Channel busy state evaluation method, device and electronic equipment

Abstract

The application discloses a channel busy state evaluation method, device and electronic equipment. The channel busy state evaluation comprises: receiving an air interface signal by using a first gain in a first time interval to obtain a first digital signal; performing a first idle channel evaluation based on the first digital signal to obtain a first idle channel evaluation result; in response to the first idle channel evaluation result being a channel busy, receiving the air interface signal by using a second gain in a second time interval to obtain a second digital signal, wherein the second gain is less than the first gain; judging whether the first digital signal has saturation distortion; in response to the first digital signal having saturation distortion, performing a second idle channel evaluation based on the second digital signal, and taking a second idle channel evaluation result as a channel busy state judgment result. Compared with the prior art, the method of the application can reduce the false alarm probability of the channel busy state evaluation when there is a signal with large energy in other channels.

Description

Technical Field

[0001] This application relates to the field of wireless communication technology, and in particular to a method, apparatus, and electronic device for assessing channel busy / idle status. Background Technology

[0002] "Listen Before Talk" (LBT) is a widely used mechanism in contention-based wireless communication. Before sending data, the communication device listens to the current channel's wireless environment to assess the current signal's busy / idle status. If the channel is busy, it waits for the channel to become idle before sending data to avoid channel usage conflicts.

[0003] Carrier Sense Multiple Access / Collision Avoidance (CSMA / CA) is a listen-before-speak mechanism used in wireless local area networks (WLANs). Before transmitting data, communication devices must perform Clear Channel Assessment (CCA). If the channel is idle, the device can compete for the channel and transmit data after winning the channel. If the channel is busy, it must wait for the channel to become idle before continuing the transmission process. For example, in the 802.11 protocol's CCA mechanism, the channel is considered busy if the signal energy present in the channel exceeds the CCA detection threshold, or if a specific signal conforming to the protocol is detected in the channel.

[0004] When a wireless LAN operates in an unlicensed frequency band, the limited number of channels within the available spectrum are often occupied simultaneously by multiple devices. When communication devices perform an idle channel assessment of the current channel, they need to receive the air interface signal, which inevitably contains signals from other channels. When the signal energy from other channels is high, it can easily cause saturation distortion in the receiver's RF analog circuitry, and the resulting nonlinear products will leak into the current channel. If the energy of the leaked signal exceeds the CCA detection threshold, even if the current air interface channel is idle, the CCA result will still show the current channel as busy, leading to delayed transmission and reduced network throughput.

[0005] The following example, using the 802.11b protocol's air interface signal, illustrates the impact of strong signals on the current channel when other channels are present. Figure 1 In the scenario shown, the current channel is idle, but there is a strong signal in the adjacent channel 40MHz away from the current channel. Figure 1The diagram illustrates the signal spectrum obtained after frequency conversion of the air interface signal using a zero-IF receiver. As can be seen, nonlinear products generated by saturation distortion in the RF analog circuit leak into the current channel, resulting in a strong signal within the current channel bandwidth. While the influence of signals from adjacent channels can be eliminated through low-pass filtering, the nonlinear products from the RF analog circuit leaking into the current channel cannot be processed, thus negatively impacting the idle channel assessment results as described above. Summary of the Invention

[0006] One objective of this application is to provide a method for reducing the false alarm probability in the current channel busy / idle state assessment when there are high-energy signals in other channels.

[0007] One aspect of this application provides a channel busy / idle state assessment method, comprising: receiving an air interface signal with a first gain in a first time interval to obtain a first digital signal; performing a first idle channel assessment based on the first digital signal to obtain a first idle channel assessment result; responding to the first idle channel assessment result indicating that the channel is busy, receiving an air interface signal with a second gain in a second time interval to obtain a second digital signal, wherein the second gain is less than the first gain; determining whether the first digital signal has saturation distortion; responding to the first digital signal having saturation distortion, performing a second idle channel assessment based on the second digital signal, and using the second idle channel assessment result as the channel busy / idle state determination result.

[0008] In some embodiments, determining whether the first digital signal has saturation distortion includes: determining whether the absolute value of the difference between the signal strength change value and the gain adjustment value exceeds a preset threshold, wherein the signal strength change value is the difference between the signal strength of the first digital signal and the signal strength of the second digital signal, and the gain adjustment value is the difference between the first gain and the second gain; in response to the absolute value of the difference between the signal strength change value and the gain adjustment value exceeding the preset threshold, confirming that the first digital signal has saturation distortion.

