CN102158436A - Channel frequency domain correlation calculation method and device, and channel estimation method and device - Google Patents

Abstract

The invention discloses a channel frequency domain correlation calculation method, a channel frequency domain correlation calculation device, a channel estimation method and a channel estimation device. The channel frequency domain correlation calculation method provided by the invention comprises the following steps of: analyzing the path delay distribution of a sample channel; analyzing the path energy distribution of the sample channel; constructing a channel model according to the path delay distribution and path energy distribution of the sample channel; and calculating channel frequency domain correlation according to the constructed channel model. The channel estimation method provided by the invention comprises the following steps of: calculating the least square channel estimation of a pilot sub-carrier; reading pre-stored channel frequency domain correlation; estimating the travel speed of a receiver relative to a transmitter; calculating channel time domain correlation according the travel speed of the receiver relative to the transmitter; calculating a minimum mean square error (MMSE) filter coefficient by utilizing the calculated channel time domain correlation and the read channel frequency domain correlation; and acquiring the channel estimation of a data sub-carrier according to the calculated MMSE filter coefficient and the least square channel estimation of the pilot sub-carrier, wherein the pre-stored channel frequency domain correlation is acquired by the channel frequency domain correlation calculation method.

Description

Channel frequency domain correlation computational methods and device, channel estimation methods and device

Technical field

Relate generally to radio communication of the present invention.Particularly, the present invention relates to a kind of channel frequency domain correlation computational methods and device thereof and channel estimation methods and device thereof.

Background technology

Be subjected to the influence on surrounding buildings thing, object, pedestrian, vehicle and ground etc., wireless signal may reflect in transmission course, refraction, diffraction and scattering etc.Therefore, the wireless signal that receives of receiving terminal has all experienced the expansion of serious decline and time delay usually.For the data of recovering to send, receiver need estimate that suffered to received signal again loss compensates to the wireless channel of signal experience.The module that channel is estimated is called channel estimation module, and the module that compensates to received signal is called balance module.Channel estimation module is vital for wireless system, and performance for estimating channel is good more, and then the error performance of system is good more, and just the correct data that receive of system are many more.

(Orthogonal Frequency Division Multiplexing, OFDM) technology is emerging in recent years transmission technology to OFDM.Ofdm system at first carries out IFFT (Inverse Fast Fourier Transform, inverse fast Fourier transform) conversion at transmitting terminal to data to be sent it is become time-domain signal, and this signal is propagated in time domain subsequently.At receiving terminal, received signal at first is converted into frequency domain by FFT (Fast Fourier Transform, fast Fourier transform), carries out operations such as equilibrium, demodulation and decoding again to recover to send data.Because transmission signals can equivalence be converted to falt fading channel after the multipath channel with fixed response time expansion of time domain experience is being converted into frequency domain, therefore ofdm system has very strong anti-fading ability, and use widely having obtained in recent years, as Wimax (Worldwide Interoperability for Microwave Access, worldwide interoperability for microwave inserts) system and LTE (Long Term Evolution, Long Term Evolution) wireless communication system such as, and DMB-T (Digital Multimedia Broadcast-Terrestrial, DMB-ground), CMMB (China Mobile Multimedia Broadcasting, China Mobile multimedia broadcasting) and DVB digital television broadcasting systems such as (Digital Video Broadcasting, digital video broadcasting).

At this, making k the frequency domain data that subcarrier carried in l the OFDM symbol is X _{K, l}, Dui Ying frequency domain equivalent received signals Y with it _{K, l}Can be expressed as

Y _k，l＝H _k，lX _k，l+N _k，l (1)

H wherein _{K, l}Be X _{K, l}The equivalent frequency domain falt fading channel of experience, N _{K, l}Be frequency domain equivalence additive white Gaussian noise, its average is zero, and variance is σ _N ²

The channel estimating of ofdm system promptly is to equivalent domain channel response H _{K, l}Estimate.(Minimum Mean Square Error, MMSE) criterion is a kind of criterion that makes evaluated error average minimum to least mean-square error.Channel estimation method based on the MMSE criterion is one of preferred channels algorithm for estimating.According to the MMSE channel estimation method, the estimated value of the channel frequency domain response at k subcarrier place in l OFDM symbol

Can calculate according to formula (2).

${\hat{H}}_{k,l}=w_{k,l}^H{\hat{H}}_{k,l}^P---\left(1\right)$

In the following formula, variable

Be subcarrier (k, the estimated value of the channel frequency domain response of l) locating, vectorial w _{K, l}Be the filter coefficient of MMSE channel estimator, vector

For being used for the estimator carrier wave (k, the channel impulse response estimation value of the pilot tone point of the channel frequency domain response of l) locating arranged and formed by previously selected.Suppose that each data subcarrier utilizes M point of observation to carry out the MMSE channel estimating, and the sequence number of this M point of observation is respectively (k ₁, l ₁), (k ₂, l ₂) ..., (k _M, l _M), so vectorial

Can be expressed as following formula (3).

According to MMSE criterion, w _{K, l}For making function J (w _{K, l}) minimum separating, wherein function J (w _{K, l}) provide by formula (4).

$J\left(w_{k,l}\right)=E\left\{{\left|\right|{\hat{H}}_{k,l}-H_{k,l}\left|\right|}^2\right\}---\left(4\right)$

According to orthogonality principle, w _{K, l}Can calculate by following formula (5).

$w_{k,l}={\mathrm{\θ}}_{k,l}^T{\mathrm{\Φ}}_{k,l}^{-1}---\left(5\right)$

Wherein, θ _{K, l}(k l) locates the cross correlation vector of domain channel response and M point of observation reception value, and it can be expressed as for subcarrier

${\mathrm{\&theta;}}_{k,l}={\left[\begin{array}{ccc}{\mathrm{\&theta;}}_{k-{\mathrm{<figure-callout\; id="1"\; label="k"\; filenames="HSA00000017552800041.png"\; state="\{\{state\}\}">k</figure-callout>}}_1,l-{\mathrm{<figure-callout\; id="1"\; label="l"\; filenames="HSA00000017552800041.png"\; state="\{\{state\}\}">l</figure-callout>}}_1}& {\mathrm{\&theta;}}_{k-{\mathrm{<figure-callout\; id="2"\; label="k"\; filenames="HSA00000017552800021.png"\; state="\{\{state\}\}">k</figure-callout>}}_2,l-{\mathrm{<figure-callout\; id="2"\; label="l"\; filenames="HSA00000017552800021.png"\; state="\{\{state\}\}">l</figure-callout>}}_2}...& {\mathrm{\&theta;}}_{k-k_M,l-l_M}\end{array}\right]}^T---\left(6\right)$

Cross correlation value in the formula (6)

M=1,2 ..., M can be expressed as

${\mathrm{\&theta;}}_{k-k_m,l-l_m}=E\{H_{k,l}\&CenterDot;{\hat{H}}_{k_m,l_m}^{*}\}---\left(7\right)$

In formula (5), matrix Φ _{K, l}Be the autocorrelation matrix of M point of observation reception value, it can be expressed as

Autocorrelation value wherein

M=1,2 ..., the expression formula of M is

${\mathrm{\&Phi;}}_{k_m-k_{m^{\&prime;}},l_m-l_{m^{\&prime;}}}=E\{{\hat{H}}_{k_m,l_m}\&CenterDot;{\hat{H}}_{k_{m^{\&prime;},}{l}_{m^{\&prime;}}}^{*}\}---\left(9\right)$

The correlation that provides in formula (7) and the formula (9) has not only comprised relativity of time domain but also comprised frequency domain correlation.Generally speaking, can think that relativity of time domain and the frequency domain correlation in this correlation is independently of one another, so formula (7) and formula (9) can be expressed as the time domain correlation and the frequency domain correlation is long-pending, shown in following formula (10) and (11).

${\mathrm{\&theta;}}_{k-k_m,l-l_m}={\mathrm{\&theta;}}_{\mathrm{\&Delta;f}}(k-k_m)\&CenterDot;{\mathrm{\&theta;}}_{\mathrm{\&Delta;t}}(l-l_m)---\left(10\right)$

${\mathrm{\&Phi;}}_{k_m-k_{m^{\&prime;}},l_m-l_{m^{\&prime;}}}=\frac{{\mathrm{<figure-callout\; id="0"\; label="N"\; filenames="HSA00000017552800021.png,HSA00000017552800052.png"\; state="\{\{state\}\}">N</figure-callout>}}_0\mathrm{\&delta;}(k_m-k_{m^{\&prime;}},l_m-l_{m^{\&prime;}})}{E_s(k_m,l_m)}+{\mathrm{\&theta;}}_{\mathrm{\&Delta;f}}(k_m-k_{m^{\&prime;}})\&CenterDot;{\mathrm{\&theta;}}_{\mathrm{\&Delta;f}}({l_m}^{}-l_{m^{\&prime;}})---\left(11\right)$

N wherein ₀Be the monolateral band power spectral density of noise, E _s(k _m, l _m) be subcarrier (k _m, l _m) carrying the transmission signal energy, function δ (k _m-k _m', l _m-l _m') expression formula as follows.

