Method and device for recovering TDD control signal of remote terminal of remote system by using MCU

Abstract

The invention belongs to the technical field of 5G. The invention provides a method for recovering a TDD (Time Division Duplexing) control signal of a remote terminal of a remote system by utilizing an MCU (Microprogrammed Control Unit). The method comprises the following steps of: 1, initializing and capturing a TDD synchronous signal interruption pin, an LNA (Low Network Alliance) control signal pin and a PA (Power Amplification) control Step 2, the MCU detects a 5G wireless frame, and initializes a timer according to a 5G wireless frame period; step 3, the MCU captures an edge flipping signal in the TDD synchronization signal, when the edge flipping signal is a falling edge, a timestamp t1 is recorded, and the edge flipping signal continues to be detected; when the edge flipping signal is a rising edge, recording a timestamp t2, controlling the signal pin to pull up the level by the LNA, controlling the signal pin to pull down the level by the PA, and starting a timer according to the time difference between the timestamp t2 and the timestamp t1; and step 4, when timer interruption arrives, the LNA controls the signal pin to pull down the level, the PA controls the signal pin to pull up the level, and the timer is stopped, so that complete TDD uplink and downlink synchronization signals are generated. And the recovery of two paths of control signals of the LNA and the PA is realized by adopting an MCU timing mode.

Description

Technical Field

[0001] The present invention belongs to the field of 5G technology, and specifically relates to a method and device for recovering TDD control signals of a remote device in a remote system by using an MCU. Background Art

[0002] In mobile communication networks, due to various reasons, it is impossible for the network to achieve complete seamless coverage. For operators, sometimes it is difficult to build and open base stations in some coverage blind areas due to cost and transmission conditions. The remote system is a mobile communication base station signal remote device, which serves as an auxiliary means of base station coverage. It can expand the service range and eliminate coverage blind areas, such as signal blind areas formed by obstacles such as mountains, buildings, and trees. In suburban areas, it can enhance the field strength, expand the coverage of suburban stations, and be set up along highways to enhance coverage efficiency. It can also solve indoor coverage, such as signal attenuation signal blind areas in large buildings, underground shopping malls, tunnels and other attenuation signal blind areas.

[0003] When the coaxial micro-distribution or analog fiber-optic remote repeater products work in TDD mode, high-precision uplink and downlink timing synchronization is required between the near-end device and the far-end device. In the prior art, the first solution is to add two AM modulators to the near-end device to modulate the PA_TDD control signal and the LNA_TDD control signal onto two carrier signals respectively, and the far-end device recovers the PA_TDD and LNA_TDD control signals respectively through two envelope detection and comparator circuits. The circuit of this solution is complex and the cost is high. Another solution is to generate a protection time slot by passing a TDD control signal transmitted from the near-end device through a link delay buffer circuit. The disadvantage of this solution is that the solution is complex, difficult to debug, and inflexible. Summary of the invention

[0004] The present invention aims to solve the problems in the prior art that the TDD control signal recovery circuit of the remote device is complex, costly, difficult to debug and inflexible, and provides a method for realizing the TDD control signal recovery of the remote device of the remote system by using an MCU, comprising the following steps:

[0005] Step 1: MCU initializes and captures the TDD synchronization signal interrupt pin, LNA control signal pin, and PA control signal pin;

[0006] Step 2: MCU detects the 5G wireless frame and initializes the timer according to the 5G wireless frame period;

[0007] Step 3: MCU captures the edge flip signal in the TDD synchronization signal. When the edge flip signal is a falling edge, it records the timestamp t1 and continues to detect the edge flip signal. When the edge flip signal is a rising edge, it records the timestamp t2, the LNA control signal pin pulls the level high, the PA control signal pin pulls the level low, and starts the timer according to the time difference between the time stamp t2 and the time stamp t1.

[0008] Step 4: When the timer interrupt arrives, the LNA control signal pin pulls the level low, and the PA control signal pin pulls the level high to stop the timer, thereby generating a complete TDD uplink and downlink synchronization signal.

[0009] In some embodiments, in step 1, the MCU initializes GPIO pin A as an interrupt pin for capturing a TDD synchronization signal; initializes GPIO pin B as an LNA control signal pin, and sets pin B to a low level for generating an LNA signal; and initializes GPIO pin C as a PA control signal pin, and sets pin C to a high level for generating a PA control signal.

[0010] In some embodiments, in step 2, the MCU detects the 5G wireless frame, and when the 5G wireless frame structure is a single cycle, initializes timer 1; when the 5G wireless frame structure is a double cycle, initializes timer 1 and timer 2;

[0011] In step 3, when the 5G wireless frame structure is a single cycle, start timer 1; when the 5G wireless frame structure is a double cycle, start timer 1 or timer 2 according to the time difference between the interval t2 and the interval t1.

