength and the updated signal compensation value.

[0042] In summary, the signal compensation system for RoF (Radio over Fiber) communication of the present invention can measure the current signal strength of the radio frequency signal in real time through the signal measurement unit, and can immediately compensate for signal attenuation caused by lines or hardware components through the signal compensation unit, without the need for signal attenuation testing through additional test signals, thereby improving convenience and maintaining signal transmission quality. Furthermore, the signal compensation system for RoF communication of the present invention can also detect in real time whether the compensated signal strength is within the normal operating signal strength range through the power amplifier, and can detect temporary or long-term abnormal signal strength conditions. The compensation value can then be adjusted under different conditions through the signal compensation unit to achieve a "fast decrease, slow increase" signal strength control mechanism, thereby improving signal transmission efficiency and signal quality.

[0043] The detailed description of the preferred embodiments above is intended to more clearly illustrate the features and spirit of the present invention, and is not intended to limit the scope of the invention to the preferred embodiments disclosed above. Rather, the aim is to cover various modifications and equivalent arrangements within the scope of the patent claims made by this invention. Therefore, the scope of the patent claims made by this invention should be interpreted in the broadest possible sense based on the foregoing description, so as to cover all possible modifications and equivalent arrangements.

[0044] S: Signal compensation system for RoF (RoFi) communication

[0045] 1: First device

[0046] 11: First Signal Transmitter

[0047] 12: First Signal Receiver

[0048] 2: Second device

[0049] 21: Second signal transmitter

[0050] 22: Second signal receiver

[0051] 23: Signal Measurement Unit

[0052] 24: Signal Compensation Unit

[0053] 25: Power Amplifier

[0054] 26: Antenna

[0055] 3: Third device

[0056] 31: First optical fiber

[0057] Smax: Maximum signal strength

[0058] Smin: Lower limit of signal strength

[0059] BS: Base Station

[0060] S1~S8, S711~S713, S72~S73, S721~S723: Steps

Claims

1. A signal compensation system for RoF (RoFi) communication, comprising: a first device communicatively connected to a base station and used to receive a radio frequency (RF) signal emitted by the base station, the first device including a first signal transmitter for transmitting the RF signal at a preset signal strength; a first optical fiber communicatively connected to the first signal transmitter and used to transmit the RF signal; and a second device, further including: a second signal receiver communicatively connected to the first optical fiber and used to receive the RF signal; and a signal measurement unit connected to the second signal receiver. The signal measurement unit measures a current signal strength of the radio frequency signal; a signal compensation unit, connected to the signal measurement unit and storing the preset signal strength of the first signal transmitter, generates a signal compensation value based on the preset signal strength and the current signal strength, and generates an adjusted signal strength based on the current signal strength and the signal compensation value; and a power amplifier, connected to the signal compensation unit and having a signal strength range value, the signal strength range value including a lower limit value, the power amplifier being used to transmit the radio frequency signal; wherein... When the adjustment signal strength is within the range of signal strength values, the power amplifier transmits the radio frequency signal with the adjustment signal strength; wherein, when the adjustment signal strength is less than the lower limit of the signal strength, the signal compensation unit increases a specific compensation value to the signal compensation value at regular intervals to generate an updated signal compensation value, and generates an updated adjustment signal strength based on the current signal strength and the updated signal compensation value.

2. The signal compensation system for fiber optic wireless (RoF) communication as described in claim 1, wherein the signal strength range includes an upper limit value and the lower limit value is the upper limit value multiplied by a safety factor.

3. The signal compensation system for fiber optic wireless (RoF) communication as described in claim 2, wherein when the adjusted signal strength is greater than the upper limit of the signal strength, the signal compensation unit calculates the upper limit of the signal strength and the lower limit of the signal strength to generate a signal strength difference, and generates the updated signal compensation value based on the signal compensation value and the signal strength difference.

4. The signal compensation system for fiber optic wireless (RoF) communication as described in claim 1, wherein the signal compensation unit pre-stores a threshold number, and when the adjusted signal strength is less than the lower limit of the signal strength, the power amplifier generates an abnormal signal, and the signal compensation unit records an abnormal number of times the abnormal signal occurs, and when the abnormal number of times is greater than or equal to the threshold number, the signal compensation unit increases the specific compensation value to the signal compensation value.

5. A signal compensation method for RoF (RoFi) communication, comprising the following steps: a first signal transmitter of a first device transmits a radio frequency (RF) signal emitted by a base station at a preset signal strength; a first optical fiber transmits the RF signal; a second signal receiver of a second device receives the RF signal; a signal measurement unit of the second device measures a current signal strength of the RF signal; a signal compensation unit of the second device generates a signal compensation value based on the preset signal strength and the current signal strength, and calculates a signal compensation value based on the current signal strength and the signal compensation value. The signal compensation unit generates an adjustment signal strength; when the adjustment signal strength is within a signal strength range of a power amplifier, the power amplifier transmits the radio frequency signal with the adjustment signal strength; and when the adjustment signal strength is less than a lower limit of the signal strength of the power amplifier, the signal compensation unit increases a specific compensation value to the signal compensation value at regular intervals to generate an updated signal compensation value, and generates an updated adjustment signal strength based on the current signal strength and the updated signal compensation value, and the power amplifier transmits the radio frequency signal with the updated adjustment signal strength.

6. The signal compensation method for fiber optic wireless (RoF) communication as described in claim 5 further comprises the following steps: when the adjusted signal strength is greater than an upper limit value of the signal strength of the power amplifier, the signal compensation unit calculates the upper limit value and the lower limit value of the signal strength to generate a signal strength difference; the signal compensation unit generates an updated signal compensation value based on the signal compensation value and the signal strength difference, and generates an updated adjusted signal strength based on the current signal strength and the updated signal compensation value; and the power amplifier transmits the radio frequency signal with the updated adjusted signal strength.

7. The signal compensation method for fiber optic wireless (RoF) communication as described in claim 6, wherein in the step of increasing the specific compensation value to the signal compensation value every certain time interval when the adjusted signal strength is less than the lower limit of the signal strength to generate the updated signal compensation value, and generating the updated adjusted signal strength based on the current signal strength and the updated signal compensation value, the method further comprises the following steps: when the adjusted signal strength is less than the lower limit of the signal strength, the power amplifier generates an abnormal signal; the signal compensation unit records an abnormality count of the abnormal signal; and when the abnormality count is greater than or equal to a threshold value, the signal compensation unit increases the specific compensation value to the signal compensation value every certain time interval to generate the updated signal compensation value, and generates the updated adjusted signal strength based on the current signal strength and the updated signal compensation value.

8. The signal compensation method for fiber optic wireless (RoF) communication as described in claim 6, wherein before the step of the first signal transmitter of the first device transmitting the radio frequency signal emitted by the base station with the preset signal strength, the method further comprises the step of the first device transmitting the preset signal strength to the second device.

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