A radio frequency link switching system based on dynamic spectrum sensing

Abstract

The application discloses a kind of based on dynamic spectrum sensing's radio frequency link switching system, specifically relates to the field of radio frequency link switching technology in new generation mobile communication base station, for solving the problem that the radio frequency link reconfiguration exists switching inertia period in prior art spectrum situation information exists time effectiveness deviation, leading to the problem that target link is unavailable after switching;It is whether the reconfiguration process state of radio frequency link is in switching inertia period by judging and in switching inertia period when prohibiting triggering new radio frequency link switching, in not in switching inertia period, the causal event chain of frequency point occupation state change is constructed to exclude parasitic cavity to obtain original available spectrum cavity, dissipate time is extracted using causal event chain to divide burst type or periodic type, and whether monotone decreasing and without rebound after verifying the dissipation trajectory of burst type, allow to initiate switching when meeting the conditions.

Description

Technical Field

[0001] This invention relates to the field of radio frequency link switching technology in next-generation mobile communication base stations, and more specifically, to a radio frequency link switching system based on dynamic spectrum sensing. Background Technology

[0002] Radio frequency (RF) link handover technology is one of the key technologies in next-generation mobile communication base station equipment used to improve spectrum resource utilization efficiency and communication link reliability. With the continuous increase in base station deployment density and the increasing complexity of the wireless spectrum environment, the spectrum sensing module on the base station side collects broadband spectrum information in real time to obtain the occupancy status, interference intensity, and signal characteristics of each frequency band, providing input for RF link handover decisions. During the handover process, the base station's baseband processing unit constructs a spectrum situation map based on the sensing data, identifies the communication quality of the current link and the availability of alternative links, and completes the RF link reconfiguration at the target carrier frequency, beam pointing, or antenna port mapping levels. Limited by the physical characteristics of RF front-end devices, the link reconfiguration process includes local oscillator locking, power amplifier bias establishment, and beamforming weight loading. The response time required for these steps objectively constitutes the minimum operating cycle for an RF link to perform a handover operation.

[0003] Existing technologies typically use idle frequency bands or low-interference channels obtained from spectrum sensing as the switching target when making radio frequency link switching decisions. However, the acquisition, transmission, and processing of spectrum sensing data introduce time delays, causing time discrepancies in the available channels marked in the spectrum situation map. After receiving a switching command, the radio frequency link enters a reconfiguration phase, during which the link cannot carry effective data transmission or respond to new switching commands. When the spectrum environment changes rapidly, switching decisions based on outdated spectrum situation information cannot ensure that the target link is still available when the reconfiguration is completed. This results in the link facing interference or resource collisions immediately after the switch, affecting the transmission reliability of the base station-side communication system equipment and the quality of service for users. Summary of the Invention

[0004] To overcome the aforementioned deficiencies of the prior art, the present invention provides a radio frequency link switching system based on dynamic spectrum sensing to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A radio frequency link switching system based on dynamic spectrum sensing includes: The information acquisition module is used to acquire spectrum situation information generated by dynamic spectrum sensing and the reconfiguration process status of the radio frequency link; The inertia judgment module is used to determine whether the reconfiguration process of the RF link is in the handover inertia period. If so, it prevents the triggering of a new RF link handover. The hole removal module is used to construct a causal event chain of frequency point occupancy status changes by using spectrum situation information and historical spectrum situation information if the reconfiguration process of the RF link is not in the switching inertia period, and to identify and remove parasitic holes triggered by adjacent frequency point occupancy events to obtain native available spectrum holes. The hole segmentation module is used to extract the dissipation time of causal disturbance events generated on adjacent frequency points during the period from the formation to the stabilization of native available spectrum holes using causal event chains, and to classify native available spectrum holes into burst-type native available spectrum holes or periodic native available spectrum holes based on the dissipation time. The trajectory judgment module is used only when it belongs to the sudden type of native available spectrum hole to extract the dissipation trajectory of the causal disturbance event within the dissipation time and to determine whether the dissipation trajectory shows a monotonically decreasing and non-rebounding convergence trend. The switching execution module is used to allow switching to the target RF link corresponding to a bursty natively available spectrum hole when the dissipation trajectory shows a monotonically decreasing and non-rebounding convergence trend.

[0006] Furthermore, the system acquires spectrum situational information generated by dynamic spectrum sensing and the reconfiguration process status of RF links, including: Broadband spectrum data is collected by a dedicated sensing antenna, and broadband spectrum data is collected in idle time slots by a service antenna. The broadband spectrum data collected by the dedicated sensing antenna and the broadband spectrum data collected by the service antenna are fused to obtain spectrum situation information. The reconfiguration process status of the RF link is obtained by monitoring the local oscillator lock-on completion signal, the power amplifier bias setup completion signal, and the beamforming weight loading completion signal of the RF link.

[0007] Furthermore, determine whether the RF link reconfiguration process is in the handover inertia period; if so, prevent triggering a new RF link handover, including: When any one of the following signals is incomplete: local oscillator lock-on completion signal, power amplifier bias setup completion signal, or beamforming weight loading completion signal, the RF link reconfiguration process is determined to be in the switching inertia period, and triggering a new RF link switch is prohibited.

[0008] Furthermore, if the RF link reconfiguration process is not in the handover inertia period, then using spectrum situation information and historical spectrum situation information, a causal event chain of frequency occupancy status changes is constructed to identify and filter out parasitic holes triggered by adjacent frequency occupancy events, thus obtaining natively available spectrum holes, including: When the local oscillator lock-on completion signal, the power amplifier bias establishment completion signal, and the beamforming weight loading completion signal are all in the completed state, it is determined that the reconfiguration process of the RF link is not in the switching inertia period. Arrange the occupancy status change events of each frequency point in the spectrum situation information in chronological order, compare them with the occupancy status change events of the corresponding frequency points in the historical spectrum situation information, associate the occupancy status change events that occur earlier in time with the occupancy status change events that occur later, and construct a causal event chain of frequency point occupancy status changes. In the causal event chain of frequency occupancy status changes, for available spectrum holes in the spectrum situation information, it is detected whether the occurrence event of the available spectrum hole is later in time than and causally related to the occupancy event of the adjacent frequency point. Available spectrum holes with a detection result of yes are identified as parasitic holes triggered by the occupancy event of the adjacent frequency point. Parasitic holes are removed from the available spectrum holes in the spectrum situation information to obtain the native available spectrum holes.

