A method and system for combining based on mixer phase shift adjustment

Abstract

The application relates to the technical field of signal combination, and particularly discloses a signal combination method and system based on mixer phase shift adjustment, which comprises the following steps: at least two radio frequency front end links are arranged to simultaneously receive signals, and at least two received signals are combined before an analog-to-digital converter to obtain a mixed signal; the mixed signal is subjected to analog-to-digital conversion, and phase estimation is performed on the mixed signal in a digital domain; and the phase estimation result is fed back to a mixer of at least one radio frequency front end link, so that the phase shift of the mixer of the at least one radio frequency front end link is controlled, and the phase shift operation required by signal combination is realized while the signal is down-converted in the link. The application designs a signal combination method based on mixer phase shift adjustment, adjusts the phases of different signals, optimizes the combination of the signals, improves the overall quality of the received signals, and further improves the reliability of signal transmission.

Description

Technical Field

[0001] This invention relates to the field of pooling and merging technology, and specifically to a pooling and merging method and system based on mixer phase shift adjustment. Background Technology

[0002] Diversity combining is a signal processing technique used in wireless communication systems to improve the reliability and quality of received signals by combining multiple copies of the same signal transmitted through different paths. To achieve diversity combining, the receiver needs to be equipped with multiple antennas to receive signal copies from different paths.

[0003] The basic principle of diversity is to receive multiple copies of the same information through multiple channels (time, frequency, or space). Because the transmission characteristics of these channels differ, the fading of the signal copies will not be the same. The receiver can then use the information contained in the multiple copies to reconstruct the original transmitted signal with relatively accurate results. To use diversity combining, the receiver must have two or more antennas and be able to receive signals from each of these antennas separately. Because the distance between the transmitter and each antenna varies, these signals may arrive at different phases. These phase differences cause interference and fading, thus degrading the quality of the received signal.

[0004] In existing technologies, because these signals may have different phases due to differences in path length, directly combining them can lead to interference and signal quality degradation. By adjusting the phase of signals received from different antennas with different phases, the receiver can optimize the combination of signals to improve the overall quality of the received signal. Therefore, it is necessary to design a diversity merging method based on mixer phase shift adjustment to optimize the phase of signals with different phases, thereby further improving the overall quality of the received signal. Summary of the Invention

[0005] The purpose of this invention is to provide a batch merging method based on mixer phase shift adjustment to solve the above-mentioned technical problems.

[0006] The objective of this invention can be achieved through the following technical solutions:

[0007] S1: Set at least two RF front-end links to receive signals simultaneously, and combine at least two received signals before the analog-to-digital converter to obtain a mixed signal;

[0008] S2: The mixed signal is converted from analog to digital, and the phase of the mixed signal is estimated in the digital domain;

[0009] S3: Feed back the phase estimation result to the mixer of at least one RF front-end link, thereby controlling the phase shift of the mixer of the at least one RF front-end link, and realizing the phase shift operation required for diversity combining while downconverting the received signal of the link.

[0010] As a further aspect of the present invention: steps S1-S3 are performed in the synchronization field of the received frame, and the received signal thereafter maintains the mixer phase shift obtained in step S3.

[0011] As a further aspect of the present invention: S2 includes the following steps:

[0012] S21: Calculate the channel parameters of the mixed signal, adjust the mixed signal according to the phase shift value A+na, output the corresponding phase shift value when the intensity of the mixed signal reaches the peak value and record it as the ideal phase shift value, where A is the preset initial phase shift value, a is the preset change gradient, and n=1, 2, 3, ...;

[0013] S22: Apply the ideal phase shift value to the mixed signal to obtain the corrected mixed signal, and combine the corrected mixed signal to generate a multi-channel merged signal.

[0014] As a further aspect of the present invention: in step S1, the mixed signal is obtained in the synchronization field portion of the received frame.

[0015] As a further aspect of the present invention: in step S21, the method for adjusting the mixed signal specifically includes:

[0016] In a two-dimensional coordinate system, generate the waveform corresponding to the mixed signal, preset a reference point and obtain the signal strength of the mixed signal at the reference point, move the waveform corresponding to the mixed signal by A+na units, and stop moving when the signal strength of the mixed signal at the reference point reaches the peak value.

