CN104219686B

CN104219686B - A kind of frequency spectrum sensing method and equipment

Info

Publication number: CN104219686B
Application number: CN201310213741.3A
Authority: CN
Inventors: 蒋成钢; 杨宇; 李媛媛; 白文岭; 胡金玲
Original assignee: China Academy of Telecommunications Technology CATT
Current assignee: China Academy of Telecommunications Technology CATT; Datang Mobile Communications Equipment Co Ltd
Priority date: 2013-05-31
Filing date: 2013-05-31
Publication date: 2018-06-19
Anticipated expiration: 2033-05-31
Also published as: CN104219686A

Abstract

The invention discloses a kind of frequency spectrum sensing method and equipment, this method includes：Network side equipment determines that cognitive radio system needs silent frequency resource and time resource；The network side equipment generates the silent pattern of cell using the frequency resource and time resource；The network side equipment utilizes the received signal progress frequency spectrum perception on the corresponding resource location of the silence pattern；And/or the silent pattern is sent to the terminal device in the cell by the network side equipment, and the received signal progress frequency spectrum perception on the corresponding resource location of the silence pattern is utilized by the terminal device.In the embodiment of the present invention, it can reduce with influence of the interior frequency spectrum perception to cognitive radio system handling capacity, to improve throughput of system, and improve the frequency spectrum service efficiency of cognitive radio system；In addition, the interruption of communication link will not be brought due to execution frequency spectrum perception, so as to reduce due to propagation delay time caused by frequency spectrum perception.

Description

Spectrum sensing method and device

Technical Field

The present invention relates to the field of communications technologies, and in particular, to a spectrum sensing method and device.

Background

With the rapid development of mobile communication services, the contradiction between the increasing broadband wireless communication demand and the limited spectrum resources is becoming more and more obvious, and although the LTE (Long Term Evolution) system has adopted the techniques of OFDM (Orthogonal Frequency Division Multiplexing), MIMO (Multiple-input Multiple-Output), etc. to improve the spectrum utilization, these cannot fundamentally solve the problem of spectrum resource shortage. With the rapid development of mobile services, telecom operators will face more severe spectrum resource shortage problem. On the other hand, the frequency spectrum of some wireless communication systems is almost idle in time and region, for example, for the broadcast television frequency band, as the transmission capacity of digital transmission is greatly improved, with the development of the broadcast television system from analog transmission to digital transmission, many broadcast television frequency bands are in idle state for a long time, precious wireless resources are wasted, and other many wireless communication systems are proved that the frequency spectrum is not fully utilized.

To solve the problem of shortage of spectrum resources, CR (Cognitive Radio) technology has been widely focused. The CR is an intelligent wireless communication system, can obtain available idle frequency band resources at the current position through spectrum sensing, and can use the idle frequency band opportunistically, thereby improving the spectrum use efficiency and relieving the situation of spectrum resource shortage. The CR can sense the external environment, and learn from the environment using artificial intelligence techniques, and adapt its internal state to the statistical characteristics of the received wireless signal by changing some operating parameters (such as transmission power, carrier frequency, modulation technique, etc.) in real time, so as to achieve the following objectives: (1) highly reliable communication at any time and at any place; (2) efficient use of spectrum resources.

To achieve the above object, the CR performs the cognitive process through a cognitive ring, which is shown in a schematic cognitive ring diagram in fig. 1 and includes the following steps: (1) sensing a frequency spectrum; (2) carrying out spectrum analysis; (3) and (5) spectrum decision. The spectrum sensing is to complete the detection of the idle spectrum by analyzing an input RF (Radio Frequency) excitation signal, and the spectrum sensing is to adopt a certain signal detection algorithm (such as an energy detection algorithm, a matched filter detection algorithm, and the like) to judge whether the spectrum is occupied by detecting whether a signal exists on a certain Frequency band, thereby completing the detection of the idle spectrum; the spectrum analysis is to complete the estimation of the channel state information and the prediction of the channel capacity according to the spectrum sensing result and the analysis of other wireless input signals; the frequency spectrum decision is a decision for obtaining the final frequency spectrum usage according to the idle frequency spectrum resources obtained by frequency spectrum sensing and a frequency spectrum analysis result, and the decision comprises the decision of frequency points, bandwidth, transmitting power, a modulation mode and the like.

The spectrum sensing completes the detection of idle spectrum resources by binary signal detection of frequency bands, and when an authorization system signal is detected on a certain detected frequency band, the frequency band is considered to be occupied; when no authorized system signal is detected on a certain detected frequency band, the frequency band is considered to be idle. Furthermore, the frequency spectrum sensing needs to periodically sense the working frequency point of the current cognitive system, so that the working state of the frequency point authorization system is monitored, and meanwhile, the working state of the non-working frequency point authorization system is also monitored, so that a certain spare frequency point is ensured to be used by the cognitive system for spare. The spectrum sensing of the working frequency point of the CR system is generally called in-band spectrum sensing; the spectrum sensing of the non-working frequency points of the CR system is generally called out-of-band spectrum sensing. As shown in fig. 2, a diagram of in-band spectrum sensing and out-of-band spectrum sensing is shown.

In various application scenarios, the spectrum sensing capability is required to be able to detect a weak authorization system Signal, which requires spectrum sensing to obtain high detection performance in a low SNR (Signal to Noise Ratio) environment. However, spectrum sensing in a low SNR environment is easily affected by interference, and if the cognitive system is still operating while performing in-band spectrum sensing, spectrum sensing will be severely interfered by the cognitive system, thereby greatly reducing the accuracy of spectrum sensing and ultimately affecting the performance of the CR system.

Therefore, at present, it is necessary to keep the cognitive system silent for the inband spectrum sensing, that is, when performing the inband spectrum sensing, the CR system does not transmit any signal over the entire bandwidth, and keeps the radio silent; sensing whether the working frequency point of the CR system is re-occupied by other authorized systems in the silent time; during the non-silent period, the CR transmits communication related information at the frequency point, and a schematic diagram of the silent period is shown in fig. 3.

In the process of implementing the invention, the inventor finds that at least the following problems exist in the prior art:

in the current spectrum sensing method, in order to avoid the interference of the system to the in-band spectrum sensing, the CR system needs to keep the radio silence of the full bandwidth at a certain time and perform the in-band spectrum sensing at the time; since the radio system is completely in a silent state during the silent period, no communication data can be transmitted, thereby causing a waste of radio resources. Further, if the period for performing spectrum sensing is relatively short or the duration for each time spectrum sensing is relatively long, the reduction in system throughput is significant. Furthermore, since radio transmissions are periodically interrupted, there may be an increase in the delay of the transmission.

Disclosure of Invention

The embodiment of the invention provides a frequency spectrum sensing method and device, which aim to improve the frequency spectrum use efficiency.

In order to achieve the above object, an embodiment of the present invention provides a spectrum sensing method, including:

the method comprises the steps that network side equipment determines frequency resources and time resources which need to be silenced of a cognitive radio system;

the network side equipment generates a silent pattern of a cell by using the frequency resource and the time resource;

the network side equipment performs spectrum sensing by using signals received at the resource position corresponding to the silence pattern; and/or the network side equipment sends the silent pattern to the terminal equipment in the cell, and the terminal equipment performs spectrum sensing by using the signal received at the resource position corresponding to the silent pattern.

The embodiment of the invention provides a frequency spectrum sensing method, which comprises the following steps:

the terminal equipment receives the silent pattern notified by the network side equipment; the network side equipment generates and informs the terminal equipment of the silent pattern by using the frequency resource and the time resource after determining the frequency resource and the time resource which are required by the cognitive radio system to be silent;

and the terminal equipment performs spectrum sensing by using the signals received at the resource position corresponding to the silent pattern.

An embodiment of the present invention provides a network side device, where the network side device includes:

the device comprises a determining module, a judging module and a judging module, wherein the determining module is used for determining frequency resources and time resources which need to be silenced of the cognitive radio system;

a generating module, configured to generate a muting pattern of a cell using the frequency resources and the time resources;

a first processing module, configured to perform spectrum sensing by using a signal received at a resource location corresponding to the muting pattern; and/or sending the muting pattern to terminal equipment in the cell, and performing spectrum sensing by the terminal equipment by using signals received at the resource position corresponding to the muting pattern.

An embodiment of the present invention provides a terminal device, where the terminal device includes:

the receiving module is used for receiving the silent pattern notified by the network side equipment; the network side equipment generates and informs the terminal equipment of the silent pattern by using the frequency resource and the time resource after determining the frequency resource and the time resource which are required by the cognitive radio system to be silent;

and the spectrum sensing module is used for sensing the spectrum by utilizing the signals received at the resource positions corresponding to the silence patterns.