[0012] In some embodiments, when the 5G radio frame structure is a single cycle, the initialization timer 1 has a duration equal to the total uplink time in the 5G radio frame cycle;

[0013] When the 5G wireless frame structure is a dual cycle, the initialization timer 1 is equal to the total uplink time in the period before the dual cycle of the 5G wireless frame; the initialization timer 2 is equal to the total uplink time in the period after the dual cycle of the 5G wireless frame.

[0014] In some embodiments, in step 3, when the edge flip signal in the TDD synchronization signal is a rising edge, the timestamp t2 is recorded, and after the LNA control signal pin is pulled high, after a preset protection interval delay, the PA control signal pin is pulled low;

[0015] In step 4, when the timer interrupt arrives, the LNA control signal pin pulls the level down, and after a preset protection interval delay of two, the PA control signal pin pulls the level up.

[0016] In some embodiments, the protection interval delay 1 and the protection interval delay 2 are both preset to 5us.

[0017] In some embodiments, step 5 is also included: the MCU detects whether the 5G wireless frame is modified, and if so, proceeds to step 2, otherwise proceeds to step 3.

[0018] The present invention also provides a remote device that uses an MCU to implement TDD control signal recovery, including a combiner, a detector, a low-pass filter, a comparator and an MCU; the MCU is used to implement TDD control signal recovery according to any of the above-mentioned methods for implementing TDD control signal recovery of a remote device of a remote system using an MCU.

[0019] The present invention also provides a remote system for recovering TDD control signals using MCU, including a near-end machine and a far-end machine for recovering TDD control signals using MCU as described above, wherein the near-end machine and the far-end machine are connected via a coaxial network or optical fiber.

[0020] The present invention also provides a computer-readable storage medium, on which a computer program is stored, and the computer program is used to implement any one of the above-mentioned methods for recovering TDD control signals of a remote device in a remote system by using an MCU.

[0021] The beneficial effects of the present invention are as follows: the present invention innovatively utilizes the original MCU chip of the remote device without increasing the hardware cost, and adopts the MCU timing method to realize the recovery of the two-way control signals of LNA and PA, thereby solving the problems of the complexity of the existing hardware solution and the difficulty of debugging. In addition, a protection interval is added in the control time slot of opening the two-way control signals of LNA and PA, thereby preventing the generation of self-excitation and damage to LNA. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 , structural diagram of optical fiber repeater station in the background technology of the present invention.

[0023] Figure 2 , structural diagram of the optical fiber repeater station in Example 1 of the present invention.

[0024] Figure 3 , schematic diagram of switch control of the power amplifier and low noise amplifier in Embodiment 1 of the present invention.

[0025] Figure 4 , MCU processing flow chart in Example 1 of the present invention.

[0026] Figure 5 , 5ms single-cycle TDD signal recovery diagram in Example 2 of the present invention. DETAILED DESCRIPTION

[0027] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0028] Example 1

[0029] In this example, a remote system is provided for realizing TDD control signal recovery by MCU, such as Figure 1 As shown, it includes a proximal machine and a distal machine, and the proximal machine and the distal machine are connected via a coaxial network or an optical fiber.

[0030] like Figure 2 The near-end device includes a radio frequency signal input terminal, a TDD control signal input terminal, a combiner, and a radio frequency switch. The far-end device includes a combiner, a detector, a low-pass filter, a comparator, and an MCU.

[0031] Among them, this example innovatively uses the original MCU chip of the remote machine, and adopts the MCU timing method to realize the recovery of the two control signals of LNA and PA without increasing the hardware cost, solving the problems of complex existing hardware solutions and difficult debugging. Among them, the switch control principle of the power amplifier and low noise amplifier is as follows Figure 3 shown.

[0032] Specifically, such as Figure 4 As shown, the MCU works as follows:

[0033] Step 1: MCU initializes and captures the TDD synchronization signal interrupt pin, LNA control signal pin, and PA control signal pin. Specifically, MCU initializes GPIO pin A to capture the edge flip signal in the TDD synchronization signal; initializes GPIO pin B and sets pin B to a low level to generate the LNA signal; initializes GPIO pin C and sets pin C to a high level to generate the PA control signal.

[0034] Step 2: The MCU detects the 5G wireless frame and initializes the timer according to the 5G wireless frame period.

[0035] When the 5G wireless frame structure is a single cycle: initialize timer 1, and the duration of timer 1 is the total uplink time in the 5G wireless frame cycle.

