CN101286754B - Method, communication device for acquiring channel information - Google Patents

Abstract

The invention relates to the field of communication and the embodiment of the invention discloses a method for obtaining channel information, and communication devices applied to the method. The method of the invention includes that: a first communication device receives a downlink pilot emitted by a second communication device and superimposes the received downlink pilot and an uplink pilot to generate a mixed pilot which is then sent to the second communication device; the second communication device receives the mixed pilot and carries out estimation to an uplink channel according to the received mixed pilot and the given uplink pilot so as to obtain the parameters of the uplink channel; the second communication device recovers to obtain the mixed pilot emitted by the first communication device according to the parameters of the uplink channel and then obtains the parameters of a downlink channel according to the mixed pilot emitted by the first communication device, the given uplink pilot and the given downlink pilot which are recovered to be obtained. The technical proposal of the embodiment of the invention can not only realize the estimation of the uplink channel and obtain the parameters of the downlink channel, but also reduce the cost on the feedback, compared with the prior art.

Description

Obtain method, the communication equipment of channel information

Technical field

The present invention relates to the communications field, particularly a kind of method, communication equipment that obtains channel information.

Background technology

In wireless communication system, signal can be subject to the impact of transmission channel in transmission course, and declines or distort, and receiving terminal is in order to recover the signal of emission source, usually need to estimate the transmitting physical channel, eliminate the impact of channel on transmitting by the method for equilibrium.Figure 1 shows that a typical wireless communication configuration schematic diagram, as shown, use 102 pairs of signals of code converter to encode at emission source 101,103 pairs of Signal codings of modulator are modulated, and the signal after will modulating sends on the channel 104, signal is in the transmission course of channel 104, can be subject to the interference of noise source 105, and add noise, signal arrives receiving terminal through channel, receiving terminal carries out 106: use the channel estimating preequalization that channel 104 is carried out estimation balancing, recover the signal that transmitting terminal is launched; Then, the signal that recovers is carried out demodulation via demodulator 107, decipher read signal by the signal after 108 pairs of demodulation of decoder again.

Yet because there is additive noise in receiving terminal, balanced effect tends to be subject to the impact of additive noise, and for example: ZF (Zero Forcing is called for short ZF) equalizer is in the situation that can cause the amplification of noise than low signal-to-noise ratio; Least mean-square error (Minimum Mean square Error is called for short MMSE) need to carry out complicated variance to noise at receiving terminal and estimate computing although equalizer can suppress the impact of noise more effectively; Some of in addition other, are not suitable for real system and use because amount of calculation is excessive yet such as: maximum likelihood algorithm etc.

For this reason, prior art has proposed an effective solution: at transmitting terminal signal is carried out preliminary treatment, such as single reception antenna (the Single-Input Single-Output of single transmit, abbreviation SISO) carries out pre-equalization process in the system, need carry out precoding processing in multi-emitting multiple receive antenna (Multiple Input Multiple Output the is called for short MIMO) system.

At transmitting terminal signal is carried out pretreated benefit and mainly contains following 3 points:

First: in the characteristics of transmitting terminal according to transmission channel, signal is carried out corresponding preliminary treatment, can improve the decline of channel, avoid receiving terminal amplification to noise when processing the deep fade channel.

Second: in down link, adopt this technology the main processing to signal can be placed on transmitting terminal (such as the base station), can take full advantage of so the strong advantage of disposal ability of transmitting terminal, simultaneously, also greatly reduce the processing load of weak receiving terminal (such as terminal) of disposal ability, receiving terminal only need simply be processed signal can reach good systematic function.

The 3rd: transmitting terminal can according to each user's channel characteristic, be implemented rational channel dispatch strategy.

According to the transmission channel characteristics signal is carried out pretreated technical scheme at transmitting terminal, be the precoding technique of closed loop in mimo system, the application of its technology can improve the performance of system.

Yet, in the SISO system, realize preequalization at down link, realize in mimo system that perhaps a pretreated main specification requirement of precoding etc. is: transmitting terminal needs known down channel.

For so that transmitting terminal can be known the parameter of downlink channel, in 802.20 present standards, provide a kind of technical scheme, it specifically, terminal estimates forward link according to the forward direction public guide frequency, and calculating is to the pre-coding matrix of this terminal optimum, then with the call number of pre-coding matrix, the order of channel and channel quality indication (the Channel Quality Indicator of this down link, be called for short CQI), form with signaling feeds back to the base station, and precoding can be carried out to sending data according to feedack in the base station.In the signaling of the feedback of wherein stipulating in this standard, the call number of feedback precoding needs 6 bits, and the order of feedback channel needs 2 bits.

The present inventor finds that there is following defective at least in the technical scheme that provides in the 802.20 present standards in carrying out process of the present invention:

1, the processing load of terminal increases: terminal needs to make the code book of judgement to determine to adopt according to the down channel that estimates, and amount of calculation is large.

2, can't guarantee that terminal is to the correctness of transmitting terminal feeding back downlink link information parameter in the transmission course of returning transmitting terminal (base station) base station: because the impact of channel fading, this parameter may be in the transmission process distorted, transmitting terminal (base station) can't obtain correct downlink parameter.