Compared with the prior art, the embodiment of the invention at least has the following advantages: in the embodiment of the invention, the network side equipment determines the frequency resource and the time resource of the cognitive radio system which need to be silenced, generates the corresponding silence pattern by using the frequency resource and the time resource, and performs spectrum sensing on the signal received at the resource position corresponding to the silence pattern, so that the cognitive radio system is prevented from keeping the radio silence with the full bandwidth at a certain time, the cognitive radio system can transmit communication data at the time, the interruption of a communication link due to the execution of spectrum sensing is avoided, and the transmission delay caused by the spectrum sensing is reduced. In addition, the cognitive radio system is prevented from keeping full-bandwidth radio silence at a certain time, so that the waste of radio resources can be reduced, and the spectrum use efficiency of the cognitive radio system is improved. In addition, if the period for executing spectrum sensing is relatively short or the duration time for executing spectrum sensing each time is relatively long, because the cognitive radio system is prevented from keeping the radio of the full bandwidth silent at a certain time, the influence of in-band spectrum sensing on the throughput of the cognitive radio system can be reduced, so that the system throughput is improved.

Drawings

In order to more clearly illustrate the technical solution of the present invention, the drawings needed to be used in the description of the embodiments will be briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present invention, and it is obvious for those skilled in the art to obtain other drawings based on the drawings without creative efforts.

FIG. 1 is a schematic illustration of a prior art cognitive ring;

FIG. 2 is a diagram of in-band spectrum sensing and out-of-band spectrum sensing in the prior art;

FIG. 3 is a schematic diagram of a quiet period in the prior art;

fig. 4 is a schematic flowchart of a spectrum sensing method according to an embodiment of the present invention;

fig. 5 is a schematic diagram of frequency spectrum sensing of working frequency points of a cognitive radio system according to an embodiment of the present invention;

FIG. 6 is a diagram of the power spectral densities of DTMB and CMMB in accordance with a first embodiment of the invention;

FIG. 7 is a diagram illustrating a silence pattern according to a first embodiment of the present invention;

fig. 8 is a schematic diagram of DTMB power spectral density with dual pilot signals inserted therein according to an embodiment of the present invention;

FIG. 9 is a schematic diagram of the power spectral density of an ATSC signal with a pilot signal inserted therein according to one embodiment of the present invention;

FIG. 10 is a diagram illustrating a silence pattern according to a first embodiment of the present invention;

FIG. 11 is a power spectral density diagram of a PAL-D signal according to a first embodiment of the present invention;

FIG. 12 is a diagram illustrating a silence pattern according to a first embodiment of the present invention;

fig. 13 and fig. 14 are schematic processing flows of spectrum sensing in the first embodiment of the present invention;

fig. 15 is a schematic diagram illustrating a determination of whether each channel is available according to a sensing result in the channel according to an embodiment of the present invention;

fig. 16 is a schematic flowchart of a spectrum sensing method according to a second embodiment of the present invention;

fig. 17 is a schematic structural diagram of a network-side device according to a third embodiment of the present invention;

fig. 18 is a schematic structural diagram of a terminal device according to a fourth embodiment of the present invention.

Detailed Description

The technical solutions in the present invention will be described clearly and completely with reference to the accompanying drawings, and it is obvious that the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example one

For the problems existing in the prior art, an embodiment of the present invention provides a spectrum sensing method, which is applicable to a cognitive radio system adopting an OFDM multiple Access manner, and includes but is not limited to a TD-LTE (Time Division-long Time Evolution, Time Division long term Evolution) system, an LTE system, a WiMAX (Worldwide Interoperability for microwave Access) system, and the like, as shown in fig. 4, the spectrum sensing method includes the following steps:

step 401, a network side device (such as a base station device) determines frequency resources and time resources that a cognitive radio system needs to be muted. The determination mode of the time resource can be configured according to requirements.

In a preferred implementation manner of the embodiment of the present invention, the determining, by a network side device, a frequency resource that needs to be muted in a cognitive radio system specifically includes: when the in-band spectrum sensing is selected to be executed, the network side equipment determines the frequency resources of the cognitive radio system which need to be silenced according to the prior information of the authorization system corresponding to the working frequency point of the cognitive radio system (namely the prior information of the authorization system signal possibly existing at the working frequency point of the cognitive radio system).

The spectrum sensing detects the working state of the authorization system on the frequency band of interest through signal detection, and the signal characteristics of the authorization system on the frequency band of interest are generally known in advance, including a central frequency point possibly occupied by a signal, the bandwidth of the signal, the modulation mode adopted by the signal, and the like. To study a relatively large number of scenarios: the cognitive radio system may use a scenario of a broadcast service idle spectrum for example, in china, broadcast services may occupy a plurality of discrete frequency bands from 526.5kHz to 806MHz, and according to a television channel division table, the bandwidth of each standard television channel is 8MHz, that is, the bandwidth of a television signal is about 8MHz, and one television signal occupies one channel. Further, the following signal characteristics are currently found: broadcast television signals of some systems have distinct characteristics in the frequency domain, such as: a dual pilot signal with relatively high power may be inserted into a DTMB (Digital Television Multimedia Broadcasting) signal at a frequency, and the power of a frequency position of the dual pilot signal is obviously higher than that of a frequency position occupied by a data part when viewed from a frequency domain; the ATSC (Advanced television services Committee) signal also inserts a pilot signal in frequency. In addition, from the perspective of spectrum sensing, by detecting these pilot signals, it can be determined whether there is a licensed system signal for this channel.

In the embodiment of the present invention, a network side device determines, according to prior information of an authorization system corresponding to a working frequency point of a cognitive radio system, a frequency resource that needs to be muted in the cognitive radio system, which specifically includes:

in the first case, when the power spectral densities of the grant system signals (i.e., grant system signals that may exist on the channel to be perceived) corresponding to the channel to be perceived at the working frequency point of the cognitive radio system are uniformly distributed in the frequency domain, for the spectrum perception of the channel, the network side device determines that the frequency resources (i.e., frequency positions) that the cognitive radio system needs to silence are uniformly distributed in the channel to be perceived. In addition, the frequency bandwidth and time resources of the cognitive radio system which need to be muted can be configured according to requirements.

In a second case, when an authorized system signal (i.e., an authorized system signal that may exist on a channel to be perceived) corresponding to a channel to be perceived at a working frequency point of the cognitive radio system contains a signal (i.e., a high-power pilot signal is present in a frequency domain) that is greater than a specified power (used for representing high power and can be set according to an actual experience value) in the frequency domain, for spectrum perception of the channel, the network-side device determines that a frequency resource (i.e., a frequency position) that the cognitive radio system needs to be muted is in a frequency position (i.e., in a high-power pilot position) that is greater than. In addition, the frequency bandwidth of the cognitive radio system needing to be silenced is configured according to the bandwidth of the high-power pilot signal of the authorized system signal, and the time resource of the cognitive radio system needing to be silenced can be configured according to the requirement.

In a third case, when the power spectral densities of the authorized system signals (i.e., authorized system signals that may exist on the channel to be perceived) corresponding to the channel to be perceived at the working frequency point of the cognitive radio system are centrally distributed at a specific frequency location (i.e., the power spectral densities are centrally distributed at some frequency locations), for spectrum perception of the channel, the network side device determines that the frequency resources (i.e., frequency locations) that the cognitive radio system needs to silence are located at the specific frequency location (i.e., the frequency location where power is centrally distributed). In addition, the frequency bandwidth of the cognitive radio system needing to be muted is configured according to the frequency bandwidth distributed in the signal power centralization of the authorization system, and the time resource of the cognitive radio system needing to be muted can be configured according to the requirement.

Step 402, the network side device generates a muting pattern of a cell by using frequency resources and time resources. Wherein the muting pattern specifically includes but is not limited to: a system frame, a subframe or an OFDM symbol and a subcarrier or a set of subcarriers; specifically, the muting pattern specifically includes: the method comprises the steps that system frame resources needing to be silenced by the cognitive radio system, subframe resources or OFDM symbol resources needing to be silenced by the cognitive radio system, and subcarrier resources or subcarrier set resources needing to be silenced by the cognitive radio system.

Step 401 and step 402 are described in detail below with reference to specific embodiments.

In this embodiment, the acquisition mode of the authorization system signal characteristic information on each channel can be dynamically obtained through external input, for example, by dynamically querying a database storing the authorization system signal characteristic information on each channel; in addition, for frequency channels which do not change in long-term spectrum use, the authorized system signal characteristic information on each frequency channel can be stored in advance in the radio communication system in a static manner. As shown in fig. 5, a schematic diagram of spectrum sensing of working frequency points of a cognitive radio system is shown, and a selection manner of frequency resources and time resources that the cognitive radio system needs to silence when an authorized system signal has a uniform power spectral density distribution, a high-power pilot signal, and a concentrated power spectral density distribution is given below with reference to fig. 5.