[0017] As a further aspect of the present invention: in step S1, the mixed signal is also used to achieve time and frequency synchronization between the transmitter and the transmitter.

[0018] As a further aspect of the present invention: in step S2, when generating the mixed signal, the two signals are given different analog gains.

[0019] As a further aspect of the present invention: In step S2, blind phase estimation gradually narrows the search range by using a bisection method to ensure that the phase difference between at least two signals is within 120 degrees, thus achieving diversity gain, and then a smaller phase difference value is used.

[0020] As a further aspect of the present invention: in step S2, the mixed signal includes more than one version, each version corresponding to a different combination of analog gains of the two signals.

[0021] An analog diversity merging system based on mixer phase shift adjustment includes: at least two radio frequency front-end links, each having a corresponding receiving antenna, and the at least two radio frequency front-end links sharing a local oscillator and an analog-to-digital converter; the at least two radio frequency front-end links are configured to receive signals simultaneously, and the at least two received signals are merged before the analog-to-digital converter to obtain a mixed signal;

[0022] Phase estimation module: configured to perform phase estimation in the digital domain for the mixed signal after analog-to-digital converter;

[0023] Adjustment module: Based on the phase estimation results, controls the phase shift of the mixer of at least one RF front-end link, so that the phase shift operation required for diversity combining is achieved while the received signal of the link is downconverted.

[0024] As a further aspect of the present invention: an analog diversity combining system based on mixer phase shift adjustment is configured to receive pulse ultrawideband signals.

[0025] The beneficial effects of this invention are as follows: This invention designs a diversity merging method based on mixer phase shift adjustment. By optimizing the phase of signals received from different antennas with different phases, the combination of signals is optimized to improve the overall quality of the received signal and further improve the reliability of signal transmission. Attached Figure Description

[0026] The invention will now be further described with reference to the accompanying drawings.

[0027] Figure 1 This is a flowchart illustrating a method and system for combining and distributing components based on mixer phase shift adjustment according to the present invention.

[0028] Figure 2 This is the basic framework of the present invention, which is a batch merging method and system based on mixer phase shift adjustment;

[0029] Figure 3 This invention relates to a basic architecture for a dual-antenna receiver based on a mixer phase shift adjustment-based diversity merging method and system.

[0030] Figure 4 This invention relates to a basic architecture for a multi-antenna receiver based on a mixer phase shift adjustment-based diversity merging method and system.

[0031] Figure 5 This is a vector operation diagram of a batch union method and system for mixer phase shift adjustment according to the present invention;

[0032] Figure 6 This is a schematic diagram of the binary method for reducing the phase difference range of a mixer-based phase shift adjustment combination method and system according to the present invention.

[0033] Figure 7 This is the practical basic framework of the present invention, which is a batch merging method and system based on mixer phase shift adjustment. Detailed Implementation

[0034] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0035] Please see Figure 1 As shown, the present invention is a convergence merging method based on mixer phase shift adjustment, comprising the following steps:

[0036] S1: Set at least two RF front-end links to receive signals simultaneously, and combine at least two received signals before the analog-to-digital converter to obtain a mixed signal;

[0037] S2: The mixed signal is converted from analog to digital, and the phase of the mixed signal is estimated in the digital domain;

[0038] S3: Feed back the phase estimation result to the mixer of at least one RF front-end link, thereby controlling the phase shift of the mixer of the at least one RF front-end link, and realizing the phase shift operation required for diversity combining while downconverting the received signal of the link.

[0039] It should be noted that signal loss in the transmission path and antenna signal strength are two key factors that directly affect the quality and accuracy of information transmission.

[0040] First, the signal loss along the transmission path needs to be calculated based on the distance between the transmitter and the antenna. From a physical perspective, a signal gradually attenuates with increasing distance during propagation. This attenuation is primarily influenced by the transmitter and the distance between them. Specifically, when a transmitter emits a signal, it spreads into the surrounding space as a spherical wave. As the propagation distance increases, the area of ​​the sphere increases, while the signal energy remains uniformly distributed across this expanding sphere. According to the law of conservation of energy, the signal energy received per unit area decreases accordingly, leading to a decrease in signal strength—this is path loss.