[0009] In some embodiments, the method further includes: confirming that the first digital signal does not have saturation distortion in response to the absolute value of the difference between the signal strength change value and the gain adjustment value not exceeding a preset threshold; and using the first idle channel evaluation result as the channel busy / idle state determination result.

[0010] In some embodiments, performing a second idle channel assessment based on the second digital signal and using the second idle channel assessment result as the channel busy / idle state determination result includes: if the first idle channel assessment result is triggered based on an energy detection method, then comparing the second signal strength with the magnitude of a second energy detection threshold; in response to the second signal strength being greater than the second energy detection threshold, determining the channel state as busy, otherwise determining the channel state as idle.

[0011] In some embodiments, the first idle channel assessment uses a first energy detection threshold for energy detection, and the second energy detection threshold is greater than or equal to the difference between the first energy detection threshold and the gain adjustment value, wherein the gain adjustment value is the difference between the first gain and the second gain.

[0012] In some embodiments, performing a second idle channel assessment based on the second digital signal and using the second idle channel assessment result as the channel busy / idle state determination result includes: if the first idle channel assessment result is triggered based on carrier sensing, then using carrier sensing to detect whether the second digital signal contains a second sequence; in response to detecting the second sequence, then determining that the channel state is busy, otherwise determining that the channel state is idle.

[0013] In some embodiments, the first idle channel assessment uses a first sequence for carrier sensing, the length of which is greater than or equal to the length of the second sequence.

[0014] In some embodiments, before receiving the air interface signal with the second gain, the method further includes: determining a gain reduction value based on the signal strength of the first digital signal; and subtracting the gain reduction value from the first gain to obtain the second gain.

[0015] In some embodiments, the length of the first time interval is greater than the length of the second time interval.

[0016] Another aspect of this application provides a channel busy / idle state assessment apparatus, comprising: a receiving unit configured to receive an air interface signal using a first gain in a first time interval and output a first digital signal, and to receive the air interface signal using a second gain in a second time interval when the first idle channel assessment result indicates that the channel is busy, thereby obtaining a second digital signal, wherein the second gain is less than the first gain; a first idle channel assessment unit configured to perform a first idle channel assessment based on the first digital signal and output the first idle channel assessment result; a gain adjustment unit configured to, in response to the first idle channel assessment result indicating that the channel is busy, set the receiving unit to receive the air interface signal using the second gain in the second time interval; a saturation distortion judgment unit configured to determine whether the first digital signal exhibits saturation distortion; and a second idle channel assessment unit configured to, in response to the presence of saturation distortion in the first digital signal, perform a second idle channel assessment based on the second digital signal and use the second idle channel assessment result as the channel busy / idle state determination result.

[0017] Another aspect of this application provides an electronic device comprising: a receiver, a memory, and a processor, wherein the receiver is configured to receive an air interface signal under the control of the processor and obtain a digital signal; the memory stores instructions executable by the processor, the instructions causing the processor to perform the following steps: controlling the receiver to receive the air interface signal with a first gain in a first time interval to obtain a first digital signal; performing a first idle channel assessment based on the first digital signal to obtain a first idle channel assessment result; in response to the first idle channel assessment result indicating that the channel is busy, controlling the receiver to receive the air interface signal with a second gain in a second time interval to obtain a second digital signal; determining whether the first digital signal exhibits saturation distortion; and in response to the first digital signal exhibiting saturation distortion, performing a second idle channel assessment based on the second digital signal, and using the second idle channel assessment result as the channel busy / idle state determination result.

[0018] The above is an overview of this application, and there may be simplifications, generalizations, and omissions of details. Therefore, those skilled in the art should recognize that this section is merely illustrative and not intended to limit the scope of this application in any way. This overview section is neither intended to identify the key or essential features of the claimed subject matter nor to serve as an aid in determining the scope of the claimed subject matter. Attached Figure Description

[0019] The above and other features of this application will become more fully clear through the following description and appended claims, in conjunction with the accompanying drawings. It is understood that these drawings depict only a few embodiments of the application and should not be construed as limiting the scope of the application. The application will be described more clearly and in more detail through the use of the drawings.