(1) When the power spectral density of the signal of the authorization system is uniformly distributed in the frequency domain, such as: the DTMB signal without double pilot frequency insertion adopts OFDM modulation mode, and the signal after shaping and filtering occupies about 8MHz bandwidth in frequency domain; or, the signal of the CMMB (China Mobile Multimedia Broadcasting) signal modulated by the OFDM also occupies a bandwidth of about 8 MHz; the power spectral densities of the two signals are uniformly distributed in the frequency domain over a bandwidth of about 8MHz, as shown in fig. 6, which is a schematic diagram of the power spectral densities of DTMB and CMMB.

For spectrum sensing of the signal occupation channel (8 MHz bandwidth) of the above type, the silent period positions of the frequency domain are uniformly distributed in the 8MHz bandwidth of the channel, and the silent positions can be configured according to requirements, such as 1, 2, 4, and the like. In addition, the bandwidth of each frequency quiet period can also be configured according to requirements, such as: 50kHz, 100kHz, etc. In addition, the silent period time length, period, etc. can also be configured according to the requirement, for example, the silent period time length is 2ms, 5ms, etc., and the period is 500ms, 1s, etc.

It should be noted that the above parameters are chosen appropriately to ensure accurate perception of channel occupancy. As shown in fig. 7, is a silence pattern diagram in which the silence periods are uniformly spread in frequency within an 8MHz bandwidth, lasting 2ms in time.

(2) To achieve synchronization, channel estimation, the grant system signal may insert a pilot signal in frequency, which has a relatively high power ratio. Such as: the DTMB signal will insert dual pilot signals into the transmitted signal, the power of the signal is equivalent to-16 dB of the data power, i.e. the total power of the two dual pilot signals is 1/40 of the data part power of the DTMB whole frequency band; however, the position where the pilot frequency appears is obviously higher in power spectral density than the data part, and in the frequency domain, the dual pilot frequency signal is a +/-3.78 MHz spectral line; fig. 8 is a schematic diagram of the power spectral density of the DTMB signal with the dual pilot signal inserted. For another example: ATSC modulates a signal by VSB (Vestigial Side Band), and inserts a single-frequency pilot signal into a-2.69 MHz position of a generated baseband signal, where the power of the pilot signal is 11.3dB lower than the average power of a data part, that is, the total power of the pilot signal is approximately 0.074 times of the power of the data part of the entire frequency Band of ATSC; however, the pilot signal appears at a position with significantly higher power than the data portion in terms of power spectral density, as shown in fig. 9, which is a schematic diagram of the power spectral density of the ATSC signal with the pilot signal inserted.

For spectrum sensing of the signal occupying channel (6 MHz or 8MHz bandwidth) of the above type, the quiet period position of the frequency domain only needs to exist at the frequency position where the pilot frequency appears, and the bandwidth of the frequency quiet period can be configured according to requirements, such as: 10kHz, 50kHz, 100kHz, etc.; the silent period time length, period, etc. can also be configured according to the requirement, for example, the silent period time length is 2ms, 5ms, etc., and the period is 500ms, 1s, etc.

It should be noted that the above parameters are chosen appropriately to ensure accurate perception of channel occupancy. As shown in fig. 10, a silence pattern diagram in which a silence period occurs in frequency at a frequency location where a pilot location exists, and lasts 2ms in time.

(3) Another class of signals has a signal power spectral density centered over some frequency bandwidth over the bandwidth it occupies. Such as: PAL-D (Phase Alternating Line-Delay Line Phase-by-Line) television signal, it adopts analog Modulation, and its accompanying sound signal adopts FM (Frequency Modulation) Modulation, the central Frequency and image signal central Frequency are separated by 6.5MHz, the maximum Frequency deviation is 50kHz, the signal bandwidth is about 130kHz, and the power of the image signal is mainly concentrated near the baseband; further, the VSB-modulated PAL-D signal is a power spectral density diagram of the PAL-D signal in an 8MHz channel, as shown in fig. 11, where the two peaks represent the image signal and the audio signal, respectively.

For spectrum sensing of the above type of signal occupying channel (8 MHz bandwidth), the quiet-period position of the frequency domain only needs to exist at the frequency position in the signal power set (for PAL-D signals appearing at the frequency position where image and audio signals exist), and the quiet-period bandwidth is determined according to the frequency bandwidth in the signal power set, such as: for frequency locations where PAL-D audio signals occur, the quiet-period frequency bandwidth may be chosen to be greater than 130 kHz; in addition, the silent period time length, period, etc. can also be configured according to the requirement, for example, the silent period time length is 2ms, 5ms, etc., and the period is 500ms, 1s, etc.

It should be noted that the above parameters are chosen appropriately to ensure accurate perception of channel occupancy. As shown in fig. 12, a silence pattern diagram in which a silence period exists only at a frequency position where image and audio signals exist, lasting 2ms in time.

Step 403, the network side device performs spectrum sensing by using the signal received at the resource location corresponding to the muting pattern (i.e. the uplink resource location corresponding to the muting pattern); and/or the network side device sends the muting pattern to the terminal device in the corresponding cell, and the terminal device performs spectrum sensing by using the signal received at the resource position corresponding to the muting pattern (i.e. the downlink resource position corresponding to the muting pattern).

In a preferred embodiment of the present invention, the network side device performs spectrum sensing by using a signal received at a resource location corresponding to the muting pattern, which specifically includes but is not limited to the following cases:

in the first situation, a network side device receives a signal on a subframe resource or an OFDM symbol resource that a cognitive radio system needs to be muted, based on an existing communication link signal and data processing process, the network side device selects an FFT (fast fourier transform) output signal of a frequency position corresponding to a subcarrier resource that the cognitive radio system needs to be muted or a frequency position corresponding to a subcarrier set resource, and performs signal detection processing on the FFT output signal of a corresponding position to obtain a spectrum sensing result of whether a channel to be sensed is occupied.

And in the second situation, the network side equipment receives signals on subframe resources or OFDM symbol resources which need to be silenced in the cognitive radio system, and based on the narrow-band filter, the network side equipment filters signals at frequency positions corresponding to subcarrier resources or frequency positions corresponding to subcarrier set resources which need to be silenced in the cognitive radio system, and performs signal detection processing on the filtered signals to obtain a spectrum sensing result of whether a channel to be sensed is occupied.

In addition, for a multi-antenna system, a received signal on one antenna can be used independently, and the processing procedure of the first condition or the second condition is adopted to obtain a spectrum sensing result of whether a channel to be sensed is occupied; OR, the received signals of multiple antennas may be used jointly to obtain a result of whether the channel to be sensed is occupied, for example, the processing procedure of the above first case OR the above second case is used to obtain a decision result of each antenna, and then the combining results of each antenna are combined by using the OR criterion, so as to obtain a final result of whether the channel to be sensed is occupied.

In the embodiment of the present invention, after the network side device generates the muting pattern of the cell by using the frequency resource and the time resource, the network side device may further send the muting pattern to the terminal device in the cell, and the terminal device receives the muting pattern of the cell corresponding to the frequency resource and the time resource that the cognitive radio system needs to be muted, which are notified by the network side device, and performs spectrum sensing by using a signal received at a resource position corresponding to the muting pattern (i.e., a downlink resource position corresponding to the muting pattern).

In a preferred embodiment, the network side device may generate an index of the muting pattern by using the muting pattern corresponding to the frequency resource and the time resource that the cognitive radio system needs to mute, and broadcast the index of the muting pattern to the terminal devices in the cell to which the network side device belongs through the system message; further, the terminal device obtains the index of the muting pattern of the local cell by monitoring the system message broadcasted by the local cell, and determines the muting pattern corresponding to the index of the muting pattern, that is, the system frame number of the cognitive radio system that needs muting, the subframe number or OFDM symbol number of the cognitive radio system that needs muting, and the subcarrier number or subcarrier set number of the cognitive radio system that needs muting.

In a preferred embodiment of the present invention, the terminal device performs spectrum sensing by using a signal received at a resource location corresponding to the muting pattern, which specifically includes but is not limited to the following cases:

in the first situation, the terminal device receives signals on subframe resources or OFDM symbol resources which need to be muted in the cognitive radio system, based on existing communication link signals and data processing processes, the terminal device selects FFT output signals at frequency positions corresponding to subcarrier resources or frequency positions corresponding to subcarrier set resources which need to be muted in the cognitive radio system, and performs signal detection processing on the FFT output signals at corresponding positions to obtain a spectrum sensing result whether a channel to be sensed is occupied.

