Phase noise compensation method based on same pilot sequence, application device and system

Abstract

This invention discloses a phase noise compensation method, application device, and system based on identical pilot sequences, belonging to the field of wireless communication technology. The method includes: receiving identical target pilots on n subcarriers and demodulating them to obtain n corresponding demodulated signals y. k,m Based on n demodulated signals y k,m By determining the relevant quantities in the relation and performing phase compensation on the demodulated signal, an estimated value of the transmitted signal is obtained. This invention considers the influence of phase noise and constructs the relationship between the original transmitted signal, the demodulated signal, and the phase noise correlation quantities. First, the parameters are calculated using the target pilot and its demodulated signal, and then phase compensation is performed to estimate the transmitted signal, thereby improving the accuracy of phase noise estimation and compensation.

Description

Technical Field

[0001] This invention belongs to the field of wireless communication technology, and more specifically, relates to a phase noise compensation method, application device and system based on the same pilot sequence. Background Technology

[0002] With the rapid development of wireless communication, from the analog era of 1G to the high-speed digital era of 5G, the communication frequency bands used are getting higher and higher, bringing higher transmission rates, larger transmission bandwidth, and lower transmission latency. 5G has already used some millimeter wave frequency bands, and the future 6G will inevitably expand on the use of even higher frequency millimeter waves based on 5G. In the millimeter wave frequency band, as the frequency increases, the deterioration of the communication system by phase noise will become more and more serious. Therefore, it is necessary to estimate and compensate for phase noise to eliminate its interference.

[0003] Filter bank based multicarrier-offset quadrature amplitude modulation (FBMC-OQAM) is a potential alternative to OFDM. It employs carefully designed prototype filters to shape the transmitted signal, reducing spectral sidelobe leakage and out-of-band interference. It eliminates the need for a guard band and achieves high spectral efficiency. However, in FBMC-OQAM systems, the presence of imaginary interference significantly impacts the accuracy of phase noise estimation and compensation. Therefore, common phase noise compensation methods often involve designing symbols around the pilot to eliminate imaginary interference before performing phase noise estimation and compensation. However, in practice, imaginary interference is difficult to completely eliminate; therefore, relying solely on imaginary interference for phase noise estimation and compensation does not yield high accuracy. Summary of the Invention

[0004] In view of the above-mentioned defects or improvement needs of the existing technology, the present invention provides a phase noise compensation method, application device and system based on the same pilot sequence, the purpose of which is to improve the accuracy of phase noise estimation and compensation.

[0005] To achieve the above objectives, according to one aspect of the present invention, a phase noise compensation method based on the same pilot sequence is provided, applied to a signal receiving device, the phase noise compensation method comprising:

[0006] Step S1: Receive and demodulate the target pilot signals on n subcarriers to obtain the demodulated signals on n corresponding subcarriers. The pilot symbol d of the target pilot at each time-frequency index (k, m) is... k，m The corresponding demodulated signal is y k，mWhere k is the subcarrier index, m is the pilot symbol index, and n≥2; the target pilot is the target pilot inserted by the signal transmitting device on the corresponding subcarrier and the target pilots inserted on the n subcarriers are the same;

[0007] Step S2: Based on the n demodulated signals y at pilot symbol index m k，m Determine the relation sinusoidal correlation quantity Cosine correlation quantity in, This refers to the phase noise correlation at index m of each pilot symbol;

[0008] Step S3: Based on the obtained sinusoidal correlation quantity Cosine correlation quantity Demodulated signal at time-frequency index (k, m) Phase compensation is performed to obtain an estimate of the transmitted signal inserted at the time-frequency index (k, m). In the formula, Demodulated signals The real and imaginary parts of the demodulated signal This is the demodulated signal corresponding to the transmitted signal.

[0009] According to another aspect of the present invention, a signal receiving device is provided for performing the phase noise compensation method based on the same pilot sequence described above.

[0010] According to another aspect of the present invention, a phase noise compensation method based on the same pilot sequence is provided, applied to a signal transmitting device, the phase noise compensation method comprising:

[0011] After inserting the same target pilot on any n subcarriers, the signal is transmitted to the aforementioned signal receiving device, so that the signal receiving device calculates the sinusoidal and cosine correlation of the phase noise based on the received target pilot and performs phase compensation on the demodulated signal to obtain an estimate of the transmitted signal, where n≥2.

