A frequency offset estimation structure and method for single-carrier millimeter wave transmission

Abstract

The present invention relates to the field of optical fiber and terahertz communication technology, and discloses a frequency deviation estimation structure and method for single-carrier millimeter wave transmission. The method is a low-complexity frequency deviation estimation algorithm based on phase folding forward feedback and phase jump accumulation backward feedback fusion. As a key step of the frequency deviation estimation scheme, for the phase folding feedforward part, the data is subjected to angle calculation, remainder calculation and other operations to eliminate the modulation phase, and the estimated frequency deviation is obtained by summing and averaging. For the phase jump accumulation part, the phase jumps in the same direction are accumulated, and the accumulated phase deviation is converted into accumulated frequency deviation through function operation, and finally the estimated frequency deviation is obtained through integration ratio control fusion. In terms of application scenarios, the present invention can become a superior candidate for the research and application of real-time frequency deviation estimation schemes in future optical fiber and terahertz systems.

Description

Technical Field

[0001] The present invention relates to the technical field of optical fiber and terahertz communication, and in particular to a frequency deviation estimation structure and method for single-carrier millimeter wave transmission. Background Art

[0002] Millimeter wave communication has a wide range of application potential, especially in communication capacity and industrial Internet. To support these applications, fiber-optic radio technology is widely used in millimeter wave communication, providing flexible carrier frequency generation and high transmission rate. In addition, the application of FPGA in real-time digital signal processing (DSP) is extremely critical, because of its low power consumption and high flexibility, it occupies an important position in DSP design. Traditional frequency offset estimation methods have complexity and delay problems in real-time DSP, while the phase folding (PF) method significantly reduces the demand for DSP resources by simplifying the calculation. However, the performance degrades significantly in low signal-to-noise ratio environments. It is particularly important to achieve low-complexity, high-speed parallel and reliable real-time frequency offset estimation.

[0003] Therefore, it is necessary to provide a low-complexity, high-speed, parallel and reliable frequency offset estimation structure and method for single-carrier millimeter wave transmission to solve the above technical problems. Summary of the invention

[0004] The purpose of the present invention is to provide a frequency offset estimation structure and method for single-carrier millimeter wave transmission, so as to realize low-complexity real-time parallel frequency offset estimation and ensure the high efficiency and stability of transmission.

[0005] To implement the above technology, the design scheme of the present invention provides a frequency offset estimation structure for single-carrier millimeter wave transmission, including: (1) a phase folded feedforward frequency offset estimation structure, including a data cache partitioner 1, an angle solver 1, a phase folder, and a weighted averager;

[0006] (2) Proportional control structure, including phase deviation-frequency deviation converter and proportional integral fusion;

[0007] (3) a phase jump cumulative frequency offset estimation structure, including a data buffer partitioner 2, a quartic function solver, an angle solver 2, a divider, a jump detector, and a jump accumulator;

[0008] (4) Frequency offset compensation structure, including a frequency offset compensator.

[0009] Preferably, the phase folding feedforward frequency offset estimation structure is used to implement low-complexity real-time parallel frequency offset estimation, wherein:

[0010] Data cache partitioner 1 is used to cache data arriving from the previous stage and to divide the window for phase folding and frequency offset estimation;

[0011] Angle solver 1 is used to find the angle of cached data;

[0012] The phase folder is used to eliminate the modulation phase;

[0013] The weighted averager is used to average multiple frames of data.

[0014] Preferably, the proportional control structure is used to fuse the feedforward and feedback estimated frequency deviations at different times, wherein:

[0015] The phase deviation-frequency deviation converter is used to convert the feedback estimated phase deviation into a frequency deviation;

[0016] The proportional-integral fuser is used to fuse the feedforward and feedback estimated frequency deviations at different times.

[0017] Preferably, the phase jump cumulative frequency offset estimation structure is used to count the number of jumps, wherein:

[0018] The data buffer partitioner 2 is used to buffer the data arriving from the previous stage and to estimate the phase accumulation frequency hopping offset window;

[0019] The quartic function solver is used to eliminate the modulation phase of the signal;

[0020] Angle solver 2 is used to find the angle of the data;

[0021] The divider is used to eliminate the phase doubling caused by the fourth power calculation;

[0022] The transition detector is used to detect the phase ambiguity caused by the fourth power;

[0023] The transition accumulator is used to count the number of transitions.