And in the second situation, the terminal equipment receives signals on subframe resources or OFDM symbol resources which need to be muted in the cognitive radio system, and based on the narrow-band filter, the terminal equipment filters signals at frequency positions corresponding to subcarrier resources or frequency positions corresponding to subcarrier set resources which need to be muted in the cognitive radio system, and performs signal detection processing on the filtered signals to obtain a spectrum sensing result of whether a channel to be sensed is occupied.

The following describes in detail a process of performing spectrum sensing on a signal received by the network side device and/or the terminal device at a resource location corresponding to the muting pattern, with reference to a specific embodiment.

In this embodiment, after the network side device and/or the terminal device obtains a muting pattern (i.e., a system frame that the cognitive radio system needs muting, a subframe or an OFDM symbol that the cognitive radio system needs muting, and a subcarrier or a subcarrier set that the cognitive radio system needs muting), it detects whether there is a signal of the authorized system at a PRB (Physical resource block) position (which is PRB resource information and corresponds to the subcarrier or the subcarrier set that the cognitive radio system needs muting) on a subframe resource of a corresponding system frame resource, and the detection method may include, but is not limited to, the following manners:

the first method is as follows: for a system adopting an OFDM multiple access method, when a network side device and/or a terminal device receives a signal, a time domain signal is transformed to a frequency domain by FFT transformation during baseband processing to recover a transmitted signal. After the network side device and/or the terminal device obtains the system frame that the cognitive radio system needs to be muted, the subframe that the cognitive radio system needs to be muted, and the corresponding PRB resource information, for the subframe that there is a quiet period, the FFT output signal corresponding to the corresponding PRB is used for signal detection, and the specific detection method may adopt energy detection, that is: the average power of the FFT output signal is directly counted, and the counted average power is compared with a decision threshold to obtain the result of the presence or absence of the signal, and the processing flow of the spectrum sensing is shown in fig. 13.

The second method comprises the following steps: after the network side device and/or the terminal device obtains the system frame of the cognitive radio system needing silence, the subframe of the cognitive radio system needing silence and the corresponding PRB resource information, for the subframe of the system frame with the silence period, a narrow-band filter is adopted to filter out a signal for spectrum sensing, the center frequency and the bandwidth of the filter are determined according to the position of the silent PRB, and the working time of the filter is determined by the position of the silent system frame, the subframe and the OFDM symbol. Further, a signal detection method may be used for the filtered signal to detect whether an authorized system signal exists, such as: the network side device and/or the terminal device may perform correlation processing on the filtered signal and the known signal, and compare the maximum value of the correlation result with a decision threshold to obtain a result of whether the signal exists or not; or, directly counting the power of the filtered signal, and comparing the counted power with a decision threshold to obtain a result of whether the signal exists, where a processing flow of the spectrum sensing is shown in fig. 14.

In addition, when processing is performed, spectrum sensing processing may be performed on received signals of a plurality of antennas at a plurality of subframe positions and a plurality of silent PRB resource positions jointly used. One way of processing is: the sensing result is obtained by adopting the spectrum sensing method on each independent silent resource, and the independent silent resource is a resource which can be distinguished by time-frequency space (corresponding subframe, PRB and antenna). Assume that the perceived result on each independent silence resource is: di, a final judgment result can be obtained by combining the results of a plurality of Di; such as: di is summed (i =1, 2, … N, N being N independent resources) and the result of the summation is compared with some threshold to get the result of whether the spectrum is occupied or not. By jointly processing signals of a plurality of silent resources, gains of frequency, time and space diversity can be obtained, and the perception robustness can be effectively improved.

In the embodiment of the present invention, after the network side device and/or the terminal device performs the process of sensing the frequency spectrum by using the signal received at the resource location corresponding to the muting pattern, the network side device and/or the terminal device may further form a final decision of whether each channel is occupied according to a decision result of whether the frequency spectrum is occupied, where the specific decision process is as follows: (1) if the signal detection result of the resource position of the silent period subcarrier (or the subcarrier set) in a certain channel is occupied, the channel is judged to be occupied; if the signal detection result of the resource position of the silent period subcarrier (or the subcarrier set) in a certain channel is unoccupied, the channel is judged to be unoccupied; (2) if a plurality of silent period subcarrier (or subcarrier set) resource positions exist in a certain channel, the signal detection result of the resource positions of the plurality of parts of silent period subcarriers (or subcarrier sets) is occupied, and the channel is judged to be occupied; otherwise, it is determined as unoccupied.

The following describes in detail a process of a network side device and/or a terminal device forming a final decision of whether each channel is occupied according to a decision result of whether a spectrum is occupied, with reference to a specific embodiment.

In this embodiment, as shown in fig. 15, it is a schematic diagram that whether a channel is available is determined according to a sensing result in each channel. Such as: for an 8MHz frequency band, a silence position on a frequency is configured in the frequency band, and whether the 8MHz frequency band is available is judged according to a signal detection result on the silence position. If the signal detection result at the silent position is that an authorized system signal exists, the 8MHz frequency band is unavailable; if the detection result is that no authorized system signal exists, the 8MHz frequency band is available. In addition, if there are multiple silent frequency positions in the channel, the above method can be used to merge the decision results on each frequency resource position, and then decide whether the channel is available according to the merged result.

In the embodiment of the invention, after the network side equipment generates the silent pattern of the cell by using frequency resources and time resources, when the network side equipment performs resource scheduling (uplink resource scheduling/downlink resource scheduling), the network side equipment does not schedule terminal equipment on subframe resources which are required to be silent by a cognitive radio system on system frame resources which are required to be silent by the cognitive radio system or subcarrier resources or subcarrier set resources which are required to be silent by the cognitive radio system on OFDM symbol resources; and/or the network side equipment does not transmit signals on the subframe resources or subcarrier set resources on which the cognitive radio system needs to be silenced on the system frame resources or OFDM symbol resources on which the cognitive radio system needs to be silenced. And/or after the terminal equipment obtains the muting pattern, the terminal equipment does not transmit signals on subframe resources or subcarrier set resources, which are needed to be muted by the cognitive radio system, on system frame resources, which are needed to be muted by the cognitive radio system, or on OFDM symbol resources, which are needed to be muted by the cognitive radio system.

In a preferred implementation manner of the embodiment of the present invention, the network side device does not transmit a signal (any signal) on a subframe resource or a subcarrier set resource, which is required to be muted by the cognitive radio system, of a subframe resource or an OFDM symbol resource, which is required to be muted by the cognitive radio system, of a system frame resource, which is required to be muted by the cognitive radio system, specifically including but not limited to:

in case one, for subframe resources or OFDM symbol resources that need to be muted by a cognitive radio system, a network side device checks whether a subcarrier resource or a subcarrier set resource that needs to be muted by the cognitive radio system conflicts with a resource occupied by a Physical layer Control Channel (e.g., LTE PUCCH (Physical Uplink Control Channel)); if so, the network side equipment does not transmit any signal on the subframe resource or all subcarrier resources or subcarrier set resources on the OFDM symbol resource, which is needed to be silenced by the cognitive radio system, on the system frame resource, which is needed to be silenced by the cognitive radio system, of the cognitive radio system; if not, the network side equipment only needs to transmit no signal on the subframe resource which needs to be muted by the cognitive radio system on the system frame resource which needs to be muted by the cognitive radio system or the subcarrier resource or the subcarrier set resource which needs to be muted by the cognitive radio system on the OFDM symbol resource.

In case two, for subframe resources or OFDM symbol resources that the cognitive radio system needs to be muted, when the network side device has a Pilot (Pilot) of a corresponding communication system in subcarrier resources or subcarrier set resources that the cognitive radio system needs to be muted, the network side device does not transmit the Pilot on the subcarrier resources or subcarrier set resources that the cognitive radio system needs to be muted on the subframe resources or subcarrier set resources that the cognitive radio system needs to be muted on the system frame resources or OFDM symbol resources that the cognitive radio system needs to be muted on which the cognitive radio system needs to be muted; or, for subframe resources or OFDM symbol resources that the cognitive radio system needs to be muted, when the network side device has a Reference Signal (Reference Signal) of the corresponding communication system in subcarrier resources or subcarrier set resources that the cognitive radio system needs to be muted, the network side device does not transmit the Reference Signal in the subframe resources or subcarrier set resources that the cognitive radio system needs to be muted on the subframe resources or OFDM symbol resources that the cognitive radio system needs to be muted on the system frame resources that the cognitive radio system needs to be muted.

And in a third case, when multiple antenna transmission systems exist and each antenna port corresponds to the same muting pattern, the network side device does not transmit any signal on the subframe resource or subcarrier set resource, which is needed to be muted, of the cognitive radio system on the system frame resource, which is needed to be muted, of the cognitive radio system corresponding to each antenna port, or on the subcarrier resource or subcarrier set resource, which is needed to be muted, of the cognitive radio system on the OFDM symbol resource, of the cognitive radio system.

