UWB pulse shaping circuit based on frequency divider

Abstract

The invention belongs to the field of wireless communication, relates to a pulse shaping technology in an IR-UWB wireless transmitter, and particularly provides a UWB pulse shaping circuit based on a frequency divider, which comprises a TSPC frequency divider, combinational logic, an adjustable delay unit and an SCPA adder, wherein the TSPC frequency divider converts a rectangular pulse of a base band into four paths of pulse signals phi 1 to phi 4, the duty ratios of the four paths of pulse signals phi 1 to phi 4 are sequentially increased, the pulse signals phi 1 to phi 4 are combined through combinational logic to form pulse signals S1 and S3, the pulse signals S1 and S3 correspondingly obtain pulse signals S2 and S4 after respectively passing through the adjustable delay unit, the pulse signals S1, S2, S3 and S4 are synthesized through the SCPA adder, and a shaped pulse waveform is output. Based on a traditional frequency divider architecture, the frequency divider is combined with the adjustable delay unit to realize adjustment of multiple dimensions such as pulse shape, pulse width, amplitude and the like, and the frequency divider is simpler in circuit implementation, higher in degree of freedom, simpler to control, better in circuit robustness and capable of being applied to more application scenes.

Description

Technical Field

[0001] The invention belongs to the field of wireless communications, relates to a pulse shaping technology in an IR-UWB wireless transmitter, and specifically provides a UWB pulse shaping circuit based on a frequency divider. Background Art

[0002] IR-UWB (Impulse Ultra-Wideband) wireless transceivers have been widely used in various fields due to their high-speed data transmission, low power consumption, high-precision positioning, and strong anti-interference capabilities. They have particularly demonstrated their unique advantages in short-range wireless communications. With technological advancements and the advancement of standardization, UWB technology is gradually penetrating from professional applications into the consumer market. For example, in smartphones, keyless entry systems for cars, IoT devices, and smart home solutions, UWB technology is expected to become an important component of the 5G and future 6G communication ecosystems, promoting more efficient human-computer interaction, more accurate location services, and smarter device networking. Furthermore, with the miniaturization of UWB chips, their costs are reduced and their security is enhanced, further stimulating market demand and driving the innovation and development of UWB technology in more application scenarios.

[0003] However, UWB (ultra-wideband) technology requires the use of a wider spectrum range and faces significant challenges in spectrum resources. At the same time, different countries and regions have different management and allocation of radio spectrum, resulting in compliance and interoperability barriers for UWB devices when deployed globally. In addition, with the promotion of 5G and even 6G communication systems, the spectrum coexistence problem between UWB and emerging systems has become increasingly prominent. It is necessary to rationally plan spectrum resources while ensuring low interference between systems. This requires not only technological innovation to improve spectrum utilization efficiency, but also unified standards and specifications to ensure that UWB technology can continue to develop and be widely used in more fields.

[0004] In the design of IR-UWB wireless transceivers, the performance of the transmitter has a decisive influence on the spectrum of the transmitted signal. An excellent transmitter needs to have good spectrum sidelobe suppression capabilities and high enough spectrum utilization within the operating bandwidth to meet system compliance. However, conventional UWB transmitters only modulate and amplify rectangular pulse signals with a bandwidth of 500MHz, resulting in a large number of sidelobes in the transmitted RF signal and a low utilization of the main lobe within the operating frequency band. This greatly affects the quality of the spectrum, not only affecting the sensitivity of the received signal but also the normal operation of other devices. Therefore, to overcome the problems existing in traditional UWB transmitters, researchers have explored and proposed pulse shaping technology. By shaping the rectangular pulse signal of the UWB signal, not only does it meet the requirements of communication standards and applications in terms of timing waveform, but it also improves the ability to suppress sidelobes in the spectrum, further improving bandwidth utilization efficiency.