[0009] Furthermore, the occupancy status change events of each frequency point in the spectrum situation information are arranged in chronological order, including: recording the occupancy status change event as a frequency point identifier, event type, and event occurrence time, where the event type includes occupancy to idle and idle to occupancy; for the occupancy status change event of the first frequency point, the occupancy status change event of the second frequency point adjacent to the first frequency point is searched within the time window, and when the occurrence time of the occupancy status change event of the second frequency point is later than the occurrence time of the occupancy status change event of the first frequency point and the event type is opposite, the occupancy status change event of the first frequency point is associated with the occupancy status change event of the second frequency point.

[0010] Furthermore, by utilizing causal event chains, the dissipation time of causal disturbance events generated on adjacent frequency points during the formation and stabilization of native available spectrum holes is extracted. Based on the dissipation time, native available spectrum holes are classified into bursty native available spectrum holes or periodic native available spectrum holes, including: Locate the formation time of the native available spectrum hole in the causal event chain, and the termination time of the causal disturbance event at the adjacent frequency point after its formation. Use the time span from the formation time to the termination time as the dissipation time. Extract the occurrence cycle of native available spectrum holes from historical spectrum situation information; When the dissipation time is less than or equal to the occurrence period, the native available spectrum hole is classified as a burst-type native available spectrum hole; when the dissipation time is greater than the occurrence period, the native available spectrum hole is classified as a periodic-type native available spectrum hole.

[0011] Furthermore, the time span from the formation time to the termination time is taken as the dissipation time, including: in the causal event chain, the moment when the event type of the change in the occupancy status of the frequency point corresponding to the original available spectrum hole is changed from occupied to idle is taken as the formation time; in the causal event chain, the moment when the interference intensity corresponding to the first adjacent frequency point causal disturbance event after the formation time falls back to the baseline level before the disturbance is taken as the termination time; and the difference between the termination time and the formation time is taken as the dissipation time.

[0012] Furthermore, only when it is a sudden, natively available spectrum hole, the dissipation trajectory of the causal disturbance event within the dissipation time is extracted, and it is determined whether the dissipation trajectory shows a monotonically decreasing and non-rebounding convergence trend, including: When the native available spectrum hole is a sudden native available spectrum hole, the interference intensity corresponding to the causal disturbance events at adjacent frequency points within the dissipation time is extracted from the causal event chain and arranged in chronological order to form a dissipation trajectory. Determine whether there is a situation in the dissipation trajectory where the interference intensity at a later moment is greater than the interference intensity at a previous moment; If there is no situation where the interference intensity in the next moment is greater than that in the previous moment, then the dissipation trajectory is judged to show a monotonically decreasing convergence trend without rebound.

[0013] Furthermore, the dissipation trajectory is formed by arranging the interference intensity values ​​of causal disturbance events at adjacent frequency points corresponding to each time point within the dissipation time in chronological order to form an interference intensity sequence, and the interference intensity sequence is used as the dissipation trajectory.

[0014] Furthermore, when the dissipation trajectory exhibits a monotonically decreasing and non-rebounding convergence trend, handover to the target RF link corresponding to the burst-type natively available spectrum hole is permitted, including: The frequency points corresponding to the burst-type native available spectrum holes are determined as the target carrier frequencies; Based on the target carrier frequency generating oscillator configuration parameters, power amplifier bias configuration parameters, and beamforming weight configuration parameters; The local oscillator configuration parameters, power amplifier bias configuration parameters, and beamforming weight configuration parameters are sent to the RF front end, triggering the RF link to perform reconfiguration to switch to the target RF link.

[0015] Compared with the prior art, the present invention has the following beneficial effects: 1. By determining whether the reconfiguration process of the RF link is in the handover inertia period, new RF link handovers are prohibited during the handover inertia period. This ensures that the handover decision is synchronized with the actual completion status of hardware components such as RF front-end local oscillator locking, power amplifier bias establishment, and beamforming weight loading. This avoids issuing handover commands again before the RF link has completed its current reconfiguration, which could lead to internal link state conflicts. By constructing a causal event chain of frequency occupancy status changes, parasitic holes triggered by adjacent frequency occupancy events are identified and eliminated, resulting in native available spectrum holes. False idle frequency bands caused by adjacent channel leakage or power amplifier nonlinearity are eliminated from handover candidates in advance, reducing the uncertainty of handover target selection.

[0016] 2. By utilizing causal event chains, the dissipation time of causal disturbance events in native available spectrum holes is extracted. Based on the dissipation time, native available spectrum holes are classified into bursty native available spectrum holes or periodic native available spectrum holes. For bursty native available spectrum holes, dissipation trajectories are further extracted. When the dissipation trajectory shows a monotonically decreasing convergence trend without rebound, handover is allowed. The stability of bursty native available spectrum holes is confirmed from the perspective of the dissipation behavior of external interference sources. This ensures that the target carrier frequency is still available when the RF link is reconfigured, reduces link quality degradation caused by the recurrence of interference sources after handover, and improves the transmission reliability of base station-side communication system equipment in dynamic spectrum environments. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of a radio frequency link switching system based on dynamic spectrum sensing according to the present invention. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0019] Example: Figure 1 A schematic diagram of a radio frequency link switching system based on dynamic spectrum sensing according to the present invention is provided. The radio frequency link switching system based on dynamic spectrum sensing includes: The information acquisition module is used to acquire spectrum situation information generated by dynamic spectrum sensing and the reconfiguration process status of the radio frequency link; The inertia judgment module is used to determine whether the reconfiguration process of the RF link is in the handover inertia period. If so, it prevents the triggering of a new RF link handover. The hole removal module is used to construct a causal event chain of frequency point occupancy status changes by using spectrum situation information and historical spectrum situation information if the reconfiguration process of the RF link is not in the switching inertia period, and to identify and remove parasitic holes triggered by adjacent frequency point occupancy events to obtain native available spectrum holes. The hole segmentation module is used to extract the dissipation time of causal disturbance events generated on adjacent frequency points during the period from the formation to the stabilization of native available spectrum holes using causal event chains, and to classify native available spectrum holes into burst-type native available spectrum holes or periodic native available spectrum holes based on the dissipation time. The trajectory judgment module is used only when it belongs to the sudden type of native available spectrum hole to extract the dissipation trajectory of the causal disturbance event within the dissipation time and to determine whether the dissipation trajectory shows a monotonically decreasing and non-rebounding convergence trend. The switching execution module is used to allow switching to the target RF link corresponding to a bursty natively available spectrum hole when the dissipation trajectory shows a monotonically decreasing and non-rebounding convergence trend.