[0020] Figure 1 The diagram illustrates the signal spectrum obtained after the receiver performs frequency conversion on the air interface signal in a scenario where the current channel is idle, but there is a strong signal in an adjacent channel 40MHz away from the current channel.

[0021] Figure 2 A block diagram of a common zero-IF receiver is shown.

[0022] Figure 3 A schematic diagram of a channel busy / idle state assessment method 100 according to an embodiment of the present disclosure is shown;

[0023] Figure 4 A time allocation diagram of the main steps involved in the channel busy / idle state assessment method 100 of this disclosure is shown;

[0024] Figure 5 An embodiment of step 150 in the channel busy / idle state assessment method 100 disclosed herein;

[0025] Figure 6 An exemplary structural block diagram of a channel busy / idle state assessment apparatus 200 according to an embodiment of the present disclosure is shown;

[0026] Figure 7 An exemplary structural block diagram of the saturation distortion judgment unit 240 of the channel busy / idle state assessment device 200 is shown. Detailed Implementation

[0027] In the following detailed description, reference is made to the accompanying drawings, which form a part thereof. In the drawings, similar symbols generally denote similar components unless the context otherwise requires. The illustrative embodiments described in the detailed description, drawings, and claims are not intended to be limiting. Other embodiments and variations may be employed without departing from the spirit or scope of the subject matter of this application. It will be understood that various different configurations, substitutions, combinations, and designs can be made to the various aspects of the general description and illustrated in the drawings of this application, all of which explicitly form part of the subject matter of this application.

[0028] There are two main methods for Clear Channel Assessment (CCA): energy detection and carrier sensing. Energy detection determines if the strength of the received signal exceeds an energy detection threshold. If it does, the channel is considered busy; otherwise, it is considered idle. Carrier sensing determines if the received signal contains specific signal characteristics. If it does, the channel is considered busy; otherwise, it is considered idle. The specific signal characteristics in carrier sensing can be a specific carrier, a specific signal sequence, or other characteristics, depending on the system requirements and the specific implementation of the receiver. This disclosure does not limit the specific carrier sensing method. Wireless communication devices can use one of these two methods for CCA, or they can use both methods simultaneously. When using both CCA methods simultaneously, generally, if either method determines the channel is busy, then the channel is considered busy.

[0029] Both energy detection and carrier sensing methods involve receiving air interface signals within a certain time interval and then performing open channel assessment (CCA) based on the received signals. The length of the time interval used for idle channel assessment depends on system requirements and the specific implementation of the communication equipment. Typically, the communication equipment needs to complete the idle channel assessment within the CCA time window specified in the protocol.

[0030] Figure 2 This diagram illustrates a block diagram of a zero-IF receiver commonly used in communication equipment. In the diagram, Antenna is the antenna, LNA (Low Noise Amplifier) ​​is used to amplify the air interface signal, and the amplification factor of the LNA can be adjusted by setting its gain, and LO (Local Oscillator) is used to generate a local oscillation signal. The local oscillation signal and a 90° phase-shifted signal are mixed with the LNA output signal to obtain two signals: in-phase and quadrature signals. The diagram shows the mixer; the LPF (Low Pass Filter) is used to filter the output signal of the mixer, removing signals outside the current channel bandwidth; the PGA (Programmable Gain Amplifier) ​​is used to amplify the low-pass filtered signal to facilitate processing by subsequent modules, and its gain can also be set; the ADC (Analog-to-Digital Converter) is used to convert analog signals into digital signals; the in-phase and quadrature components, after being processed by the ADC, are represented by I and Q respectively in the diagram.

[0031] The channel busy / idle state assessment method of this disclosure will be described below with reference to the accompanying drawings.

[0032] Figure 3 A schematic diagram of a channel busy / idle state assessment method 100 according to an embodiment of the present disclosure is shown. Method 100 can be used in various communication devices employing the CCA mechanism. Figure 4 A time allocation diagram of the main steps involved in the channel busy / idle state assessment method 100 of this disclosure is shown. Figure 3 As shown, method 100 includes the following steps.

[0033] In step 110, the communication device receives the air interface signal with a first gain within the first time interval to obtain the first digital signal.