$\mathrm{\&delta;}(k_m-k_{m^{\&prime;}},l_m-l_{m^{\&prime;}})=\left\{\begin{array}{cc}1& \mathrm{if}{k}_m=k_{m^{\&prime;}}\mathrm{and}{l}_m=l_{m^{\&prime;}}\\ 0& \mathrm{otherwise}\end{array},---\left(12\right)\right.$

From top analysis as can be seen, known time domain correlation θ _{Δ t}(l-l _m) and frequency domain correlation θ _{Δ f}(k-k _m) be the precondition that the MMSE channel estimation method can smooth implementation.

Wherein, time domain correlation θ _{Δ t}(l-l _m) relevant with the type of the Doppler that relative moving speed and channel experienced of transmitting terminal and receiving terminal decline.For example, when the Doppler of channel power spectrum is a modal Clarke model in the time of (being called the Jakes model again), time domain correlation θ _{Δ t}(l-l _m) can be expressed as

θ _Δt(l-l _m)＝J ₀(2πf _dT _s(l-l _m)) (13)

Wherein, function J ₀Be first kind zero Bessel function, T _sBe system's baseband sampling cycle, f _dBe the maximum Doppler frequency of monolateral band, it is relevant with the relative moving speed of transmitting terminal and receiving terminal, can be calculated by following formula (14).

$f_d=\frac{F_G\&CenterDot;v}{c}---\left(14\right)$

In formula (14), F _GBe carrier frequency, v is the translational speed of receiving terminal with respect to transmitting terminal, and c is the light velocity.In other words, under the prerequisite of known channel Doppler type,, can obtain the time domain correlation properties of channel as long as estimate to obtain the translational speed of receiving terminal with respect to transmitting terminal.

But, to compare with the computational process of relativity of time domain, the calculating of the frequency domain correlation properties of channel is then more complicated.Because the footpath number of the time domain multipath channel that the frequency domain correlation properties and the signal of channel are experienced, the power and the time delay in every footpath are relevant.The algorithm that calculates frequency domain correlation generally is divided into two big classes, the first kind is that the time domain multipath channel that signal is experienced is estimated, second class is the definition from the channel frequency domain correlation, and a large amount of frequency domains reception pilot signals and frequency domain reception data-signal are added up to obtain the valuation of channel frequency domain correlation.No matter adopt any method, carry out synchronously in real time to the channel frequency domain correlation that estimation all needs to carry out a large amount of calculating and statistics when carrying out channel estimating, this is with the overhead that costs a lot of money and cause bigger system's time delay.

Summary of the invention

In view of this, the present invention proposes a kind of method and device and corresponding channel estimation methods and device thereof of very simple calculating channel correlation.This scheme greatly reduces the overhead when adopting the MMSE channel estimation method, the system's time delay when having reduced to adopt the MMSE channel estimation method.

To achieve these goals, according to an aspect of the present invention, provide a kind of channel frequency domain correlation computational methods, having comprised: distribute the path delay of time of analyzing samples channel; The path energy of analyzing samples channel distributes; Distribute and path energy distribution structure channel model the path delay of time according to the sample channel; And according to the channel model calculating channel frequency domain correlation that makes up.

Channel frequency domain correlation computational methods in accordance with a preferred embodiment of the present invention also comprise: according to the selected a plurality of analystal sections of time delay expansion.In this case, at distributing in path delay of time of each analystal section analyzing samples channel, and distribute at the path energy of each analystal section analyzing samples channel.

Preferably, be evenly distributed a plurality of path delays of time in each analystal section or equal difference increases progressively and distributes or other distributions.The Energy distribution in each path is linear decrease and distributes, is exponential decrease and distribute, be that homenergic evenly distributes or other distributions in each analystal section.

In a specific embodiment,, distinguish the calculating channel frequency domain correlation according to the channel model that makes up according to following formula at different maximum delay expansions:

${\mathrm{\&theta;}}_{\mathrm{\&Delta;f}}(k-k_m)=\mathrm{abs}\left(\underset{i}{\mathrm{\&Sigma;}}{\mathrm{\&sigma;}}_i^2{e}^{-\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="HSA00000017552800021.png"\; state="\{\{state\}\}">j</figure-callout>}2\mathrm{\&pi;}(k-k_m){\mathrm{\&tau;}}_i}\right)$

Wherein, θ _{Δ f}(k-k _m) be channel frequency domain correlation function, the operation of abs () expression absolute calculation, (k-k _m) be the subcarrier spacing number between two frequencies of calculating channel frequency domain correlation, i is a path sequence number, σ _i ²Be the path energy in i footpath, τ _iIt is the path delay of time in i footpath.

Here, the sample channel comprises one or more in the channels such as PA channel, EPA channel, VA channel, EVA channel, PB channel, TU channel and ETU channel.

According to another aspect of the present invention, provide a kind of channel frequency domain correlation calculation element, having comprised: the path delay of time analytic unit, distribute the path delay of time that is configured to the analyzing samples channel; The path energy analytic unit, the path energy that is configured to the analyzing samples channel distributes; The channel model construction unit is configured to distribute and path energy distribution structure channel model according to the path delay of time of sample channel; And the frequency domain correlation computing unit, be configured to according to the channel model calculating channel frequency domain correlation that makes up.

Channel frequency domain correlation calculation element in accordance with a preferred embodiment of the present invention also comprises: the analystal section selected cell is configured to according to the selected a plurality of analystal sections of time delay expansion.In this case, the path delay of time analytic unit at distributing in path delay of time of each analystal section analyzing samples channel, and the path energy analytic unit distributes at the path energy of each analystal section analyzing samples channel.

Preferably, the channel model construction unit according to the time delay in a plurality of paths in each analystal section be evenly distributed, equal difference increase progressively distribute or other distribute and each analystal section in the Energy distribution in each path be linear decrease and distribute, be exponential decrease and distribute, be that homenergic evenly distributes or the principle construction channel model of other distributions.

According to a further aspect of the invention, provide a kind of channel estimation methods, having comprised: the least square channel estimating of calculating pilot sub-carrier; Read the channel frequency domain correlation that prestores; Estimate the translational speed of receiving terminal with respect to transmitting terminal; According to the translational speed calculating channel relativity of time domain of receiving terminal with respect to transmitting terminal; Utilize channel time domain correlation of calculating and the channel frequency domain correlation that reads to calculate the MMSE filter coefficient; And the channel estimating of obtaining data subcarrier according to the least square channel estimating of MMSE filter coefficient that calculates and pilot sub-carrier.Wherein, the described channel frequency domain correlation that prestores each channel frequency domain correlation computational methods according to the present invention are obtained.

Channel estimation methods also comprises according to an embodiment of the invention: estimate the maximum delay expansion of channel; And read correspondingly the channel frequency domain correlation that prestores according to the maximum delay expansion of estimating.

Channel estimation methods according to an embodiment of the invention, utilize channel time domain correlation of calculating and the channel frequency domain correlation that reads to calculate in the MMSE filter coefficient, utilizing channel time domain correlation of calculating and the channel frequency domain correlation that reads to calculate the MMSE filter coefficient of pilot sub-carrier.In this case, the channel estimating of obtaining data subcarrier according to the least square channel estimating of MMSE filter coefficient that calculates and pilot sub-carrier comprises: utilize the MMSE filter coefficient of the pilot sub-carrier that calculates that the least square channel estimating of pilot sub-carrier is carried out MMSE filtering; And the channel of data subcarrier is estimated to obtain the channel estimating of data subcarrier according to the filtered pilot sub-carrier of MMSE.

Preferably, by the filtered pilot sub-carrier of MMSE is carried out the channel estimating that linear interpolation, second order interpolation, MMSE filtering, low-pass filtering or Spline interpolation are obtained data subcarrier.