[0036] When the 5G wireless frame structure is a dual cycle: the initialization timer 1 duration is the total uplink time in the period before the dual cycle of the 5G wireless frame; the initialization timer 2 duration is the total uplink time in the period after the dual cycle of the 5G wireless frame.

[0037] Step 3: MCU captures the TDD synchronization signal interrupt. When the edge flip signal in the TDD synchronization signal is a falling edge, the timestamp t1 is recorded and the edge flip signal is continued to be detected. When the edge flip signal in the TDD synchronization signal is a rising edge, the timestamp t2 is recorded, the LNA control signal pin is pulled high, and after a preset protection interval delay of 1, the PA control signal pin is pulled low, and the timer is started according to the time difference between the time stamp t2 and the time stamp t1. Specifically, when the 5G wireless frame structure is a single cycle, timer 1 is started; when the 5G wireless frame structure is a double cycle, timer 1 or timer 2 is started according to the time difference between the time stamp t2 and the time stamp t1.

[0038] It is worth noting that the dual cycle is divided into a front cycle and a rear cycle. The level time of LNA and PA in the front and rear cycles is different, so two timers are needed to control the level holding time of LAN and PA. Starting timer 1 or timer 2 needs to be determined based on the difference between t2 and t1.

[0039] For example: 2.5ms dual-cycle structure, there are two different types of cycles in 5ms. The first 2.5ms is the previous cycle DDDSU (including 3 downlink time slots, 1 uplink time slot, and 1 special time slot. The downlink time slot occupies 0.7 of the special time slots. Each time slot lasts about 0.5ms. The total downlink time is 3.7*0.5≈1.85ms; the total uplink time is 1.3*0.5≈

[0040] 0.65ms), the second 2.5ms later period is DDSUU (including 2 downlink time slots, 2 uplink time slots, and 1 special time slot, of which 0.7 is the downlink time slot, and the total downlink time is 2.7*0.5≈1.35ms, and the total uplink time is 2.3*0.5≈1.15ms). Among them, D represents the downlink time slot, U represents the uplink time slot, and S represents the special time slot. Then, the duration of timer 1 is 0.65ms, and the duration of timer 2 is 1.15ms.

[0041] If the time difference between t2 and t1 is about 1.85ms, select timer 1 with a time of 0.65ms to control the level holding time of LAN and PA. If the time difference between t2 and t1 is about 1.35ms, select timer 2 with a time of 1.15ms to control the level holding time of LAN and PA. That is, the sum of the difference between t2 and t1 and the selected timer duration is approximately equal to the length of one cycle of the 5G wireless frame.

[0042] Step 4: When the timer interrupt arrives, the LNA control signal pin pulls the level low. After the preset protection interval delay 2, the PA control signal pin pulls the level high to stop the timer, thereby generating a complete TDD uplink and downlink synchronization signal, and repeating step 2.

[0043] The preset guard interval delay 1 and the preset guard interval delay 2 are used to prevent the generation of self-excitation and damage to the LNA, and are set to 5us in this example.

[0044] Furthermore, the present invention supports changing the 5G wireless frame structure through external actions during the operation of the MCU. The implementation method includes step 5. After the complete TDD uplink and downlink synchronization signals are generated in step 4, the MCU re-detects the 5G wireless frame structure. When it is found that the 5G wireless frame structure has changed, it enters step 2, re-initializes the timer, and waits for the TDD synchronization signal to enter the interrupt handler. Otherwise, it enters step 3 and continues to execute the current task under the current process.

[0045] Example 2

[0046] This example takes a 5ms NR single-cycle TDD signal as an example for further explanation. Figure 5 shown.

[0047] A: The MCU obtains the 5G NR frame format as a 5ms single-cycle time slot, and the initialization timer time is 1.22ms. The 5ms single-cycle wireless frame contains 10 time slots with a structure of DDDDDDDSUU, of which there are 2 uplink time slots and one special time slot. The uplink time slot accounts for about 0.43 of the special time slots, and each time slot is about 0.5ms. The uplink time is about 2.43*0.5≈1.22ms.

[0048] B: MCU initializes GPIO pin A interrupt to capture edge flip signals in TDD control signals; MCU initializes GPIO pins B and C to restore LNA and PA control signals, sets pin B to low level to generate LNA signals, and sets pin C to high level to generate PA control signals;

[0049] C: MCU captures the edge signal in the TDD control signal, triggers the interrupt program when it is a falling edge, and records the current timestamp t1; MCU continues to capture the edge signal in the TDD control signal, triggers the interrupt program when it is a rising edge, pulls the level of the LNA control signal output pin B high, increases the protection interval delay, pulls the level of the PA control signal pin C low, and records the current timestamp t2;

[0050] F. Start the timer based on the timestamp difference between t2 and t1;

[0051] G. After waiting for 1.22ms, the timer triggers an interrupt, the LNA control signal output pin B is pulled low, the protection interval delay is increased, the PA control signal pin C is pulled high, and the timer is stopped at the same time; in this way, the MCU generates a complete LNA and PA control signal cycle, and the MCU detects whether the 5G NR frame format is modified, thereby adjusting the timer time.