[0034] Because the strength of the air interface signal is uncertain, during CCA (Continuous Communication Acquisition), to reduce the impact of noise in the RF analog circuitry, the receiver of the communication equipment typically sets the gain of the RF analog circuitry to a high value. Figure 2 Taking the zero-IF receiver shown as an example, the gain of the RF analog circuit is the same as the gain of the LNA. For ease of explanation, unless otherwise specified, the receiver gain mentioned in this disclosure refers to the gain of the receiver's RF analog circuit.

[0035] According to this disclosure, when the communication device initiates CCA, its radio frequency analog circuit uses a first gain G1 to receive the air interface signal. The specific value of the first gain G1 can be set with reference to the methods used in the aforementioned prior art communication devices, or it can be set as needed; this disclosure does not impose specific limitations. See also Figure 4 During the first CCA time window from t0 to t1, the communication device maintains a constant first gain G1. After processing, the air interface signal is converted into a first digital signal. The same-term and quadrature components of the first digital signal obtained within the first CCA time window are represented by I1 and Q1, respectively, and the number of sampling points for each component is N1.

[0036] In step 120, the communication device performs a first idle channel assessment based on the first digital signal to obtain the first idle channel assessment result.

[0037] After obtaining the first digital signal, the communication device performs a first CCA based on the first digital signal. The first CCA can use either energy detection or carrier sensing, or both. When using both methods simultaneously, if either method determines that the channel state is busy, then the channel state is determined to be busy. Therefore, the probability of missed detection when the channel is busy can be reduced.

[0038] If the result of the first idle channel assessment indicates that the channel is idle, it means that the current channel is idle and there is no situation where the receiver is saturated due to signals in other channels. Therefore, at this time, the channel state can be directly determined to be idle, and corresponding operations when the channel state is idle can be performed according to the protocol.

[0039] However, in the case where the result of the first idle channel assessment indicates that the channel is busy, according to the description of the background technology in the present disclosure, in some cases, even if the current channel is actually idle, when there are signals with relatively high energy in other channels, the radio frequency analog circuit of the receiver of the communication device is prone to saturation distortion. The resulting non-linear signals leak into the current channel and cannot be filtered out by the low-pass filter. At this time, it may also cause the first CCA result to indicate that the channel is busy. Obviously, in this case, the first CCA result is a false alarm. If the first CCA result is directly used as the channel state result, the channel utilization rate will be reduced. Therefore, according to the present disclosure, in the case where the result of the first idle channel assessment indicates that the channel is busy, step 130 is further executed.

[0040] In step 130, in response to the result of the first idle channel assessment indicating that the channel is busy, the communication device receives the air interface signal with a second gain within a second time interval to obtain a second digital signal.

[0041] In this step, if the first CCA result indicates that the channel is busy, the gain of the radio frequency analog circuit is adjusted to the second gain G2, and it is determined whether to further perform the second CCA according to the situation. As Figure 4 shown, the time from t1 to t2 is the gain adjustment interval. At time t2, the gain of the radio frequency analog circuit is adjusted to the second gain G2, and G2 < G1. Within the second CCA time window from time t2 to t3, the communication device continuously receives the air interface signal with the second gain G2. After the air interface signal is processed, a second digital signal is obtained. Similarly, the in-phase and quadrature components of the second digital signal are represented by I2 and Q2 respectively, and the number of sampling points for each component is N2. It should be noted that the length of the gain adjustment interval is usually very short, and the influence of the sampling data in this interval on the evaluation result can be basically ignored. Therefore, in some embodiments, for the convenience of implementation, the start time of the second CCA time window can also start from time t1, or from any moment within the gain adjustment interval. In some embodiments, due to requirements of relevant protocols or for reasons such as enabling the first CCA to have more sufficient evaluation samples and time, the length of the first CCA time window can be greater than the length of the second CCA time window. In other embodiments, the length of the first CCA time window can also be equal to or less than the length of the second CCA time window.

[0042] In some embodiments, the second gain G2 can be set to the first gain G1 minus a fixed value. <00,00109>In other embodiments, considering the limited dynamic range of the ADC, the signal power input to the ADC should be set to an appropriate range. The gain reduction value can be determined based on the signal strength of the first digital signal, and then the second gain G2 is obtained by subtracting the gain reduction value from the first gain G1. The gain reduction value can be determined using various methods. For example, the corresponding gain reduction value can be calculated using a pre-configured function based on the signal strength of the first digital signal; alternatively, the corresponding gain reduction value can be obtained by looking up a pre-configured table based on the signal strength of the first digital signal.

