CN117978590B

CN117978590B - Channel estimation method, chip, device, system and medium for rice channel

Info

Publication number: CN117978590B
Application number: CN202410374314.1A
Authority: CN
Inventors: 赵楠; 赵旭; 甘杰; 张玉冰; 邵将; 陈永利; 谢海燕
Original assignee: Beijing Smartchip Microelectronics Technology Co Ltd
Current assignee: Beijing Smartchip Microelectronics Technology Co Ltd
Filing date: 2024-03-29
Publication date: 2024-07-02
Anticipated expiration: 2044-03-29

Abstract

The embodiment of the invention provides a channel estimation method, a chip, a device, a system and a medium for a rice channel, belonging to the field of wireless communication. The channel estimation method comprises the following steps: acquiring a power spectrum of a pilot signal in a received signal; and estimating a channel correlation coefficient based on a vegetable factor and a maximum Doppler parameter when the power spectrum is a direct path obeying a rice distribution. According to the embodiment of the invention, whether the direct paths obeying the rice distribution exist or not is judged according to the power spectrum, then the channel correlation coefficient of the rice channel is estimated according to the rice factor and the maximum Doppler parameter for channel estimation, the accuracy of the channel correlation coefficient under the rice channel is improved, and the channel estimation accuracy and the system performance of the rice channel are further improved.

Description

Channel estimation method, chip, device, system and medium for rice channel

Technical Field

The present invention relates to the field of wireless communications, and in particular, to a method, a chip, a device, a system, and a medium for estimating a rice channel.

Background

An important characteristic of a mobile communication channel is the presence of multipath transmission, which is characterized in that the signal strength, time and carrier phase when arriving at the receiving end will vary with the variation of the transmission distances of different paths of radio waves, thereby forming an interference field at the receiving end. Because multipath transmissions are superimposed at the receiving end, the interference field sometimes increases or decreases with in-phase or reverse superposition, resulting in rapid changes in the amplitude of the received signal, which results in a rapid and deep fade.

When the main signal component exists in the received signal at the receiving end, for example, an LOS (Line of Sight) component signal, the received signal at the receiving end is formed by overlapping the main signal component (Line of Sight) and multipath signal components from different time and different phases. This signal is rice-compliant, and if a channel of a wireless communication system is rice-compliant, the channel is a rice fading channel. With the continuous establishment and use of high-speed rails, highways and the like, a new generation mobile communication system needs to perform high-speed information transmission with users moving at high speed, and under the scene, a direct path and a scattering path exist, so that the scene of a rice channel is more and more.

However, when estimating the rice channel of the mobile communication system, time domain wiener filtering is usually adopted, and further, the channel correlation coefficient of the rice channel needs to be known, but at present, the correlation coefficient of the rayleigh distribution estimation is usually adopted under the rice channel, so that the actual estimated value is inaccurate, and the channel estimation deviation and the overall system performance are reduced.

Disclosure of Invention

An object of an embodiment of the present invention is to provide a channel estimation method, a chip, an apparatus, a system, and a medium for rice channel, which are used for at least partially solving the above technical problems.

In order to achieve the above object, an embodiment of the present invention provides a channel estimation method for rice channel, including: acquiring a power spectrum of a pilot signal in a received signal; and estimating a channel correlation coefficient based on a vegetable factor and a maximum Doppler parameter when the power spectrum is a direct path obeying a rice distribution.

Optionally, the acquiring the power spectrum of the pilot signal in the received signal includes: extracting a pilot signal from the received signal; acquiring a power delay profile (Power Delay Profile, PDP) of the pilot signal; and acquiring a power spectrum of each effective path larger than a preset threshold in the PDP.

Optionally, after the obtaining the power spectrum of the pilot signal in the received signal, the channel estimation method further includes: and judging the power spectrum as the direct path or the scattering path obeying Rayleigh distribution.