Channel estimation methods in accordance with another embodiment of the present invention, utilizing channel time domain correlation of calculating and the channel frequency domain correlation that reads to calculate in the MMSE filter coefficient, utilize the MMSE filter coefficient of channel time domain correlation of calculating and the channel frequency domain correlation calculated data subcarrier that reads.In this case, obtaining in the channel estimating of data subcarrier according to the MMSE filter coefficient that calculates and the least square channel estimating of pilot sub-carrier, utilize the MMSE filter coefficient of the data subcarrier that calculates that the least square channel estimating of pilot sub-carrier is carried out MMSE filtering, obtain the channel estimating of data subcarrier.

According to a further aspect of the invention, provide a kind of channel estimating apparatus, having comprised: the pilot channel estimation unit is configured to calculate the least square channel estimating of pilot sub-carrier; The frequency domain correlation reading unit is configured to read the channel frequency domain correlation that prestores; Motion speed estimation unit is configured to estimate the translational speed of receiving terminal with respect to transmitting terminal; The relativity of time domain computing unit is configured to according to the translational speed calculating channel relativity of time domain of receiving terminal with respect to transmitting terminal; MMSE filter coefficient computing unit, the channel frequency domain correlation calculating MMSE filter coefficient that is configured to utilize the channel time domain correlation of calculating and reads; And the data channel estimation unit, be configured to obtain the channel estimating of data subcarrier according to the least square channel estimating of MMSE filter coefficient that calculates and pilot sub-carrier.Wherein, the described channel frequency domain correlation that prestores is obtained by each channel frequency domain correlation calculation element according to the present invention.

Channel estimating apparatus also comprises according to an embodiment of the invention: the time delay spread estimation unit is configured to estimate the maximum delay expansion of channel; And the frequency domain correlation reading unit is expanded the channel frequency domain correlation that prestores that reads correspondingly according to the maximum delay of estimating.

In channel estimating apparatus according to an embodiment of the invention, channel time domain correlation that the utilization of MMSE filter coefficient computing unit is calculated and the channel frequency domain correlation that reads are calculated the MMSE filter coefficient of pilot sub-carrier.In this case, the data channel estimation unit comprises: pilot tone MMSE filter cell is configured to utilize the MMSE filter coefficient of the pilot sub-carrier of calculating that the least square channel estimating of pilot sub-carrier is carried out MMSE filtering; And the data channel estimator, be configured to the channel of data subcarrier be estimated to obtain the channel estimating of data subcarrier according to the filtered pilot sub-carrier of MMSE.

Preferably, the data channel estimator is by carrying out the channel estimating that linear interpolation, second order interpolation, MMSE filtering, low-pass filtering or Spline interpolation are obtained data subcarrier to the filtered pilot sub-carrier of MMSE.

Channel estimating apparatus in accordance with another embodiment of the present invention, the MMSE filter coefficient of channel time domain correlation that the utilization of MMSE filter coefficient computing unit is calculated and the channel frequency domain correlation calculated data subcarrier that reads; And the MMSE filter coefficient of the data subcarrier that calculates of data channel estimation unit utilization carries out MMSE filtering to the least square channel estimating of pilot sub-carrier, obtains the channel estimating of data subcarrier.

In addition, according to a further aspect in the invention, also provide a kind of storage medium.Described storage medium comprises machine-readable program code, and when carrying out described program code on messaging device, described program code makes described messaging device carry out according to said method of the present invention.

In addition, in accordance with a further aspect of the present invention, also provide a kind of program product.Described program product comprises the executable instruction of machine, and when carrying out described instruction on messaging device, described instruction makes described messaging device carry out according to said method of the present invention.

Description of drawings

With reference to below in conjunction with the explanation of accompanying drawing, can understand above and other purpose of the present invention, characteristics and advantage more easily to the embodiment of the invention.Parts in the accompanying drawing are just in order to illustrate principle of the present invention.In the accompanying drawings, same or similar technical characterictic or parts will adopt identical or similar Reference numeral to represent.In the accompanying drawing:

Fig. 1 illustrates the process chart of channel frequency domain correlation computational methods according to an embodiment of the invention;

Fig. 2 is the schematic diagram of constructed according to one embodiment of present invention channel model;

Fig. 3 illustrates the block diagram of channel frequency domain correlation calculation element according to an embodiment of the invention;

Fig. 4 illustrates the process chart of channel estimation methods according to an embodiment of the invention;

Fig. 5 illustrates the block diagram of channel estimating apparatus according to an embodiment of the invention;

Fig. 6 illustrates the process chart of channel estimation methods according to another embodiment of the invention;

Fig. 7 illustrates the block diagram of channel estimating apparatus according to another embodiment of the invention;

Fig. 8 illustrates the simulation result under the EPA channel according to channel estimation methods of the present invention and device thereof;

Fig. 9 illustrates the simulation result under the EVA channel according to channel estimation methods of the present invention and device thereof; And

Figure 10 illustrates the schematic block diagram that can be used for implementing according to the computer of the method and apparatus of the embodiment of the invention.

Embodiment

To be described in detail one exemplary embodiment of the present invention in conjunction with the accompanying drawings hereinafter.For clarity and conciseness, all features of actual execution mode are not described in specification.Yet, should understand, in the process of any this practical embodiments of exploitation, must make a lot of decisions specific to execution mode, so that realize developer's objectives, for example, meet and system and professional those relevant restrictive conditions, and these restrictive conditions may change to some extent along with the difference of execution mode.In addition, might be very complicated and time-consuming though will also be appreciated that development, concerning the those skilled in the art that have benefited from present disclosure, this development only is customary task.

At this, what also need to illustrate a bit is, for fear of having blured the present invention because of unnecessary details, only show in the accompanying drawings with according to closely-related apparatus structure of the solution of the present invention and/or treatment step, and omitted other details little with relation of the present invention.In addition, it is pointed out that also element and the feature described can combine with element and the feature shown in one or more other accompanying drawing or the execution mode in an accompanying drawing of the present invention or a kind of execution mode.

Below will be at first the basic functional principle of channel frequency domain correlation computational methods according to an embodiment of the invention and device thereof be described referring to figs. 1 through Fig. 3.

As shown in Figure 1, channel frequency domain correlation computational methods according to an embodiment of the invention comprise analyzing samples channel selection step S110, analystal section selection step S120, distributional analysis in path delay of time step S130, path energy distributional analysis step S140, channel model construction step S150 and channel frequency domain correlation calculation procedure S160 etc.

At first, the sample channel that in analyzing samples channel selection step S110, is identified for analyzing.Consider in the system applies the scene that might occur, select according to one embodiment of present invention with lower channel as the sample channel that is used to analyze: PA (Pedestrian A) channel, EPA (ExtendedPedestrian A) channel, VA (Vehicular A) channel, EVA (Extended Vehicular A) channel, PB (Pedestrian B) channel, TU (Typical Urban) channel and ETU (ExtendedTypical Urb an) channel.

Then, select among the step S120, begin interval till the time delay expansion of channel constantly as whole observation interval with 0, determine analystal section as required at analystal section.For example, according to one embodiment of present invention, can select 3 analystal sections [0, T/4], [0, T/2] and [0, T], wherein T is the time delay expansion of channel model yet to be built.Certainly, also can select the analystal section of other quantity, such as, 4 analystal sections [0, T/8], [0, T/4], [0, T/2] and [0, T], or the like.

Then, in distributional analysis in path delay of time step S130,, the distribution in the path delay of time of all sample channels is added up at each analystal section.As specific embodiment, distributed the path delay of time of each sample channel of statistics gained when table 1 showed at 3 analystal sections of top selection.

Table 1 sample distribution of multipath time delay statistics

The sample channel	First analystal section [0, T/4] multipath number	Second analystal section [0, T/2] multipath number	The 3rd analystal section [0, T] multipath number
				EPA
	4	6	7

PA	1	3	4
				EVA	5	7	9
VA	2	4	6
				PB	3	4	6
ETU	6	8	9
				TU	3	5	6
On average	3.428571	5.285714	6.714286
				Select parameter	4	5	7

Next, in path energy distributional analysis step S140,, the path energy distribution of all sample channels is added up at each analystal section.Equally, as specific embodiment, the path energy that table 2 shows each sample channel of statistics gained distributes.