[0041] like Figure 2The diagram illustrates the basic framework of the entire system, representing the working principle of receiver combining. The transmitter transmits signals, and these multiple copies, passing through different channels, arrive at the receiver's multiple antennas. The receiver simultaneously receives these different copies of the signal through multiple antennas and combines them, thereby reducing or overcoming signal fading caused by multipath propagation, shadowing effects, etc., in the wireless channel, thus improving the quality of the received signal and the reliability of the communication system. Common combining techniques include selective combining, equal-gain combining, and maximum ratio combining.

[0042] in, Figure 3 and Figure 4 These are two basic architectures for a dual-antenna receiver and a multi-antenna receiver. The advantage of this architecture is that it controls diversity merging by adjusting the phase shift of the mixer, requiring minimal modification to the analog circuitry and minimal computation in the digital section, as only one mixed signal enters the DSP, eliminating the need for parallel processing of multiple digital signals. The mixer itself is an essential module in the receiver link. By controlling its phase, it simultaneously achieves down-conversion and applies different phase shifts to different signals, avoiding the need for additional modules in the signal link, thereby further reducing implementation complexity and power consumption.

[0043] Next, we need to calculate the antenna's signal strength. Antenna signal strength is a crucial indicator of signal quality, reflecting the actual strength of the signal as it reaches the antenna after traveling through the transmission path. Signal strength depends not only on the transmitter's power and transmission path losses, but also on the antenna's ability to focus and receive signals more effectively, thus improving signal strength. Conversely, a highly directional antenna can receive signals better in a specific direction, reducing interference from other directions.

[0044] It is worth noting that this invention simplifies the calculation process by ignoring obstacles in the transmission path when calculating signal transmission path loss and antenna signal strength. In actual wireless communication environments, signals often encounter various obstacles during propagation. Obstacles can cause reflection, refraction, and scattering of signals, leading to complex and diverse propagation paths. Reflection can cause some signal energy to change its propagation direction, potentially returning to the original propagation path and superimposing or canceling out other signals. However, this simplification allows for a faster and more efficient preliminary assessment and analysis of signal transmission characteristics.

[0045] In advanced wireless communication receiving systems, multiple antennas are then used to receive the same signal, thereby obtaining a copy of the signal.

[0046] After acquiring these signal copies, each signal copy is mixed with a pre-defined standard signal to obtain a mixed signal. This mixing process is equivalent to vector operations, involving comprehensive consideration of multiple key parameters such as signal amplitude and phase.

[0047] Compare the signal strengths of the two signals. If the signal strength of the mixed signal is greater than that of the copy of the mixed signal, repeat the above operation. Figure 5 As shown, signal superposition is equivalent to vector operation. If the two signals are 180 degrees (π radians) out of phase, the receiver (RX) will experience destructive interference, causing the signals to cancel each other out. However, if the phase difference is within 120 degrees, the mixed signal can have higher strength, resulting in antenna gain. Using two signals, hierarchical combining can achieve a gain of up to 2-3 dB, which is very beneficial when the received signal is weak (TX-RX distance is large). Figure 5 This demonstrates the merging operation between vectors; Figure 6 In this invention, considering the actual usage scenario, the phase difference between two (or multiple) received signals is uncertain. When it is not possible to use known signals for phase estimation, this invention proposes to control the phase shifter as follows: by using a binary method to gradually narrow the search range, such as first using a 180-degree phase shift to compare the magnitude of the mixed signals before and after, to ensure that the phase difference between at least two signals is within 120 degrees, so that diversity gain can be achieved; and then using a smaller phase difference value for further adjustment. Figure 6 The example on the left shows two scenarios. In the left example, when RX2 is phase-shifted by 180 degrees, the new mixed signal RX_m is smaller than the original mixed signal RXm, so it can be inferred that the phase difference between the received signal RX1 and the original received signal RX2 is less than 120 degrees. In the right example, the opposite is true: when RX2 is phase-shifted by 180 degrees, the new mixed signal RX_m is larger than the original mixed signal RXm, so it can be inferred that the phase difference between the received signal RX1 and the original received signal RX2 is greater than 120 degrees. This allows for faster narrowing of the blind search range.

