Automatic gain control method and system for ultra-wideband communication

Abstract

The invention discloses an automatic gain control method for ultra-wideband communication, which is used for performing automatic gain control when a receiver receives a lead code, and particularly comprises the following steps: when the receiver starts to receive and detect the lead code, performing overflow detection to judge whether gain needs to be adjusted, if so, adjusting the gain, and waiting for a signal to be stable; wherein the signal stabilization time is not later than the lead code detection ending time, and if the signal stabilization time is not needed, overflow detection is carried out again. Gain adjustment is completed in the frame synchronization period of the UWB receiver, and the power consumption of a traditional AGC circuit can be reduced while the performance is reserved.

Description

Technical Field

[0001] The present invention relates to the field of ultra-wideband technology, and in particular to an automatic gain control method and system for ultra-wideband communication. Background Art

[0002] Ultra-wideband (UWB) is a short-range wireless communication technology with the characteristics of high data rate, low power consumption and high positioning accuracy. Currently, UWB technology is widely used in many fields, such as indoor positioning, wireless sensor networks and Internet of Things (IoT) devices.

[0003] UWB systems may encounter many problems in practical applications, such as signal attenuation, multipath effects, and the impact of environmental changes on signal reception quality. To address these problems, existing UWB receivers are usually equipped with an automatic gain control (AGC) system, which dynamically adjusts the gain of the UWB receiver to keep the amplitude of the output signal within an appropriate range, making it easier for the baseband to perform subsequent processing, thereby improving the performance of the receiver. Figure 1 As shown in the figure, it needs to perform complex calculations and frequent feedback control when adjusting the gain, which consumes a lot of electricity and is difficult to meet the needs of UWB low-power applications. At the same time, in order to ensure the quality of gain adjustment, the existing AGC scheme for UWB will perform multiple gain judgments in the entire receiving process, which will not only increase the overall power consumption, but also may cause poor adjustment effects or even overshoot in the last few times of operation, affecting the overall gain adjustment effect. Specifically, the existing scheme may make adjustments at each stage of the UWB packet, but because both SFD and STS (scrambling time sequence) need to verify the received data and the data packet stage data is not known, gain adjustments at these stages will affect the processing quality of the entire UWB packet. Summary of the invention

[0004] In view of some or all of the problems in the prior art, the first aspect of the present invention provides an automatic gain control method for ultra-wideband communication, which performs automatic gain control when a receiver receives a preamble code, and the automatic gain control method comprises:

[0005] When the receiver starts to receive and detect the preamble code, an overflow detection is performed to determine whether the gain needs to be adjusted. If necessary, a new gain level is set and the signal is left to stabilize. If not, an overflow detection is performed again, where the signal is stabilized no later than the end time of the preamble code detection.

[0006] Furthermore, overflow detection includes:

[0007] Determine whether the overflow times of the signal exceed the preset times corresponding to the current gear. If so, the gain needs to be adjusted.

[0008] Further, adjusting the gain includes:

[0009] If the signal overflow times exceed the preset times corresponding to the current gear, the gain gear is reduced.

[0010] Furthermore, the time required for the signal to settle is determined by the gain circuit of the analog front end.

[0011] Furthermore, the sum of the time required for a single signal stabilization and the time required for a single overflow detection is an integer multiple of the length of a single preamble symbol (Symbol l).

[0012] Furthermore, the automatic gain control method further comprises:

[0013] During the preamble process of a UWB data packet, multiple gain adjustments are performed, wherein the number of gain adjustments is no greater than a preset value.

[0014] Further, the multiple gain adjustments include:

[0015] After the signal is stable, it is determined whether the maximum number of adjustments has been reached. If so, the adjustment is completed. If not, it is determined again whether the gain needs to be adjusted when the next preamble code element is received and detected.

[0016] Furthermore, the multiple gain adjustments also include:

[0017] If the maximum number of adjustments has been reached, report to the upper computer.

[0018] Furthermore, the automatic gain control method further comprises:

[0019] The gain is locked when the receiver's preamble detection signals frame synchronization completion.