[0020] In the specific implementation of the information acquisition module, the location of the dedicated sensing antenna on the base station side differs from that of the service antenna. The dedicated sensing antenna is independent of the service antenna array, and its receiving bandwidth is configured to cover a wide range encompassing the base station's current communication frequency band and adjacent frequency bands. The wideband RF signal received by the dedicated sensing antenna is amplified by a low-noise amplifier and then converted into wideband spectrum data collected by the dedicated sensing antenna by an analog-to-digital converter. This wideband spectrum data includes received signal strength indicators and noise limits for each frequency point. During idle time slots, the service antenna disables its data transmission and reception functions and switches to spectrum sensing mode. In spectrum sensing mode, the RF signal received by the service antenna is amplified by a low-noise amplifier and then converted into wideband spectrum data assisted by the service antenna by an analog-to-digital converter. This assisted wideband spectrum data includes received signal strength indicators and noise limits for each frequency point. Idle time slots are allocated by the base station scheduler and are embedded between the normal communication time slots of the service antenna.

[0021] The received signal strength indication (RSS) from the broadband spectrum data acquired by the dedicated sensing antenna and the received SSS from the broadband spectrum data acquired by the service antenna are weighted and fused. The weighting coefficients for this fusion are related to the angle of arrival (Angle of Arrival). The Angle of Arrival is determined by the physical distance between the dedicated sensing antenna and the service antenna, as well as the direction of arrival. The weighting coefficients are obtained from a pre-defined Angle of Arrival-Weighting Mapping Table, which stores the weighting coefficients for different Angles of Arrival. The values ​​of these weighting coefficients give higher weight to signals from the target coverage direction. The weighted fusion produces a fused RSS, which, together with the noise floor from the broadband spectrum data acquired by the dedicated sensing antenna, constitutes the spectrum situation information. This spectrum situation information reflects the energy distribution and background noise level of each frequency band perceived by the base station at the current moment.

[0022] The weighting coefficients for each entry in the preset angle-of-arrival-weighted mapping table are set through pre-measurement. After base station deployment, a standard signal source transmits calibration signals with known power in different signal angle-of-arrival directions. Dedicated sensing antennas and service antennas receive the calibration signals and record their respective received signal strength indicators. For each signal angle of arrival, the signal-to-noise ratio (SNR) of the received signal strength indicator from the dedicated sensing antenna and the received signal strength indicator from the service antenna is calculated. The normalized coefficient corresponding to the SNR ratio that maximizes the fused received signal strength indicator is used as the weighting coefficient for that signal angle of arrival and stored in the preset angle-of-arrival-weighted mapping table. The signal angle of arrival range covered by the calibration signal traverses the target coverage sector of the base station with a preset angle step size. The preset angle step size is set according to the antenna beamwidth; for example, a preset angle step size of 5 degrees.

[0023] The RF link consists of three cascaded hardware components: a local oscillator (LO), a power amplifier, and a beamforming network. The LO lock-up completion signal is output from the phase-locked loop (PLL) circuit within the LO. When the PLL's frequency lock-up detection circuit determines that the deviation between the output frequency and the target frequency is less than the lock-up threshold, the LO lock-up completion signal is set to a high level, indicating that the LO has successfully locked the frequency. The lock-up threshold is set according to the LO's frequency stability index; for example, the lock-up threshold value is 1 × 10⁻⁶. -6The power amplifier bias setup completion signal is output by the bias control circuit of the power amplifier. When the bias voltage or bias current enters the preset bias window and the settling time exceeds the settling threshold, the power amplifier bias setup completion signal is set to high level, indicating that the power amplifier has completed bias setup. The width of the preset bias window is set according to the operating point tolerance range of the power amplifier, for example, the width of the preset bias window is ±5% of the target bias value. The settling threshold is set according to the bias response time constant of the power amplifier, for example, the settling threshold value is 10 microseconds. The beamforming weight loading completion signal is output by the weight register status in the beamforming network. When the write completion flag of the weight register of all antenna channels is set to valid, the beamforming weight loading completion signal is set to high level, indicating that the beamforming weights have been loaded.

[0024] The baseband processing unit of the base station reads the level status of the local oscillator locking completion signal, the power amplifier bias establishment completion signal, and the beamforming weight loading completion signal in real time via the control bus. The baseband processing unit records the combination of the level status of the local oscillator locking completion signal, the power amplifier bias establishment completion signal, and the beamforming weight loading completion signal as the reconfiguration process status of the RF link. The value of the RF link reconfiguration process status indicates the completion status of the three hardware components: the local oscillator, the power amplifier, and the beamforming network.

[0025] The baseband processing unit is a digital signal processor chip integrated into the baseband board of the base station. It is connected to the local oscillator, power amplifier and beamforming network through the control bus, and to the spectrum sensing module through the data bus. It is responsible for performing the fusion calculation of spectrum situation information, the construction of causal event chains of frequency point occupancy status changes, the screening and classification of native available spectrum holes, the judgment of dissipation trajectory and the generation of radio frequency link switching decisions.

[0026] When any one of the following signals—Local Oscillator Lock-in Completion Signal, Power Amplifier Bias Setup Completion Signal, and Beamforming Weight Loading Completion Signal—is low, the RF link reconfiguration process status is marked as incomplete. When all three signals are high, the RF link reconfiguration process status is marked as complete. The baseband processing unit periodically reads and updates the RF link reconfiguration process status at a query cycle. The query cycle is less than the minimum operation cycle required for the RF link to complete reconfiguration; for example, the query cycle is 1 millisecond, to ensure timely status acquisition.

[0027] When implementing the inertial judgment module, after the baseband processing unit obtains the reconfiguration process status of the RF link, it compares the reconfiguration process status of the RF link with the completion level corresponding to the local oscillator lock completion signal, the completion level corresponding to the power amplifier bias establishment completion signal, and the completion level corresponding to the beamforming weight loading completion signal.