[0048] In another preferred embodiment of the present invention, steps S1-S3 are performed in the synchronization field portion of the received frame, and the received signal thereafter maintains the mixer phase shift obtained in step S3.

[0049] It's worth noting that adjusting the synchronization field of the received frame requires minimal modification to the analog circuitry and involves very little computation in the digital section. This is because only one mixed signal enters the DSP, eliminating the need for parallel processing of multiple digital signals. The mixer itself is an essential module in the receiving link, controlling its phase to simultaneously achieve down-conversion and apply different phase shifts to different signals. This avoids adding extra modules to the signal link, further reducing implementation complexity and power consumption.

[0050] In another preferred embodiment of the present invention, the following steps are included:

[0051] S21: Calculate the channel parameters of the mixed signal, adjust the mixed signal according to the phase shift value A+na, output the corresponding phase shift value when the intensity of the mixed signal reaches the peak value and record it as the ideal phase shift value, where A is the preset initial phase shift value, a is the preset change gradient, and n=1, 2, 3, ...;

[0052] S22: Apply the ideal phase shift value to the mixed signal to obtain the corrected mixed signal, and combine the corrected mixed signal to generate a multi-channel merged signal.

[0053] It is worth noting that a method for adjusting and optimizing mixed signals is described, specifically a phase shift-based adjustment strategy. A preset initial phase shift value and a varying gradient provide a flexible way to adjust the phase shift. By changing these parameters, different signal characteristics and requirements can be adapted to achieve optimal signal adjustment. Combining the corrected mixed signals to generate a multi-channel merged signal can further improve signal quality and reliability. The multi-channel merged signal can provide a higher signal-to-noise ratio and stronger anti-interference capability, thereby improving the performance of the communication system. By optimizing the phase shift value of the mixed signal, the interference effect of the signal can be improved, thereby reducing signal distortion and noise. This helps to improve the efficiency of the communication system and the data transmission rate.

[0054] In another preferred embodiment of the invention, the mixed signal is obtained in the synchronization field portion of the received frame.

[0055] It is worth noting that the received frame, as the basic unit of data transmission, typically contains multiple distinct fields, each carrying specific information. Among these, the synchronization field plays a crucial role. When the sending and receiving ends communicate, the sending end inserts a synchronization field at a specific location within the data. This field contains vital information for achieving synchronization between the sending and receiving ends. By acquiring the mixed signal from the synchronization field of the received frame, the receiving device can accurately grasp the rhythm and logic of data transmission, laying a solid foundation for subsequent signal processing and data recovery. This mechanism of acquiring the mixed signal at a specific location fully utilizes the structural characteristics of the received frame and the identifying function of the synchronization field, ensuring the efficiency and reliability of the communication system and enabling data to be transmitted accurately from the sending end to the receiving end in complex communication environments.

[0056] In another preferred embodiment of the present invention, the method for adjusting the mixed signal specifically includes:

[0057] In a two-dimensional coordinate system, generate the waveform corresponding to the mixed signal, preset a reference point and obtain the signal strength of the mixed signal at the reference point, move the waveform corresponding to the mixed signal by A+na units, and stop moving when the signal strength of the mixed signal at the reference point reaches the peak value.

[0058] It should be noted that, according to Figure 5 As mentioned above, signal superposition is equivalent to vector operation. If the phase difference between two signals is 180 degrees (π radians), the receiver (RX) will experience destructive interference, causing the signals to cancel each other out. However, if the phase difference is within 120 degrees, the mixed signal can have higher strength, achieving antenna gain. Using two signals, graded combining can achieve a gain of up to 2-3 dB, which is very beneficial when the received signal is weak (TX-RX distance is large). Controlling the diversity combining by adjusting the mixer phase shift requires minimal modification to the analog circuitry and minimal computation in the digital section, because only one mixed signal enters the DSP, eliminating the need for parallel processing of multiple digital signals. The mixer itself is an essential module in the receiver link. By controlling its phase, it simultaneously achieves down-conversion and applies different phase shifts to different signals, avoiding the addition of extra modules to the signal link, thereby further reducing implementation complexity and power consumption.

[0059] In another preferred embodiment of the invention, the mixed signal is also used to achieve time and frequency synchronization between the transmitter and the transmitter.