[0020] Based on the automatic gain control method as described above, the second aspect of the present invention provides an automatic gain control system for ultra-wideband communication, comprising:

[0021] The automatic gain adjustment module is communicatively connected with the receiver and the analog front end to receive the frame synchronization completion or timeout signal sent by the receiver, adjust the gain according to the automatic gain control method as described above, and send the gain adjustment signal to the analog front end.

[0022] The present invention provides an automatic gain control method and system for ultra-wideband communication, which is mainly designed for UWB receivers. The method and system complete gain adjustment during the frame synchronization of the UWB receiver and stop working during the high power consumption stage such as the receiver processing the scrambled time sequence (STS) or decoding, so that the power consumption of the traditional AGC circuit can be reduced while retaining the performance. In addition to receiving the received signal provided by the ADC to determine the current gain situation, the method and system only require the receiver to provide an additional frame synchronization completion / timeout signal as an end signal. The overall structure is simple and the response is fast, so it can be quickly applied to any UWB system, with wider applicability and low additional cost. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] To further illustrate the above and other advantages and features of various embodiments of the present invention, a more specific description of various embodiments of the present invention will be presented with reference to the accompanying drawings. It will be understood that these drawings only depict typical embodiments of the present invention and are therefore not to be considered as limiting the scope thereof. In the accompanying drawings, for clarity, identical or corresponding parts will be represented by identical or similar reference numerals.

[0024] Figure 1 A schematic diagram showing the structure of an existing automatic gain control system;

[0025] Figure 2 A schematic flow chart showing an existing automatic gain control method;

[0026] Figure 3 A schematic diagram showing the structure of an automatic gain control system for ultra-wideband communication according to an embodiment of the present invention;

[0027] Figure 4 A schematic flow chart showing an automatic gain control method for ultra-wideband communication according to an embodiment of the present invention;

[0028] Figure 5 A schematic diagram showing overflow detection and waiting time for signal stabilization of an automatic gain control method for ultra-wideband communication according to an embodiment of the present invention; and

[0029] Figure 6 A schematic diagram showing a comparison between an automatic gain control method for ultra-wideband communication according to an embodiment of the present invention and gain adjustment time points in the prior art is shown. DETAILED DESCRIPTION

[0030] In the following description, the present invention is described with reference to various embodiments. However, those skilled in the art will recognize that various embodiments can be implemented without one or more specific details or with other replacement and / or additional methods, materials or components. In other cases, well-known structures, materials or operations are not shown or described in detail to avoid blurring the inventive point of the present invention. Similarly, for the purpose of explanation, specific quantities, materials and configurations are set forth to provide a comprehensive understanding of embodiments of the present invention. However, the present invention is not limited to these specific details. In addition, it should be understood that the various embodiments shown in the drawings are illustrative representations and are not necessarily drawn in correct proportions.

[0031] In this specification, reference to "one embodiment" or "the embodiment" means that a particular feature, structure, or characteristic described in conjunction with the embodiment is included in at least one embodiment of the present invention. The phrase "in one embodiment" appearing in various places in this specification does not necessarily all refer to the same embodiment.

[0032] It should be noted that the embodiments of the present invention describe the process steps in a specific order, but this is only for the purpose of illustrating the specific embodiment, rather than limiting the order of the steps. On the contrary, in different embodiments of the present invention, the order of the steps can be adjusted according to the adjustment of the process.

[0033] According to the IEEE 802.15.4a standard definition, the data frame of the UWB PHY layer includes three basic parts: synchronization header, physical layer header and PDU data segment. The data frame header is divided into a synchronization header (SHR), which is used to help the receiver detect AGC settings, antenna diversity selection, timing acquisition, coarse and fine frequency recovery, data packet frame synchronization, channel evaluation and edge signal triggering and other related receiver algorithms when detecting data packets. The synchronization header includes two parts: the synchronization field and the SFD (start of frame delimiter). The first one is the synchronization field SYNC, which is generally also called the preamble. The preamble is composed of multiple identical symbol symbols repeated, and the number of symbols is optional, up to 4096. Each symbol symbol is composed of a specific code sequence. The SFD part is used to prompt the receiver that the SYNC preamble synchronization in front has ended and is ready to start receiving the physical layer header (PHR) to establish the frame timing, which is needed to mark the starting position of the frame data. In the IEEE 802.15.4z standard, in order to enhance the integrity of the data and improve the security of UWB technology in applications, a scrambled timestamp sequence STS is added. STS uses a pseudo-random sequence and encryption technology to protect the integrity of the timestamp data generated in each frame.