[0028] The completion level corresponding to the local oscillator lock-up completion signal is high, indicating that the local oscillator has completed frequency lock-up. The completion level corresponding to the power amplifier bias establishment completion signal is high, indicating that the power amplifier has completed bias establishment. The completion level corresponding to the beamforming weight loading completion signal is high, indicating that the beamforming weights have been loaded. When the level of the local oscillator lock-up completion signal is not equal to the completion level corresponding to the local oscillator lock-up completion signal, or the level of the power amplifier bias establishment completion signal is not equal to the completion level corresponding to the power amplifier bias establishment completion signal, or the level of the beamforming weight loading completion signal is not equal to the completion level corresponding to the beamforming weight loading completion signal, the baseband processing unit determines that the RF link reconfiguration process is in the handover inertia period. The handover inertia period indicates that the RF link is performing a reconfiguration operation and has not yet completed the establishment of all hardware components. During the handover inertia period, the RF link cannot carry effective data transmission, nor does it have the ability to respond to new handover commands.

[0029] After determining that the reconfiguration process of the RF link is in the handover inertia period, the baseband processing unit generates a handover prohibition command. This command suppresses the base station's handover decision module from sending a new RF link handover trigger signal to the RF front-end. The handover prohibition command is implemented internally within the baseband processing unit as an interrupt signal or flag. When the handover prohibition command is valid, handover requests initiated by the base station's Media Access Control (MAC) or Radio Resource Control (RRC) layers are temporarily suspended and do not enter the RF link handover execution process. The handover prohibition command is automatically released when the RF link reconfiguration process status changes to complete.

[0030] Actively prohibiting the triggering of new RF link switching during the switching inertia period enables the decision-making link in the sensing, decision-making and execution closed loop to remain synchronized with the actual physical state of the execution link. This avoids the internal state chaos or hardware damage of the RF link caused by receiving a new reconfiguration command before the current reconfiguration of the RF link has been completed. Compared with the approach of triggering switching based solely on spectrum situation information without considering the reconfiguration process state of the RF link, it has better timing coordination capabilities and hardware protection effects.

[0031] When implementing the void removal module, when the local oscillator locking completion signal, the power amplifier bias establishment completion signal, and the beamforming weight loading completion signal are all in the completed state, the baseband processing unit determines that the reconfiguration process of the RF link is not in the switching inertia period. The baseband processing unit then begins to process the spectrum situation information and historical spectrum situation information to construct a causal event chain of frequency point occupancy status changes.

[0032] The spectrum situation information includes the occupancy status of each frequency point at the current moment, with the occupancy status being either occupied or idle. Historical spectrum situation information contains a sequence of occupancy statuses for each frequency point within a historical time period. This sequence is composed of multiple historical occupancy statuses arranged chronologically, with the interval between historical moments matching the update cycle of the spectrum situation information. The baseband processing unit extracts the occupancy status change event for each frequency point from the spectrum situation information. This event is recorded as a frequency point identifier, event type, and event occurrence time. The event type is either occupied to idle or idle to occupied, and the event occurrence time is the moment the occupancy status changes. The frequency point identifier is used to distinguish different frequencies in the spectrum situation information; it can be the center frequency value of the corresponding frequency point or its position index number in the spectrum situation information.

[0033] The baseband processing unit arranges the occupancy status change events of each frequency point in the spectrum situation information in chronological order of their occurrence and performs a time-series comparison with the corresponding frequency point occupancy status change events in the historical spectrum situation information. This time-series comparison involves comparing the occurrence time of each frequency point occupancy status change event in the spectrum situation information with the occurrence time of the same frequency point occupancy status change events in the historical spectrum situation information.

[0034] The baseband processing unit associates occupancy status change events that occur earlier in the time sequence with those that occur later, constructing a causal event chain for frequency point occupancy status changes. The construction method is as follows: Occupancy status change events are recorded as frequency point identifiers, event types, and event occurrence times. For an occupancy status change event of the first frequency point, the unit searches for an occupancy status change event of the second frequency point adjacent to the first frequency point within the time window. If the occurrence time of the second frequency point's occupancy status change event is later than that of the first frequency point's occupancy status change event, and the event type of the second frequency point's occupancy status change event is opposite to that of the first frequency point's occupancy status change event, then the occupancy status change events of the first and second frequency points are associated, forming a causal relationship. The first frequency point refers to a frequency point in the spectrum situation information, and the second frequency point refers to a frequency point that is adjacent to the first frequency point in frequency. Adjacent means that the difference between the center frequency of the second frequency point and the center frequency of the first frequency point is one channel interval.

[0035] The time window is a time range preset based on the average rate of change of the occupancy status of the frequency points in the spectrum situation information. The start time of the time window is the time when the occupancy status change event of the first frequency point occurs, and the end time of the time window is the start time plus the preset duration. The preset duration is set according to the average change period of the occupancy status of the frequency points in the spectrum situation information. For example, the preset duration is 5 time slots.

[0036] The opposite event type means that when the event type of the occupancy status change event of the first frequency point is from occupied to idle, the event type of the occupancy status change event of the second frequency point is from idle to occupied; or when the event type of the occupancy status change event of the first frequency point is from idle to occupied, the event type of the occupancy status change event of the second frequency point is from occupied to idle. This forms a causal relationship indicating that the occupancy status change of the first frequency point is the trigger for the occupancy status change of the second frequency point. All causal relationships constitute a causal event chain of frequency point occupancy status changes.

[0037] In the causal event chain of frequency occupancy status changes, the baseband processing unit detects whether the occurrence event of an available spectrum hole in the spectrum situation information is temporally later than and causally related to the occupancy event of adjacent frequencies. An available spectrum hole is a frequency band consisting of multiple consecutive idle frequencies in the spectrum situation information. The occurrence event of an available spectrum hole is the event in which an available spectrum hole first appears in the spectrum situation information. The occurrence time of the occurrence event of an available spectrum hole is the later of the event types (occupancy to idle) among the occupancy status change events of the first and last frequencies in the available spectrum hole.