In a preferred implementation manner of the embodiment of the present invention, the terminal device does not transmit a signal (any signal) on a subframe resource or a subcarrier set resource, which is required to be muted by the cognitive radio system, of a subframe resource or an OFDM symbol resource, which is required to be muted by the cognitive radio system, of a system frame resource, which is required to be muted by the cognitive radio system, specifically including but not limited to:

in case one, for subframe resources or OFDM symbol resources that need to be muted by a cognitive radio system, a terminal device checks whether a subcarrier resource or a subcarrier set resource that needs to be muted by the cognitive radio system conflicts with a resource occupied by a Physical layer Control Channel (e.g., LTE PUCCH (Physical Uplink Control Channel)); if so, the terminal equipment does not transmit any signal on the subframe resource or all subcarrier resources or subcarrier set resources on the subframe resource or OFDM symbol resource which needs to be silenced by the cognitive radio system on the system frame resource which needs to be silenced by the cognitive radio system; if not, the terminal equipment only needs not to transmit any signal on the subframe resource which needs to be silenced by the cognitive radio system on the system frame resource which needs to be silenced by the cognitive radio system or the subcarrier resource or the subcarrier set resource which needs to be silenced by the cognitive radio system on the OFDM symbol resource.

In case two, for subframe resources or OFDM symbol resources that the cognitive radio system needs to be muted, when the terminal device has a Pilot (Pilot) of a corresponding communication system in subcarrier resources or subcarrier set resources that the cognitive radio system needs to be muted, the terminal device does not transmit the Pilot on the subcarrier resources or subcarrier set resources that the cognitive radio system needs to be muted on the subframe resources or subcarrier set resources that the cognitive radio system needs to be muted on the system frame resources or OFDM symbol resources that the cognitive radio system needs to be muted on which the cognitive radio system needs to be muted; or, for subframe resources or OFDM symbol resources that the cognitive radio system needs to be muted, when the terminal device has a Reference Signal (Reference Signal) of the corresponding communication system in subcarrier resources or subcarrier set resources that the cognitive radio system needs to be muted, the terminal device does not transmit the Reference Signal in the subframe resources or subcarrier set resources that the cognitive radio system needs to be muted on the system frame resources or OFDM symbol resources that the cognitive radio system needs to be muted on which the cognitive radio system needs to be muted.

And in a third case, when a plurality of antenna transmission systems exist and each antenna port corresponds to the same muting pattern, the terminal device does not transmit any signal on the subframe resource which needs muting by the cognitive radio system on the system frame resource which needs muting by the cognitive radio system corresponding to each antenna port or the subcarrier resource or subcarrier set resource which needs muting by the cognitive radio system on the OFDM symbol resource.

The following describes, in detail, a process in which a network side device and/or a terminal device does not transmit any signal on a subframe resource or a subcarrier set resource, which is used by a cognitive radio system and needs to be muted, on a system frame resource, which is used by the cognitive radio system and needs to be muted, or on an OFDM symbol resource, which is used by the cognitive radio system and needs to be muted, in combination with a specific embodiment.

In this embodiment, the network side device generates the silent pattern for the system according to the silent period frequency resource and the time resource and by combining the characteristics of the system. If there are multiple cells under a network side device, the network side device needs to generate a muting pattern of the cell according to frequency resources and time resources corresponding to frequency channels occupied by the cells, respectively. For the TD-LTE/LTE system, the muting pattern may specifically include: in which system frame, which PRB resources of which subframes are silent (in TD-LTE/LTE system, PRB is a resource set consisting of Nsy consecutive OFDM symbols and Nsc consecutive subcarriers). The index information of the system frame number, subframe number and PRB number of the muting can be generated based on the muting pattern, such as: the PRB resource locations of SilencePRBIndex1 and SilencePRBIndex2 in subframes No. silencesubframe 2 of the system frame SFN mod SilencePeriod = SilenceFrameIndex 1 and SilenceSubFrameIndex2 are muted.

The network side device may also send the resource index information (i.e. the index information of the muting pattern) to the terminal device in the relevant cell through a broadcasted system message, such as: the network side device adds the above-mentioned index positions SilencePeriod, SilenceFrameIndex, SilenceSubFrameIndex1, SilenceSubFrameIndex2, SilencePRBIndex1, and SilencePRBIndex2 to an SIB (System Information Block) message. Furthermore, the terminal device of the TD-LTE/LTE system obtains silent resource index information by monitoring the system message broadcast by the cell, so as to clear which PRB resources of which subframes and which system frames are silent at which cell.

When downlink transmission is carried out, the network side equipment does not transmit signals or transmits zero-power signals on the subcarrier resources corresponding to the downlink subframes of the system frame which needs to be silenced. For TD-LTE and LTE systems, because the first 2-3 OFDM symbols of the downlink subframe are control regions and other OFDM symbols are data regions, the downlink subframe needing to be silenced only silences PRB resources of a data part, and the resources of the control regions are not influenced; in addition, reference signals in the PRB data region of the mute subframe are not transmitted. When uplink transmission is carried out, the terminal equipment does not transmit signals or transmits zero-power signals on PRB resources corresponding to uplink subframes of the system frames which need to be silenced. For TD-LTE and LTE systems, because PRB resources at the edge of the working bandwidth of an uplink subframe system are occupied areas of a physical layer control channel and other PRBs are data transmission areas, the situation that silent PRB resources possibly conflict with the PRB resources occupied by the occupied areas of the physical layer control channel exists, and whether the silent PRB resources conflict with the PRB occupied areas or not needs to be judged before uplink transmission; if there is conflict, the up sub-frame is completely silent, and no signal is transmitted in the sub-frame, including physical layer control signal, data signal, pilot signal, etc.; and if the conflict does not exist, the PRB resource corresponding to the uplink subframe needing silence does not transmit the data signal and the reference signal in the PRB resource.

Furthermore, since some reference signals are transmitted periodically, such as: the positioning pilot and the uplink probing pilot frequency signal may be transmitted in a period of tens of ms. In order to reduce the effect of muting on reference signal transmission, when selecting the parameters SilencePeriod, SilenceFrameIndex, SilenceSubFrameIndex1, SilenceSubFrameIndex2, the selection of subframes where periodic reference signal transmission exists may be avoided as much as possible.

In addition, for a multi-antenna system, regardless of configuring different muting patterns for each antenna port, each antenna may be muted in the related system frame, subframe and PRB according to the above method.

Example two

The second embodiment of the present invention provides a spectrum sensing method, which is suitable for a cognitive radio system adopting an OFDM multiple access method, including but not limited to a TD-LTE system, an LTE system, a WiMAX system, and the like, and as shown in fig. 16, the spectrum sensing method includes the following steps:

step 1601, the terminal device receives the muting pattern notified by the network side device. The muting pattern is generated and notified to the terminal device by the network side device by using the frequency resource and the time resource after determining the frequency resource and the time resource which are needed to be muted by the cognitive radio system.

In a preferred implementation manner of the embodiment of the present invention, when selecting to perform in-band spectrum sensing, a network side device determines, according to prior information of an authorization system corresponding to a working frequency point of a cognitive radio system, a frequency resource that the cognitive radio system needs to silence. Specifically, when the power spectral density of an authorized system signal corresponding to a channel to be sensed at a working frequency point of a cognitive radio system is uniformly distributed in a frequency domain, for the spectrum sensing of the channel, network side equipment determines that frequency resources, which need to be muted, of the cognitive radio system are uniformly distributed in the channel to be sensed; when an authorization system signal corresponding to a channel to be sensed of a working frequency point of a cognitive radio system contains a signal with power higher than specified power in a frequency domain, for frequency spectrum sensing of the channel, network side equipment determines that a frequency resource of the cognitive radio system which needs to be silenced is in a frequency position with power higher than the specified power; when the power spectral density of an authorized system signal corresponding to a channel to be sensed of a working frequency point of a cognitive radio system is centrally distributed at a specific frequency position, for the spectrum sensing of the channel, network side equipment determines that a frequency resource which needs to be silenced by the cognitive radio system is at the specific frequency position.

In the embodiment of the present invention, the receiving, by the terminal device, the silence pattern notified by the network side device specifically includes: the terminal equipment obtains the index of the silent pattern of the local cell by monitoring the system message broadcasted by the local cell and determines the silent pattern corresponding to the index of the silent pattern. Wherein the muting pattern specifically includes but is not limited to: a system frame, a subframe or an OFDM symbol and a subcarrier or a set of subcarriers; specifically, the muting pattern specifically includes: the method comprises the steps that system frame resources needing to be silenced by the cognitive radio system, subframe resources or OFDM symbol resources needing to be silenced by the cognitive radio system, and subcarrier resources or subcarrier set resources needing to be silenced by the cognitive radio system.