[0044] In step 140, the communication device determines whether the first digital signal has saturation distortion.

[0045] When the receiver gain of a communication device is high, if the power of the air interface signal is very strong, it can easily cause saturation distortion in the receiver's RF analog circuit, resulting in saturation distortion in the digital signal output by the receiver. If the saturation distortion is caused by a signal present in the current channel, it generally will not have a significant impact on CCA, because energy-based CCA can usually determine that the channel is busy. However, if there is a strong signal in another channel, and the current channel is actually idle, the saturation distortion of the RF analog circuit may cause the CCA to misjudge the channel as busy, generating a false alarm. Although the saturation distortion of the digital signal may be caused by the saturation of the RF analog circuit, it may also be caused by the ADC input signal exceeding the ADC's range. However, the latter can be mitigated by setting the PGA gain to an appropriate value. Therefore, by determining whether there is saturation distortion in the first digital signal, the reliability of the first CCA result can be reflected to some extent.

[0046] Determining whether the first digital signal has saturation distortion can be achieved by using different methods as needed; this disclosure does not limit the specific implementation method.

[0047] For example, in some embodiments, a predetermined saturation threshold can be set, and the presence of saturation distortion in the first digital signal can be determined by judging whether the amplitude of the first digital signal exceeds the saturation threshold, or whether the proportion of the number of sampling points exceeding the saturation threshold to the total number of sampling points exceeds a preset proportion.

[0048] In other embodiments, the presence of saturation distortion in the amplitude of the first digital signal can be determined by whether the absolute value of the difference between the signal strength change value and the gain adjustment value exceeds a preset threshold. Here, the signal strength change value is the difference between the signal strength of the first digital signal and the signal strength of the second digital signal, and the gain adjustment value is the difference between the first gain and the second gain. Signal strength reflects the power of the signal and can be estimated using sampled signal values.

[0049] For ease of expression, signal strength and gain are expressed in decibels (dB) in this disclosure. The signal strengths of the first digital signal and the second digital signal are represented as RSSI1 and RSSI2, respectively. The gain adjustment value is represented as ΔG, and the signal strength change value is represented as ΔRSSI. Therefore, ΔG = G1 – G2, and ΔRSSI = RSSI1 – RSSI2. The first signal strength RSSI1 and the second signal strength RSSI2 can be calculated using the following formulas:

[0050]

[0051] Among them, I i [n] and Q i [n] represents the nth sampling point of the in-phase component and the quadrature component of the i-th digital signal, respectively.

[0052] For an ideal receiver, if the input signal power remains constant, adjusting the receiver gain will cause the received signal strength to change synchronously with the gain, and there is a one-to-one correspondence between the change in receiver gain and the change in received signal strength. If both the received signal strength and the gain are expressed in decibels, and the absolute value of the difference between the signal strength change ΔRSSI and the gain adjustment ΔG, |ΔRSSI – ΔG|, does not exceed a preset threshold δ, then the first digital signal can be considered not to have saturated. Otherwise, the first digital signal can be considered to have saturated distortion.

[0053] Those skilled in the art will understand that signal strength and gain can also be expressed without using decibels; in this case, the operators can be adjusted accordingly.

[0054] After this step is completed, if the first digital signal is found to have saturation distortion, step 150 is executed; otherwise, it indicates that the reliability of the first idle channel evaluation result is high, and the first idle channel evaluation result can be used as the channel busy / idle status determination result.

[0055] In step 150, a second idle channel assessment is performed based on the second digital signal, and the result of the second idle channel assessment is used as the result of the channel busy / idle status determination.

[0056] Step 150 can be further broken down into the following steps 151 to 153, such as Figure 5 As shown.

[0057] In step 151, the triggering method of the first idle channel evaluation result is determined.

[0058] The first CCA can employ either energy detection or carrier sensing methods, or both. In this disclosure, the triggering method for the first idle channel assessment result refers to the CCA method corresponding to obtaining the first CCA result. If both methods are used simultaneously, either CCA method can be arbitrarily selected, or the CCA method with the earlier output result can be used as the triggering method for the first CCA.