[0038] The occupancy event of an adjacent frequency point refers to an event of occupancy status change from idle to occupied that occurs at a frequency point adjacent to the boundary frequency point of an available spectrum hole. The baseband processing unit searches the causal event chain of frequency point occupancy status changes to determine whether the occurrence event of the available spectrum hole is causally related to the occupancy event of the adjacent frequency point. If a causal relationship exists and the occurrence time of the available spectrum hole is later than the occurrence time of the occupancy event of the adjacent frequency point, the available spectrum hole is recorded in the detection result as a parasitic hole triggered by the occupancy event of the adjacent frequency point. The cause of the parasitic hole is the leakage of signal energy from the adjacent frequency point to the adjacent channel, or the spectral spread caused by the nonlinearity of the power amplifier, which causes the available spectrum hole to be filled with interference when the adjacent frequency point is occupied, rather than being a truly interference-free available frequency band.

[0039] The baseband processing unit removes parasitic holes from the available spectrum holes in the spectrum situation information to obtain native available spectrum holes. The parasitic hole removal operation involves removing available spectrum holes identified as parasitic from the set of available spectrum holes used for handover target selection, retaining the available spectrum holes not identified as parasitic as the native available spectrum hole set. Native available spectrum holes indicate that their idle state is not causally dependent on the occupancy events of adjacent frequencies. When adjacent frequencies are occupied again, the native available spectrum holes will not be filled, thus providing higher availability guarantees during the handover inertia period.

[0040] Compared to existing technologies that treat all perceived available spectrum holes as handover candidates without distinguishing their causes, this approach identifies and filters out parasitic holes by constructing a causal event chain of frequency occupancy changes. This can eliminate available spectrum holes that disappear due to adjacent frequency occupancy events during the handover inertia period in advance, reducing the uncertainty of handover target selection.

[0041] When implementing the hole segmentation module, after obtaining the native available spectrum holes, the baseband processing unit uses the causal event chain of frequency point occupancy status changes to extract the dissipation time of the causal disturbance events generated by the native available spectrum holes to adjacent frequency points from the formation to the stabilization period, and classifies the native available spectrum holes into burst-type native available spectrum holes or periodic-type native available spectrum holes based on the dissipation time.

[0042] The baseband processing unit locates the formation time of natively available spectrum holes within the causal event chain of frequency occupancy status changes. A natively available spectrum hole consists of multiple consecutively idle frequencies in the spectrum situation information. In the causal event chain of frequency occupancy status changes, the occurrence time of the event type "occupied to idle" among the occupancy status change events corresponding to the natively available spectrum hole records the moment when the frequency in the natively available spectrum hole changes from an occupied state to an idle state. The baseband processing unit takes the later occurrence time of the event type "occupied to idle" among the occupancy status change events corresponding to the natively available spectrum hole as the formation time of the natively available spectrum hole. The formation time represents the starting point when the natively available spectrum hole is fully formed and becomes usable.

[0043] The baseband processing unit terminates its work when the interference intensity of the first adjacent frequency causal disturbance event after the formation time falls back to the pre-disturbance baseline level within the causal event chain of frequency occupancy changes. An adjacent frequency causal disturbance event refers to a causal disturbance event triggered by the formation of a native available spectrum hole, occurring at a frequency adjacent to the boundary frequency of that hole within the causal event chain of frequency occupancy changes. The interference intensity corresponding to the adjacent frequency causal disturbance event is the received signal strength indication (RSI) of the adjacent frequency, extracted from the spectrum situation information. The pre-disturbance baseline level is the moving average of the RSI of the adjacent frequency before the formation time of the native available spectrum hole. This moving average is calculated based on the RSI of a preset number of historical moments before the formation time. The preset number is set according to the update rate of the spectrum situation information; for example, the preset number is 10 historical moments. When the current value of the received signal strength indication at adjacent frequency points falls back to within a preset percentage range of the pre-disturbance reference level for the first time after the formation time, the moment when it first falls back to within the preset percentage range of the pre-disturbance reference level is taken as the termination time. The preset percentage range is set according to the measurement tolerance of the received signal strength indication at adjacent frequency points, for example, the preset percentage range is ±10% of the pre-disturbance reference level. The termination time indicates that the interference effect of the formation of the native available spectrum hole on external adjacent frequency points has basically dissipated and the electromagnetic environment has recovered to a level close to the stable level before the hole formation.

[0044] The baseband processing unit uses the difference between the termination time and the formation time as the dissipation time. The dissipation time is calculated as: Tdiss = Tstop - Tform; where Tdiss represents the dissipation time, Tstop represents the termination time, and Tform represents the formation time. The dimension of the dissipation time is time, consistent with the dimensions of the termination and formation times. The magnitude of the dissipation time reflects the time required for the original available spectrum hole to essentially dissipate from its formation to the point where its interference with adjacent external frequencies is largely eliminated.

[0045] The baseband processing unit extracts the occurrence period of native available spectrum holes from historical spectrum situation information. The occurrence period of native available spectrum holes is a statistical value of the time interval between two consecutive occurrences of a native available spectrum hole in the historical spectrum situation information. The baseband processing unit extracts the time interval between all consecutive occurrences of native available spectrum holes within a historical time period from the historical spectrum situation information, and calculates the average of these time intervals. This average is used as the occurrence period of the native available spectrum hole. The length of the historical time period is set according to the rate of change of the spectrum environment; for example, the length of the historical time period is set to 50 times the average occurrence interval of the number of occurrences of native available spectrum holes to ensure statistical stability.

[0046] The baseband processing unit compares the dissipation time with the occurrence period of native available spectrum holes. When the dissipation time is less than or equal to the occurrence period of native available spectrum holes, it means that the dissipation speed of the interference effect of native available spectrum holes on external adjacent frequency points is not slower than the occurrence rhythm of native available spectrum holes themselves. The dissipation process of native available spectrum holes can be completed before the next occurrence period of native available spectrum holes arrives. The cause of this type of native available spectrum hole is usually the sudden disappearance of external sudden interference sources. The baseband processing unit classifies native available spectrum holes as sudden native available spectrum holes.