[0012] In one embodiment, the same target pilot is inserted on two subcarriers; wherein the target pilots inserted on the two subcarriers are subjected to opposite imaginary interference symbols at any identical pilot symbol index.

[0013] In one embodiment, the communication system is an FBMC-OQAM system using a PHYDYAS filter, where adjacent pilot symbols of the target pilot on the same subcarrier are opposite numbers, and pilot symbols on adjacent subcarriers above and below the target pilot at the same pilot symbol index are opposite numbers.

[0014] In one embodiment, at 4 r In the modulation mode, the absolute value of each target pilot symbol is 2. r -1.

[0015] In one embodiment, the two subcarriers into which the target pilot is inserted are adjacent subcarriers.

[0016] In one embodiment, the difference in imaginary interference between the target pilots inserted on the two subcarriers at any identical pilot symbol index is maximized.

[0017] According to another aspect of the present invention, a signal transmitting device is provided for performing the above-described phase noise compensation method based on the same pilot sequence.

[0018] According to another aspect of the present invention, a communication system with phase noise compensation function is provided, comprising:

[0019] The aforementioned signal transmitting equipment and the aforementioned signal receiving equipment, wherein:

[0020] The transmitting device is used to transmit to the receiving device after inserting the same target pilot on any n subcarriers, where n≥2;

[0021] The receiving device is used to calculate the sinusoidal and cosine correlation of the phase noise based on the received target pilot and to perform phase compensation on the demodulated signal to obtain an estimate of the transmitted signal.

[0022] In summary, compared with the prior art, the above-described technical solutions conceived by this invention can achieve the following beneficial effects:

[0023] This invention analyzes the communication process of the FBMC-OQAM communication system, considers the influence of phase noise, and constructs the relationship between the original transmitted signal, the demodulated signal, and the phase noise-related quantities. This relationship reflects the real part y of the demodulated signal. R k，m , imaginary part y I k，m The original transmitted signal d of the inserted subcarrier k，m and the sinusoidal correlation of phase noise Cosine correlation quantity Based on this relationship, this invention proposes a phase noise compensation method, application device, and system based on the same pilot sequence. First, the sinusoidal correlation quantity in the formula is calculated using the target pilot and its demodulated signal. Cosine correlation quantity Then, based on the calculated sinusoidal correlation... Cosine correlation quantity Estimate the transmitted signal to achieve phase compensation and improve the accuracy of phase noise estimation and compensation.

[0024] Furthermore, make the pilot symbol d at any symbol index... i，m and pilot symbol d j，m The signs of the imaginary interferences are opposite, which can make the difference between the imaginary interferences of the two demodulated signals larger, thus making the corresponding points of the two demodulated signals farther apart on the complex plane, thereby improving the accuracy of line fitting.

[0025] Furthermore, the design rules for the values ​​of each pilot symbol are as follows: in 4 r In the modulation mode, the absolute value of each target pilot symbol is 2. r -1. Based on this design rule, the pilot power can be matched with the normal transmitted signal power.

[0026] Furthermore, by selecting two adjacent subcarriers to insert the target pilot, and then inserting two additional subcarriers to insert the coordination pilot, a total of only 4 subcarriers are used, achieving high-precision phase compensation with less subcarrier resources. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the FBMC-OQAM communication system model structure according to an embodiment;

[0028] Figure 2 This is a flowchart illustrating the steps of a phase noise compensation method according to one embodiment;

[0029] Figure 3 The distribution of demodulated OQAM symbols under 16QAM modulation in the complex plane in an ideal FBMC-OQAM system under conditions of no phase noise and channel white Gaussian noise interference, as an example;

[0030] Figure 4 The distribution of demodulated OQAM symbols in the complex plane under 16QAM modulation in an FBMC-OQAM system under phase noise and channel white Gaussian noise interference, as shown in one embodiment.