Optionally, the determining that the power spectrum is the direct path or a scattering path following the rayleigh distribution includes: acquiring a power difference of each position m on the power spectrum relative to a later position m+1; selecting a corresponding m value from the acquired power differences under the condition that the current power difference is a positive value and the latter power difference is a negative value; acquiring a peak-to-average ratio of a position represented by the selected m value on the power spectrum; when the peak-to-average ratio is larger than a preset threshold, determining that the position represented by the corresponding m value is the peak position; when the number of the peak positions is 1, judging that the corresponding power spectrum is a direct path; when the number of the peak positions is 0, judging the corresponding power spectrum as noise; and when the number of the peak positions is greater than 1, judging the corresponding power spectrum as a scattering path.

Optionally, before the estimating the channel correlation coefficient based on the gaussian factor and the maximum doppler parameter, the channel estimation method further includes: acquiring the Gaussian factor according to the power spectrum; and/or Doppler estimation is carried out on the scattering path so as to obtain the maximum Doppler parameter.

Optionally, the estimating the channel correlation coefficient based on the gaussian factor and the maximum doppler parameter includes: estimating a trigonometric function value associated with an arrival angle of a line-of-sight component signal in the pilot signal according to the maximum Doppler parameter and the direct path; and determining the channel correlation coefficient according to the Gaussian factor and the estimated trigonometric function value.

Optionally, the trigonometric function value is a cosine valueIt is calculated by the following formula:

Wherein, As a result of the maximum doppler parameter,For the angle of arrival of the line-of-sight component signal in the pilot signal,The time domain impulse response of the ith symbol of the direct path,The time domain impulse response of the (i + 1) th symbol of the direct path,In order to be a symbol time period,To take outIs used for the phase of the (c) signal,To take outIs a complex conjugate of (a) and (b).

Alternatively, the channel correlation coefficientCalculated using the following:

Wherein, K is a vegetable factor, Representing the time interval when the channel correlation coefficient is calculated,Is a first class of 0-order bessel functions,Is an exponential function.

On the other hand, the embodiment of the invention also provides a chip, which comprises a memory and a processor, wherein the memory stores a computer program capable of running on the processor, and the processor realizes any channel estimation method for rice channels when executing the computer program.

On the other hand, the embodiment of the invention also provides a channel estimation device for rice channels, which comprises: the power spectrum acquisition module is used for acquiring the power spectrum of the pilot signal in the received signal; and a channel estimation module for estimating a channel correlation coefficient based on a vegetable factor and a maximum Doppler parameter when the power spectrum is a direct path obeying a rice distribution.

Optionally, the power spectrum acquisition module is configured to acquire a power spectrum of a pilot signal in a received signal, including: extracting a pilot signal from the received signal; acquiring a power delay spectrum PDP of the pilot signal; and acquiring a power spectrum of each effective path larger than a preset threshold in the PDP.

Optionally, the channel estimation device further includes: and the judging module is used for judging the power spectrum as the direct path or the scattering path obeying Rayleigh distribution after acquiring the power spectrum of the pilot signal in the received signal.

Optionally, the determining module is configured to determine that the power spectrum is the direct path or a scattering path obeying rayleigh distribution, including: acquiring a power difference of each position m on the power spectrum relative to a later position m+1; selecting a corresponding m value from the acquired power differences under the condition that the current power difference is a positive value and the latter power difference is a negative value; acquiring a peak-to-average ratio of a position represented by the selected m value on the power spectrum; when the peak-to-average ratio is larger than a preset threshold, determining that the position represented by the corresponding m value is the peak position; when the number of the peak positions is 1, judging that the corresponding power spectrum is a direct path; when the number of the peak positions is 0, judging the corresponding power spectrum as noise; and when the number of the peak positions is greater than 1, judging the corresponding power spectrum as a scattering path.

Optionally, the channel estimation module estimates a channel correlation coefficient based on a gaussian factor and a maximum doppler parameter, including: estimating a trigonometric function value associated with an arrival angle of a line-of-sight component signal in the pilot signal according to the maximum Doppler parameter and the direct path; and determining the channel correlation coefficient according to the Gaussian factor and the estimated trigonometric function value.

