Method for synchronization maintenance and fast wake-up of a wireless communication system

Abstract

This invention relates to the field of wireless communication technology and discloses a method for maintaining synchronization and fast wake-up in a wireless communication system, comprising the following specific steps: Each of the transmitting and receiving ends of the wireless communication system is equipped with an independent clock source; the transmitting end sends a synchronization frame; the receiving end detects the synchronization frame sent by the transmitting end, and the system enters closed-loop synchronization; the wireless communication system enters normal operating state; in normal operating state, the receiving end receives the signal sent by the transmitting end, determines the optimal sampling point by slowly adjusting the receiving end timing, and adjusts the receiving end timing to synchronize with the transmitting end timing; the transmitting end sends a silence command, and after receiving the silence command, the receiving end enters a timing maintenance state; synchronization is maintained through the clock sources of the transmitting and receiving ends. This invention solves the problem that existing technologies cannot maintain synchronization for long periods and has the characteristic of avoiding detection and exposure due to transmission issues.

Description

Technical Field

[0001] This invention relates to the field of wireless communication technology, and more specifically, to a method for maintaining synchronization and fast wake-up in a wireless communication system. Background Technology

[0002] After being activated, the wireless communication system needs to enter a radio silent working mode during the on-duty state and maintain synchronization for a long time. When communication services are required, it must quickly enter the state and the wireless communication system must be able to wake up quickly and restore the wireless communication link.

[0003] Conventional wireless communication systems need to periodically send maintenance frames to maintain the timing and routing relationships between communication nodes. However, sending maintenance frames can expose the communication system to detection.

[0004] The receiving end of the communication system uses a high-multiplier clock sampling and detection method to detect the synchronization frame of the transmitting end, obtaining the burst periodic signal and TOD information synchronized with the transmitting end. The receiving end uses the burst periodic signal and TOD information to adjust the local timing and determine the optimal sampling point. The selection of the sampling point is crucial for system data transmission and reception. A large deviation between the selected sampling point and the optimal sampling point can lead to a decrease in the system's error correction capability, bit errors, or even link interruption. Therefore, the adjustment of the sampling point must be very careful, and the adjustment range should not be too large. However, the system application conditions dictate that it needs to quickly enter a working state, requiring the sampling point timing to be adjusted to the correct position as soon as possible. This rapid adjustment contradicts the requirement for stable sampling points.

[0005] A prior art method and apparatus for TDMA time slot synchronization calibration. The method includes: at least one slave device receiving a synchronization frame from a master device; the synchronization frame including a first count value of a timer counter in the master device; at least one slave device parsing the synchronization frame to obtain the first count value; and for each slave device, adjusting the TDMA time slot of the slave device according to the first count value and a second count value of the timer counter in the slave device, so as to keep the TDMA time slot of the slave device synchronized with the TDMA time slot of the master device.

[0006] However, existing technologies have the problem of not being able to maintain synchronization for a long time. Therefore, how to invent a synchronization maintenance method for a wireless communication system that can maintain synchronization for a long time is a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0007] In order to solve the problem that existing technologies cannot maintain synchronization for a long time, this invention provides a synchronization maintenance method for wireless communication systems that can maintain synchronization for a long time, which has the characteristic of avoiding detection and exposure due to transmission.

[0008] To achieve the above-mentioned objectives of this invention, the technical solution adopted is as follows: A synchronization maintenance method for a wireless communication system includes the following specific steps: Each of the transmitting and receiving ends of the wireless communication system is equipped with an independent clock source. The sending end sends a synchronization frame; the receiving end detects the synchronization frame sent by the sending end, and the system enters closed-loop synchronization; The wireless communication system enters normal operation mode. In normal operation mode, the receiver receives the signal sent by the transmitter, determines the optimal sampling point by slowly adjusting the receiver timing, and adjusts the receiver timing to synchronize with the transmitter timing. The sending end sends a silence command, and after receiving the silence command, the receiving end enters the timing hold state; Synchronization is maintained through clock sources at both the sending and receiving ends.

[0009] Preferably, the stability of the independent clock source is ≤ ±5ppb.