[0052] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0053] The above-mentioned embodiments only express the implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the present application. It should be pointed out that, for a person of ordinary skill in the art, several modifications and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the attached claims.

Claims

1. A method for recovering TDD control signals of a remote device in a remote system using MCU, characterized in that: The following steps are involved: Step 1: MCU initializes and captures the TDD synchronization signal interrupt pin, LNA control signal pin, and PA control signal pin; Step 2: MCU detects the 5G wireless frame and initializes the timer according to the 5G wireless frame period; Step 3: MCU captures the edge flip signal in the TDD synchronization signal. When the edge flip signal is a falling edge, it records the timestamp t1 and continues to detect the edge flip signal. When the edge flip signal is a rising edge, it records the timestamp t2, the LNA control signal pin pulls the level high, the PA control signal pin pulls the level low, and starts the timer according to the time difference between the time stamp t2 and the time stamp t1. Step 4: When the timer interrupt arrives, the LNA control signal pin pulls the level low, and the PA control signal pin pulls the level high to stop the timer, thereby generating a complete TDD uplink and downlink synchronization signal.

2. The method for recovering TDD control signals of a remote device in a remote system by using an MCU according to claim 1, characterized in that: In the step 1, the MCU initializes GPIO pin A as an interrupt pin for capturing TDD synchronization signals; initializes GPIO pin B as an LNA control signal pin, and sets pin B to a low level for generating an LNA signal; initializes GPIO pin C as a PA control signal pin, and sets pin C to a high level to generate a PA control signal.

3. The method for recovering TDD control signals of a remote device in a remote system by using an MCU according to claim 1 or 2, characterized in that: In the step 2, the MCU detects the 5G wireless frame, and when the 5G wireless frame structure is a single cycle, initializes timer 1; when the 5G wireless frame structure is a double cycle, initializes timer 1 and timer 2; In step 3, when the 5G wireless frame structure is a single cycle, start timer 1; when the 5G wireless frame structure is a double cycle, start timer 1 or timer 2 according to the time difference between the interval t2 and the interval t1.

4. The method for recovering TDD control signals of a remote device in a remote system by using an MCU according to claim 3, characterized in that: When the 5G wireless frame structure is a single cycle, the initialization timer 1 has a duration equal to the total uplink time in the 5G wireless frame cycle; When the 5G wireless frame structure is a dual cycle, the initialization timer 1 is equal to the total uplink time in the period before the dual cycle of the 5G wireless frame; the initialization timer 2 is equal to the total uplink time in the period after the dual cycle of the 5G wireless frame.

5. The method for recovering TDD control signals of a remote device in a remote system by using an MCU according to claim 4, characterized in that: In the step 3, when the edge flip signal in the TDD synchronization signal is a rising edge, the timestamp t2 is recorded, and after the LNA control signal pin is pulled high, after a preset protection interval delay, the PA control signal pin is pulled low; In step 4, when the timer interrupt arrives, the LNA control signal pin pulls the level down, and after a preset protection interval delay of two, the PA control signal pin pulls the level up.

6. The method for recovering TDD control signals of a remote device in a remote system by using an MCU according to claim 5, characterized in that: The protection interval delay 1 and the protection interval delay 2 are both preset to 5us.

7. The method for recovering TDD control signals of a remote device in a remote system by using an MCU according to claim 6, characterized in that: It also includes step 5: MCU detects whether the 5G wireless frame is modified, if so, it goes to step 2, otherwise it goes to step 3.

8. A remote device for realizing TDD control signal recovery using MCU, comprising a combiner, a detector, a low-pass filter, a comparator and an MCU, characterized in that: The MCU is used to realize TDD control signal recovery according to the method for realizing TDD control signal recovery of a remote device of a remote system using an MCU according to any one of claims 1 to 7.

9. A remote system for realizing TDD control signal recovery using MCU, comprising a near-end device, characterized in that: It also includes a remote device for realizing TDD control signal recovery using MCU as described in claim 8, wherein the near-end device is connected to the remote device via a coaxial network or an optical fiber.

10. A computer-readable storage medium, characterized in that: The storage medium stores a computer program, and the computer program is used to implement the method for recovering TDD control signals of a remote device in a remote system by using an MCU as described in any one of claims 1 to 7.

Images