[0024] Preferably, the frequency offset compensation structure is used to convert the estimated frequency offset into a phase to perform estimated frequency offset compensation, wherein:

[0025] The frequency offset compensator is used to achieve frequency offset compensation.

[0026] The present invention also proposes a method for estimating frequency offset of carrier millimeter wave transmission, which is applied to the above-mentioned frequency offset estimation structure of single-carrier millimeter wave transmission, and the method comprises the following steps:

[0027] First, the data is cached in the data cache partitioner 1 according to the algorithm calculation delay, and the data is divided into blocks according to the frequency deviation window length. Then, the angle is calculated by the angle solver 1, and the angle of the data is obtained by taking the modulus of 2pi in the phase folder, and the angle greater than pi / 4 is folded to [0, pi / 4] to eliminate the modulation phase. Here, pi is the mathematical constant π, which represents half a period of the signal phase.

[0028] Then the estimated frequency offset calculated from the multiple frames of data is cached and weighted averaged in a weighted averager; the phase folded estimated frequency offset value and the phase accumulated jump value are passed through a phase offset-frequency offset converter and a proportional integral fusion device to obtain the current frequency offset estimate; finally, the frequency offset compensator is used to compensate and obtain the compensated frequency offset;

[0029] The phase accumulation hopping frequency offset estimation module first partitions and caches the data in the data cache partitioner 2 according to the window length and delay based on the idea of ​​fourth-power phase offset compensation;

[0030] Then the data is fourth-powered in a fourth-power function solver to eliminate the modulation phase, the angle is calculated in an angle solver 2 and divided by 4 in a divider to obtain an estimated phase deviation without eliminating the phase ambiguity;

[0031] In the jump detector, the phase jump exceeding pi / 4 is marked, and the jump direction is also marked; in the jump accumulator, the vector jump mark and the jump frame number are accumulated and counted and fed back to the phase deviation-frequency deviation converter to obtain the feedback estimated frequency deviation, which is finally proportionally integrated with the feedforward estimated frequency deviation to obtain the final estimated frequency deviation and compensate it.

[0032] Compared with the related art, the frequency offset estimation structure and method for single-carrier millimeter wave transmission provided by the present invention has the following beneficial effects:

[0033] Low complexity and high-speed parallelism: The present invention significantly reduces the computational complexity of frequency offset estimation through the phase folding feedforward and jump cumulative feedback methods, while realizing high-speed parallel frequency offset estimation and improving processing efficiency.

[0034] Efficiency and stability: The present invention ensures the efficiency and stability of millimeter wave transmission, and is particularly suitable for application scenarios requiring high transmission rate and low latency, such as communication capacity and industrial Internet.

[0035] Robustness in low signal-to-noise ratio environments: Compared with traditional frequency offset estimation methods, the present invention exhibits better robustness in low signal-to-noise ratio environments and can estimate frequency offset more accurately.

[0036] Real-time and flexibility: The implementation based on FPGA enables the present invention to have the ability of real-time digital signal processing. At the same time, the low power consumption and high flexibility of FPGA further enhance its advantages in practical applications.

[0037] Wide application potential: The present invention is applicable to photon-assisted millimeter-wave communication systems, and provides important technical support for the widespread application of millimeter-wave communications, especially in scenarios requiring high-precision frequency offset estimation. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1A schematic diagram of a frequency offset estimation structure for single-carrier millimeter wave transmission provided by the present invention.

[0039] Figure numerals: 1. Data cache partitioner 1; 2. Angle solver 1; 3. Phase folder; 4. Weighted averager; 5. Proportional integral fusion; 6. Frequency offset compensator; 7. Data cache partitioner 2; 8. Quartic function solver; 9. Angle solver 2; 10. Divider; 11. Transition detector; 12. Transition accumulator. DETAILED DESCRIPTION

[0040] The present invention will be further described below in conjunction with the accompanying drawings and implementation modes.

[0041] Please refer to Figure 1 , Figure 1 A schematic diagram of the frequency offset estimation structure of single-carrier millimeter wave transmission provided by the present invention.