[0059] If the first CCA is triggered by energy detection, then proceed to step 152; if the first CCA is triggered by carrier sensing, then proceed to step 153.

[0060] In step 152, the second signal strength is compared with the second energy detection threshold, and the channel state is determined based on the comparison result.

[0061] If the second signal strength RSSI2 is greater than the second energy detection threshold γ2, the channel state is determined to be busy; otherwise, the channel state is determined to be idle.

[0062] It should be noted that the first signal strength RSSI1 is calculated using the first digital signal, while the second signal strength RSSI2 is calculated using the second digital signal. Since the receiver gains corresponding to the first and second digital signals are different, the difference in receiver gain should be considered when setting the first energy detection threshold γ1 and the second energy detection threshold γ2. The first energy detection threshold γ1 is the energy detection threshold when the first CCA uses the energy detection method.

[0063] The second energy detection threshold γ2 can be set as the difference between the first energy detection threshold γ1 and the gain adjustment value ΔG, i.e., γ2 = γ1 – ΔG.

[0064] In some embodiments, in order to increase the probability of detecting a busy channel, the second energy detection threshold γ2 can be set to be less than the difference between the first energy detection threshold γ1 and the gain adjustment value ΔG, i.e., γ2 < γ1 – ΔG.

[0065] In some embodiments, in order to reduce the false alarm probability of a busy channel, the second energy detection threshold γ2 can be set to be greater than the difference between the first energy detection threshold γ1 and the gain adjustment value ΔG, i.e., γ2>γ1–ΔG.

[0066] In step 153, carrier sensing is used to detect whether the second digital signal contains the second sequence, and the channel state is determined based on the detection result.

[0067] If the second digital signal contains the second sequence, the channel state is determined to be busy; otherwise, the channel state is determined to be idle.

[0068] In existing technologies, CCA (Continuous Comparison) can be performed by detecting whether the received signal contains a characteristic sequence. This characteristic sequence is a sequence contained in the signal transmitted by other devices, and it is usually determined according to the communication protocol used by the communication device. Additionally, such as Figure 4 As shown, communication protocols typically require CCA to be completed within a specified CCA time window. However, according to the method of this disclosure, the CCA time window specified by the protocol includes a first CCA time window and a second CCA time window. Therefore, in this disclosure, both the first and second CCA time windows are shorter than the CCA time window specified by the communication protocol, or shorter than the CCA time of a conventional receiver using this communication protocol. In this disclosure, CCA is performed using a first sequence as the feature sequence in the first CCA time window, and a second sequence as the feature sequence in the second CCA time window. The first and second sequences can be parts of the feature sequences used by conventional receivers; for example, the first part of the feature sequence used by a conventional receiver can be used as the first sequence, and the remaining latter part as the second sequence.

[0069] The lengths of the first sequence and the second sequence can be reasonably determined based on the lengths of the first CCA time window and the second CCA time window. In some embodiments, the length of the first sequence may be greater than or equal to the length of the second sequence. In other embodiments, the length of the first sequence may be less than the length of the second sequence.

[0070] It should be noted that steps 152 and 153 above are independent, and there is no specific order in their execution. Which step is executed depends on the triggering method of the first CCA. After either step is completed, the channel busy / idle status determination result can be output.

[0071] After method 100 is executed, the channel busy / idle status assessment result can be obtained. If the assessment result indicates that the channel is busy, the communication device performs the corresponding operation when the channel status is busy; otherwise, it performs the corresponding operation when the channel status is idle. The corresponding operation based on the channel busy / idle status can be implemented using the same method as existing receiver technologies, and therefore will not be elaborated further.

[0072] This disclosure also provides a channel busy / idle state assessment device. Figure 6 This is an exemplary structural block diagram of a channel busy / idle state assessment apparatus 200 according to an embodiment of the present disclosure. The apparatus 200 can be used to implement the channel busy / idle state assessment method 100 of the present disclosure. Figure 6 As shown, the device 200 includes a receiving unit 210, a first CCA unit 220, a gain adjustment unit 230, a saturation distortion judgment unit 240, and a second CCA unit 250. The structure and operation of each unit of the device 200 are briefly described below with reference to the accompanying drawings. Further details can be found in the description of the channel busy / idle state assessment method 100.