[0047] When the dissipation time is greater than the occurrence cycle of native available spectrum holes, it means that the dissipation speed of the interference effect of native available spectrum holes on external adjacent frequency points is slower than the occurrence rhythm of native available spectrum holes themselves. The dissipation process of native available spectrum holes spans multiple occurrence cycles of native available spectrum holes. The cause of this type of native available spectrum hole is usually the periodic scheduling silence of the system itself. The baseband processing unit classifies native available spectrum holes into periodic native available spectrum holes.

[0048] By comparing the dissipation time with the occurrence period of native available spectrum holes, the causes of native available spectrum holes can be distinguished. This allows for the identification of sudden native available spectrum holes that are suitable for rapid utilization during the handover inertia period, thus avoiding post-handover interference caused by incomplete dissipation when using periodic native available spectrum holes as handover targets.

[0049] When implementing the trajectory judgment module, when the native available spectrum hole is classified as a burst-type native available spectrum hole, the baseband processing unit extracts the dissipation trajectory of the causal disturbance event of the adjacent frequency point from the causal event chain of the frequency point occupancy status change within the dissipation time, and judges whether the dissipation trajectory shows a monotonically decreasing convergence trend without rebound.

[0050] The baseband processing unit extracts the interference intensity corresponding to causal disturbance events at adjacent frequencies within the dissipation time from the causal event chain of frequency occupancy changes, and arranges them in chronological order to form a dissipation trajectory. The interference intensity corresponding to the causal disturbance events at adjacent frequencies is the received signal strength indication of the adjacent frequency. The dissipation time includes multiple discrete time points, and the time interval between two adjacent discrete time points is equal to the update period of the spectrum situation information. The baseband processing unit arranges the received signal strength indication values ​​of the causal disturbance events at adjacent frequencies corresponding to each time point within the dissipation time into an interference intensity sequence in chronological order, and uses the interference intensity sequence as the dissipation trajectory. The elements in the interference intensity sequence are arranged in chronological order, and the time interval between adjacent elements in the interference intensity sequence is the update period of the spectrum situation information.

[0051] The baseband processing unit traverses adjacent elements in the interference intensity sequence to determine if there is a situation in the dissipation trajectory where the interference intensity at a later time is greater than that at a previous time. This is done by comparing the received signal strength indication (RSI) of the (i+1)th element in the interference intensity sequence with the RSI of the ith element, where i is a positive integer from 1 to N-1, and N is the total number of elements in the interference intensity sequence. If there exists any i such that the RSI of the (i+1)th element is greater than that of the ith element, the baseband processing unit determines that there is a situation in the dissipation trajectory where the interference intensity at a later time is greater than that at a previous time. This situation indicates that the interference intensity at adjacent frequencies has rebounded during the dissipation process. The rebound suggests that the external factors causing the burst-type native available spectrum hole may only be temporarily hidden rather than truly disappeared, and these external factors may reactivate and reoccupy the frequency band corresponding to the burst-type native available spectrum hole at any time. When the total number of elements N in the interference intensity sequence is less than 2, there are no adjacent elements in the interference intensity sequence for comparison, and the baseband processing unit determines that there is no situation in the dissipation trajectory where the interference intensity at the next moment is greater than the interference intensity at the previous moment.

[0052] When none of the adjacent elements in the interference intensity sequence satisfy the condition that the received signal strength indication value of the (i+1)th element is greater than the received signal strength indication value of the ith element, the baseband processing unit determines that there is no situation in the dissipation trajectory where the interference intensity at a later moment is greater than that at a previous moment, and determines that the dissipation trajectory exhibits a monotonically decreasing and non-rebounding convergence trend. A monotonically decreasing and non-rebounding convergence trend indicates that the interference intensity at adjacent frequency points continues to decrease after the formation of a burst-type natively available spectrum hole without any rebound, meaning the external interference source has completely disappeared or moved away. The burst-type natively available spectrum hole will remain idle in subsequent observations of the causal event chain of frequency point occupancy changes, possessing a high confidence level of continued availability during the handover inertia period.

[0053] Compared to the approach of making handover decisions solely based on the current idle state in the spectrum situation information without verifying the stability of the idle state, this method extracts the dissipation trajectory and determines whether the dissipation trajectory exhibits a monotonically decreasing and non-rebounding convergence trend. From the perspective of the dissipation behavior of external interference sources, it verifies the stability and persistence of sudden native available spectrum holes. This reduces the probability of encountering sudden recurrence of interference sources after handover, and improves the accuracy of handover decisions and the reliability of the link after handover.

[0054] When implementing the switching execution module, if the dissipation trajectory is determined to show a monotonically decreasing and non-rebounding convergence trend, the baseband processing unit allows the switching to be initiated to the target RF link corresponding to the burst-type natively available spectrum hole.

[0055] The frequency corresponding to a burst-type natively available spectrum hole is determined as the target carrier frequency. A burst-type natively available spectrum hole consists of multiple consecutive idle frequency points in the spectrum situation information. The frequency point corresponding to the burst-type natively available spectrum hole includes the center frequency value of each frequency point within the burst-type natively available spectrum hole. The baseband processing unit selects the center frequency value of one frequency point from the frequency points corresponding to the burst-type natively available spectrum hole as the target carrier frequency. The selection method is to take the center frequency value of the frequency point at the center of the burst-type natively available spectrum hole, or to take the center frequency value of the frequency point with the highest signal-to-noise ratio within the burst-type natively available spectrum hole. The target carrier frequency is the carrier frequency that carries data transmission after the RF link handover.

[0056] The system generates local oscillator configuration parameters, power amplifier bias configuration parameters, and beamforming weight configuration parameters based on the target carrier frequency. The local oscillator configuration parameters include the target local oscillator frequency, which is equal to the target carrier frequency minus the baseband intermediate frequency (IF). The baseband IF is the IF frequency used in the digital up-conversion processing within the baseband processing unit. The power amplifier bias configuration parameters include target values ​​for bias voltage or bias current. These target values ​​are obtained from a preset frequency band-bias mapping table based on the linearity and efficiency requirements of the power amplifier in the target carrier frequency band. This preset frequency band-bias mapping table stores the target values ​​for bias voltage or bias current corresponding to each frequency band supported by the base station. The power amplifier bias configuration parameters also include a temperature compensation coefficient. This temperature compensation coefficient is obtained from a preset temperature-compensation coefficient mapping table based on the current temperature sensor reading of the power amplifier. This preset temperature-compensation coefficient mapping table stores temperature compensation coefficient values ​​corresponding to different temperature ranges. The beamforming weight configuration parameters include the phase offset and amplitude weighting values ​​of each antenna channel in the antenna array. The phase offset and amplitude weighting values ​​of each antenna channel in the antenna array are calculated by the beamforming algorithm based on the wavelength of the target carrier frequency and the direction of arrival of the user equipment. The beamforming algorithm uses the wavelength of the target carrier frequency to determine the phase difference corresponding to the spacing between antenna channels, and uses the direction of arrival of the user equipment to determine the phase offset and amplitude weighting values ​​of the antenna channels, so that the main lobe of the synthesized beam points to the direction of arrival of the user equipment.