[0010] Furthermore, the receiving end detects the synchronization frame sent by the sending end, and the system enters closed-loop synchronization. The specific steps are as follows: The receiver identifies synchronization frames by detecting and matching specific predefined features in the synchronization frames; Identify burst periodic signals and TOD information in the synchronization frame; the receiving end divides time slots based on the time information of the burst periodic signals and TOD information; The receiving end performs sending and receiving in the allocated time slots.

[0011] Furthermore, the optimal sampling point is determined by slowly adjusting the timing of the receiver. Specifically, based on the timing deviation between the transmitted signal and the received signal, a slow adjustment strategy is adopted. The timing of the signal is adjusted in steps less than a set threshold using a correction algorithm to determine the optimal sampling point.

[0012] Furthermore, after entering the timing hold state, the timing of the signal received by the receiver is detected in real time, and the clock sources of the transmitter and receiver are slowly adjusted to maintain stable synchronization.

[0013] Furthermore, the timing hold state has a maximum hold time limit; after the time limit is reached, the timing hold state is automatically exited and the search synchronization state is entered. Furthermore, in the aforementioned search synchronization state, the sending end sends a synchronization frame to the receiving end. Based on the received synchronization frame, the receiving end obtains the burst periodic signal and TOD information synchronized with the sending end. The receiving end uses the burst periodic signal and TOD information to directly adjust the local timing, enabling the receiving end to enter a normal working state.

[0014] Furthermore, the receiver directly adjusts the local timing using burst periodic signals and TOD information. Specifically, it adopts a direct adjustment strategy without additional timing processing, and directly adjusts the baseband timing to match the timing of the transmitter through a correction algorithm.

[0015] A fast wake-up method for a wireless communication system includes the following specific steps: The sending end issues an exit silence command; When the receiver receives the exit silence command, it enters the fast wake-up state. In the fast wake-up state, the transmitter sends a synchronization frame, determines the optimal sampling point by quickly adjusting the receiver timing, and adjusts the receiver timing to synchronize with the transmitter timing. The wireless communication system has entered normal operating condition.

[0016] Preferably, the optimal sampling point is determined by quickly adjusting the receiver timing, and the receiver timing is adjusted to synchronize with the transmitter timing. The specific steps are as follows: Based on the timing deviation between the transmitted signal and the received signal, a fast adjustment strategy is adopted. The timing of the signal is quickly adjusted using a correction algorithm with an adjustment step greater than a set threshold to determine the optimal sampling position. Considering potential erroneous correlations, a maximum adjustment step is set.

[0017] The beneficial effects of this invention are as follows: This invention discloses a design based on a highly stable clock, which enables the timing of multiple communication nodes in the system to remain synchronized for a long time. In normal operation, the optimal sampling point is determined by slowly adjusting the timing of the receiving end and then entering a timing-maintaining state, thus solving the problem of not being able to maintain synchronization for a long time. It also has the feature of avoiding detection and exposure caused by transmission. Attached Figure Description

[0018] Figure 1 This is a flowchart illustrating a synchronization maintenance method for a wireless communication system according to the present invention.

[0019] Figure 2 This is a schematic diagram of the transmission and reception timing and optimal sampling reference point of a synchronization maintenance method for a wireless communication system according to the present invention.

[0020] Figure 3 This is a state transition diagram of synchronization maintenance and fast wake-up in a fast wake-up method for a wireless communication system according to the present invention. Detailed Implementation

[0021] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments.

[0022] Example 1 like Figure 1As shown, a synchronization maintenance method for a wireless communication system includes the following specific steps: Each of the transmitting and receiving ends of the wireless communication system is equipped with an independent clock source. The sending end sends a synchronization frame; the receiving end detects the synchronization frame sent by the sending end, and the system enters closed-loop synchronization; The wireless communication system enters normal operation mode. In normal operation mode, the receiver receives the signal sent by the transmitter, determines the optimal sampling point by slowly adjusting the receiver timing, and adjusts the receiver timing to synchronize with the transmitter timing. The sending end sends a silence command, and after receiving the silence command, the receiving end enters the timing hold state; Synchronization is maintained through clock sources at both the sending and receiving ends.