On the other hand, the embodiment of the invention also provides a communication device, which comprises the random channel estimation device aiming at the rice channel or the chip.

On the other hand, the embodiment of the invention also provides a wireless communication system which comprises the communication device.

In another aspect, an embodiment of the present invention further provides a machine-readable storage medium, where instructions are stored on the machine-readable storage medium, where the instructions are configured to cause a machine to perform any of the foregoing channel estimation methods for rice channels.

Through the technical scheme, the embodiment of the invention judges whether the direct paths obeying the rice distribution exist according to the power spectrum, and estimates the channel correlation coefficient of the rice channel according to the rice factor and the maximum Doppler parameter for channel estimation, thereby improving the accuracy of the channel correlation coefficient under the rice channel and further improving the channel estimation accuracy and the system performance of the rice channel.

Additional features and advantages of embodiments of the invention will be set forth in the detailed description which follows.

Drawings

The accompanying drawings are included to provide a further understanding of embodiments of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description serve to explain, without limitation, the embodiments of the invention. In the drawings:

Fig. 1 is a flow chart of a channel estimation method for rice channel according to an embodiment of the present invention;

FIG. 2 is a flow chart of acquiring a power spectrum in an example of an embodiment of the invention;

fig. 3 is a flow chart of a PDP for acquiring a pilot signal in an example of an embodiment of the present invention;

FIG. 4 is a schematic flow chart of determining a direct path or a scattering path according to a power spectrum in an example of an embodiment of the invention;

FIG. 5 is a block diagram of an implementation of estimating channel correlation coefficients in an example of an embodiment of the invention;

fig. 6 is a schematic structural diagram of a channel estimation device for rice channel according to an embodiment of the present invention; and

Fig. 7 is a schematic structural diagram of a chip according to another embodiment of the present invention.

Detailed Description

The following describes the detailed implementation of the embodiments of the present invention with reference to the drawings. It should be understood that the detailed description and specific examples, while indicating and illustrating the invention, are not intended to limit the invention.

To facilitate a clearer understanding of the embodiments of the present invention, a description is given of rice channel related knowledge.

The probability density function of the Rice distribution is called the Rice (Rice) density function, as follows:

（1）

where R is the envelope of a sine (or cosine) signal plus a narrow-band gaussian random signal, the parameter a is the peak value of the main signal amplitude, Is the power of the multipath signal component,Is a first class of 0-order bessel functions,Is an exponential function. From this equation (1), the rice distribution can be understood as effectively the sum of the main signal and the multipath signal components following the rayleigh distribution.

The rice distribution is described by the usual parameter K, called the rice factor, which is the ratio of the direct-path power to the scattered-path power, i.eWhen a=0, the rice distribution is converted into the rayleigh distribution. The direct path refers to a path where no object is blocked between a transmitter and a receiver in a wireless communication system, and the power of the direct path is usually large. And in the presence of a direct path, the current channel environment obeys the rice distribution.

In a fading scenario in which LOS is present, the rice channel can be expressed as:

（2）

Wherein, Representing the rice channel, K is the rice factor, and the maximum Doppler (doppler) is，V is the speed of movement of the terminal relative to the base station, c is the speed of light,Random phase for LOS; is the angle between the LOS and the terminal, i.e., the angle of arrival of the LOS; Impulse response for scattering path; for the total power of the received signal, i.e 。

For the above equation (2), normalized autocorrelation is performed on the rice channel, and the following time domain correlation coefficient is obtained:

（3）

Wherein the time domain correlation coefficient is the channel correlation coefficient of the rice channel to be estimated in the embodiment of the invention, and the channel correlation coefficient Is a common parameter in the field of wireless communications for measuring the correlation of signals during the transmission of the associated channel.

Further, the channel correlation coefficient of the formula (3) may be expressed as the sum of the autocorrelation of the LOS and the autocorrelation of the scattering path, that is, as shown in the following formula:

（4）

In the method, in the process of the invention, AndThe normalized autocorrelation coefficients of the LOS and the normalized autocorrelation coefficients of the scattering path,Representing the time interval when the channel correlation coefficient is calculated.