[0057] The local oscillator (LO) configuration parameters, power amplifier bias configuration parameters, and beamforming weight configuration parameters are sent to the RF front-end, triggering the RF link to perform reconfiguration and switch to the target RF link. The baseband processing unit writes the LO configuration parameters to the LO's configuration register, the power amplifier bias configuration parameters to the power amplifier's bias control register, and the beamforming weight configuration parameters to the beamforming network's weight register via the control bus. Once all these parameters are written, the baseband processing unit triggers the RF link to begin reconfiguration. The RF link adjusts the LO output frequency according to the LO configuration parameters, adjusts the power amplifier's operating point according to the power amplifier bias configuration parameters, and adjusts the phase offset and amplitude weighting values ​​of the antenna channels in the beamforming network according to the beamforming weight configuration parameters. After the reconfiguration operation is complete, the RF link operates at the target carrier frequency and carries data transmission through that frequency.

[0058] Compared to the approach of performing handover based solely on the current idle state in the spectrum situation information without verifying the dissipation trajectory, this approach only allows handover to be initiated when the dissipation trajectory shows a monotonically decreasing and non-rebounding convergence trend. This ensures that the timing of the handover decision is synchronized with the objective fact that the external interference source has completely disappeared, avoiding handover operations when the interference source has not completely dissipated or may be reactivated, thereby improving the stability of the communication link after handover.

[0059] All calculations involved in the embodiments are performed using dimensionless numerical values, and the preset parameters and thresholds in the calculations can be set by those skilled in the art according to actual conditions.

[0060] This technical solution can be flexibly deployed, for example, as embedded software running on device hardware, or installed on personal computers or other smart terminals with user interfaces, thus adapting to various hardware environments and usage requirements.

[0061] The above solutions can be implemented in software, hardware, firmware, or a combination thereof. When implemented in software, they are presented, in whole or in part, as a computer program product, containing one or more computer instructions or programs. When these instructions or programs are loaded and executed on a computer, results are produced corresponding to the processes or functions of the embodiments of this application. The computer can be a general-purpose computer, a special-purpose computer, a computer network, or other programmable device. Computer instructions can be stored in a computer-readable storage medium or transmitted from one medium to another via wired or wireless means, such as from a website, server, or data center via wired means such as fiber optic cables, twisted-pair cables, or coaxial cables, or wireless means such as infrared or microwaves to another site. A computer-readable storage medium refers to any usable medium that a computer can access or a data storage device such as a server or data center that contains one or more usable media, including magnetic media such as floppy disks, hard disks, and magnetic tapes, optical media such as DVDs, and semiconductor media such as solid-state drives.

[0062] The specific working process of the system, device and module can be found in the method embodiment, and will not be repeated here.

[0063] The disclosed systems, devices, and methods can be implemented in other ways. The device embodiments are for illustrative purposes only, and the module division is only a logical division. In practice, different divisions can be implemented, such as merging or integrating multiple modules or components, or omitting some features. Coupling, direct coupling, or communication connections between the components can be achieved through interfaces, while indirect coupling or communication connections can take electrical, mechanical, or other forms.

[0064] The modules described as separate components may or may not be physically separated. The components shown as modules can be physical hardware or software, and can be deployed centrally or distributed across multiple network nodes. Some or all of the modules can be selected to achieve the purpose of this embodiment, depending on actual needs.

[0065] The functional modules in each embodiment can be integrated into one processing module, or they can exist independently, or two or more modules can be integrated into one.

[0066] If the functionality is implemented as a software module and used as an independent product, it can be stored in a computer-readable storage medium. Under this understanding, the substantial contribution of the technical solution of this application can be embodied in the form of a software product. This computer software product is stored in a storage medium and contains instructions to cause a computer device, such as a personal computer, server, or network device, to execute all or part of the steps of the methods in the embodiments of this application. The storage medium includes any medium capable of storing program code, such as a USB flash drive, portable hard drive, read-only memory, random access memory, magnetic disk, or optical disk.

[0067] The above are merely specific embodiments of this application, and the scope of protection of this application is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the scope of the technology disclosed in this application should fall within the scope of protection of this application.

Claims

1. A radio frequency link switching system based on dynamic spectrum sensing, characterized in that, include: The information acquisition module is used to acquire spectrum situation information generated by dynamic spectrum sensing and the reconfiguration process status of the radio frequency link; The inertia judgment module is used to determine whether the reconfiguration process of the RF link is in the handover inertia period. If so, it prevents the triggering of a new RF link handover. The hole removal module is used to construct a causal event chain of frequency point occupancy status changes by using spectrum situation information and historical spectrum situation information if the reconfiguration process of the RF link is not in the switching inertia period, and to identify and remove parasitic holes triggered by adjacent frequency point occupancy events to obtain native available spectrum holes. The hole segmentation module is used to extract the dissipation time of causal disturbance events generated on adjacent frequency points during the period from the formation to the stabilization of native available spectrum holes using causal event chains, and to classify native available spectrum holes into burst-type native available spectrum holes or periodic native available spectrum holes based on the dissipation time. The trajectory judgment module is used only when it belongs to the sudden type of native available spectrum hole to extract the dissipation trajectory of the causal disturbance event within the dissipation time and to determine whether the dissipation trajectory shows a monotonically decreasing and non-rebounding convergence trend. The switching execution module is used to allow switching to the target RF link corresponding to a bursty natively available spectrum hole when the dissipation trajectory shows a monotonically decreasing and non-rebounding convergence trend.