[0031] Figure 5 This is a schematic diagram of the distribution of the imaginary interference response factor of a PHYDYAS filter with an odd sign index, according to an embodiment.

[0032] Figure 6 This is a schematic diagram of the distribution of the imaginary interference response factor of a PHYDYAS filter in an embodiment when the sign index is even.

[0033] Figure 7 This is a schematic diagram illustrating a pilot structure example of one embodiment;

[0034] Figure 8The figure shows a performance comparison of one embodiment under conditions of no phase noise compensation, original phase noise compensation, and using the phase noise compensation based on the same pilot proposed in this invention. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention. Furthermore, the technical features involved in the various embodiments of this invention described below can be combined with each other as long as they do not conflict with each other.

[0036] like Figure 1 The diagram shown is a structural model of an FBMC-OQAM communication system in one embodiment, which includes a signal transmitting device and a signal receiving device. In the signal transmitting device, the original transmitted signal {d} 0，m , ..., d k，m , ..., d K-1，m After inserting K subcarriers for modulation, the modulated transmission signal s[n] is obtained. The transmission signal s[n] is subject to phase noise from the transmitting end radio frequency circuit. After being affected by the signal, the signal reaches the receiving device through the channel, where it will also be affected by the phase noise of the receiving device's radio frequency circuit. Due to the influence of [various factors], the receiving device ultimately receives signal r[n]. After modulation and demodulation, the received signal r[n] yields the demodulated signal {y} on K subcarriers. 0，m , ..., y k，m , ..., y K-1，m}, y k，m For the corresponding d k，m The demodulated signal. Under noise-free conditions, the demodulated signal y... k，m With the original transmitted signal d k，m They are exactly the same; however, in reality, communication systems are subject to time-varying noise interference. Therefore, the demodulated signal y is affected by noise. k，m With the original transmitted signal d k，m There will be some deviation. Therefore, phase noise estimation is required, and phase noise compensation is performed on the demodulated signal based on the phase noise estimate to reduce the demodulated signal y. k，m With the original transmitted signal d k，m The deviation between them causes the demodulated signal y k，m As close as possible to the original transmitted signal d k，m .

[0037] Based on this, the present invention analyzes the communication process of the FBMC-OQAM communication system, considers the influence of phase noise, constructs the relationship between the original transmitted signal, the demodulated signal and the phase noise, and proposes a phase noise compensation method based on the same pilot sequence and corresponding application equipment and system.

[0038] First, the analysis process of the FBMC-OQAM communication system in this invention will be introduced.

[0039] Based on the FBMC-OQAM communication system model, considering an ideal channel model, only phase noise and Gaussian white noise interference exist. Since the phase noise changes slowly in the time domain, it can be assumed that the phase noise remains essentially constant within the range of adjacent symbols. Therefore, the demodulated symbol at the time-frequency point (k0, m0)... It can be represented as:

[0040]

[0041] in, It is phase noise interference at symbol index m0; The original transmitted symbol for inserting a subcarrier at the time-frequency point (k0, m0); The time frequency point (k0, m0) The interference is caused by the imaginary part of the surrounding symbols; η is Gaussian white noise.

[0042] As can be seen from the above formula (1), the presence of imaginary interference will seriously affect the accuracy of phase noise estimation and compensation. Therefore, commonly used phase noise compensation methods design symbols around the pilot to eliminate the imaginary interference received by the pilot symbols before performing phase noise estimation and compensation. Considering that imaginary interference is difficult to completely eliminate, this embodiment of the invention does not attempt to design pilot symbols to completely eliminate imaginary interference, but uses imaginary interference information to estimate and compensate for phase noise.

[0043] The transmitted symbol obtained after modulation of a real-number input sequence in an FBMC-OQAM communication system can be represented as:

[0044]

[0045] Where, d k，m This is the original transmission sequence with inserted subcarriers. The transmitted signal s[n] is subject to phase noise from the transmitting end's RF circuitry. After being affected by the signal, the signal reaches the receiving device through the channel, where it will also be affected by the phase noise of the receiving device's radio frequency circuit. The impact.