In channel estimation in a wireless communication system, time domain wiener filtering is generally adopted, so that the time domain correlation coefficient of the formula (3) needs to be known, and the inter-carrier interference introduced at high speed also needs to be subjected to interference suppression according to the maximum Doppler, and the two values are currently estimated according to Rayleigh distribution and are inaccurate. Accordingly, the embodiment of the invention provides a new estimating scheme of the channel correlation coefficient of the rice channel.

Fig. 1 is a flow chart of a channel estimation method for rice channel according to an embodiment of the present invention. As shown in fig. 1, the method includes the following steps S100 to S200.

Step S100, a power spectrum of a pilot signal in the received signal is acquired.

Step S200, estimating a channel correlation coefficient based on the Gaussian factor and the maximum Doppler parameter when the power spectrum is the direct path obeying the rice distribution.

In a preferred embodiment, as shown in FIG. 2, the step S100 further includes the following steps S110-S130.

Step S110, extracting a pilot signal from the received signal.

For example, a transmitter is used to transmit pilot signals, and a receiver extracts pilot signals from received signals based on pilot locations.

Step S120, obtaining a power delay profile (Power Delay Profile, PDP) of the pilot signal.

In an example, as shown in fig. 3, a PDP of a pilot signal may be acquired through the following steps S121 to S123.

Step S121, LS channel estimation is performed on the pilot signal, so as to obtain the frequency domain channel response of the pilot position.

In this example, assuming that the received signal for the pilot position is y=hx+n, the LS estimate for the pilot position is:

（5）

Where y=hx+n, where Y represents a frequency domain received signal at the pilot subcarrier location, H represents a frequency domain channel response at the pilot subcarrier location, X represents a frequency domain transmitted signal at the pilot subcarrier location, N represents gaussian white noise at the pilot subcarrier location, and conj (X) represents a conjugate of X.

Step S122, performing Fast Fourier Transform (FFT) on the LS channel estimation value of the frequency domain to obtain a time domain impulse response.

Following the above example, a time domain impulse response is derived based on equation (5):

（6）

in step S123, a power delay profile PDP in the time domain is calculated.

Following the above example, a power delay profile PDP is obtained on the basis of equation (6):

（7）

Step S130, obtaining the power spectrum of each effective path larger than a preset threshold in the PDP.

With the above example in mind, the PDP of equation (7) may be filtered first to select an effective diameter greater than a predetermined threshold. Specifically, the PDP of formula (7) is filtered to obtainThen, the noise power is calculated in the noise area of the PDP:

（8）

Wherein Nstart is the start position of the noise region, nend is the end position of the noise region, nstart and Nend are configuration parameters, which can be configured according to the current channel condition, etc. Representation ofPDP filter value corresponding to the i-th index of (b).

Further, a path greater than a threshold Noise NoiseThreshold is selected as the effective path, where NoiseThreshold is the Noise factor, defaulting to 2.5, but is a configurable value, which is not limited herein.

Further, for each selected effective diameterForms a vector from M OFDM symbolsThen FFT transforming to obtainThen square to obtain power spectrumThe specific procedures are shown in the following formulas (9) to (11):

（9）

（10）

（11）

returning to fig. 1, after the step S100 of acquiring the power spectrum and before the step S200 is performed, the method for estimating a channel of the rice channel may further include: and judging the power spectrum as the direct path or the scattering path obeying Rayleigh distribution.

In a preferred embodiment, as shown in fig. 4, the corresponding judgment scheme can be described as the following steps S410-S450.

Step S410, obtaining a power difference of each position m on the power spectrum with respect to a subsequent position m+1.

Examples corresponding to equations (5) - (11) above are received, and the forward and backward power differences for each position m on the power spectrum are calculated using the following equation：

（12）

Step S420, selecting the corresponding m value from the obtained power differences when the current power difference is a positive value and the latter power difference is a negative value.

The value of m is selected to satisfy the following condition:

，（13）

Step S430, obtaining a peak-to-average ratio of the position represented by the selected m value on the power spectrum.