Table 2 sample multipath energy distribution statistics data

The sample channel	First analystal section [0, T/4] multipath energy accounts for the gross energy ratio	Second analystal section [0, T/2] multipath energy accounts for the gross energy ratio	The 3rd analystal section [0, T] multipath energy accounts for the gross energy ratio
				EPA	94.02823％	99.73275％	100.00000％
PA	88.93453％	99.53326％	100.00000％
				EVA	90.20566％	97.98566％	100.00000％
VA	87.02543％	97.98128％	100.00000％
				PB	86.67225％	93.10198％	100.00000％
ETU	84.11011％	96.88237％	100.00000％
				TU	80.70734％	96.21473％	100.00000％
On average	87.38336％	97.34743％	100.00000％
				Select parameter
	87％	97％	100％

Afterwards, in channel model construction step S150, distributing according to the path energy that distributes in path delay of time of the sample channel that obtains in distributional analysis in path delay of time step S130 and obtain in path energy distributional analysis step S140 makes up channel model.Here, distribution in the path delay of time and path energy with each the sample channel shown in table 1 and the table 2 are distributed as example, first analystal section [0, T/4] multipath number mean value is 3.429 as can be seen, and its average multipath energy accounts for 87.3834% of gross energy, second analystal section [0, T/2] multipath number mean value is 5.286, its average multipath energy accounts for 97.347%, the three analystal section [0 of gross energy, T] multipath number mean value is 6.714, its average multipath energy accounts for 100.000% of gross energy.According to above average data, distribute and the path energy distribution is chosen as in the path delay of time of the channel model of this structure, first analystal section [0, T/4] multipath number is 4, and its multipath energy accounts for 87% of gross energy, second analystal section [0, T/2] multipath number is 5, its multipath energy accounts for 97%, the three analystal section [0 of gross energy, T] multipath number is 7, its multipath energy accounts for 100% of gross energy.Fig. 2 has provided the schematic diagram of the channel model that makes up.

As shown in Figure 2,, 4 footpaths are arranged in interval [0, T/4], 1 footpath is arranged in interval [T/4, T/2], 2 footpaths are arranged in interval [T/2, T] according to the parameter of selecting.According to one embodiment of present invention, can suppose [0, T/4] in 4 the footpath time delay be evenly distributed, interval [T/4, T/2] interior evenly distribution of 1 footpath, maximum delay expansion place that second interior footpath of interval [T/2, T] places channel, and first footpath in interval [T/2, T] is positioned at the center in this interval.In addition, also can make the time delay equal difference in every footpath increase progressively distribution etc.In addition, in each analystal section, the selection parameter that the gross energy obedience table 2 of multipath provides, the Energy distribution in every footpath is linear decrease.In addition, also can make the Energy distribution in every footpath be exponential decrease distributes, makes every footpath to be homenergic evenly to distribute or make every footpath energy be other possible distributions or the like.

At last, in channel frequency domain correlation calculation procedure S160, according to the channel model that in channel model construction step S150, makes up, the frequency domain correlation of calculating channel.In ofdm system, it is generally acknowledged that the maximum delay expansion of the time domain multipath channel that it experiences can not surpass the length of the Cyclic Prefix of system's employing, so the length of Cyclic Prefix is a parameter with reference significance.In different applied environments, different proportion that can the selective system circulating prefix-length, such as 1/8,2/8,3/8,4/8,5/8,6/8,7/8,8/8 circulating prefix-length, as the maximum delay expansion of channel model, calculate the channel frequency domain correlation of different delay expansion according to following formula (15).

${\mathrm{\&theta;}}_{\mathrm{\&Delta;f}}(k-k_m)=\mathrm{abs}\left(\underset{i}{\mathrm{\&Sigma;}}{\mathrm{\&sigma;}}_i^2{e}^{-\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="HSA00000017552800021.png"\; state="\{\{state\}\}">j</figure-callout>}2\mathrm{\&pi;}(k-k_m){\mathrm{\&tau;}}_i}\right)---\left(15\right)$

Wherein, θ _{Δ f}(k-k _m) be channel frequency domain correlation function, the operation of abs () expression absolute calculation, (k-k _m) be the subcarrier spacing number between two frequencies of calculating channel frequency domain correlation, i is a path sequence number, σ _i ²Be the path energy in i footpath, τ _iIt is the path delay of time in i footpath.

LTE TDD (the Time Division Duplex that has user's DRS (Dedicated Reference Signal) (UE-Specific Reference Signal) in this consideration, time division duplex) concrete condition of system, and hypothesis treats that estimating resource is restricted to 1 Resource Block (Resource Block, so integer variable (k-k RB), _m) interval can be set to [0,10].Following table 3 has provided the maximum delay expansion of channel model and has elected 4/8 circulating prefix-length, (k-k as _m) the concrete result of calculation of channel frequency domain correlation when value is [0,10].

Table 3 channel frequency domain correlation result of calculation

(k-k m)	?θ Δf(k-k m)
		0	1
2	0.997809

4	0.991323
		6	0.980802
8	0.96666
		10	0.949455

Here, use in the time of the result of calculation of channel frequency domain correlation calculation procedure S160 can being stored as form in order to channel estimating apparatus work.

Also it is to be noted in addition, it is not essential for the present invention that analyzing samples channel recited above selects step S110 and analystal section to select step S120, but can be as required for steps such as the direct execution route time delay distribution of given sample channel analytical procedure S130, path energy distributional analysis step S140, channel model construction step S150 and channel frequency domain correlation calculation procedure S160.

The operation principle of channel frequency domain correlation calculation element according to an embodiment of the invention is described below in conjunction with Fig. 3.As shown in Figure 3, the channel frequency domain correlation calculation element according to this embodiment comprises: the path delay of time, analytic unit 320, and distribute the path delay of time that is configured to the analyzing samples channel; Path energy analytic unit 330, the path energy that is configured to the analyzing samples channel distributes; Channel model construction unit 340 is configured to distribute and path energy distribution structure channel model according to the path delay of time of sample channel; And frequency domain correlation computing unit 350, be configured to according to the channel model calculating channel frequency domain correlation that makes up.

In addition, channel frequency domain correlation calculation element according to an embodiment of the invention can also comprise analystal section selected cell 310, is configured to according to the selected a plurality of analystal sections of time delay expansion.In this case, the path delay of time analytic unit 320 at distributing in path delay of time of each analystal section analyzing samples channel, and path energy analytic unit 330 distributes at the path energy of each analystal section analyzing samples channel.

Here, the sample channel can comprise the one or more channels in PA channel, EPA channel, VA channel, EVA channel, PB channel, TU channel and ETU channel or the like.

Because at the included analystal section selected cell 310 of channel frequency domain correlation calculation element according to the present invention, the path delay of time, analytic unit 320, path energy analytic unit 330, channel model construction unit 340, and included with the above-described channel frequency domain correlation computational methods respectively analystal section selection step S120 of the processing in the frequency domain correlation computing unit 350, distributional analysis in path delay of time step S130, path energy distributional analysis step S140, channel model construction step S150, and the processing among the channel frequency domain correlation calculation procedure S160 is similar, therefore for the sake of brevity, omit detailed description in these unit at this.

Below 1 to 3 described the operation principle of channel frequency domain correlation computational methods and channel frequency domain correlation calculation element according to an embodiment of the invention in conjunction with the accompanying drawings, described in detail below in conjunction with accompanying drawing 4 to 7 and use above-mentioned channel frequency domain correlation computational methods and the channel estimation methods of channel frequency domain correlation calculation element and the operation principles of channel estimating apparatus.

Fig. 4 illustrates the process chart of channel estimation methods according to an embodiment of the invention.As shown in Figure 4, channel estimation methods according to this embodiment comprises pilot tone LS (Least Square, least square) channel estimation steps S410, maximum delay spread estimation step S420, channel frequency domain correlation read step S430, moving speed estimation step S440, channel time domain correlation calculations step S450, MMSE filter coefficient calculation procedure S460, pilot tone MMSE filter step S470 and data subcarrier channel estimation steps S480 etc.

At first, in pilot tone LS channel estimation steps S410, the domain channel response at system pilot subcarrier place is estimated.Suppose that pilot tone subcarrier of living in is for (k, l), then its LS channel estimation results can be expressed as

$H_{k,l}^{\mathrm{LS}}=\frac{Y_{k,l}}{X_{k,l}}---\left(16\right)$

Wherein, Y _{K, l}Be pilot tone X _{K, l}The reception value.

In maximum delay spread estimation step S420, the maximum delay expansion of time domain multipath channel is estimated.And, the maximum delay expansion of the multipath channel that in channel frequency domain correlation read step S430 estimation among the maximum delay spread estimation step S420 is obtained rounds up, promptly choose one not only greater than it but also with its immediate preset value, round the selected preset value in back according to this then the corresponding channel frequency domain correlation form that prestores read.

Here it is pointed out that because with regard to LTE TDD system, user's DRS (Dedicated Reference Signal) has no idea to be used to estimate the expansion of multipath channel maximum delay, so this maximum delay spread estimation step S420 is not essential for the present invention.In this case, therefore the channel frequency domain correlation form that can only prestore omits maximum delay spread estimation step S420, and the form that directly the channel frequency domain correlation that prestores prestored in channel frequency domain correlation read step S430 is read and got final product.