[0073] The receiving unit 210 is configured to receive an air interface signal with a first gain in a first time interval and output a first digital signal, and to receive an air interface signal with a second gain in a second time interval to obtain a second digital signal, wherein the second gain is less than the first gain.

[0074] The first CCA unit 220 is configured to perform a first idle channel assessment based on a first digital signal and output the first idle channel assessment result.

[0075] The gain adjustment unit 230 is configured to, in response to a first idle channel assessment result indicating that the channel is busy, set the receiving unit 210 to receive the air interface signal with a second gain during a second time interval.

[0076] The saturation distortion judgment unit 240 is configured to judge whether the first digital signal has saturation distortion and output the judgment result.

[0077] Figure 7 An exemplary structural block diagram of the saturation distortion determination unit 240 is shown. For example... Figure 7 As shown, the saturation distortion judgment unit 240 includes a signal strength change value calculation module 241, a gain adjustment value calculation module 242, a difference calculation module 243 between the signal strength change value and the gain adjustment value, and a threshold comparison module 244.

[0078] The signal strength change value calculation module 241 is configured to calculate the difference between the signal strength of the first digital signal and the signal strength of the second digital signal to obtain the signal strength change value.

[0079] The gain adjustment value calculation module 242 is configured to calculate the difference between the first gain and the second gain to obtain the gain adjustment value.

[0080] The difference between signal strength change value and gain adjustment value calculation module 243 is used to calculate the absolute value of the difference between the signal strength change value and the gain adjustment value.

[0081] The threshold comparison module 244 is configured to compare whether the absolute value of the difference between the signal strength change value and the gain adjustment value exceeds a preset threshold. If it does not exceed the threshold, it is confirmed that the first digital signal does not have saturation distortion; otherwise, if it exceeds the threshold, it is confirmed that the first digital signal has saturation distortion.

[0082] The second CCA unit 250 is configured to perform a second idle channel assessment based on the second digital signal in response to the presence of saturation distortion in the first digital signal, and use the second idle channel assessment result as the channel busy / idle state determination result.

[0083] This disclosure also provides an electronic device including a receiver, a memory, and a processor, which can be used to implement the aforementioned channel busy / idle state assessment method 100. The receiver is configured to receive an air interface signal and obtain a digital signal under the control of the processor; the memory stores instructions executable by the processor, which, when executed by the processor, can perform the operations of each step of the channel busy / idle state assessment method 100.

[0084] Those skilled in the art can understand and implement other modifications to the disclosed embodiments by reading the specification, the disclosure, the drawings, and the appended claims. In the claims, the word "comprising" does not exclude other elements and steps, and the words "a" or "an" do not exclude a plurality. In practical applications of this application, a single part may perform the function of multiple technical features referenced in the claims. Any reference numerals in the claims should not be construed as limiting the scope.

Claims

1. A method for assessing the busy / idle state of a channel, characterized in that, The method includes: The first digital signal is obtained by receiving the air interface signal with the first gain within the first time interval. A first idle channel assessment is performed based on the first digital signal to obtain the first idle channel assessment result; In response to the first idle channel assessment result being that the channel is busy, the second gain is used to receive the air interface signal during the second time interval to obtain the second digital signal, wherein the second gain is less than the first gain; Determine whether the first digital signal has saturation distortion; and In response to the presence of saturation distortion in the first digital signal, a second idle channel assessment is performed based on the second digital signal, and the result of the second idle channel assessment is used as the result of determining the channel busy / idle status.

2. The method according to claim 1, characterized in that, Determining whether the first digital signal has saturation distortion includes: Determine whether the absolute value of the difference between the signal strength change value and the gain adjustment value exceeds a preset threshold, wherein the signal strength change value is the difference between the signal strength of the first digital signal and the signal strength of the second digital signal, and the gain adjustment value is the difference between the first gain and the second gain; If the absolute value of the difference between the signal strength change value and the gain adjustment value exceeds a preset threshold, it is confirmed that the first digital signal has saturation distortion.

3. The method according to claim 2, characterized in that, The method further includes: In response to the absolute value of the difference between the signal strength change value and the gain adjustment value not exceeding a preset threshold, it is confirmed that the first digital signal does not have saturation distortion; The first idle channel evaluation result is used as the channel busy / idle status determination result.