The example taken above uses the following equation to calculate the peak-to-average ratio:

（14）

Where M represents the number of OFDM symbols, and may also refer to the number of terms of PTP _{path_i}.

Step S440, when the peak-to-average ratio is greater than a preset threshold, determining that the position represented by the corresponding m value is the peak position.

For example, if the peak-to-average ratioGreater than a preset threshold RatioThreshold (default value of 3, configurable), the peak position is considered.

Step S450, find all peak positions, and: when the number of the peak positions is 1, judging that the path_i corresponding to the corresponding power spectrum is a direct path and marking as; When the number of the peak positions is 0, judging that the path_i corresponding to the corresponding power spectrum is noise; and when the number of the peak positions is greater than 1, judging that the path_i corresponding to the corresponding power spectrum is a scattering path, and marking as。

Returning to fig. 1, the method for estimating a rice channel may further include: acquiring the Gaussian factor according to the power spectrum; and/or Doppler estimation is carried out on the scattering path so as to obtain the maximum Doppler parameter.

For this, the soilis factor K can be obtained from the direct path power and the scattered path power, taking into account the examples corresponding to the above formulae:

（15）

Wherein, For the time delay power corresponding to the direct path,Is the delay power corresponding to the non-direct path.

In addition, the maximum doppler parameter can be estimated according to the scattering path obeying the rayleigh distribution, and the estimation method is mature in the field, for example, the estimation method can be a doppler estimation method based on a scene such as correlation, ML and the like.

Returning to fig. 1, for step S200, estimating the channel correlation coefficient based on the gaussian factor and the maximum doppler parameter preferably includes: estimating a trigonometric function value associated with an arrival angle of a line-of-sight component signal in the pilot signal according to the maximum Doppler parameter and the direct path; and determining the channel correlation coefficient according to the Gaussian factor and the estimated trigonometric function value.

For this, take the example corresponding to each of the above formulas, the trigonometric function value may be a cosine value, which is noted as corresponding to formula (2). Further, according to the maximum Doppler parameterAnd the direct path estimation formula (2)：

（16）

Wherein,For the angle of arrival of the LOS in the pilot signal,The time domain impulse response of the ith symbol of the direct path,The time domain impulse response of the (i + 1) th symbol of the direct path,In order to be a symbol time period,To take outIs used for the phase of the (c) signal,To take outIs a complex conjugate of (a) and (b).

ObtainingThereafter, based on the Gaussian factor K and the estimatedCombining (4) to obtain the final channel correlation coefficient。

Note that, cosine valueBy way of example, other forms of trigonometric function values may be employed.

Accordingly, the embodiment of the invention judges whether the direct paths obeying the rice distribution exist or not through the power spectrum of the pilot signal, estimates the channel correlation coefficient of the rice channel based on the rice factor and the maximum Doppler parameter, can obtain more accurate channel correlation coefficient aiming at the rice channel, and can use the channel correlation coefficient for time domain wiener filtering so as to ensure the accuracy of rice channel estimation of a mobile communication system and improve the system performance.

Further, in conjunction with the steps and correlation formulas mentioned in the above examples, fig. 5 provides a block diagram of an implementation of estimating channel correlation coefficients in an example of an embodiment of the present invention. As shown in fig. 5, based on the calculated angle, for the received signal, the channel correlation coefficient may be output by sequentially going through the following steps S1 to S9 using, for example, a calculation chip, a computer, a server, or the like.

Step S1, extracting pilot frequency. Wherein, the steps correspond to the above-mentioned step S110, step S121, formula (5) and the like.

Step S2, FFT is carried out to the time domain. Wherein, the step corresponds to the step S122 and the formula (6).

Step S3, calculating the PDP selection effective diameter. Wherein, the steps correspond to the above-described step S123, step S130, and equations (7) - (8).

And S4, forming a vector for each effective diameter. Wherein, the formula (9) corresponds to the above.

And S5, calculating a power spectrum after FFT conversion. Wherein, the formulae (10) - (11) correspond to the above.