But, if other system, for example utilize public reference signal (Common ReferenceSignal) to do the LTE system of channel estimating, then can frequency domain channel be converted into time domain and carry out de-noising by the estimated result of public reference signal, at last according to the time domain channel estimated result, the maximum delay spread estimation of rough estimate channel.Generally speaking, even the error of the maximum delay spread estimation value of channel is bigger, still can obtain the good channel estimation effect.Choosing the corresponding channel frequency domain correlation form that prestores according to the maximum delay spread estimation of estimating in channel frequency domain correlation read step S430 then reads.

In addition, in moving speed estimation step S440, receiving terminal is estimated with respect to the translational speed of transmitting terminal, and the receiving terminal that utilization is estimated in moving speed estimation step S440 in channel time domain correlation calculations step S450 is with respect to the estimated result of the translational speed of transmitting terminal, according to the relativity of time domain of top formula (13) and formula (14) calculating channel.Specifically,, with regard to LTE TDD system, can adopt public reference signal,, estimate the translational speed of receiving terminal by estimating the relativity of time domain of the channel that public reference signal experienced for the estimation of translational speed.

Should be noted that at this, also can carry out moving speed estimation step S440 and channel time domain correlation calculations step S450 earlier, and then carry out maximum delay spread estimation step S420 and channel frequency domain correlation read step S430, as long as can obtain the frequency domain correlation and the relativity of time domain of channel.

After in channel frequency domain correlation read step S430 and channel time domain correlation calculations step S450, obtaining the frequency domain correlation and relativity of time domain of channel respectively, in MMSE filter coefficient calculation procedure S460, calculate cross correlation vector θ and autocorrelation matrix Φ respectively and calculate the MMSE filter coefficient according to formula (5) according to formula recited above (10) and (11).In this specific embodiment, in order to save computing time, only utilize channel time domain correlation of in channel time domain correlation calculations step S450, calculating and the channel frequency domain correlation that in channel frequency domain correlation read step S430, reads to calculate the MMSE filter coefficient of pilot sub-carrier.

Next, in pilot tone MMSE filter step S470, utilize the MMSE filter coefficient of the pilot sub-carrier of MMSE filter coefficient calculation procedure S460 calculating that the domain channel response at the pilot sub-carrier place of pilot tone LS channel estimation steps S410 output is carried out filtering, thereby improve the reliability of the domain channel response at these pilot sub-carrier places.

Then, in data subcarrier channel estimation steps S480, utilize the domain channel response estimated value at the pilot sub-carrier place of passing through MMSE filtering of pilot tone MMSE filter step S470 output, treat the domain channel response at the data subcarrier place in the estimating resource and estimate.In estimation procedure, concrete estimation way is unrestricted, adopt generally speaking the simplest time domain and frequency domain respectively the channel estimation methods of linear interpolation can obtain very ideal results.Certainly, also can adopt methods such as second order interpolation, MMSE filtering, low-pass filtering and Spline interpolation.

For example, when in data subcarrier channel estimation steps S480, adopting the channel estimation methods of linear interpolation, can be at first the domain channel response estimated value through the pilot sub-carrier place of MMSE filtering be analyzed, if channel changes along time domain and changes along frequency domain faster than channel, then advanced line frequency territory linear interpolation utilizes frequency domain linear interpolation result to carry out the time domain linear interpolation again.Otherwise, then carry out the time domain linear interpolation earlier, utilize the time domain linear interpolation result to carry out the frequency domain linear interpolation again.

With the channel estimation results output of data subcarrier channel estimation steps S480, be used for operations such as the follow-up equilibrium of receiver, demodulation at last.

Here it is pointed out that the channel frequency domain correlation that prestores of reading is to calculate acquisition by channel frequency domain correlation computational methods or the channel frequency domain correlation calculation element according to each embodiment of the present invention recited above in channel frequency domain correlation read step S430.

Below in conjunction with Fig. 5 channel estimating apparatus according to an embodiment of the invention is described.As shown in Figure 5, comprise according to the channel estimating apparatus of this embodiment: pilot channel estimation unit 501 is configured to calculate the least square channel estimating of pilot sub-carrier; Frequency domain correlation reading unit 507 is configured to read the channel frequency domain correlation that prestores; Motion speed estimation unit 504 is configured to estimate the translational speed of receiving terminal with respect to transmitting terminal; Relativity of time domain computing unit 505 is configured to according to the translational speed calculating channel relativity of time domain of receiving terminal with respect to transmitting terminal; MMSE filter coefficient computing unit 506, the channel frequency domain correlation calculating MMSE filter coefficient that is configured to utilize the channel time domain correlation of calculating and reads; And data channel estimation unit 510, be configured to obtain the channel estimating of data subcarrier according to the least square channel estimating of MMSE filter coefficient that calculates and pilot sub-carrier.In the channel estimating apparatus according to this embodiment, the described channel frequency domain correlation that prestores that frequency domain correlation reading unit 507 reads also is to calculate acquisition by channel frequency domain correlation computational methods or the channel frequency domain correlation calculation element according to each embodiment of the present invention recited above.

In addition, channel estimating apparatus according to this embodiment, in order to simplify computation complexity, MMSE filter coefficient computing unit 506 only utilizes the MMSE filter coefficient of the channel time domain correlation of relativity of time domain computing unit 505 calculating and the channel frequency domain correlation calculating pilot sub-carrier that frequency domain correlation reading unit 507 reads.In this case, data channel estimation unit 510 comprises: pilot tone MMSE filter cell 502 is configured to utilize the MMSE filter coefficient of the pilot sub-carrier that MMSE filter coefficient computing unit 506 calculates that the least square channel estimating of the pilot sub-carrier of pilot channel estimation unit 501 outputs is carried out MMSE filtering; And data channel estimator 503, be configured to the channel of data subcarrier be estimated to obtain the channel estimating of data subcarrier according to the filtered pilot sub-carrier of MMSE of pilot tone MMSE filter cell 502 outputs.

Data channel estimator 503 can adopt the simplest time domain and the frequency domain channel estimation methods of linear interpolation respectively when estimating, can obtain very ideal results.Certainly, also can adopt methods such as second order interpolation, MMSE filtering, low-pass filtering and Spline interpolation.Channel estimation methods with the employing linear interpolation is an example, can be at first the domain channel response estimated value through the pilot sub-carrier place of MMSE filtering be analyzed, if channel changes along time domain and changes along frequency domain faster than channel, then advanced line frequency territory linear interpolation utilizes frequency domain linear interpolation result to carry out the time domain linear interpolation again.Otherwise, then carry out the time domain linear interpolation earlier, utilize the time domain linear interpolation result to carry out the frequency domain linear interpolation again.

In addition, at utilizing public reference signal to do the LTE system etc. of channel estimating, channel estimating apparatus can also comprise time delay spread estimation unit 508 according to an embodiment of the invention, is configured to estimate the maximum delay expansion of channel.In this case, frequency domain correlation reading unit 507 is expanded the channel frequency domain correlation that prestores that reads correspondingly according to the maximum delay of time delay spread estimation unit 508 estimations.

Because the pilot channel estimation unit 501 that comprises according to the channel estimating apparatus of this embodiment, time delay spread estimation unit 508, frequency domain correlation reading unit 507, motion speed estimation unit 504, relativity of time domain computing unit 505, MMSE filter coefficient computing unit 506, pilot tone MMSE filter cell 502, and the pilot tone LS channel estimation steps S410 that comprises with the top channel estimation methods of describing with reference to accompanying drawing 4 respectively of the processing procedure in the data channel estimator 503, maximum delay spread estimation step S420, channel frequency domain correlation read step S430, moving speed estimation step S440, channel time domain correlation calculations step S450, MMSE filter coefficient calculation procedure S460, pilot tone MMSE filter step S470, and the processing among the data subcarrier channel estimation steps S480 is similar, therefore for the sake of brevity, omit its detailed description at this.

Next 6 and 7 the operation principle of channel estimation methods and channel estimating apparatus is according to another embodiment of the present invention described with reference to the accompanying drawings.

Fig. 6 illustrates the process chart of channel estimation methods according to another embodiment of the invention.As shown in Figure 6, the channel estimation methods according to this embodiment comprises pilot tone LS channel estimation steps S610, maximum delay spread estimation step S620, channel frequency domain correlation read step S630, moving speed estimation step S640, channel time domain correlation calculations step S650, MMSE filter coefficient calculation procedure S660 and MMSE filter step S670 etc.