[0034] The process of the existing automatic gain control method is as follows Figure 2 As shown, it includes the steps of initialization, receiver startup, overflow detection, gear position judgment, adjustment of new gear position, and judgment of whether the adjustment is completed. In addition, the existing AGC scheme for UWB will perform multiple gain situation judgments in the entire receiving process, which will not only increase the overall power consumption, but also may have poor adjustment effect or even overshoot in the last few times of operation, affecting the overall gain adjustment effect. After research, the inventor found that the fundamental reason for the poor gain adjustment effect of this method is that the received data needs to be checked in the SFD and STS stages, while the data packet stage data is not known. Therefore, gain adjustment in these stages will affect the processing quality of the entire UWB packet. The preamble is a fixed sequence agreed in advance by the host computer, so gain adjustment at this stage has the least effect on the UWB packet.

[0035] Based on this, the present invention provides an automatic gain control system for ultra-wideband communication, such as Figure 3 As shown, the automatic gain control system includes an automatic gain adjustment module AGC, which is communicatively connected to the receiver and the analog front end. In addition to receiving the receiving signal provided by the ADC to determine the current gain situation, the receiver only needs to provide an additional frame synchronization completion / timeout signal as an end signal. The automatic gain control system completes the gain adjustment during the frame synchronization of the UWB receiver, and stops working during the high power consumption stage such as the receiver processing the scrambling time sequence (STS) or decoding. The overall structure is simple, the power consumption is low, and the response is fast. It can be quickly applied to any UWB system with low additional cost.

[0036] Based on the automatic gain control system, Figure 4 FIG. 1 is a flow chart showing an automatic gain control method for ultra-wideband communication according to an embodiment of the present invention. Figure 4 As shown, an automatic gain control method for ultra-wideband communication includes:

[0037] First, in step 401, initialization is performed, and the gain level is set to a default value;

[0038] Next, in step 402, overflow detection is performed. In one embodiment of the present invention, the receiver starts to receive and process the preamble code locally as the starting point of the overflow detection of the entire AGC process. When the receiver starts to receive and detect the preamble code, overflow detection is performed to determine whether the gain needs to be adjusted. If necessary, enter step 403 to adjust the gain. If not, continue to perform overflow detection. In one embodiment of the present invention, overflow detection includes determining whether the number of overflows of the signal exceeds the preset value corresponding to the current gear. If it exceeds, it indicates that the gain needs to be adjusted. The signal overflow threshold and the preset upper limit of the overflow number corresponding to the current gear can be preconfigured. In one embodiment of the present invention, the starting point of each round of overflow detection is based on the start of detection of a group of preamble code symbols, and stops before the end of detection of each group of preamble code symbols to ensure that there is enough time for the ADC signal to stabilize at the new gain. In a spoof embodiment of the present invention, the duration of a single round of overflow detection can be customized by the user;

[0039] In step 403, the gain is adjusted. When the number of signal overflows exceeds the preset value corresponding to the current gear, it means that the gain is not suitable and the gain needs to be adjusted. In one embodiment of the present invention, if the number of signal overflows exceeds the preset value corresponding to the current gear, the gain is reduced to another gear. After the gain adjustment is completed, it is necessary to wait for the ADC signal to stabilize at the new gain. Figure 5 A schematic diagram showing overflow detection and waiting signal stabilization time of an automatic gain control method for ultra-wideband communication according to an embodiment of the present invention is shown, wherein det_period is the time of each round of overflow detection, and Auto_agc_settl eT is the time of waiting signal stabilization. In one embodiment of the present invention, the time of waiting signal stabilization is determined by the gain circuit of the analog front end. In order to ensure the consistency of each round of adjustment, when determining the time of a single round of overflow detection, the user should make the sum of the time required for a single signal stabilization and the time required for a single overflow detection an integer multiple of the length of a single preamble symbol (Symbol l);

[0040] In practical applications, gain adjustment often cannot be completed in one time, but may require multiple adjustments. Based on this, in one embodiment of the present invention, multiple gain adjustments can be performed during the preamble process of a UWB data packet, wherein the number of gain adjustments is not greater than a preset value, and the preset value is user-defined. Based on this, in one embodiment of the present invention, after a single gain adjustment is completed and the signal is stable, step 404 is entered to determine whether the number of adjustments has reached the maximum number of adjustments.