[0046] The received signal r[n] can be represented as:

[0047]

[0048] Where η[n] is Gaussian white noise interference. Since phase noise is in the form of Gaussian colored noise in the time domain, the following approximation can be considered: Then the received signal r[n] can be further expressed as:

[0049]

[0050] Substituting the expression for s[n] in equation (2) into equation (4) above, we can obtain:

[0051]

[0052] Then, the demodulation symbol at the time-frequency point (k0, m0) It can be represented as:

[0053]

[0054] in, This represents the neighborhood of the time-frequency point (k0, m0). Phase noise is assumed here. Since the phase noise changes slowly within the sampling time of each symbol m, we can conclude that for any symbol m0, the phase noise it experiences... To simplify the analysis, we only focus on the effect of phase noise and ignore the effects of channel noise and Gaussian white noise. Therefore, the above equation can be simplified to:

[0055]

[0056] Transforming equation (7) into a more general expression for the received signal:

[0057]

[0058] Transform the above equation (8) by changing d k，m Referring to the left side of the equation, we get:

[0059]

[0060] Taking the real part of both sides of equation (9) above can eliminate the interference of the imaginary part. k，m Impact:

[0061]

[0062] Among them, y R k，m y I k，m y k，m The real and imaginary parts.

[0063] Observe the above equation (10), let y R k，m Let y be the independent variable. I k，m As the dependent variable, it can be represented by an equivalent linear equation:

[0064]

[0065] Through the above analysis and derivation, the relation (11) is obtained, which constructs the real part y of the demodulated signal. R k，m , imaginary part y I k，m The original transmitted signal d of the inserted subcarrier k，m and the sinusoidal correlation of phase noise Cosine correlation quantity The relationship. Once the sinusoidal correlation quantity is determined... Cosine correlation quantity The receiving device obtains the demodulated signal y k，m Then, the original signal d transmitted by the transmitting device can be estimated based on the relationship of formula (11). k，m .

[0066] Based on the above analysis results, this invention proposes a phase noise compensation method, application device and system based on the same pilot sequence, with the aim of improving the accuracy of phase noise estimation and compensation.

[0067] Example 1

[0068] like Figure 2 The diagram shows a flowchart of a phase noise compensation method based on the same pilot sequence in one embodiment, which is applied to a signal receiving device and mainly includes the following steps.

[0069] Step S1: Receive and demodulate the target pilot signals on n subcarriers to obtain the demodulated signals on n corresponding subcarriers. The pilot symbol d of the target pilot at each time-frequency index (k, m) is... k，m The corresponding demodulated signal is y k，m Where k is the subcarrier index, m is the pilot symbol index, and n≥2; the target pilot is the target pilot inserted by the signal transmitting device on the corresponding subcarrier, and the target pilots inserted on the n subcarriers are the same.

[0070] Step S2: Based on the n demodulated signals y at pilot symbol index m k，m Determine the relation sinusoidal correlation quantity Cosine correlation quantity in, This represents the phase noise correlation at index m of each pilot symbol.

[0071] Based on the previous analysis, before using equation (11) to estimate the transmitted signal, it is necessary to determine the sinusoidal correlation quantity. Cosine correlation quantity The present invention determines the sinusoidal correlation quantity through the above steps S1 and S2. Cosine correlation quantity

[0072] When d k，m When fixed, the relationship of formula (11) The equation is a straight line, representing the distribution of the demodulated signal in the complex plane. The parameters in the relation are calculated by solving for these parameters. The line needs to be determined in the complex plane. Based on the slope and intercept of the line, the parameters can be calculated.

[0073] Determining the distribution line of the demodulated signal in the complex plane requires at least two sets of demodulated signals. Therefore, in this invention, the transmitting device inserts the same target pilot on any n subcarriers and transmits it to the receiving device. The receiving device receives the corresponding signals and demodulates them to obtain n corresponding demodulated signals. Here, the target pilot is a known signal, which is a sequence of pilot symbols. The pilot symbol sequences on multiple subcarriers form an array, d k，m The pilot symbol d at each time-frequency index (k, m) k，m , which represents the m-th pilot symbol in the pilot inserted on the k-th subcarrier. Based on the n corresponding demodulated signals y obtained from demodulation. k，m This allows us to determine the distribution line of the demodulated signal at pilot symbol index m, and from the calculated... Parameters in This parameter reflects the phase noise information of the channel at pilot symbol index m.