The pilot tone LS channel estimation steps S610 that comprises in the channel estimation methods according to this embodiment, maximum delay spread estimation step S620, channel frequency domain correlation read step S630, moving speed estimation step S640, and the pilot tone LS channel estimation steps S410 that comprises in the channel estimation methods described with reference accompanying drawing 4 respectively of the processing procedure of channel time domain correlation calculations step S650, maximum delay spread estimation step S420, channel frequency domain correlation read step S430, moving speed estimation step S440, and the processing procedure of channel time domain correlation calculations step S450 is similar, therefore for the sake of brevity, omit its detailed description at this.

Different with the MMSE filter coefficient that only calculates pilot sub-carrier among the MMSE filter coefficient calculation procedure S460 that reference Fig. 4 describes, in MMSE filter coefficient calculation procedure S660, then utilize the MMSE filter coefficient of channel time domain correlation of in channel time domain correlation calculations step S650, calculating and the channel frequency domain correlation calculated data subcarrier that in channel frequency domain correlation read step S630, reads according to this embodiment.Then, in MMSE filter step S670, the MMSE filter coefficient of the data subcarrier that utilization is calculated in MMSE filter coefficient calculation procedure S660 carries out MMSE filtering to the least square channel estimating of the pilot sub-carrier of pilot tone LS channel estimation steps S610 output, so that obtain the channel estimating of data subcarrier.With the channel estimation results output of MMSE filter step S670, be used for operations such as the follow-up equilibrium of receiver, demodulation at last.

Equally, it is pointed out that here because with regard to LTE TDD system, user's DRS (Dedicated Reference Signal) has no idea to be used to estimate the expansion of multipath channel maximum delay, so this maximum delay spread estimation step S620 is not essential for the present invention yet.In this case, therefore the channel frequency domain correlation form that can only prestore omits maximum delay spread estimation step S620, and the form that directly the channel frequency domain correlation that prestores prestored in channel frequency domain correlation read step S630 is read and got final product.

Similarly, if other system, for example utilize public reference signal to do the LTE system of channel estimating, then can frequency domain channel be converted into time domain and carry out de-noising by the estimated result of public reference signal, at last according to the time domain channel estimated result, the maximum delay spread estimation of rough estimate channel.Choosing the corresponding channel frequency domain correlation form that prestores according to the maximum delay spread estimation of estimating in channel frequency domain correlation read step S630 then reads.

Equally, in channel estimation methods according to this embodiment, also can carry out moving speed estimation step S640 and channel time domain correlation calculations step S650 earlier, and then carry out maximum delay spread estimation step S620 and channel frequency domain correlation read step S630, as long as can obtain the frequency domain correlation and the relativity of time domain of channel.

Here it is pointed out that also that the channel frequency domain correlation that prestores of reading also is to calculate acquisition by channel frequency domain correlation computational methods or the channel frequency domain correlation calculation element according to each embodiment of the present invention recited above in channel frequency domain correlation read step S630.

Below in conjunction with Fig. 7 description channel estimating apparatus according to another embodiment of the invention.As shown in Figure 7, comprise according to the channel estimating apparatus of this embodiment: pilot channel estimation unit 701 is configured to calculate the least square channel estimating of pilot sub-carrier; Frequency domain correlation reading unit 707 is configured to read the channel frequency domain correlation that prestores; Motion speed estimation unit 704 is configured to estimate the translational speed of receiving terminal with respect to transmitting terminal; Relativity of time domain computing unit 705 is configured to according to the translational speed calculating channel relativity of time domain of receiving terminal with respect to transmitting terminal; MMSE filter coefficient computing unit 706, the channel frequency domain correlation calculating MMSE filter coefficient that is configured to utilize the channel time domain correlation of calculating and reads; And data channel estimation unit 703, be configured to obtain the channel estimating of data subcarrier according to the least square channel estimating of MMSE filter coefficient that calculates and pilot sub-carrier.In the channel estimating apparatus according to this embodiment, the described channel frequency domain correlation that prestores that frequency domain correlation reading unit 707 reads also is to calculate acquisition by channel frequency domain correlation computational methods or the channel frequency domain correlation calculation element according to each embodiment of the present invention recited above.

Similarly, different with 506 MMSE filter coefficients that calculate pilot sub-carrier of MMSE filter coefficient computing unit that reference Fig. 5 describes, in MMSE filter coefficient computing unit 706, then utilize in relativity of time domain computing unit 705 the channel time domain correlation calculated and the MMSE filter coefficient of the channel frequency domain correlation calculated data subcarrier that reads at frequency domain correlation reading unit 707 according to this embodiment.Then, in data channel estimation unit 703, utilize the MMSE filter coefficient of the data subcarrier of MMSE filter coefficient computing unit 706 calculating that the least square channel estimating of the pilot sub-carrier of pilot channel estimation unit 701 outputs is carried out MMSE filtering, so that obtain the channel estimating of data subcarrier.With the channel estimation results output of data channel estimation unit 703, be used for operations such as the follow-up equilibrium of receiver, demodulation at last.

Equally, at utilizing public reference signal to do the LTE system etc. of channel estimating, channel estimating apparatus can also comprise time delay spread estimation unit 708 according to an embodiment of the invention, is configured to estimate the maximum delay expansion of channel.In this case, frequency domain correlation reading unit 707 is expanded the channel frequency domain correlation that prestores that reads correspondingly according to the maximum delay of time delay spread estimation unit 708 estimations.

Here it is pointed out that equally that the channel frequency domain correlation that prestores that frequency domain correlation reading unit 707 is read also is to calculate acquisition by channel frequency domain correlation computational methods or the channel frequency domain correlation calculation element according to each embodiment of the present invention recited above.

In addition, because the pilot channel estimation unit 701 that comprises in the channel estimating apparatus according to this embodiment, time delay spread estimation unit 708, frequency domain correlation reading unit 707, motion speed estimation unit 704, and the pilot channel estimation unit 501 that comprises in the channel estimating apparatus described with reference Fig. 5 respectively of the processing procedure of relativity of time domain computing unit 705, time delay spread estimation unit 508, frequency domain correlation reading unit 507, motion speed estimation unit 504, and the processing procedure of relativity of time domain computing unit 505 is similar, therefore for the sake of brevity, omit its detailed description at this.

Fig. 8 and Fig. 9 have provided the simulation result under EPA channel and EVA channel according to channel estimation methods of the present invention and channel estimating apparatus respectively.This emulation is to carry out under the LTE TDD system that adopts user's DRS (Dedicated Reference Signal), and hypothesis treats that estimating resource is restricted to 1 Resource Block.This algorithm supposes that the maximum delay of channel expands to 4/8 circulating prefix-length when calculating channel frequency domain correlation.Wherein, the true maximum delay expansion of EPA channel is 410ns.4/8 circulating prefix-length is 2343.7ns approximately.As can be seen, although the estimated value deviation of channel length is very big, the result of channel estimating is still very desirable.This has fully proved the robustness and the validity of channel frequency domain correlation computational methods of the present invention and device and channel estimation methods and device thereof.

In addition, still needing here is pointed out that, each forms module in the said apparatus, the unit can be configured by the mode of software, firmware, hardware or its combination.Dispose spendable concrete means or mode and be well known to those skilled in the art, do not repeat them here.Under situation about realizing by software or firmware, from storage medium or network the program that constitutes this software is installed to the computer with specialized hardware structure (all-purpose computer 1100 for example shown in Figure 10), this computer can be carried out various functions etc. when various program is installed.

In Figure 10, CPU (CPU) 1101 carries out various processing according to program stored among read-only memory (ROM) 1102 or from the program that storage area 1108 is loaded into random-access memory (ram) 1103.In RAM 1103, also store data required when CPU 1101 carries out various processing or the like as required.CPU 1101, ROM 1102 and RAM 1103 are connected to each other via bus 504.Input/output interface 1105 also is connected to bus 1104.

Following parts are connected to input/output interface 1105: importation 1106 (comprising keyboard, mouse or the like), output 1107 (comprise display, such as cathode ray tube (CRT), LCD (LCD) etc. and loud speaker etc.), storage area 1108 (comprising hard disk etc.), communications portion 1109 (comprising that network interface unit is such as LAN card, modulator-demodulator etc.).Communications portion 1109 is handled such as the internet executive communication via network.As required, driver 1110 also can be connected to input/output interface 1105.Detachable media 1111 can be installed on the driver 1110 as required such as disk, CD, magneto optical disk, semiconductor memory or the like, makes the computer program of therefrom reading be installed to as required in the storage area 1108.