In step 1602, the terminal device performs spectrum sensing by using the signal received at the resource location corresponding to the muting pattern.

In a preferred embodiment of the present invention, after the terminal device obtains the muting pattern, the terminal device does not transmit a signal on the subframe resource or subcarrier set resource, which is required to be muted by the cognitive radio system, on the subframe resource or OFDM symbol resource, which is required to be muted by the cognitive radio system, on the system frame resource, which is required to be muted by the cognitive radio system.

in case one, for subframe resources or OFDM symbol resources that need to be muted by a cognitive radio system, a terminal device checks whether subcarrier resources or subcarrier set resources that need to be muted by the cognitive radio system conflict with resources occupied by a physical layer control channel (e.g., LTE PUCCH); if so, the terminal equipment does not transmit any signal on the subframe resource or all subcarrier resources or subcarrier set resources on the OFDM symbol resource, which is needed to be silenced by the cognitive radio system, on the system frame resource, which is needed to be silenced by the cognitive radio system, of the cognitive radio system; if not, the terminal equipment only needs to transmit no signal on the subframe resource which needs to be silenced by the cognitive radio system on the system frame resource which needs to be silenced by the cognitive radio system or the subcarrier resource which needs to be silenced by the cognitive radio system on the OFDM symbol resource.

In case two, for the subframe resource or OFDM symbol resource that the cognitive radio system needs to be muted, when the terminal device has the pilot frequency of the corresponding communication system in the subcarrier resource or subcarrier set resource that the cognitive radio system needs to be muted, the terminal device does not transmit the pilot frequency in the subcarrier resource or subcarrier set resource that the cognitive radio system needs to be muted in the subframe resource or OFDM symbol resource that the cognitive radio system needs to be muted in the system frame resource that the cognitive radio system needs to be muted; or, for the subframe resource or OFDM symbol resource that the cognitive radio system needs to be muted, when the terminal device has the reference signal of the corresponding communication system in the subcarrier resource or subcarrier set resource that the cognitive radio system needs to be muted, the terminal device does not transmit the reference signal in the subcarrier resource or subcarrier set resource that the cognitive radio system needs to be muted in the subframe resource or OFDM symbol resource that the cognitive radio system needs to be muted in the system frame resource that the cognitive radio system needs to be muted.

EXAMPLE III

Based on the same inventive concept as the above method, an embodiment of the present invention further provides a network-side device, as shown in fig. 17, where the network-side device includes:

a determining module 11, configured to determine frequency resources and time resources that the cognitive radio system needs to be muted;

a generating module 12, configured to generate a muting pattern of a cell by using the frequency resources and the time resources;

a first processing module 13, configured to perform spectrum sensing by using a signal received at a resource location corresponding to the muting pattern; and/or sending the muting pattern to terminal equipment in the cell, and performing spectrum sensing by the terminal equipment by using signals received at the resource position corresponding to the muting pattern.

The determining module 11 is specifically configured to determine, according to prior information of an authorization system corresponding to a working frequency point of a cognitive radio system, a frequency resource that needs to be muted of the cognitive radio system.

The determining module 11 is specifically configured to determine that frequency resources, which need to be muted, of the cognitive radio system are uniformly distributed in a channel to be perceived when power spectral densities of authorization system signals corresponding to the channel to be perceived of a working frequency point of the cognitive radio system are uniformly distributed in a frequency domain; or,

when an authorization system signal corresponding to a channel to be sensed of a working frequency point of a cognitive radio system contains a signal with power higher than specified power in a frequency domain, determining that frequency resources needing to be silenced of the cognitive radio system are in a frequency position with power higher than the specified power; or,

when the power spectral densities of authorized system signals corresponding to channels to be sensed of working frequency points of a cognitive radio system are distributed in a specific frequency position in a centralized manner, determining that frequency resources which need to be silenced of the cognitive radio system are in the specific frequency position.

The first processing module 13 is specifically configured to generate an index of the muting pattern, and broadcast the index of the muting pattern through a system message; and the terminal equipment acquires the index of the silent pattern by monitoring the system message broadcasted by the cell and determines the silent pattern corresponding to the index of the silent pattern.

The silence pattern generated by the generation module 12 specifically includes: the method comprises the steps that a cognitive radio system needs silent system frame resources, cognitive radio system needs silent subframe resources or Orthogonal Frequency Division Multiplexing (OFDM) symbol resources, and cognitive radio system needs silent subcarrier resources or subcarrier set resources.

The first processing module 13 is further configured to not schedule the terminal device on the subframe resource or subcarrier set resource, which is required by the cognitive radio system to be muted, on the subframe resource or OFDM symbol resource, which is required by the cognitive radio system to be muted, on the system frame resource, which is required by the cognitive radio system to be muted, when performing resource scheduling; and/or the presence of a gas in the gas,

and transmitting no signal on the subframe resource or subcarrier set resource which needs to be silenced by the cognitive radio system on the system frame resource which needs to be silenced by the cognitive radio system or the OFDM symbol resource which needs to be silenced by the cognitive radio system.

The first processing module 13 is specifically configured to check whether a subcarrier resource or a subcarrier set resource that needs to be muted by the cognitive radio system conflicts with a resource occupied by a physical layer control channel; if so, not transmitting signals on subframe resources or all subcarrier resources or subcarrier set resources on OFDM symbol resources, which are needed to be silenced by the cognitive radio system, on system frame resources, which are needed to be silenced by the cognitive radio system, of the cognitive radio system; if not, no signal is transmitted on the subframe resource which needs to be silenced by the cognitive radio system on the system frame resource which needs to be silenced by the cognitive radio system or the subcarrier resource which needs to be silenced by the cognitive radio system on the OFDM symbol resource; or,

when pilot frequency exists in the subcarrier resources or subcarrier set resources which are needed to be silenced by the cognitive radio system, the pilot frequency is not transmitted on the subframe resources or subcarrier set resources which are needed to be silenced by the cognitive radio system on the system frame resources or OFDM symbol resources which are needed to be silenced by the cognitive radio system; or when the reference signal exists in the subcarrier resource or the subcarrier set resource which the cognitive radio system needs to be muted, the reference signal is not transmitted on the subframe resource or the subcarrier set resource which the cognitive radio system needs to be muted on the subframe resource or the OFDM symbol resource which the cognitive radio system needs to be muted on the system frame resource which the cognitive radio system needs to be muted; or,

when a plurality of antenna transmitting systems exist and each antenna port corresponds to the same muting pattern, no signal is transmitted on subframe resources or subcarrier set resources, required to be muted, of the cognitive radio system on system frame resources, required to be muted, of the cognitive radio system corresponding to each antenna port or on OFDM symbol resources.

The first processing module 13 is specifically configured to receive a signal on a subframe resource or an OFDM symbol resource that the cognitive radio system needs to be muted, select an output signal at a frequency position corresponding to a subcarrier resource or a frequency position corresponding to a subcarrier set resource that the cognitive radio system needs to be muted, and perform signal detection processing on the output signal at a corresponding position to obtain a spectrum sensing result indicating whether a channel to be sensed is occupied; or,

receiving signals on subframe resources or OFDM symbol resources which need to be silenced by a cognitive radio system, filtering the signals at the frequency positions corresponding to subcarrier resources or frequency positions corresponding to subcarrier set resources which need to be silenced by the cognitive radio system, and performing signal detection processing on the filtered signals to obtain a spectrum sensing result of whether a channel to be sensed is occupied.

The modules of the device can be integrated into a whole or can be separately deployed. The modules can be combined into one module, and can also be further split into a plurality of sub-modules.

EXAMPLE III

Based on the same inventive concept as the above method, an embodiment of the present invention further provides a terminal device, as shown in fig. 17, where the terminal device includes:

a receiving module 21, configured to receive a muting pattern notified by a network side device; the network side equipment generates and informs the terminal equipment of the silent pattern by using the frequency resource and the time resource after determining the frequency resource and the time resource which are required by the cognitive radio system to be silent;

and a spectrum sensing module 22, configured to perform spectrum sensing by using the signal received at the resource location corresponding to the muting pattern.

The receiving module 21 is specifically configured to obtain an index of a muting pattern of the local cell by monitoring a system message broadcasted by the local cell, and determine the muting pattern corresponding to the index of the muting pattern.

The muting pattern received by the receiving module 21 specifically includes: the method comprises the steps that a cognitive radio system needs silent system frame resources, cognitive radio system needs silent subframe resources or Orthogonal Frequency Division Multiplexing (OFDM) symbol resources, and cognitive radio system needs silent subcarrier resources or subcarrier set resources.