[0074] For example, to obtain the n demodulated signals y at the pilot symbol index m. k，m The slope and intercept of the distribution line in the complex plane. as well as Calculate the sinusoidal correlation of the phase noise at pilot symbol index m. Cosine correlation quantity In the complex plane, the y-axis represents the imaginary part, and the x-axis represents the real part.

[0075] like Figure 3 The figure shows the distribution of demodulated OQAM symbols in the complex plane under 16QAM modulation without phase noise interference. Without phase noise interference, all demodulated OQAM symbols are distributed on the four straight lines perpendicular to the horizontal axis: -3, -1, 1, and 3.

[0076] like Figure 4The diagram shows the distribution of demodulated OQAM symbols in the complex plane under 16QAM modulation with phase noise interference. If phase noise interference is present, the lines originally perpendicular to the horizontal axis undergo rotation and diffusion, and all four lines rotate at the same angle. In this case, the phase noise correlation can be calculated by fitting a specific expression of the linear equation. and

[0077] In one embodiment, n can be equal to 2 or greater than 2. When n is equal to 2, a straight line can be directly determined by two points. When n is greater than 2, the distribution line can be determined by fitting.

[0078] Step S3: Based on the obtained sinusoidal correlation quantity Cosine correlation quantity Demodulated signal at time-frequency index (k, m) Phase compensation is performed to obtain an estimate of the transmitted signal inserted at the time-frequency index (k, m). In the formula, Demodulated signals The real and imaginary parts of the demodulated signal This is the demodulated signal corresponding to the transmitted signal.

[0079] Since wireless channel noise is time-varying, pilot signals are inserted into some subcarriers each time a signal is transmitted, and the signal to be transmitted is inserted into the remaining subcarriers. At the receiving device, the pilot signal is a known signal, and channel noise information is obtained through the pilot signal, while the transmitted signal needs to be estimated based on the channel noise information.

[0080] In this invention, some subcarriers carry the target pilot symbol d. k，m Some subcarriers carry the transmitted signal The signal receiving device obtains the pilot symbol d k，m The demodulated signal y k，m It also received the sent signal. The demodulated signal. Steps S1 and S2 above are based on the pilot symbol d. k，m The demodulated signal y k，m Determine the channel noise information at pilot symbol index m, i.e., determine the sinusoidal correlation quantity. Cosine correlation quantity Then, based on the relationship in formula (11), estimate the transmitted signal at the time-frequency index (k, m). This achieves phase noise compensation of the demodulated signal, making the estimation result closer to the actual transmitted signal.

[0081] In general, this invention analyzes the communication process of the FBMC-OQAM communication system, considers the influence of phase noise, and constructs the relationship between the original transmitted signal, the demodulated signal, and the phase noise correlation quantity. Based on this relationship, the sinusoidal correlation quantity in the formula is first calculated using the target pilot and its demodulated signal. Cosine correlation quantity Then, based on the calculated sinusoidal correlation... Cosine correlation quantity Estimate the transmitted signal to achieve phase compensation and improve the accuracy of phase noise estimation and compensation.

[0082] Example 2

[0083] This embodiment proposes a signal receiving device for performing the steps in Embodiment 1.

[0084] Specifically, the signal receiving device may include the following modules:

[0085] The receiving module is used to receive target pilot signals on n subcarriers;

[0086] The demodulation module is used to demodulate the target pilot signal, obtaining demodulated signals on n corresponding subcarriers. The pilot symbol d of the target pilot signal at each time-frequency index (k, m) is... k，m The corresponding demodulated signal is y k，m ;

[0087] The parameter calculation module is used to calculate the parameters based on the n demodulated signals y at pilot symbol index m. k，m Determine the relation sinusoidal correlation quantity Cosine correlation quantity

[0088] The phase compensation module is based on the obtained sinusoidal correlation quantity. Cosine correlation quantity Demodulated signal at time-frequency index (k, m) Phase compensation is performed to obtain an estimate of the transmitted signal inserted at the time-frequency index (k, m).