Realizing by software under the situation of above-mentioned series of processes, such as detachable media 1111 program that constitutes software is being installed such as internet or storage medium from network.

It will be understood by those of skill in the art that this storage medium is not limited to shown in Figure 10 wherein having program stored therein, distribute separately so that the detachable media 1111 of program to be provided to the user with equipment.The example of detachable media 1111 comprises disk (comprising floppy disk (registered trade mark)), CD (comprising compact disc read-only memory (CD-ROM) and digital universal disc (DVD)), magneto optical disk (comprising mini-disk (MD) (registered trade mark)) and semiconductor memory.Perhaps, storage medium can be hard disk that comprises in ROM 1102, the storage area 1108 or the like, computer program stored wherein, and be distributed to the user with the equipment that comprises them.

The present invention also proposes a kind of program product that stores the instruction code that machine readable gets.When described instruction code is read and carried out by machine, can carry out above-mentioned method according to the embodiment of the invention.

Correspondingly, being used for carrying the above-mentioned storage medium that stores the program product of the instruction code that machine readable gets is also included within of the present invention open.Described storage medium includes but not limited to floppy disk, CD, magneto optical disk, storage card, memory stick or the like.

In the above in the description to the specific embodiment of the invention, can in one or more other execution mode, use in identical or similar mode at the feature that a kind of execution mode is described and/or illustrated, combined with the feature in other execution mode, or the feature in alternative other execution mode.

Should emphasize that term " comprises/comprise " existence that refers to feature, key element, step or assembly when this paper uses, but not get rid of the existence of one or more further feature, key element, step or assembly or additional.

In addition, the time sequencing of describing during method of the present invention is not limited to is to specifications carried out, also can according to other time sequencing ground, carry out concurrently or independently.Therefore, the execution sequence of the method for describing in this specification is not construed as limiting technical scope of the present invention.

Although the present invention is disclosed above by description to specific embodiments of the invention,, should be appreciated that all above-mentioned embodiment and example all are illustrative, and not restrictive.Those skilled in the art can design various modifications of the present invention, improvement or equivalent in the spirit and scope of claims.These modifications, improvement or equivalent also should be believed to comprise in protection scope of the present invention.

Remarks

1. 1 kinds of channel frequency domain correlation of remarks computational methods comprise:

Distribute the path delay of time of analyzing samples channel;

The path energy of analyzing samples channel distributes;

Distribute and path energy distribution structure channel model the path delay of time according to the sample channel; And

According to the channel model calculating channel frequency domain correlation that makes up.

Remarks 2. also comprises according to remarks 1 described channel frequency domain correlation computational methods:

According to the selected a plurality of analystal sections of time delay expansion; And

Wherein, at distributing in path delay of time of each analystal section analyzing samples channel, and distribute at the path energy of each analystal section analyzing samples channel.

Remarks 3. is according to remarks 2 described channel frequency domain correlation computational methods, wherein

The time delay in a plurality of paths in each analystal section is evenly distributed or equal difference increases progressively distribution; And

The Energy distribution in each path is linear decrease and distributes or be exponential decrease and distribute or be homenergic and evenly distribute in each analystal section.

Remarks 4. wherein at different maximum delay expansions, is distinguished the calculating channel frequency domain correlation according to following formula according to the channel model that makes up according to remarks 3 described channel frequency domain correlation computational methods:

${\mathrm{\&theta;}}_{\mathrm{\&Delta;f}}(k-k_m)=\mathrm{abs}\left(\underset{i}{\mathrm{\&Sigma;}}{\mathrm{\&sigma;}}_i^2{e}^{-\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="HSA00000017552800021.png"\; state="\{\{state\}\}">j</figure-callout>}2\mathrm{\&pi;}(k-k_m){\mathrm{\&tau;}}_i}\right)$

Wherein, θ _{Δ f}(k-k _m) be channel frequency domain correlation function, the operation of abs () expression absolute calculation, (k-k _m) be the subcarrier spacing number between two frequencies of calculating channel frequency domain correlation, i is a path sequence number, σ _i ²Be the path energy in i footpath, τ _iIt is the path delay of time in i footpath.

Remarks 5. is according to remarks 4 described channel frequency domain correlation computational methods, and wherein the sample channel comprises one or more in PA channel, EPA channel, VA channel, EVA channel, PB channel, TU channel and the ETU channel.

6. 1 kinds of channel frequency domain correlation of remarks calculation element comprises:

The path delay of time analytic unit, distribute the path delay of time that is configured to the analyzing samples channel;

The path energy analytic unit, the path energy that is configured to the analyzing samples channel distributes;

The channel model construction unit is configured to distribute and path energy distribution structure channel model according to the path delay of time of sample channel; And

The frequency domain correlation computing unit is configured to according to the channel model calculating channel frequency domain correlation that makes up.

Remarks 7. also comprises according to remarks 6 described channel frequency domain correlation calculation elements:

The analystal section selected cell is configured to according to the selected a plurality of analystal sections of time delay expansion; And

Wherein, the path delay of time analytic unit at distributing in path delay of time of each analystal section analyzing samples channel, and the path energy analytic unit distributes at the path energy of each analystal section analyzing samples channel.

Remarks 8. is according to remarks 7 described channel frequency domain correlation calculation elements, wherein the channel model construction unit be evenly distributed according to the time delay in a plurality of paths in each analystal section or equal difference increase progressively distribute and each analystal section in the Energy distribution in each path be linear decrease and distribute or be exponential decrease and distribute or be the equally distributed principle construction channel model of homenergic.

Remarks 9. is according to remarks 8 described channel frequency domain correlation calculation elements, and wherein the frequency domain correlation computing unit is distinguished calculating channel frequency domain correlation according to following formula according to the channel model that the channel model construction unit makes up at different maximum delay expansions:

${\mathrm{\&theta;}}_{\mathrm{\&Delta;f}}(k-k_m)=\mathrm{abs}\left(\underset{i}{\mathrm{\&Sigma;}}{\mathrm{\&sigma;}}_i^2{e}^{-\mathrm{<figure-callout\; id="2"\; label="j"\; filenames="HSA00000017552800021.png"\; state="\{\{state\}\}">j</figure-callout>}2\mathrm{\&pi;}(k-k_m){\mathrm{\&tau;}}_i}\right)$

Wherein, θ _{Δ f}(k-k _m) be channel frequency domain correlation function, the operation of abs () expression absolute calculation, (k-k _m) be the subcarrier spacing number between two frequencies of calculating channel frequency domain correlation, i is a path sequence number, σ _i ²Be the path energy in i footpath, τ _iIt is the path delay of time in i footpath.

Remarks 10. is according to remarks 9 described channel frequency domain correlation calculation elements, and wherein the sample channel comprises one or more in PA channel, EPA channel, VA channel, EVA channel, PB channel, TU channel and the ETU channel.

11. 1 kinds of channel estimation methods of remarks comprise:

Calculate the least square channel estimating of pilot sub-carrier;

Read the channel frequency domain correlation that prestores;

Estimate the translational speed of receiving terminal with respect to transmitting terminal;

According to the translational speed calculating channel relativity of time domain of receiving terminal with respect to transmitting terminal;

Utilize channel time domain correlation of calculating and the channel frequency domain correlation that reads to calculate the MMSE filter coefficient; And

Obtain the channel estimating of data subcarrier according to the least square channel estimating of MMSE filter coefficient that calculates and pilot sub-carrier,

Wherein, the described channel frequency domain correlation that prestores is obtained according to the arbitrary described channel frequency domain correlation computational methods in the remarks 1 to 5.

Remarks 12. also comprises according to remarks 11 described channel estimation methods:

Estimate the maximum delay expansion of channel; And

Expand the channel frequency domain correlation that prestores that reads correspondingly according to the maximum delay of estimating.

Remarks 13. is according to remarks 12 described channel estimation methods, wherein

Utilize channel time domain correlation of calculating and the channel frequency domain correlation that reads to calculate in the MMSE filter coefficient, utilizing channel time domain correlation of calculating and the channel frequency domain correlation that reads to calculate the MMSE filter coefficient of pilot sub-carrier; And

The channel estimating of obtaining data subcarrier according to the least square channel estimating of MMSE filter coefficient that calculates and pilot sub-carrier comprises:

Utilize the MMSE filter coefficient of the pilot sub-carrier that calculates that the least square channel estimating of pilot sub-carrier is carried out MMSE filtering; And

According to the filtered pilot sub-carrier of MMSE the channel of data subcarrier is estimated to obtain the channel estimating of data subcarrier.