2. The radio frequency link switching system based on dynamic spectrum sensing according to claim 1, characterized in that, Acquire spectrum situational information generated by dynamic spectrum sensing and the reconfiguration process status of RF links, including: Broadband spectrum data is collected by a dedicated sensing antenna, and broadband spectrum data is collected in idle time slots by a service antenna. The broadband spectrum data collected by the dedicated sensing antenna and the broadband spectrum data collected by the service antenna are fused to obtain spectrum situation information. The reconfiguration process status of the RF link is obtained by monitoring the local oscillator lock-on completion signal, the power amplifier bias setup completion signal, and the beamforming weight loading completion signal of the RF link.

3. The radio frequency link switching system based on dynamic spectrum sensing according to claim 1, characterized in that, Determine if the RF link reconfiguration process is in the handover inertia period. If so, prevent triggering new RF link handovers, including: When any one of the following signals is incomplete: local oscillator lock-on completion signal, power amplifier bias setup completion signal, or beamforming weight loading completion signal, the RF link reconfiguration process is determined to be in the switching inertia period, and triggering a new RF link switch is prohibited.

4. The radio frequency link switching system based on dynamic spectrum sensing according to claim 1, characterized in that, If the RF link reconfiguration process is not in the handover inertia period, then using spectrum situation information and historical spectrum situation information, a causal event chain of frequency occupancy status changes is constructed to identify and filter out parasitic holes triggered by adjacent frequency occupancy events, thus obtaining natively available spectrum holes, including: When the local oscillator lock-on completion signal, the power amplifier bias establishment completion signal, and the beamforming weight loading completion signal are all in the completed state, it is determined that the reconfiguration process of the RF link is not in the switching inertia period. Arrange the occupancy status change events of each frequency point in the spectrum situation information in chronological order, compare them with the occupancy status change events of the corresponding frequency points in the historical spectrum situation information, associate the occupancy status change events that occur earlier in time with the occupancy status change events that occur later, and construct a causal event chain of frequency point occupancy status changes. In the causal event chain of frequency occupancy status changes, for available spectrum holes in the spectrum situation information, it is detected whether the occurrence event of the available spectrum hole is later in time than and causally related to the occupancy event of the adjacent frequency point. Available spectrum holes with a detection result of yes are identified as parasitic holes triggered by the occupancy event of the adjacent frequency point. Parasitic holes are removed from the available spectrum holes in the spectrum situation information to obtain the native available spectrum holes.

5. A radio frequency link switching system based on dynamic spectrum sensing according to claim 4, characterized in that, The occupancy status change events of each frequency point in the spectrum situation information are arranged in chronological order, including: recording the occupancy status change event as frequency point identifier, event type and event occurrence time, and the event type including occupancy to idle and idle to occupancy; for the occupancy status change event of the first frequency point, the occupancy status change event of the second frequency point adjacent to the first frequency point is searched within the time window. When the occurrence time of the occupancy status change event of the second frequency point is later than the occurrence time of the occupancy status change event of the first frequency point and the event type is opposite, the occupancy status change event of the first frequency point is associated with the occupancy status change event of the second frequency point.

6. The radio frequency link switching system based on dynamic spectrum sensing according to claim 1, characterized in that, The dissipation time of causal disturbance events generated on adjacent frequency points during the formation and stabilization period of native available spectrum holes is extracted using causal event chains. Based on the dissipation time, native available spectrum holes are classified into bursty native available spectrum holes or periodic native available spectrum holes, including: Locate the formation time of the native available spectrum hole in the causal event chain, and the termination time of the causal disturbance event at the adjacent frequency point after its formation. Use the time span from the formation time to the termination time as the dissipation time. Extract the occurrence cycle of native available spectrum holes from historical spectrum situation information; When the dissipation time is less than or equal to the occurrence period, the native available spectrum hole is classified as a burst-type native available spectrum hole; when the dissipation time is greater than the occurrence period, the native available spectrum hole is classified as a periodic-type native available spectrum hole.

7. A radio frequency link switching system based on dynamic spectrum sensing according to claim 6, characterized in that, The time span from the formation time to the termination time is taken as the dissipation time, including: in the causal event chain, the moment when the event type of the change in the occupancy status of the frequency point corresponding to the original available spectrum hole is changed from occupied to idle is taken as the formation time; in the causal event chain, the moment when the interference intensity corresponding to the first adjacent frequency point causal disturbance event after the formation time falls back to the baseline level before the disturbance is taken as the termination time; the difference between the termination time and the formation time is taken as the dissipation time.

8. A radio frequency link switching system based on dynamic spectrum sensing according to claim 1, characterized in that, Only when it is a sudden, natively available spectrum hole, extract the dissipation trajectory of the causal perturbation event within the dissipation time, and determine whether the dissipation trajectory shows a monotonically decreasing and non-rebounding convergence trend, including: When the native available spectrum hole is a sudden native available spectrum hole, the interference intensity corresponding to the causal disturbance events at adjacent frequency points within the dissipation time is extracted from the causal event chain and arranged in chronological order to form a dissipation trajectory. Determine whether there is a situation in the dissipation trajectory where the interference intensity at a later moment is greater than the interference intensity at a previous moment; If there is no situation where the interference intensity in the next moment is greater than that in the previous moment, then the dissipation trajectory is judged to show a monotonically decreasing convergence trend without rebound.

9. A radio frequency link switching system based on dynamic spectrum sensing according to claim 8, characterized in that, The dissipation trajectory is formed by arranging the interference intensity values ​​of causal disturbance events at adjacent frequency points corresponding to each time point within the dissipation time in chronological order to form an interference intensity sequence, and the interference intensity sequence is used as the dissipation trajectory.

10. A radio frequency link switching system based on dynamic spectrum sensing according to claim 1, characterized in that, When the dissipation trajectory exhibits a monotonically decreasing and non-rebounding convergence trend, handover to the target RF link corresponding to the burst-type natively available spectrum hole is permitted, including: The frequency points corresponding to the burst-type native available spectrum holes are determined as the target carrier frequencies; Based on the target carrier frequency generating oscillator configuration parameters, power amplifier bias configuration parameters, and beamforming weight configuration parameters; The local oscillator configuration parameters, power amplifier bias configuration parameters, and beamforming weight configuration parameters are sent to the RF front end, triggering the RF link to perform reconfiguration to switch to the target RF link.

Images