[0060] It should be noted that in actual communication, the receiver needs to maintain a high degree of synchronization with the transmitter in terms of time and frequency to ensure that data can be transmitted and received accurately.

[0061] From a time synchronization perspective, mixed signals contain specific time-related information. By accurately parsing and processing the received mixed signal, the receiver can obtain the time reference information used by the transmitter. For example, in some digital communication systems, specific clock signals or timestamp information may be embedded in the mixed signal. By identifying and extracting this information, the receiver can calibrate its own clock to keep it synchronized with the transmitter's clock. This time synchronization is crucial for the accuracy of data transmission, because any tiny time deviation can lead to errors or confusion in data transmission, affecting the overall performance of the communication system.

[0062] In another preferred embodiment of the invention, when generating the mixed signal, the two signals are given different analog gains.

[0063] It's important to note that by assigning different analog gains to these two signals, their intensity differences can be effectively balanced. This ensures that during the subsequent mixing process, the overall quality and effect of the final mixed signal will not be affected by either signal being too strong or too weak. From a technical perspective, this involves precise control of the signal amplification circuit and reasonable adjustment of relevant parameters. This allows the two signals to be mixed in a more suitable state after analog gain processing, thus providing high-quality and stable mixed signals for numerous applications such as audio processing and communication systems, meeting the stringent signal processing requirements of different scenarios.

[0064] In another preferred embodiment of the invention, blind phase estimation gradually narrows the search range by using a bisection method to ensure that the phase difference between at least two signals is within 120 degrees, thus achieving diversity gain, and then uses an even smaller phase difference value.

[0065] It should be noted that, according to Figure 6 It can be seen that when the phase difference between the two received signals is an uncertain value, it is impossible to use a known signal for phase estimation. This invention proposes to control the phase shifter as follows: by using a binary method to gradually narrow the search range, such as first using a 180-degree phase shift to compare the magnitude of the mixed signals before and after, to ensure that the phase difference between at least the two signals is within 120 degrees and there is diversity gain; and then using a smaller phase difference value for further adjustment. Figure 6The example on the left shows two scenarios. In the left example, when RX2 is phase-shifted by 180 degrees, the new mixed signal RX_m is smaller than the original mixed signal RXm, so it can be inferred that the phase difference between the received signal RX1 and the original received signal RX2 is less than 120 degrees. In the right example, the opposite is true: when RX2 is phase-shifted by 180 degrees, the new mixed signal RX_m is larger than the original mixed signal RXm, so it can be inferred that the phase difference between the received signal RX1 and the original received signal RX2 is greater than 120 degrees. This allows for faster narrowing of the blind search range.

[0066] In another preferred embodiment of the invention, the mixed signal comprises more than one version, each version corresponding to a different combination of analog gains of the two signals.

[0067] It's worth noting that in certain application scenarios, when it's necessary to emphasize the high-frequency components of one signal while weakening low-frequency interference in another, a higher analog gain is set for the former to increase the proportion of its high-frequency components in the mixed signal; while a relatively lower analog gain is configured for the latter to reduce the impact of its low-frequency components on the overall mixed signal. Through this diverse combination of analog gain methods, multiple versions of the mixed signal can be derived, each offering unique advantages for different application requirements.

[0068] An analog diversity merging system based on mixer phase shift adjustment includes:

[0069] At least two radio frequency front-end links, each having a corresponding receiving antenna, and the at least two radio frequency front-end links sharing a local oscillator and an analog-to-digital converter; the at least two radio frequency front-end links are configured to receive signals simultaneously, and at least two received signals are combined before the analog-to-digital converter to obtain a mixed signal;

[0070] Phase estimation module: configured to perform phase estimation in the digital domain for the mixed signal after analog-to-digital converter;

[0071] Adjustment module: Based on the phase estimation results, controls the phase shift of the mixer of at least one RF front-end link, so that the phase shift operation required for diversity combining is achieved while the received signal of the link is downconverted.

[0072] Ultra-wideband (UWB) pulse technology is a popular technique for precise positioning and tracking applications. It utilizes short-duration radio wave pulses that can penetrate walls and other obstacles. This makes it ideal for applications such as ranging, location tracking, asset tracking, and high-speed wireless data transmission.