And S6, judging whether the Rayleigh channel or the rice channel is judged according to the power spectrum. Wherein, the steps S410-S450 and formulas (12) - (14) are corresponding to those shown in FIG. 4.

Step S7, calculating the rice factor K. Wherein the formula (15) corresponds to the above.

Step S8, calculating the maximum Doppler parameter sum. Wherein, the formula (16) corresponds to the above.

And S9, outputting a correlation coefficient according to the estimated value.

Through the steps S1-S9, it is easy to know that in the embodiment of the present invention, for each effective path in the time domain, whether the path obeys the rayleigh distribution or the rice distribution is determined according to the power spectrum, then the rice factor is estimated, and further the maximum doppler estimation based on the rayleigh distribution and the channel correlation coefficient estimation under the rice channel are performed, so that the present invention has at least the following two advantages.

On the one hand, the maximum Doppler estimation is still carried out based on Rayleigh distribution, and compared with the scheme of additionally acquiring the sub-frame frequency offset value, the calculated amount is reduced, and the maximum Doppler estimation value can be rapidly acquired to carry out interference suppression aiming at a high-speed channel transmission scene.

On the other hand, the channel correlation coefficient is estimated based on the Gaussian factor and the maximum Doppler parameter, so that the accuracy of the channel correlation coefficient under the rice channel is improved, and the channel estimation accuracy and the system performance of the rice channel can be improved.

Fig. 6 is a schematic structural diagram of a channel estimation device for rice channel according to an embodiment of the present invention, which is based on the same inventive concept as the channel estimation method of the above embodiment.

As shown in fig. 6, the channel estimation apparatus includes: a power spectrum acquisition module 100, configured to acquire a power spectrum of a pilot signal in a received signal; and a channel estimation module 200, configured to estimate a channel correlation coefficient based on a rice factor and a maximum doppler parameter when the power spectrum is a direct path obeying a rice distribution.

In a preferred embodiment, the power spectrum acquisition module 100 is configured to acquire a power spectrum of a pilot signal in a received signal, including: extracting a pilot signal from the received signal; acquiring a power delay spectrum PDP of the pilot signal; and acquiring a power spectrum of each effective path larger than a preset threshold in the PDP.

In a preferred embodiment, the channel estimation device further comprises: and the judging module 300 is configured to judge the power spectrum as the direct path or the scattering path following the rayleigh distribution after the power spectrum of the pilot signal in the received signal is obtained.

In a more preferred embodiment, the determining module 300 is configured to determine that the power spectrum is the direct path or a scattering path following a rayleigh distribution, including: acquiring a power difference of each position m on the power spectrum relative to a later position m+1; selecting a corresponding m value from the acquired power differences under the condition that the current power difference is a positive value and the latter power difference is a negative value; acquiring a peak-to-average ratio of a position represented by the selected m value on the power spectrum; when the peak-to-average ratio is larger than a preset threshold, determining that the position represented by the corresponding m value is the peak position; when the number of the peak positions is 1, judging that the corresponding power spectrum is a direct path; when the number of the peak positions is 0, judging the corresponding power spectrum as noise; and when the number of the peak positions is greater than 1, judging the corresponding power spectrum as a scattering path.

Optionally, the channel estimation module 200 estimates a channel correlation coefficient based on a gaussian factor and a maximum doppler parameter, including: estimating a trigonometric function value associated with an arrival angle of a line-of-sight component signal in the pilot signal according to the maximum Doppler parameter and the direct path; and determining the channel correlation coefficient according to the Gaussian factor and the estimated trigonometric function value.

For more implementation details and effects of the channel estimation device, reference is made to the above embodiments of the channel estimation method for rice channel, and no further description is given here.

Fig. 7 is a schematic structural diagram of a chip according to another embodiment of the present invention, for example, a receiver chip, which includes a memory and a processor, wherein the memory stores a computer program executable on the processor, and the processor implements the steps of the channel estimation method for rice channel according to the above embodiment when executing the computer program.