[0005] At present, the commonly used pulse shaping methods are mostly based on the delay line unit shaping method, the specific circuit is as follows Figure 1 As shown, the circuit delays the rectangular pulse representing the baseband signal, delays the signal by cascading multiple delay units with adjustable delay, and then superimposes multiple groups of delayed baseband signals through SCPA, and finally transmits a triangular-shaped pulse waveform to achieve the shaping of the rectangular pulse signal. However, the shaping method based on the delay line unit has some insurmountable shortcomings: 1) The circuit control is complex, and each group of delay units requires a multi-bit control line; 2) The circuit is easily affected by PVT, and in actual application, the time of the delay unit needs to be calibrated to offset the impact of PVT, and the calibration process is relatively complicated; 3) The pulse shaping shape is fixed and cannot meet the requirements for pulse shape in different application scenarios. In response to these problems, the present invention provides a UWB pulse shaping circuit based on a frequency divider, which provides a new technical solution for pulse shaping technology in IR-UWB wireless transmitters. Summary of the Invention

[0006] The purpose of the present invention is to provide a UWB pulse shaping circuit based on a frequency divider, which is based on the frequency divider architecture and combined with an adjustable delay unit to achieve adjustment of multiple dimensions such as pulse shape, pulse width, amplitude, etc., and the circuit is more simple and efficient.

[0007] To achieve the above object, the technical solution adopted by the present invention is:

[0008] A UWB pulse shaping circuit based on a frequency divider, characterized by comprising: a TSPC frequency divider, combinational logic, an adjustable delay unit and an SCPA adder; wherein:

[0009] The TSPC divider converts the baseband rectangular pulse into four pulse signals Φ1 to Φ4 with increasing duty cycles. The pulse signals Φ1 to Φ4 are combined through combinational logic to form pulse signals S1 and S3. The pulse signals S1 and S3 pass through the adjustable delay unit to obtain pulse signals S2 and S4 respectively. The pulse signals S1, S2, S3, and S4 are synthesized through the SCPA adder to output a shaped pulse waveform.

[0010] Furthermore, the duty cycles of the pulse signals Φ1 to Φ4 are distributed between 10% and 90%.

[0011] Furthermore, the pulse periods of the pulse signals Φ1 to Φ4 are consistent and fixed at 2 ns.

[0012] Furthermore, the pulse signals Φ1 and Φ4 are combined to form the pulse signal S1 , and the pulse signals Φ2 and Φ3 are combined to form the pulse signal S3 .

[0013] Furthermore, the UWB pulse shaping circuit based on the frequency divider includes two dynamic adjustment dimensions: first, the delay time adjustment of the adjustable delay unit, and second, the signal amplitude of the pulse signals S1, S2, S3, and S4 in the SCPA adder.

[0014] Based on the above technical solution, the beneficial effects of the present invention are:

[0015] The present invention provides a UWB pulse shaping circuit based on a frequency divider. Based on the frequency divider architecture, it is combined with an adjustable delay unit to achieve adjustment of multiple dimensions such as pulse shape, pulse width, and amplitude, and has the following advantages:

[0016] 1) The present invention is based on a frequency divider architecture and utilizes conventional frequency divider circuits, making circuit implementation simpler;

[0017] 2) The present invention can adjust the shape of the pulse from multiple dimensions such as pulse width and pulse amplitude, with a higher degree of freedom and can be applied to more application scenarios;

[0018] 3) The present invention uses fewer adjustable delay units, which makes control simpler and improves circuit robustness. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 The figure is a schematic diagram of the structure of a pulse shaping circuit based on a delay line unit in the prior art.

[0020] Figure 2 Schematic diagram of the structure of the UWB pulse shaping circuit based on the frequency divider in the present invention.

[0021] Figure 3 The figure is a schematic diagram of the working principle of the UWB pulse shaping circuit based on the frequency divider in the present invention.

[0022] Figure 4 Schematic diagram of the structure of the TSPC frequency divider in the UWB pulse shaping circuit based on the frequency divider in the present invention.

[0023] Figure 5 This is a schematic structural diagram of the adjustable delay unit in the UWB pulse shaping circuit based on the frequency divider in the present invention.

[0024] Figure 6 It is a structural diagram of the SCPA adder in the UWB pulse shaping circuit based on the frequency divider in the present invention. DETAILED DESCRIPTION

[0025] In order to make the purpose, technical solutions and beneficial effects of the present invention more clearly understood, the present invention is further described in detail below with reference to the accompanying drawings and embodiments.