Remarks 14. is according to remarks 13 described channel estimation methods, wherein by the filtered pilot sub-carrier of MMSE is carried out the channel estimating that linear interpolation, second order interpolation, MMSE filtering, low-pass filtering or Spline interpolation are obtained data subcarrier.

Remarks 15. is according to remarks 12 described channel estimation methods, wherein

Utilizing channel time domain correlation of calculating and the channel frequency domain correlation that reads to calculate in the MMSE filter coefficient, utilize the MMSE filter coefficient of channel time domain correlation of calculating and the channel frequency domain correlation calculated data subcarrier that reads; And

Obtaining in the channel estimating of data subcarrier according to the MMSE filter coefficient that calculates and the least square channel estimating of pilot sub-carrier, utilize the MMSE filter coefficient of the data subcarrier that calculates that the least square channel estimating of pilot sub-carrier is carried out MMSE filtering, obtain the channel estimating of data subcarrier.

16. 1 kinds of channel estimating apparatus of remarks comprise:

The pilot channel estimation unit is configured to calculate the least square channel estimating of pilot sub-carrier;

The frequency domain correlation reading unit is configured to read the channel frequency domain correlation that prestores;

Motion speed estimation unit is configured to estimate the translational speed of receiving terminal with respect to transmitting terminal;

The relativity of time domain computing unit is configured to according to the translational speed calculating channel relativity of time domain of receiving terminal with respect to transmitting terminal;

MMSE filter coefficient computing unit, the channel frequency domain correlation calculating MMSE filter coefficient that is configured to utilize the channel time domain correlation of calculating and reads; And

The data channel estimation unit is configured to obtain according to the least square channel estimating of MMSE filter coefficient that calculates and pilot sub-carrier the channel estimating of data subcarrier,

Wherein, the described channel frequency domain correlation that prestores is by obtaining according to the arbitrary described channel frequency domain correlation calculation element in the remarks 6 to 10.

Remarks 17. also comprises according to remarks 16 described channel estimating apparatus:

The time delay spread estimation unit is configured to estimate the maximum delay expansion of channel; And

The frequency domain correlation reading unit is expanded the channel frequency domain correlation that prestores that reads correspondingly according to the maximum delay of estimating.

Remarks 18. is according to remarks 17 described channel estimating apparatus, wherein

Channel time domain correlation that the utilization of MMSE filter coefficient computing unit is calculated and the channel frequency domain correlation that reads are calculated the MMSE filter coefficient of pilot sub-carrier; And

The data channel estimation unit comprises

Pilot tone MMSE filter cell is configured to utilize the MMSE filter coefficient of the pilot sub-carrier of calculating that the least square channel estimating of pilot sub-carrier is carried out MMSE filtering; And

The data channel estimator is configured to according to the filtered pilot sub-carrier of MMSE the channel of data subcarrier be estimated to obtain the channel estimating of data subcarrier.

Remarks 19. is according to remarks 18 described channel estimating apparatus, wherein

The data channel estimator is by carrying out the channel estimating that linear interpolation, second order interpolation, MMSE filtering, low-pass filtering or Spline interpolation are obtained data subcarrier to the filtered pilot sub-carrier of MMSE.

Remarks 20. is according to remarks 17 described channel estimating apparatus, wherein

The MMSE filter coefficient of channel time domain correlation that the utilization of MMSE filter coefficient computing unit is calculated and the channel frequency domain correlation calculated data subcarrier that reads; And

The MMSE filter coefficient of the data subcarrier that the utilization of data channel estimation unit is calculated carries out MMSE filtering to the least square channel estimating of pilot sub-carrier, obtains the channel estimating of data subcarrier.

Claims (10)

1. channel frequency domain correlation computational methods comprise:

Distribute the path delay of time of analyzing samples channel;

The path energy of analyzing samples channel distributes;

Distribute and path energy distribution structure channel model the path delay of time according to the sample channel; And

According to the channel model calculating channel frequency domain correlation that makes up.

2. channel frequency domain correlation computational methods according to claim 1 also comprise:

According to the selected a plurality of analystal sections of time delay expansion; And

Wherein, at distributing in path delay of time of each analystal section analyzing samples channel, and distribute at the path energy of each analystal section analyzing samples channel.

3. channel frequency domain correlation computational methods according to claim 2, wherein

The time delay in a plurality of paths in each analystal section is evenly distributed or equal difference increases progressively distribution; And

The Energy distribution in each path is linear decrease and distributes or be exponential decrease and distribute or be homenergic and evenly distribute in each analystal section.

4. channel frequency domain correlation calculation element comprises:

The path delay of time analytic unit, distribute the path delay of time that is configured to the analyzing samples channel;

The path energy analytic unit, the path energy that is configured to the analyzing samples channel distributes;

The channel model construction unit is configured to distribute and path energy distribution structure channel model according to the path delay of time of sample channel; And

The frequency domain correlation computing unit is configured to according to the channel model calculating channel frequency domain correlation that makes up.

5. channel frequency domain correlation calculation element according to claim 4 also comprises:

The analystal section selected cell is configured to according to the selected a plurality of analystal sections of time delay expansion; And

Wherein, the path delay of time analytic unit at distributing in path delay of time of each analystal section analyzing samples channel, and the path energy analytic unit distributes at the path energy of each analystal section analyzing samples channel.

6. channel frequency domain correlation calculation element according to claim 5, wherein the channel model construction unit be evenly distributed according to the time delay in a plurality of paths in each analystal section or equal difference increase progressively distribute and each analystal section in the Energy distribution in each path be linear decrease and distribute or be exponential decrease and distribute or be the equally distributed principle construction channel model of homenergic.

7. channel estimation methods comprises:

Calculate the least square channel estimating of pilot sub-carrier;

Read the channel frequency domain correlation that prestores;

Estimate the translational speed of receiving terminal with respect to transmitting terminal;

According to the translational speed calculating channel relativity of time domain of receiving terminal with respect to transmitting terminal;

Utilize channel time domain correlation of calculating and the channel frequency domain correlation that reads to calculate the MMSE filter coefficient; And

Obtain the channel estimating of data subcarrier according to the least square channel estimating of MMSE filter coefficient that calculates and pilot sub-carrier,

Wherein, the described channel frequency domain correlation that prestores is obtained according to the arbitrary described channel frequency domain correlation computational methods in the claim 1 to 3.

8. channel estimation methods according to claim 7, wherein

Utilize channel time domain correlation of calculating and the channel frequency domain correlation that reads to calculate in the MMSE filter coefficient, utilizing channel time domain correlation of calculating and the channel frequency domain correlation that reads to calculate the MMSE filter coefficient of pilot sub-carrier; And

The channel estimating of obtaining data subcarrier according to the least square channel estimating of MMSE filter coefficient that calculates and pilot sub-carrier comprises:

Utilize the MMSE filter coefficient of the pilot sub-carrier that calculates that the least square channel estimating of pilot sub-carrier is carried out MMSE filtering; And

According to the filtered pilot sub-carrier of MMSE the channel of data subcarrier is estimated to obtain the channel estimating of data subcarrier.

9. channel estimating apparatus comprises:

The pilot channel estimation unit is configured to calculate the least square channel estimating of pilot sub-carrier;

The frequency domain correlation reading unit is configured to read the channel frequency domain correlation that prestores;

Motion speed estimation unit is configured to estimate the translational speed of receiving terminal with respect to transmitting terminal;

The relativity of time domain computing unit is configured to according to the translational speed calculating channel relativity of time domain of receiving terminal with respect to transmitting terminal;

MMSE filter coefficient computing unit, the channel frequency domain correlation calculating MMSE filter coefficient that is configured to utilize the channel time domain correlation of calculating and reads; And

The data channel estimation unit is configured to obtain according to the least square channel estimating of MMSE filter coefficient that calculates and pilot sub-carrier the channel estimating of data subcarrier,

Wherein, the described channel frequency domain correlation that prestores is by obtaining according to the arbitrary described channel frequency domain correlation calculation element in the claim 4 to 6.

10. channel estimating apparatus according to claim 9, wherein

Channel time domain correlation that the utilization of MMSE filter coefficient computing unit is calculated and the channel frequency domain correlation that reads are calculated the MMSE filter coefficient of pilot sub-carrier; And

The data channel estimation unit comprises

Pilot tone MMSE filter cell is configured to utilize the MMSE filter coefficient of the pilot sub-carrier of calculating that the least square channel estimating of pilot sub-carrier is carried out MMSE filtering; And

The data channel estimator is configured to according to the filtered pilot sub-carrier of MMSE the channel of data subcarrier be estimated to obtain the channel estimating of data subcarrier.

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