4. The method according to claim 1, characterized in that, The second idle channel assessment is performed based on the second digital signal, and the result of the second idle channel assessment is used as the channel busy / idle status determination result, including: If the first idle channel evaluation result is triggered based on energy detection, then the second signal strength is compared with the second energy detection threshold. If the second signal strength is greater than the second energy detection threshold, the channel state is determined to be busy; otherwise, the channel state is determined to be idle.

5. The method according to claim 4, characterized in that, The first idle channel assessment uses a first energy detection threshold for energy detection, and the second energy detection threshold is greater than or equal to the difference between the first energy detection threshold and the gain adjustment value, wherein the gain adjustment value is the difference between the first gain and the second gain.

6. The method according to claim 1, characterized in that, The second idle channel assessment is performed based on the second digital signal, and the result of the second idle channel assessment is used as the channel busy / idle status determination result, including: If the first idle channel evaluation result is triggered based on carrier sensing, then carrier sensing is used to detect whether the second digital signal contains the second sequence; In response to the detection of the second sequence, the channel state is determined to be busy; otherwise, the channel state is determined to be idle.

7. The method according to claim 6, characterized in that, The first idle channel assessment uses a first sequence for carrier sensing, the length of which is greater than or equal to the length of the second sequence.

8. The method according to claim 1, characterized in that, Before employing a second gain to receive the air interface signal, the method further includes: Based on the signal strength of the first digital signal, determine the gain reduction value; The second gain is obtained by subtracting the gain reduction value from the first gain.

9. The method according to claim 1, characterized in that, The length of the first time interval is greater than the length of the second time interval.

10. A channel busy / idle state assessment device, characterized in that, The device includes: A receiving unit is configured to receive an air interface signal with a first gain in a first time interval and output a first digital signal, and to receive an air interface signal with a second gain in a second time interval when the first idle channel assessment result is that the channel is busy, thereby obtaining a second digital signal, wherein the second gain is less than the first gain. The first idle channel evaluation unit is configured to perform a first idle channel evaluation based on the first digital signal and output the first idle channel evaluation result. A gain adjustment unit is configured to, in response to the first idle channel assessment result being that the channel is busy, set the receiving unit to receive the air interface signal with the second gain during the second time interval; A saturation distortion determination unit is configured to determine whether the first digital signal exhibits saturation distortion; and The second idle channel evaluation unit is configured to perform a second idle channel evaluation based on the second digital signal in response to the presence of saturation distortion in the first digital signal, and use the second idle channel evaluation result as the channel busy / idle state determination result.

11. The apparatus according to claim 10, characterized in that, The saturation distortion judgment unit includes: The signal strength change value calculation module is configured to calculate the difference between the signal strength of the first digital signal and the signal strength of the second digital signal to obtain the signal strength change value; A gain adjustment value calculation module is configured to calculate the difference between the first gain and the second gain to obtain a gain adjustment value; A module for calculating the difference between the signal strength change value and the gain adjustment value is configured to calculate the absolute value of the difference between the signal strength change value and the gain adjustment value; and The threshold comparison module is configured to compare whether the absolute value of the difference between the signal strength change value and the gain adjustment value exceeds a preset threshold. If it does not exceed the preset threshold, it is confirmed that the first digital signal does not have saturation distortion; otherwise, it is confirmed that the first digital signal has saturation distortion.

12. An electronic device, comprising: Receiver, memory, and processor, among which The receiver is configured to receive air interface signals and obtain digital signals under the control of the processor; The memory stores instructions that can be executed by the processor, which cause the processor to perform the following steps: The receiver is controlled to receive the air interface signal with a first gain in a first time interval to obtain a first digital signal; A first idle channel assessment is performed based on the first digital signal to obtain the first idle channel assessment result; In response to the first idle channel assessment result being that the channel is busy, the receiver is controlled to receive the air interface signal with a second gain in the second time interval to obtain the second digital signal; Determine whether the first digital signal has saturation distortion; In response to the presence of saturation distortion in the first digital signal, a second idle channel assessment is performed based on the second digital signal, and the result of the second idle channel assessment is used as the result of determining the channel busy / idle status.

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