[0089] Example 3

[0090] This embodiment proposes a phase noise compensation method based on the same pilot sequence for use in signal transmitting equipment. This method is used in conjunction with the signal receiving equipment in Embodiment 2.

[0091] The method includes: inserting the same target pilot on any n subcarriers and transmitting it to the signal receiving device in Embodiment 2, so that the signal receiving device calculates the sinusoidal correlation and cosine correlation of the phase noise based on the received target pilot and performs phase compensation on the demodulated signal to obtain an estimate of the transmitted signal.

[0092] from Figure 4 As can be seen, the effect of phase noise on the distribution line of demodulated OQAM symbols in the complex plane includes not only rotation but also dispersion. In addition, Gaussian white noise interference can also cause dispersion. When using two points to determine a straight line, in order to increase the accuracy of the fitted line, the line should be determined based on two points that are as far apart as possible. That is, the distance between the two points should be as far as possible to ensure that the dispersion of the points will not cause significant interference to the fitted line.

[0093] Therefore, in one embodiment, when a straight line is determined using two points, i.e., when the same target pilot is inserted on two subcarriers, the target pilot and its surrounding pilots can be designed so that the imaginary interference values ​​of the target pilots inserted on the two subcarriers at any identical pilot symbol index are opposite in sign. For example, the pilot symbol of the target pilot inserted on the i-th subcarrier at symbol index m is d. i，m The target pilot inserted on the j-th subcarrier has a pilot symbol of d at symbol index m. j，m pilot symbol d i，m and pilot symbol d j，m All will be subject to imaginary interference. In this embodiment, the pilot symbol d at any symbol index m is made to... i，m and pilot symbol d j，m The signs of the imaginary interferences are opposite, which can make the imaginary parts of the two demodulated signals differ significantly, thus making the corresponding points of the two demodulated signals far apart on the complex plane, thereby improving the accuracy of line fitting.

[0094] The FBMC-OQAM system typically uses a PHYDYAS filter. This embodiment explains the design of the pilot signal in conjunction with the characteristics of the PHYDYAS filter.

[0095] like Figure 5 and Figure 6The diagram shows the distribution of the imaginary interference factor of a PHYDYAS filter. For any pilot symbol located on the k0th subcarrier with a symbol index of m0, the surrounding imaginary interference factors follow this distribution. Once the filter type is determined, this distribution of the imaginary interference factor can also be determined. Based on this determined distribution, the pilot structure can be designed to maximize the difference in imaginary interference between two target pilot signals at any symbol index. In one embodiment, for an FBMC-OQAM system using a PHYDYAS filter, the pilot structure design rule can be: adjacent pilot symbols of the target pilot on the same subcarrier have opposite numbers, and pilot symbols on adjacent subcarriers of the target pilot at the same pilot symbol index have opposite numbers. Under this design rule, the imaginary interference experienced by the two target pilot symbols at any symbol index can be made opposite, thus resulting in a large difference in the imaginary parts of the two demodulated signals. It should be noted here that the pilot on the adjacent subcarriers with the target pilot subcarrier can be either the target pilot or the coordination pilot. The coordination pilot is the pilot applied to other adjacent subcarriers to adjust the imaginary part interference of the target pilot.

[0096] In one embodiment, the design rule for the values ​​of each pilot symbol is: in 4 r In the modulation mode, the absolute value of each target pilot symbol is 2. r -1. Based on this design rule, the pilot power can be matched with the normal transmitted signal power.