[0023] In one specific embodiment, the stability of the independent clock source is ≤ ±5ppb.

[0024] In this embodiment, based on a highly stable independent clock source, the receiver uses a high-multiplier working clock sampling and detection method to detect the synchronization frame sent by the transmitter, and obtains the burst periodic signal and time information synchronized with the master station. The receiver uses the burst periodic signal and time information to divide the time slots, and then the receiver performs transmission and reception on the divided time slots. In this way, the entire communication system forms a closed-loop synchronization in the frequency hopping cycle.

[0025] Example 2 More specifically, in one embodiment, the receiving end detects the synchronization frame sent by the sending end, and the system enters closed-loop synchronization. The specific steps are as follows: The receiver identifies synchronization frames by detecting and matching specific predefined features in the synchronization frames; Identify burst periodic signals and TOD information in the synchronization frame; the receiving end divides time slots based on the time information of the burst periodic signals and TOD information; The receiving end performs sending and receiving in the allocated time slots.

[0026] In one specific embodiment, the optimal sampling point is determined by slowly adjusting the timing of the receiver. Specifically, based on the timing deviation between the transmitted signal and the received signal, a slow adjustment strategy is adopted, and the timing of the signal is adjusted by a correction algorithm with an adjustment step smaller than a set threshold to determine the optimal sampling point.

[0027] In this embodiment, there are 8 signal sampling points at the transmitting and receiving ends, with a threshold of 0.5 sampling points and a slow adjustment step of 1 / 6 of a sampling point. Slow adjustment is used for small-scale adjustments, ensuring relatively stable sampling positions and preventing excessive deviations, thus avoiding oscillations caused by repeated adjustments.

[0028] In one specific embodiment, after entering the timing hold state, the phase of the signal received by the receiver is detected in real time, and stable synchronization is maintained by slowly adjusting the clock sources of the transmitter and receiver.

[0029] In one specific embodiment, the timing hold state has a maximum hold time limit; after the time limit is reached, the timing hold state is automatically exited and the search synchronization state is entered. In one specific embodiment, during the search synchronization state, the sending end sends a synchronization frame to the receiving end. Based on the received synchronization frame, the receiving end obtains a burst periodic signal and TOD information synchronized with the sending end. The receiving end uses the burst periodic signal and TOD information to directly adjust the local timing, enabling the receiving end to enter a normal working state.

[0030] In this embodiment, synchronization is maintained using a local high-stability clock source with a clock stability of ≤±5ppb. The maximum maintenance time is 10.4 hours, after which the synchronization automatically terminates. In one specific embodiment, the receiver directly adjusts the local timing using burst periodic signals and TOD information. Specifically, it uses a direct adjustment algorithm without additional processing to directly adjust the baseband timing to be consistent with that of the transmitter through a correction algorithm.

[0031] In this embodiment, direct adjustment is applicable to the unsynchronized state. The direct adjustment strategy can be used to adjust in one step and quickly enter the normal working state.

[0032] Example 3 A fast wake-up method for a wireless communication system includes the following specific steps: The sending end issues an exit silence command; When the receiver receives the exit silence command, it enters the fast wake-up state. In the fast wake-up state, the transmitter sends a synchronization frame, determines the optimal sampling point by quickly adjusting the receiver timing, and adjusts the receiver timing to synchronize with the transmitter timing. The wireless communication system has entered normal operating condition.

[0033] In one specific embodiment, the optimal sampling point is determined by fast-adjusting the receiver timing, and the receiver timing is adjusted to synchronize with the transmitter timing. The specific steps are as follows: Based on the timing deviation between the transmitted signal and the received signal, a fast adjustment strategy is adopted. The timing of the signal is adjusted by a correction algorithm with an adjustment step greater than a set threshold to determine the optimal sampling position. Considering potential erroneous correlations, a maximum adjustment step is set.

[0034] In this embodiment, there are 8 signal sampling points at the transmitting end and the receiving end, the threshold is set to 0.5 sampling points, and the fast adjustment step is 1 sampling point.