The processor comprises a kernel, and the kernel fetches the corresponding program unit from the memory. The kernel may be provided with one or more kernel parameters to achieve channel correlation coefficient estimation for the rice channel.

The memory may include volatile memory, random Access Memory (RAM), and/or nonvolatile memory, such as Read Only Memory (ROM) or flash memory (flash RAM), in a computer readable medium, the memory including at least one memory chip.

The embodiment of the invention also provides a communication device, which comprises the chip of the embodiment or the random channel estimation device aiming at the rice channel. The communication device is for example a receiver.

The embodiment of the invention also provides a wireless communication system which comprises the communication device. In case the communication device is, for example, a receiver, the wireless communication system is, for example, a communication system comprising a transmitter and a receiver.

The embodiment of the invention also provides a machine-readable storage medium, which stores instructions for causing a machine to perform the channel estimation method for rice channels according to the above embodiment.

It will be appreciated by those skilled in the art that embodiments of the present application may be provided as a method, system, or computer program product. Accordingly, the present application may take the form of an entirely hardware embodiment, an entirely software embodiment or an embodiment combining software and hardware aspects. Furthermore, the present application may take the form of a computer program product embodied on one or more computer-usable storage media (including, but not limited to, disk storage, CD-ROM, optical storage, and the like) having computer-usable program code embodied therein.

The present application is described with reference to flowchart illustrations and/or block diagrams of methods, apparatus (systems) and computer program products according to embodiments of the application. It will be understood that each flow and/or block of the flowchart illustrations and/or block diagrams, and combinations of flows and/or blocks in the flowchart illustrations and/or block diagrams, can be implemented by computer program instructions. These computer program instructions may be provided to a processor of a general purpose computer, special purpose computer, embedded processor, or other programmable data processing apparatus to produce a machine, such that the instructions, which execute via the processor of the computer or other programmable data processing apparatus, create means for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be stored in a computer-readable memory that can direct a computer or other programmable data processing apparatus to function in a particular manner, such that the instructions stored in the computer-readable memory produce an article of manufacture including instruction means which implement the function specified in the flowchart flow or flows and/or block diagram block or blocks.

These computer program instructions may also be loaded onto a computer or other programmable data processing apparatus to cause a series of operational steps to be performed on the computer or other programmable apparatus to produce a computer implemented process such that the instructions which execute on the computer or other programmable apparatus provide steps for implementing the functions specified in the flowchart flow or flows and/or block diagram block or blocks.

In one typical configuration, a computing device includes one or more processors (CPUs), input/output interfaces, network interfaces, and memory.

The memory may include volatile memory in a computer-readable medium, random Access Memory (RAM) and/or nonvolatile memory, etc., such as Read Only Memory (ROM) or flash RAM. Memory is an example of a computer-readable medium.

Computer readable media, including both non-transitory and non-transitory, removable and non-removable media, may implement information storage by any method or technology. The information may be computer readable instructions, data structures, modules of a program, or other data. Examples of storage media for a computer include, but are not limited to, phase change memory (PRAM), static Random Access Memory (SRAM), dynamic Random Access Memory (DRAM), other types of Random Access Memory (RAM), read Only Memory (ROM), electrically Erasable Programmable Read Only Memory (EEPROM), flash memory or other memory technology, compact disc read only memory (CD-ROM), digital Versatile Discs (DVD) or other optical storage, magnetic cassettes, magnetic tape magnetic disk storage or other magnetic storage devices, or any other non-transmission medium, which can be used to store information that can be accessed by a computing device. Computer-readable media, as defined herein, does not include transitory computer-readable media (transmission media), such as modulated data signals and carrier waves.

It should also be noted that the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising one … …" does not exclude the presence of other like elements in a process, method, article, or apparatus that comprises an element.

The foregoing is merely exemplary of the present application and is not intended to limit the present application. Various modifications and variations of the present application will be apparent to those skilled in the art. Any modification, equivalent replacement, improvement, etc. which come within the spirit and principles of the application are to be included in the scope of the claims of the present application.