[0097] For example, such as Figure 7 The diagram shows the pilot design for an FBMC-OQAM system using a PHYDYAS filter. Identical target pilots are inserted on the 1st and 2nd subcarriers, and coordination pilots are inserted on the adjacent 0th and 3rd subcarriers. These coordination pilots are designed based on the target pilots and the distribution of the imaginary interference influence factor, aiming to ensure that the imaginary interference received by the two target pilot symbols at any symbol index is opposite. This embodiment uses 16QAM modulation, i.e., 4... r =16, r=2, so the absolute value of each target pilot symbol is 2. r -1 = 3. Based on the design rules of pilot structures, the target pilot d on the same subcarrier... k，m The adjacent pilot symbols are opposite numbers, and the target pilot d on the 1st and 2nd subcarriers. k，mThe sequence is 3, -3, 3, -3, ... Simultaneously, the pilot symbols on the subcarriers with target pilots and adjacent subcarriers with coordination pilots at the same pilot symbol index are opposite numbers. Therefore, the coordination pilot on the 0th subcarrier is a sequence of -3, 3, -3, 3, ..., and the coordination pilot on the 3rd subcarrier is also a sequence of -3, 3, -3, 3, ... At this time, for any two target pilot symbols at any index, the difference in their imaginary interference is opposite. For each target pilot symbol, its imaginary interference comes from the superposition of left-right first-order interference, top-bottom first-order interference, and 45° angle first-order interference. For example, taking m=4 as an example, d 1,4 The left-right first-order interference is (-3)*jβ + (-3)*(-jβ) = 0, the top-bottom first-order interference is (-3)*(-jα) + 3*jα = 6jα, and the 45° angle first-order interference is 3*(-jγ) + (-3)*(-jγ) = 0. 2，4 The left-right first-order interference is (-3)*jβ+(-3)*(-jβ)=0, the top-bottom first-order interference is 3*(-jα)+(-3)*jα=-6jα, and the 45° angle first-order interference is 3*(-jγ)+(-3)*(-jγ)=0. 1，4 The imaginary interference is 6jα,d 2，4 The imaginary interference is -6jα, and since they are opposites, the imaginary part of the corresponding adjustment signal is far apart.

[0098] This embodiment selects two adjacent subcarriers to insert the target pilot, and only requires two additional subcarriers to insert the coordination pilot, occupying a total of only 4 subcarriers. This achieves high-precision phase compensation with minimal subcarrier resources. In other embodiments, non-adjacent subcarriers can also be selected to insert the target pilot. In this case, more coordination pilots are designed to increase the difference in the imaginary part interference of the target pilot symbols.

[0099] The above embodiment simplifies the design by making both left and right first-order interference and 45° angle first-order interference zero, increasing the distance between the two demodulated signals only by reversing the signs of the upper and lower first-order interferences. If only accuracy is considered, the design can be implemented from various dimensions to ensure that the pilot d inserted on the two subcarriers... k，m The design maximizes the difference in imaginary interference at any symbol index, thereby maximizing the distance between the two demodulated signals to further improve accuracy.

[0100] It should be noted that the above example is a PHYDYAS filter, but the present invention is not limited to using a PHYDYAS filter. Other types of filters can also be used, as long as the difference in the imaginary interference received by the pilot symbols at any symbol index of the two target pilot sequences is large, so that the imaginary parts of the two demodulated signals are significantly different, thereby making the corresponding points of the two demodulated signals far apart in the complex plane.

[0101] Example 4

[0102] This embodiment proposes a signal transmitting device, which is used in conjunction with the signal receiving device in Embodiment 2 to perform the steps in Embodiment 2.

[0103] Example 5

[0104] This embodiment proposes a communication system with phase noise compensation function, including the signal transmitting device in Embodiment 4 and the signal receiving device in Embodiment 2. The transmitting device is used to insert the same target pilot d on any n subcarriers. k，m The signal is then transmitted to the receiving device, where m is the pilot symbol index, k is the subcarrier index, and n≥2; the receiving device uses the received target pilot d... k，m The sinusoidal and cosine correlation quantities of the phase noise are calculated, and phase compensation is performed on the demodulated signal to obtain an estimate of the transmitted signal. The specific steps performed by each device are described above and will not be repeated here.

[0105] The beneficial effects of this invention are explained below with reference to specific simulation experiments. The phase noise model used in the simulation is a single-pole zero-point power spectral density model, and data from the IEEE 802.11ad standard are used, with the carrier center frequency f. c =60GHz, phase noise sampling rate f s =640MHz, with a fixed total carrier bandwidth. Since this invention focuses on the impact of phase noise on the system, it is assumed that the receiver has obtained ideal channel information and the channel impact is perfectly balanced. The prototype filter used in the FBMC-OQAM system is a PHYDYAS filter with an overlap factor of α=4. It uses 16QAM modulation with 256 subcarriers, and each subcarrier transmits 100 QAM symbols.