The terminal device further includes: and the second processing module 23 is configured to not transmit a signal on the subframe resource or subcarrier set resource, which is needed to be muted by the cognitive radio system, on the system frame resource, which is needed to be muted by the cognitive radio system, or on the OFDM symbol resource, which is needed to be muted by the cognitive radio system.

The second processing module 23 is specifically configured to check whether a subcarrier resource or a subcarrier set resource that needs to be muted by the cognitive radio system conflicts with a resource occupied by a physical layer control channel; if so, not transmitting signals on subframe resources or all subcarrier resources or subcarrier set resources on OFDM symbol resources, which are needed to be silenced by the cognitive radio system, on system frame resources, which are needed to be silenced by the cognitive radio system, of the cognitive radio system; if not, no signal is transmitted on the subframe resource which needs to be silenced by the cognitive radio system on the system frame resource which needs to be silenced by the cognitive radio system or the subcarrier resource which needs to be silenced by the cognitive radio system on the OFDM symbol resource; or,

The spectrum sensing module 22 is specifically configured to receive signals on subframe resources or OFDM symbol resources that the cognitive radio system needs to be muted, select output signals at frequency positions corresponding to subcarrier resources or frequency positions corresponding to subcarrier set resources that the cognitive radio system needs to be muted, and perform signal detection processing on the output signals at corresponding positions to obtain a spectrum sensing result indicating whether a channel to be sensed is occupied; or,

Through the above description of the embodiments, those skilled in the art will clearly understand that the present invention may be implemented by software plus a necessary general hardware platform, and certainly may also be implemented by hardware, but in many cases, the former is a better embodiment. Based on such understanding, the technical solutions of the present invention may be embodied in the form of a software product, which is stored in a storage medium and includes instructions for causing a computer device (which may be a personal computer, a server, or a network device) to execute the methods according to the embodiments of the present invention.

Those skilled in the art will appreciate that the drawings are merely schematic representations of one preferred embodiment and that the blocks or flow diagrams in the drawings are not necessarily required to practice the present invention.

Those skilled in the art will appreciate that the modules in the devices in the embodiments may be distributed in the devices in the embodiments according to the description of the embodiments, and may be correspondingly changed in one or more devices different from the embodiments. The modules of the above embodiments may be combined into one module, or further split into multiple sub-modules.

The above-mentioned serial numbers of the embodiments of the present invention are merely for description and do not represent the merits of the embodiments.

The above disclosure is only for a few specific embodiments of the present invention, but the present invention is not limited thereto, and any variations that can be made by those skilled in the art are intended to fall within the scope of the present invention.

Claims

1. A method for spectrum sensing, the method comprising:

the network side equipment performs spectrum sensing by using signals received at the resource position corresponding to the silence pattern; the network side equipment sends the silent pattern to terminal equipment in the cell, and the terminal equipment performs spectrum sensing by using signals received at the resource position corresponding to the silent pattern;

wherein, the sending, by the network side device, the silence pattern to the terminal device in the cell specifically includes:

the network side equipment generates an index of the silent pattern and broadcasts the index of the silent pattern through a system message; and the terminal equipment acquires the index of the silent pattern by monitoring the system message broadcasted by the cell and determines the silent pattern corresponding to the index of the silent pattern.

2. The method of claim 1, wherein the determining, by the network-side device, the frequency resource that needs to be muted by the cognitive radio system specifically includes:

and the network side equipment determines the frequency resources needing silence of the cognitive radio system according to the prior information of the authorization system corresponding to the working frequency point of the cognitive radio system.

3. The method according to claim 2, wherein the network side device determines, according to the prior information of the authorization system corresponding to the working frequency point of the cognitive radio system, the frequency resource that the cognitive radio system needs to silence, specifically including:

when the power spectral density of an authorization system signal corresponding to a channel to be perceived of a working frequency point of a cognitive radio system is uniformly distributed in a frequency domain, the network side equipment determines that frequency resources, which need to be silenced, of the cognitive radio system are uniformly distributed in the channel to be perceived; or,

when an authorization system signal corresponding to a channel to be sensed of a working frequency point of a cognitive radio system contains a signal with power higher than specified power in a frequency domain, the network side equipment determines that a frequency resource of the cognitive radio system which needs to be silenced is in a frequency position with power higher than the specified power; or,

when the power spectral densities of the authorized system signals corresponding to the channels to be sensed of the working frequency points of the cognitive radio system are distributed in a specific frequency position in a centralized manner, the network side equipment determines that the frequency resources which need to be silenced of the cognitive radio system are in the specific frequency position.

4. The method of claim 1, wherein the muting pattern specifically comprises:

the method comprises the steps that a cognitive radio system needs silent system frame resources, cognitive radio system needs silent subframe resources or Orthogonal Frequency Division Multiplexing (OFDM) symbol resources, and cognitive radio system needs silent subcarrier resources or subcarrier set resources.

5. The method of claim 4, wherein after the network-side device generates the muting pattern of the cell using the frequency resources and the time resources, the method further comprises:

when resource scheduling is carried out, the network side equipment does not schedule terminal equipment on subframe resources which are required to be silenced by the cognitive radio system on system frame resources which are required to be silenced by the cognitive radio system or subcarrier resources or subcarrier set resources which are required to be silenced by the cognitive radio system on OFDM symbol resources; and/or the presence of a gas in the gas,

the network side equipment does not transmit signals on subframe resources which are needed to be silenced by the cognitive radio system on system frame resources which are needed to be silenced by the cognitive radio system or subcarrier resources which are needed to be silenced by the cognitive radio system on OFDM symbol resources or subcarrier set resources.

6. The method of claim 5, wherein the network-side device does not transmit signals on subframe resources or subcarrier set resources on which the cognitive radio system needs to be muted on system frame resources on which the cognitive radio system needs to be muted or on OFDM symbol resources on which the cognitive radio system needs to be muted, specifically comprising:

the network side equipment checks whether the subcarrier resources or subcarrier set resources required to be silenced by the cognitive radio system conflict with the resources occupied by the physical layer control channel; if so, the network side equipment does not transmit signals on subframe resources or all subcarrier resources or subcarrier set resources on OFDM symbol resources, which are needed to be silenced by the cognitive radio system, on system frame resources, which are needed to be silenced by the cognitive radio system, of the cognitive radio system; if not, the network side equipment does not transmit signals on the subframe resources which are required to be silenced by the cognitive radio system on the system frame resources which are required to be silenced by the cognitive radio system or the subcarrier resources or the subcarrier set resources which are required to be silenced by the cognitive radio system on the OFDM symbol resources; or,

when pilot frequency exists in the subcarrier resources or subcarrier set resources which need to be silenced by the cognitive radio system, the network side equipment does not transmit the pilot frequency on the subframe resources or subcarrier set resources which need to be silenced by the cognitive radio system on the system frame resources or OFDM symbol resources which need to be silenced by the cognitive radio system; or when the reference signal exists in the subcarrier resource or the subcarrier set resource which the cognitive radio system needs to be muted, the network side device does not transmit the reference signal on the subframe resource or the subcarrier set resource which the cognitive radio system needs to be muted on the subframe resource or the OFDM symbol resource which the cognitive radio system needs to be muted on the system frame resource which the cognitive radio system needs to be muted; or,

when a plurality of antenna transmission systems exist and each antenna port corresponds to the same muting pattern, the network side device does not transmit signals on subframe resources, which are needed to be muted by the cognitive radio system, on system frame resources, which are needed to be muted by the cognitive radio system, corresponding to each antenna port, or on subcarrier resources, or subcarrier set resources, which are needed to be muted by the cognitive radio system, on OFDM symbol resources, corresponding to each antenna port.

7. The method of claim 4, wherein the performing, by the network-side device, spectrum sensing by using the signal received at the resource location corresponding to the muting pattern specifically includes:

the network side equipment receives signals on subframe resources or OFDM symbol resources which need to be silenced by a cognitive radio system, selects output signals of frequency positions corresponding to subcarrier resources or frequency positions corresponding to subcarrier set resources which need to be silenced by the cognitive radio system, and performs signal detection processing on the output signals of corresponding positions to obtain a spectrum sensing result of whether a channel to be sensed is occupied; or,

the network side equipment receives signals on subframe resources or OFDM symbol resources which need to be silenced by the cognitive radio system, filters the signals of frequency positions corresponding to subcarrier resources or frequency positions corresponding to subcarrier set resources which need to be silenced by the cognitive radio system, and performs signal detection processing on the filtered signals to obtain a spectrum sensing result of whether a channel to be sensed is occupied.