Claims

1. A channel estimation method for rice channels, comprising:

Acquiring a power spectrum of a pilot signal in a received signal;

Judging the power spectrum as a direct path obeying the rice distribution or a scattering path obeying the Rayleigh distribution;

doppler estimation is carried out on the scattering path so as to obtain the maximum Doppler parameter; and

Estimating a channel correlation coefficient based on a vegetable factor and the maximum doppler parameter when the power spectrum is the direct path, comprising: estimating a cosine value associated with an arrival angle of a line-of-sight component signal in the pilot signal according to the maximum Doppler parameter and the power spectrum of the direct path; and determining the channel correlation coefficient according to the Gaussian factor and the estimated cosine value.

2. The method of channel estimation according to claim 1, wherein said acquiring a power spectrum of a pilot signal in a received signal comprises:

extracting a pilot signal from the received signal;

Acquiring a power delay spectrum PDP of the pilot signal; and

And acquiring a power spectrum of each effective path larger than a preset threshold in the PDP.

3. The channel estimation method according to claim 1, wherein said determining that the power spectrum is a direct path following a rice distribution or a scattering path following a rayleigh distribution comprises:

acquiring a power difference of each position m on the power spectrum relative to a later position m+1;

Selecting a corresponding m value from the acquired power differences under the condition that the current power difference is a positive value and the latter power difference is a negative value;

Acquiring a peak-to-average ratio of a position represented by the selected m value on the power spectrum;

when the peak-to-average ratio is larger than a preset threshold, determining that the position represented by the corresponding m value is the peak position;

When the number of the peak positions is 1, judging that the corresponding power spectrum is a direct path;

when the number of the peak positions is 0, judging the corresponding power spectrum as noise; and

And when the number of the peak positions is greater than 1, judging the corresponding power spectrum as a scattering path.

4. The channel estimation method of claim 1 wherein prior to said estimating channel correlation coefficients based on a gaussian factor and a maximum doppler parameter, said channel estimation method further comprises:

and acquiring the Gaussian factor according to the power spectrum.

5. The channel estimation method of claim 4 wherein the cosine values are recorded asAnd is calculated by the following formula:

6. The channel estimation method of claim 5 wherein the channel correlation coefficients areCalculated using the following:

7. A channel estimation device for rice channel, comprising:

the power spectrum acquisition module is used for acquiring the power spectrum of the pilot signal in the received signal;

The judging module is used for judging that the power spectrum is a direct path obeying the rice distribution or a scattering path obeying the Rayleigh distribution; and

A channel estimation module, configured to estimate a channel correlation coefficient based on a gaussian factor and a maximum doppler parameter when the power spectrum is the direct path, where the maximum doppler parameter is obtained by performing doppler estimation on the scattering path;

Wherein the channel estimation module estimates a channel correlation coefficient based on a vegetable factor and a maximum Doppler parameter, comprising: estimating a cosine value associated with an arrival angle of a line-of-sight component signal in the pilot signal according to the maximum Doppler parameter and the power spectrum of the direct path; and determining the channel correlation coefficient according to the Gaussian factor and the estimated cosine value.

8. The channel estimation device of claim 7 wherein the power spectrum acquisition module for acquiring a power spectrum of a pilot signal in a received signal comprises:

extracting a pilot signal from the received signal;

Acquiring a power delay spectrum PDP of the pilot signal; and

9. The channel estimation device of claim 7, wherein the determining module configured to determine the power spectrum as a direct path that follows a rice distribution or a scattering path that follows a rayleigh distribution comprises:

10. A chip comprising a memory and a processor, the memory storing a computer program executable on the processor, the processor implementing the channel estimation method for rice channels according to any of claims 1 to 6 when the computer program is executed.

11. A communication device comprising a channel estimation device for rice channels according to any of claims 7 to 9 or comprising a chip according to claim 10.

12. A wireless communication system comprising the communication apparatus of claim 11.

13. A machine-readable storage medium having stored thereon instructions for causing a machine to perform the channel estimation method for rice channels of any one of claims 1 to 6.