[0042] A frequency offset estimation structure for single-carrier millimeter wave transmission proposed by the present invention includes:

[0043] (1) Phase folding feedforward frequency offset estimation structure:

[0044] Data cache partitioner 1: used to cache the data arriving from the previous stage and to divide the window for phase folding and frequency offset estimation;

[0045] Angle solver 1 2: used to find the angle of cached data;

[0046] A phase folder 3, used to eliminate the modulation phase;

[0047] Weighted averager 4: used to average multiple frames of data;

[0048] (2) Proportional control structure:

[0049] Phase deviation-frequency deviation converter: used to convert the feedback estimated phase deviation into frequency deviation;

[0050] Proportional-integral fusion device 5: used to fuse the feedforward and feedback estimated frequency deviations at different times;

[0051] (3) Phase jump cumulative frequency offset estimation structure:

[0052] Data cache partitioner 2 7: used to cache the data arriving from the previous stage and for phase accumulation, hopping frequency offset estimation windowing;

[0053] Quartic function solver 8: used to eliminate the modulation phase of the signal;

[0054] Angle solver 2 9: used to find the angle of the data;

[0055] Divider 10: used to eliminate the phase doubling caused by the fourth power calculation;

[0056] Transition detector 11: used to detect phase ambiguity caused by the fourth power;

[0057] Transition accumulator 12: used to count the number of transitions;

[0058] (4) Frequency deviation compensation structure:

[0059] Frequency offset compensator 6: used to convert the estimated frequency offset into a phase to perform estimated frequency offset compensation.

[0060] The present invention also proposes a frequency offset estimation method for carrier millimeter wave transmission, which is applied to the frequency offset estimation structure of the single-carrier millimeter wave transmission. The method comprises the following steps: first, in a data cache partitioner 1, data is cached according to the delay calculated by the algorithm, and data is divided into blocks according to the frequency offset window length. Then, the angle is calculated by an angle solver 2, and the angle of the data is obtained by taking the modulus of 2pi in a phase folder 3, and the angle greater than pi / 4 is folded to [0, pi / 4] to eliminate the modulation phase, where pi is a mathematical constant π, representing half a period of the signal phase;

[0061] Then the estimated frequency offset calculated from the multiple frames of data is cached and weighted averaged in the weighted averager 4; the phase folded estimated frequency offset value and the phase accumulated jump value are passed through the phase offset-frequency offset converter and the proportional integral fusion device 5 to obtain the current frequency offset estimation value; finally, the frequency offset compensator 6 performs compensation to obtain the compensated frequency offset;

[0062] The phase accumulation hopping frequency offset estimation module is first based on the idea of ​​fourth-power phase offset compensation. First, the data is partitioned and cached in the data cache partitioner 2 7 according to the window length and delay;

[0063] The data is then fourth-powered in a fourth-power function solver 8 to eliminate the modulation phase, the angle is calculated in an angle solver 9 and divided by 4 in a divider 10 to obtain an estimated phase deviation without eliminating the phase ambiguity;

[0064] In the jump detector 11, the phase jump exceeding pi / 4 is marked, and the jump direction is marked; in the jump accumulator 12, the vector jump mark and the jump frame number are accumulated and counted and fed back to the phase deviation-frequency deviation converter to obtain the feedback estimated frequency deviation, and finally the final estimated frequency deviation is obtained by proportional integration fusion with the feedforward estimated frequency deviation and compensated.

[0065] The frequency offset estimation structure and method for single-carrier millimeter wave transmission provided by the present invention realizes high-precision, low-complexity, and high-real-time frequency offset estimation through the coordinated work of the above-mentioned modules and structures, and provides a stable and reliable frequency offset compensation solution for the photon-assisted millimeter wave system.

[0066] The above descriptions are merely embodiments of the present invention and are not intended to limit the patent scope of the present invention. Any equivalent structure or equivalent process transformation made using the contents of the present invention specification and drawings, or directly or indirectly applied in other related technical fields, are also included in the patent protection scope of the present invention.