8. A method for spectrum sensing, the method comprising:

the terminal equipment performs spectrum sensing by using signals received at the resource position corresponding to the silent pattern;

the receiving, by the terminal device, the silence pattern notified by the network side device specifically includes:

the terminal equipment acquires the index of the silent pattern of the local cell by monitoring the system message broadcasted by the local cell and determines the silent pattern corresponding to the index of the silent pattern.

9. The method of claim 8, wherein the muting pattern comprises:

10. The method of claim 9, wherein after the terminal device receives the muting pattern notified by the network-side device, the method further comprises:

the terminal equipment does not transmit signals on subframe resources which are needed to be silenced by the cognitive radio system on system frame resources which are needed to be silenced by the cognitive radio system or subcarrier resources which are needed to be silenced by the cognitive radio system on OFDM symbol resources or subcarrier set resources.

11. The method as claimed in claim 10, wherein the terminal device does not transmit signals on the subframe resources or subcarrier set resources on which the cognitive radio system needs to be muted on the system frame resources on which the cognitive radio system needs to be muted or on the OFDM symbol resources on which the cognitive radio system needs to be muted, specifically comprising:

the terminal equipment checks whether the subcarrier resources or subcarrier set resources required to be silenced by the cognitive radio system conflict with the resources occupied by the physical layer control channel; if so, the terminal equipment does not transmit signals on subframe resources or all subcarrier resources or subcarrier set resources on OFDM symbol resources, which are needed to be silenced by the cognitive radio system, on system frame resources, which are needed to be silenced by the cognitive radio system, of the terminal equipment; if not, the terminal equipment does not transmit signals on the subframe resources which are required to be silenced by the cognitive radio system on the system frame resources which are required to be silenced by the cognitive radio system or the subcarrier resources which are required to be silenced by the cognitive radio system on the OFDM symbol resources or the subcarrier set resources; or,

when pilot frequency exists in the subcarrier resources or subcarrier set resources which need to be silenced by the cognitive radio system, the terminal equipment does not transmit the pilot frequency on the subframe resources or subcarrier set resources which need to be silenced by the cognitive radio system on the system frame resources or OFDM symbol resources which need to be silenced by the cognitive radio system; or, when a reference signal exists in the subcarrier resource or the subcarrier set resource which the cognitive radio system needs to silence, the terminal device does not transmit the reference signal on the subframe resource or the subcarrier set resource which the cognitive radio system needs to silence on the subframe resource or the OFDM symbol resource which the cognitive radio system needs to silence on the system frame resource which the cognitive radio system needs to silence; or,

when a plurality of antenna transmission systems exist and each antenna port corresponds to the same muting pattern, the terminal device does not transmit signals on subframe resources, which are needed to be muted by the cognitive radio system, on system frame resources, which are needed to be muted by the cognitive radio system, corresponding to each antenna port, or on subcarrier resources, or subcarrier set resources, which are needed to be muted by the cognitive radio system, on OFDM symbol resources, corresponding to each antenna port.

12. The method of claim 9, wherein the performing, by the terminal device, spectrum sensing using the signal received at the resource location corresponding to the muting pattern specifically includes:

the terminal equipment receives signals on subframe resources or OFDM symbol resources which need to be silenced by a cognitive radio system, selects output signals of frequency positions corresponding to subcarrier resources or subcarrier set resources which need to be silenced by the cognitive radio system, and performs signal detection processing on the output signals of corresponding positions to obtain a spectrum sensing result of whether a channel to be sensed is occupied; or,

the terminal equipment receives signals on subframe resources or OFDM symbol resources which need to be silenced in the cognitive radio system, filters the signals at the frequency positions corresponding to subcarrier resources or frequency positions corresponding to subcarrier set resources which need to be silenced in the cognitive radio system, and performs signal detection processing on the filtered signals to obtain a spectrum sensing result of whether a channel to be sensed is occupied.

13. A network side device, characterized in that the network side device comprises:

a first processing module, configured to perform spectrum sensing by using a signal received at a resource location corresponding to the muting pattern; the silent pattern is sent to the terminal equipment in the cell, and the terminal equipment performs spectrum sensing by using the signals received at the resource position corresponding to the silent pattern;

the first processing module is specifically configured to generate an index of the muting pattern, and broadcast the index of the muting pattern through a system message; and the terminal equipment acquires the index of the silent pattern by monitoring the system message broadcasted by the cell and determines the silent pattern corresponding to the index of the silent pattern.

14. The network-side device of claim 13,

the determining module is specifically configured to determine, according to prior information of an authorization system corresponding to a working frequency point of a cognitive radio system, a frequency resource that needs to be muted of the cognitive radio system.

15. The network-side device of claim 14,

the determining module is specifically configured to determine that frequency resources of the cognitive radio system that need to be muted are uniformly distributed in a channel to be perceived when power spectral densities of authorization system signals corresponding to the channel to be perceived of a working frequency point of the cognitive radio system are uniformly distributed in a frequency domain; or,

16. The network-side device of claim 13,

the silence pattern generated by the generation module specifically includes: the method comprises the steps that a cognitive radio system needs silent system frame resources, cognitive radio system needs silent subframe resources or Orthogonal Frequency Division Multiplexing (OFDM) symbol resources, and cognitive radio system needs silent subcarrier resources or subcarrier set resources.

17. The network-side device of claim 16,

the first processing module is further configured to not schedule the terminal device on subframe resources or subcarrier set resources, which are needed to be muted, of the cognitive radio system on system frame resources, which are needed to be muted, of the cognitive radio system or on OFDM symbol resources, which are needed to be muted, of the cognitive radio system when resource scheduling is performed; and/or the presence of a gas in the gas,

18. The network-side device of claim 17,

the first processing module is specifically configured to check whether a subcarrier resource or a subcarrier set resource that needs to be muted by the cognitive radio system conflicts with a resource occupied by a physical layer control channel; if so, not transmitting signals on subframe resources or all subcarrier resources or subcarrier set resources on OFDM symbol resources, which are needed to be silenced by the cognitive radio system, on system frame resources, which are needed to be silenced by the cognitive radio system, of the cognitive radio system; if not, no signal is transmitted on the subframe resource which needs to be silenced by the cognitive radio system on the system frame resource which needs to be silenced by the cognitive radio system or the subcarrier resource which needs to be silenced by the cognitive radio system on the OFDM symbol resource; or,

19. The network-side device of claim 16,

the first processing module is specifically configured to receive signals on subframe resources or OFDM symbol resources that the cognitive radio system needs to be muted, select output signals at frequency positions corresponding to subcarrier resources or frequency positions corresponding to subcarrier set resources that the cognitive radio system needs to be muted, and perform signal detection processing on the output signals at corresponding positions to obtain a spectrum sensing result of whether a channel to be sensed is occupied; or,

20. A terminal device, characterized in that the terminal device comprises:

the spectrum sensing module is used for sensing a spectrum by utilizing signals received at the resource position corresponding to the silence pattern;

the receiving module is specifically configured to obtain an index of a muting pattern of a local cell by monitoring a system message broadcasted by the local cell, and determine the muting pattern corresponding to the index of the muting pattern.

21. The terminal device of claim 20,

the silence pattern received by the receiving module specifically includes: the method comprises the steps that a cognitive radio system needs silent system frame resources, cognitive radio system needs silent subframe resources or Orthogonal Frequency Division Multiplexing (OFDM) symbol resources, and cognitive radio system needs silent subcarrier resources or subcarrier set resources.

22. The terminal device of claim 21, further comprising:

and the second processing module is used for not transmitting signals on the subframe resources or subcarrier set resources on which the cognitive radio system needs to be silenced on the system frame resources or OFDM symbol resources on which the cognitive radio system needs to be silenced.

23. The terminal device of claim 22,

the second processing module is specifically configured to check whether a subcarrier resource or a subcarrier set resource that needs to be muted by the cognitive radio system conflicts with a resource occupied by a physical layer control channel; if so, not transmitting signals on subframe resources or all subcarrier resources or subcarrier set resources on OFDM symbol resources, which are needed to be silenced by the cognitive radio system, on system frame resources, which are needed to be silenced by the cognitive radio system, of the cognitive radio system; if not, no signal is transmitted on the subframe resource which needs to be silenced by the cognitive radio system on the system frame resource which needs to be silenced by the cognitive radio system or the subcarrier resource which needs to be silenced by the cognitive radio system on the OFDM symbol resource; or,

24. The terminal device of claim 21,

the spectrum sensing module is specifically used for receiving signals on subframe resources or OFDM symbol resources which need to be muted in the cognitive radio system, selecting output signals of frequency positions corresponding to subcarrier resources or subcarrier set resources which need to be muted in the cognitive radio system, and performing signal detection processing on the output signals of corresponding positions to obtain a spectrum sensing result of whether a channel to be sensed is occupied; or,