[0106] like Figure 8 As shown, the phase noise compensation scheme without phase noise compensation, the original phase noise compensation scheme, and the dual-row identical pilot phase noise compensation scheme proposed in this invention are compared. It can be seen that as the signal-to-noise ratio increases, the BER performance of the algorithm proposed in this invention is significantly better than that of the phase noise compensation scheme without phase noise compensation and the original phase noise compensation scheme.

[0107] Those skilled in the art will readily understand that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A phase noise compensation method based on the same pilot sequence, characterized in that, The phase noise compensation method, applied to signal receiving equipment, includes: Step S1: Receive and demodulate the target pilot signals on n subcarriers to obtain the demodulated signals on n corresponding subcarriers. The pilot symbol d of the target pilot at each time-frequency index (k,m) is... k,m The corresponding demodulated signal is y k,m Where k is the subcarrier index, m is the pilot symbol index, and n≥2; the target pilot is the target pilot inserted by the signal transmitting device on the corresponding subcarrier and the target pilots inserted on the n subcarriers are the same; Step S2: Based on the n demodulated signals y at pilot symbol index m k,m Determine the relation sinusoidal correlation quantity in Cosine correlation quantity in, This refers to the phase noise correlation at index m of each pilot symbol; Step S3: Based on the obtained sinusoidal correlation quantity Cosine correlation quantity Demodulated signal at time-frequency index (k,m) Phase compensation is performed to obtain an estimate of the transmitted signal inserted at the time-frequency index (k,m). In the formula, Demodulated signals The real and imaginary parts of the demodulated signal This is the demodulated signal corresponding to the transmitted signal.

2. A signal receiving device, characterized in that, Used to perform the phase noise compensation method based on the same pilot sequence as described in claim 1.

3. A phase noise compensation method based on the same pilot sequence, characterized in that, The phase noise compensation method, applied to signal transmitting equipment, includes: After inserting the same target pilot on any n subcarriers, the signal is transmitted to the signal receiving device of claim 2, so that the signal receiving device calculates the sinusoidal and cosine correlation of the phase noise based on the received target pilot and performs phase compensation on the demodulated signal to obtain an estimated value of the transmitted signal, where n≥2.

4. The phase noise compensation method based on the same pilot sequence as described in claim 3, characterized in that, The same target pilot is inserted on two subcarriers; wherein the imaginary interference symbols of the target pilots inserted on the two subcarriers are opposite at any identical pilot symbol index.

5. The phase noise compensation method based on the same pilot sequence as described in claim 4, characterized in that, The communication system is an FBMC-OQAM system using PHYDYAS filters. The adjacent pilot symbols of the target pilot on the same subcarrier are opposite numbers, and the pilot symbols of the upper and lower adjacent subcarriers of the target pilot at the same pilot symbol index are opposite numbers.

6. The phase noise compensation method based on the same pilot sequence as described in claim 5, characterized in that, In 4 r In the modulation mode, the absolute value of each target pilot symbol is 2. r -1.

7. The phase noise compensation method based on the same pilot sequence as described in claim 5, characterized in that, The two subcarriers into which the target pilot is inserted are adjacent subcarriers.

8. The phase noise compensation method based on the same pilot sequence as described in claim 4, characterized in that, The difference in the imaginary interference of the target pilot inserted on the two subcarriers at any identical pilot symbol index is maximized.

9. A signal transmitting device, characterized in that, Used to perform the phase noise compensation method based on the same pilot sequence as described in any one of claims 3 to 8.

10. A communication system with phase noise compensation function, characterized in that, include: The signal transmitting device of claim 9 and the signal receiving device of claim 2, wherein: The transmitting device is used to transmit to the receiving device after inserting the same target pilot on any n subcarriers, where n≥2; The receiving device is used to calculate the sinusoidal and cosine correlation of the phase noise based on the received target pilot and to perform phase compensation on the demodulated signal to obtain an estimate of the transmitted signal.

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