Claims

1. A frequency offset estimation structure for single-carrier millimeter wave transmission, characterized in that: include: A phase folding feedforward frequency offset estimation structure, comprising a data cache partitioner (1), an angle solver (2), a phase folder (3), and a weighted averager (4); A proportional control structure, including a phase deviation-frequency deviation converter and a proportional integral fusion device (5); A phase jump cumulative frequency deviation estimation structure, comprising a data cache partitioner 2 (7), a quartic function solver (8), an angle solver 2 (9), a divider (10), a jump detector (11), and a jump accumulator (12); The frequency deviation compensation structure comprises a frequency deviation compensator (6).

2. The frequency offset estimation structure for single-carrier millimeter wave transmission as claimed in claim 1, characterized in that: The phase folding feedforward frequency offset estimation structure is used to realize low-complexity real-time parallel frequency offset estimation, wherein: The data buffer partitioner 1 (1) is used to buffer the data arriving from the previous stage and to divide the window for phase folding frequency offset estimation; Angle solver 1 (2) is used to solve the angle of the cached data; The phase folder (3) is used to eliminate the modulation phase; The weighted averager (4) is used to average multiple frames of data.

3. The frequency offset estimation structure for single-carrier millimeter wave transmission as claimed in claim 1, characterized in that: The proportional control structure is used to fuse the feedforward and feedback estimated frequency deviations at different times, wherein: The phase deviation-frequency deviation converter is used to convert the feedback estimated phase deviation into a frequency deviation; The proportional integral fuser (5) is used to fuse the feedforward and feedback estimated frequency deviations at different times.

4. The frequency offset estimation structure for single-carrier millimeter wave transmission as claimed in claim 1, characterized in that: The phase jump cumulative frequency deviation estimation structure is used to count the number of jumps, where: The data buffer partitioner 2 (7) is used to buffer the data arriving from the previous stage and to estimate the phase accumulation frequency hopping offset window; The quartic function solver (8) is used to eliminate the modulation phase of the signal; Angle solver 2 (9) is used to solve the angle of the data; The divider (10) is used to eliminate the phase doubling caused by the fourth power calculation; The jump detector (11) is used to detect the phase ambiguity caused by the fourth power; The transition accumulator (12) is used to count the number of transitions.

5. The frequency offset estimation structure for single-carrier millimeter wave transmission as claimed in claim 1, characterized in that: The frequency offset compensation structure is used to convert the estimated frequency offset into a phase to perform estimated frequency offset compensation, wherein: The frequency offset compensator (6) is used to achieve frequency offset compensation.

6. A method for estimating frequency offset of carrier millimeter wave transmission, characterized in that: The method is applied to the frequency offset estimation structure of single-carrier millimeter wave transmission according to any one of claims 1 to 5 above, and the method comprises the following steps: First, the data is cached in the data cache partitioner 1 (1) according to the algorithm to calculate the delay, and the data is divided into blocks according to the frequency deviation window length. Then, the angle is calculated by the angle solver 1 (2), and the angle of the data is obtained in the phase folder (3). The modulo 2pi is taken, and the angle greater than pi / 4 is folded to [0, pi / 4] to eliminate the modulation phase, where pi is a mathematical constant π, representing half a period of the signal phase; Then, the estimated frequency offset calculated from the multiple frames of data is cached and weighted averaged in a weighted averager (4); the phase folded estimated frequency offset value and the phase accumulated jump value are passed through a phase offset-frequency offset converter and a proportional integral fusion device (5) to obtain a current frequency offset estimation value; finally, the frequency offset compensator (6) performs compensation to obtain a compensated frequency offset; The phase accumulation hopping frequency offset estimation module is first based on the idea of ​​fourth power phase offset compensation, firstly partitioning and caching the data in the data cache partitioner 2 (7) according to the window length and delay; Then the data is fourth-powered in a fourth-power function solver (8) to eliminate the modulation phase, the angle is calculated in an angle solver 2 (9) and divided by 4 in a divider (10) to obtain an estimated phase deviation without eliminating the phase ambiguity; In the jump detector (11), the phase jump exceeding pi / 4 is marked, and the jump direction is marked; in the jump accumulator (12), the vector jump mark and the jump frame number are accumulated and counted and fed back to the phase deviation-frequency deviation converter to obtain the feedback estimated frequency deviation, and finally the proportional integral fusion with the feedforward estimated frequency deviation is performed to obtain the final estimated frequency deviation and compensate it.

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