[0035] In this embodiment, a maximum adjustment step is set to address potential false correlations, thus preventing single false correlations, adjustments exceeding limits, and consequently, sampling position errors and link interruptions. Calculations show that 10 rapid adjustments are sufficient to achieve the correct alignment, and based on the TDMA cycle, a stable normal operating state can be reached within 1 second.

[0036] In this embodiment, in a wireless communication system, the synchronization retention time is approximately 20 minutes and the wake-up time is 30 seconds when using traditional methods. After adopting the technical solution of this invention, the synchronization retention time is 10.4 hours and the wake-up time is 1 second, significantly improving both synchronization retention and wake-up times.

[0037] Obviously, the above embodiments of the present invention are merely examples for clearly illustrating the present invention, and are not intended to limit the implementation of the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the claims of the present invention.

Claims

1. A method for maintaining synchronization and fast wake-up in a wireless communication system, characterized in that: The specific steps include the following: An independent clock source is set up at both the transmitting and receiving ends of the wireless communication system; the stability of the independent clock source is ≤ ±5ppb. The sending end sends a synchronization frame; the receiving end detects the synchronization frame sent by the sending end, and the system enters closed-loop synchronization; The wireless communication system enters normal operation mode. In normal operation mode, the receiver receives the signal sent by the transmitter, determines the optimal sampling point by slowly adjusting the receiver timing, and adjusts the receiver timing to synchronize with the transmitter timing. The sending end sends a silence command, and after receiving the silence command, the receiving end enters the timing hold state; Synchronization is maintained through clock sources at both the sending and receiving ends; The sending end issues an exit silence command; When the receiver receives the exit silence command, it enters the fast wake-up state. In the fast wake-up state, the transmitter sends a synchronization frame, determines the optimal sampling point by quickly adjusting the receiver timing, and adjusts the receiver timing to synchronize with the transmitter timing. The wireless communication system has entered normal operating condition; The method for determining the optimal sampling point by slowly adjusting the timing of the receiver is as follows: based on the timing deviation between the transmitted signal and the received signal, a slow adjustment strategy is adopted, and the timing of the signal is adjusted stepwise by a correction algorithm with a step size less than a set threshold to determine the optimal sampling point. The steps for determining the optimal sampling point by quickly adjusting the receiver timing and synchronizing it with the transmitter timing are as follows: Based on the timing deviation between the transmitted signal and the received signal, a fast adjustment strategy is adopted. The timing of the signal is dynamically adjusted by using a correction algorithm with an adjustment step greater than a set threshold to determine the optimal sampling position.

2. The synchronization maintenance and fast wake-up method for a wireless communication system according to claim 1, characterized in that: The receiving end detects the synchronization frame sent by the sending end, and the system enters closed-loop synchronization. The specific steps are as follows: The receiver identifies synchronization frames by detecting and matching predefined features in the synchronization frames; Identify burst periodic signals and TOD information in the synchronization frame; the receiving end divides time slots based on the time information of the burst periodic signals and TOD information; The receiving end performs sending and receiving in the allocated time slots.

3. The synchronization maintenance and fast wake-up method for a wireless communication system according to claim 2, characterized in that: After entering the timing hold state, the phase of the signal received by the receiver is detected in real time, and stable synchronization is maintained by slowly adjusting the clock sources of the transmitter and receiver.

4. The synchronization maintenance and fast wake-up method for a wireless communication system according to claim 2, characterized in that: The timing hold state has a maximum hold time limit; after the time limit is reached, the timing hold state will automatically exit and enter the search synchronization state.

5. The synchronization maintenance and fast wake-up method for a wireless communication system according to claim 4, characterized in that: In the search synchronization state, the sending end sends a synchronization frame to the receiving end. The receiving end obtains the burst periodic signal and TOD information synchronized with the sending end based on the received synchronization frame. The receiving end uses the burst periodic signal and TOD information to directly adjust the local timing, so that the receiving end enters the normal working state.

6. The synchronization maintenance and fast wake-up method for a wireless communication system according to claim 5, characterized in that: The receiver directly adjusts the local timing using burst periodic signals and TOD information. Specifically, it adopts a direct adjustment strategy without additional processing and uses a correction algorithm to directly adjust the local timing to be consistent with the transmitter timing.

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