[0041] In step 404, it is determined whether the maximum adjustment times have been reached. After the signal is stable, it is determined whether the adjustment times have reached the maximum adjustment times. If so, the adjustment is automatically stopped and reported to the upper computer. If not, overflow detection is performed again when receiving and detecting the next preamble code element. It should be understood that the overflow detection threshold at this time is the current gain level, that is, the overflow times threshold corresponding to the adjusted gain level; and

[0042] Finally, the gain is locked in step 405. The gain is locked when the preamble code detection part of the receiver sends a frame synchronization completion signal, and also synchronously receives a frame synchronization timeout signal as an abnormal end point.

[0043] like Figure 6 As shown, through the automatic gain control method and system of the present invention, the entire automatic gain control process can be compressed in a very short time, and controlled within the time period of receiving the matching preamble code, which has low power consumption and low timing requirements. Compared with the traditional AGC solution, only a few signals of the preamble code processing module need to be introduced to complete the optimization.

[0044] Although various embodiments of the present invention are described above, it should be understood that they are presented as examples only and not as limitations. It is obvious to those skilled in the relevant art that various combinations, modifications and changes can be made thereto without departing from the spirit and scope of the present invention. Therefore, the breadth and scope of the present invention disclosed herein should not be limited by the exemplary embodiments disclosed above, but should only be defined according to the attached claims and their equivalents.

Claims

1. An automatic gain control method for ultra-wideband communication, characterized in that: Automatic gain control is performed when the receiver receives the preamble code, and the automatic gain control method comprises the steps of: When the receiver starts receiving and detecting the preamble, an overflow check is performed to determine whether the gain needs to be adjusted: If necessary, adjust the gain and wait for the signal to be stable, wherein the signal is stable no later than the end time of the preamble code detection; and If not necessary, perform overflow detection again.

2. The automatic gain control method according to claim 1, characterized in that: Overflow detection includes the following steps: Determine whether the signal overflow times exceed the preset times corresponding to the current gain front gear position. If so, adjust the gain.

3. The automatic gain control method according to claim 1, wherein: Adjusting the gain involves the following steps: If the signal overflow times exceed the preset times corresponding to the current gain level, the gain level is reduced.

4. The automatic gain control method according to claim 1, wherein: The time required for the signal to settle is determined by the gain circuitry of the analog front end.

5. The automatic gain control method according to claim 1, characterized in that: The sum of the time required for a single signal stabilization and the time required for a single overflow detection is an integer multiple of the length of a single preamble code element.

6. The automatic gain control method according to claim 1, characterized in that: During the preamble process of a UWB data packet, multiple gain adjustments are performed, wherein the number of gain adjustments is no greater than a preset value.

7. The automatic gain control method according to claim 1, wherein: Also includes the steps: After the signal is stable, determine whether the gain adjustment times have reached the maximum adjustment times: If it has been reached, the adjustment is complete; and If not, overflow detection is performed again when the next preamble code element is received and detected.

8. The automatic gain control method according to claim 7, characterized in that: Also includes the steps: If the gain adjustment times have reached the maximum number of times, report to the upper computer.

9. The automatic gain control method according to claim 1, wherein: Also includes the steps: The gain is locked when the receiver's preamble detection signals frame synchronization completion.

10. An automatic gain control system for ultra-wideband communication, characterized in that: include: An automatic gain adjustment module is communicatively connected to the receiver and the analog front end to receive a frame synchronization completion or timeout signal sent by the receiver, and the automatic gain adjustment module is configured to adjust the gain according to the automatic gain control method according to any one of claims 1 to 9, and send a gain adjustment signal to the analog front end.

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