[0026] This embodiment provides a UWB pulse shaping circuit based on a frequency divider, the structure of which is as follows: Figure 2 As shown, it includes: a TSPC frequency divider, a combinational logic, an adjustable delay unit and an SCPA adder; wherein:

[0027] The TSPC divider converts the baseband rectangular pulse into four pulse signals Φ1 to Φ4 with increasing duty cycles. The duty cycles of the pulse signals Φ1 to Φ4 are distributed between 10% and 90%, and the period of each pulse signal is consistent and fixed at 2ns, corresponding to the 500MHz bandwidth of the UWB signal; the combinational logic combines the pulse signals Φ1 to Φ4 to form pulse signals S1 and S3. The pulse signals S1 and S3 also have different duty cycles, wherein the pulse signals Φ1 and Φ4 are combined to form the pulse signal S1, and the pulse signals Φ2 and Φ3 are combined to form the pulse signal S3; the pulse signals S1 and S3 are respectively passed through the adjustable delay unit to obtain the pulse signals S2 and S4, and the delay time of the two can be digitally configured; the pulse signals S1, S2, S3, and S4 are synthesized by the SCPA adder to output a shaped pulse waveform, and finally the shaped UWB waveform is transmitted after LC filtering.

[0028] From the working principle: the working principle of the above-mentioned UWB pulse shaping circuit based on the frequency divider is as follows: Figure 3 As shown, there are two dynamic adjustment dimensions of pulse shaping:

[0029] 1) Adjust the rising and falling edge delay times of the pulse signals S2 and S4 based on the adjustable delay unit;

[0030] 2) Based on the SCPA adder, the signal amplitude of the pulse signals S1, S2, S3, and S4 is adjusted when they are cumulatively combined;

[0031] At the same time, combining the above two dynamic adjustment dimensions can generate pulse waveforms of various shapes.

[0032] Furthermore, the TSPC frequency divider implementation circuit is as follows Figure 4 As shown, the delay unit circuit is as follows Figure 5 As shown, the SCPA adder is as Figure 6 As shown;

[0033] The delay unit circuit adopts the Current-Starved circuit structure, dynamically adjusts the size of the input inverter current, and can adjust the RC charging time, thereby delaying the rising edge or falling edge of the pulse; specifically, the delay time τ is proportional to the ratio of capacitance to current, and can be adjusted by adjusting the resistor R BIAS The resistance value can be used to adjust the current of the delay unit. It can be seen that R BIAS The smaller the current I DELAY The larger the value, the smaller the delay time τ, and vice versa, that is, τ∝C inv / I delay .

[0034] In the SCPA adder, S1, S2, S3, and S4 serve as input signals for a group of SCPAs, each consisting of eight subunits. This adjusts the amplitude information of the pulse signal and adds the four groups of signals together to ultimately achieve pulse shaping. Specifically, by controlling the enable of AM1, AM2, AM3, and AM4, the amplitude of each signal group can be independently adjusted.

[0035] The above description is only a specific embodiment of the present invention. Any feature disclosed in this specification, unless otherwise stated, can be replaced by other equivalent or alternative features with similar purposes; all disclosed features, or all steps in the methods or processes, except for mutually exclusive features and / or steps, can be combined in any way.

Claims

1. A UWB pulse shaping circuit based on a frequency divider, characterized in that: include: TSPC frequency divider, combinational logic, adjustable delay unit and SCPA adder; among them: The TSPC divider converts the baseband rectangular pulse into four pulse signals Φ1 to Φ4 with increasing duty cycles. The pulse signals Φ1 to Φ4 are combined through combinational logic to form pulse signals S1 and S3. The pulse signals S1 and S3 pass through the adjustable delay unit to obtain pulse signals S2 and S4 respectively. The pulse signals S1, S2, S3, and S4 are synthesized through the SCPA adder to output a shaped pulse waveform.

2. The UWB pulse shaping circuit based on a frequency divider according to claim 1, characterized in that: The duty ratios of the pulse signals Φ1 to Φ4 are distributed between 10% and 90%.

3. The UWB pulse shaping circuit based on a frequency divider according to claim 1, characterized in that: The pulse periods of the pulse signals Φ1 to Φ4 are consistent and fixed at 2ns.

4. The UWB pulse shaping circuit based on a frequency divider according to claim 1, characterized in that: The pulse signals Φ1 and Φ4 are combined to form the pulse signal S1 , and the pulse signals Φ2 and Φ3 are combined to form the pulse signal S3 .

5. The UWB pulse shaping circuit based on a frequency divider according to claim 1, characterized in that: The UWB pulse shaping circuit based on the frequency divider includes two dynamic adjustment dimensions: first, the delay time adjustment of the adjustable delay unit, and second, the signal amplitude of the pulse signals S1, S2, S3, and S4 in the SCPA adder.

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