[0073] This analog diversity combining system based on mixer phase shift adjustment can be configured to receive pulsed ultra-wideband signals, thereby further improving the performance of ultra-wideband communication systems.

[0074] In another preferred embodiment of the invention, an analog diversity combining system based on mixer phase shift adjustment is configured to receive pulse ultrawideband signals.

[0075] The foregoing has provided a detailed description of one embodiment of the present invention, but the content described is merely a preferred embodiment and should not be considered as limiting the scope of the invention. All equivalent variations and modifications made within the scope of the claims of this invention should still fall within the patent coverage of this invention.

Claims

1. A convergence merging method based on mixer phase shift adjustment, characterized in that, This method is applicable to low-cost receivers having at least two RF front-end links, each having a corresponding receiving antenna, and the at least two RF front-end links sharing a local oscillator and an analog-to-digital converter. The method includes the following steps: S1: Set at least two RF front-end links to receive signals simultaneously, and combine at least two received signals before the analog-to-digital converter to obtain a mixed signal; S2: The mixed signal is converted from analog to digital, and the phase of the mixed signal is estimated in the digital domain; S21: Calculate the channel parameters of the mixed signal, adjust the mixed signal according to the phase shift value A+na, output the corresponding phase shift value when the intensity of the mixed signal reaches the peak value and record it as the ideal phase shift value, where A is the preset initial phase shift value, a is the preset change gradient, and n=1, 2, 3, ...; S22: Apply the ideal phase shift value to the mixed signal to obtain a corrected mixed signal, and combine the corrected mixed signal to generate a multi-channel merged signal; The specific methods for adjusting mixed signals include: In a two-dimensional coordinate system, generate the waveform corresponding to the mixed signal, preset a reference point and obtain the signal strength of the mixed signal at the reference point, move the waveform corresponding to the mixed signal by A+na units, and stop moving when the signal strength of the mixed signal at the reference point reaches the peak value. S3: Feed back the phase estimation result to the mixer of at least one RF front-end link, thereby controlling the phase shift of the mixer of the at least one RF front-end link, and realizing the phase shift operation required for diversity combining while downconverting the received signal of the link.

2. The method for combining frequencies based on mixer phase shift adjustment according to claim 1, characterized in that, Steps S1-S3 are performed in the synchronization field of the received frame, and the received signal thereafter maintains the mixer phase shift obtained in step S3.

3. The method for combining frequencies based on mixer phase shift adjustment according to claim 1, characterized in that, In step S1, the mixed signal is obtained in the synchronization field portion of the received frame.

4. The method for combining frequencies based on mixer phase shift adjustment according to claim 1, characterized in that, In step S1, the mixed signal is also used to achieve time and frequency synchronization between the transmitter and the transmitter.

5. The method for combining frequencies based on mixer phase shift adjustment according to claim 1, characterized in that, In step S2, when generating the mixed signal, the two signals are given different analog gains.

6. The method for combining frequencies based on mixer phase shift adjustment according to claim 1, characterized in that, In step S2, blind phase estimation gradually narrows the search range by using a bisection method to ensure that the phase difference between at least two signals is within 120 degrees, thus achieving diversity gain, and then uses an even smaller phase difference value.

7. The method for combining and distributing components based on mixer phase shift adjustment according to claim 1, characterized in that, In step S2, the mixed signal contains more than one version, each version corresponding to a different combination of analog gains of the two signals.

8. An analog diversity merging system based on mixer phase shift adjustment, characterized in that, include: At least two radio frequency front-end links, each having a corresponding receiving antenna, and the at least two radio frequency front-end links sharing a local oscillator and an analog-to-digital converter; The at least two RF front-end links are configured to receive signals simultaneously, and the at least two received signals are combined before the analog-to-digital converter to obtain a mixed signal; Phase estimation module: configured to perform phase estimation in the digital domain for the mixed signal after analog-to-digital converter; Adjustment module: Based on the phase estimation results, controls the phase shift of the mixer of at least one RF front-end link, so that the phase shift operation required for diversity combining is achieved while the received signal of the link is downconverted.

9. The analog diversity combining system based on mixer phase shift adjustment according to claim 8 is configured to receive pulse ultrawideband signals.

Images