In addition, for so that transmitting terminal can be known the parameter of downlink channel, and utilize this downlink channel parameters to carry out preequalization or precoding processing, and also there is the another kind of wider technical scheme of using in the prior art: the direct channels feedback strategy, specifically:

Terminal is after receiving down-bound pilot frequency signal, down channel is estimated, obtain the parameter of down channel, then the parameter of the down channel that estimates is encoded, consist of an OFDM (Orthogonal Frequency Division Multiplexing with ascending pilot frequency again, abbreviation OFDM) symbol is sent to the base station, wherein, take the odd subcarriers of this OFDM symbol through the descending channel information behind the coding, ascending pilot frequency takies the even subcarriers of this OFDM symbol, after the base station receives signal, ascending pilot frequency according to even subcarriers carries out uplink channel estimation first, utilization recovers to obtain the down channel parameter that terminal sends to the estimated result of up channel.

The inventor finds the technical scheme of this direct channels feedback strategy in carrying out process of the present invention, still have at least following defective:

Descending channel information uses odd subcarriers to feed back to the base station through after encoding, and takies certain channel resource;

Simultaneously, this down channel parameter gathers still in the process of transmission may exist distortion, makes transmitting terminal can't obtain the parameter of correct down channel.

Summary of the invention

The embodiment of the invention provides a kind of method of obtaining channel information, realizes also obtaining the parameter of down channel in to uplink channel estimation, and reduces feedback overhead.

The embodiment of the invention also provides a kind of method of obtaining channel information, realizes also obtaining the parameter of down channel in to uplink channel estimation, and reduces feedback overhead.

The embodiment of the invention also provides a kind of communication equipment, reduces feedback overhead, so that the communication equipment of opposite end in to uplink channel estimation, also obtains the parameter of down channel.

The embodiment of the invention also provides a kind of communication equipment, makes this communication equipment in to uplink channel estimation, also obtains the parameter of down channel.

The embodiment of the invention also provides a kind of communication equipment, makes this communication equipment in to uplink channel estimation, also obtains the parameter of down channel.

The method of obtaining channel information that the embodiment of the invention provides can comprise:

The first communication equipment receives the descending pilot frequency that second communication equipment issues, and descending pilot frequency and the ascending pilot frequency stack that receives generated hybrid pilot, and described hybrid pilot is sent to described second communication equipment;

Described second communication equipment receives described hybrid pilot, and according to the hybrid pilot that receives and known ascending pilot frequency, up channel is estimated, obtains the up channel parameter;

Described second communication equipment is estimated the closed loop channel according to known descending pilot frequency and the hybrid pilot that receives, is obtained the closed loop channel parameter;

Described second communication equipment obtains the down channel parameter according to described closed loop channel parameter, described up channel parameter.

The method of obtaining channel information that the embodiment of the invention provides can comprise:

The first communication equipment receives the descending pilot frequency that second communication equipment issues, and descending pilot frequency and the ascending pilot frequency stack that receives generated hybrid pilot, and described hybrid pilot is sent to described second communication equipment;

Described second communication equipment receives described hybrid pilot, and according to the hybrid pilot that receives and known ascending pilot frequency, up channel is estimated, obtains the up channel parameter;

Described second communication equipment recovers to obtain the hybrid pilot of described the first communication equipment emission according to described up channel parameter;

Described second communication equipment according to the hybrid pilot of the first communication equipment emission that recovers to obtain, known ascending pilot frequency, known descending pilot frequency, obtain the down channel parameter.

The communication equipment that the embodiment of the invention provides can comprise:

Receiving element is used for receiving the descending pilot frequency that second communication equipment issues;

The pilot codes unit, the descending pilot frequency and the ascending pilot frequency that are used for receiving superpose, and consist of hybrid pilot;

Transmitting element is used for sending described hybrid pilot to described second communication equipment.

The communication equipment that the embodiment of the invention provides can comprise:

The descending pilot frequency coding unit is encoded for the descending pilot frequency that subtend second communication equipment issues, and the form of described descending pilot frequency on time domain satisfied:

$\underset{n}{\mathrm{\&Sigma;}}{p_{\mathrm{dl}}^i}^{*}\left(t\right)p_{\mathrm{dl}}^j(n-t)=\left\{\begin{array}{cc}a& n=0\\ 0& 0<n\&le;L_{\mathrm{dl}}+L_{\mathrm{ul}}\end{array}\right.,$

Wherein said

The descending pilot frequency that issues to described second communication equipment for the antenna i of this communication equipment

Conjugation,

Be the descending pilot frequency that the antenna j of this communication equipment issues to described second communication equipment, L _DlBe the time delay extension length of down channel, L _UlBe the time delay extension length of up channel, a is the real number greater than zero,

$\underset{n}{\mathrm{\&Sigma;}}{p_{\mathrm{ul}}^i}^{*}\left(t\right)p_{\mathrm{dl}}^j(n-t)=0$ 0<n≤L _ul+L _dl，

Wherein, described

Be the ascending pilot frequency of second communication device antenna i to the transmission of this communication equipment

Conjugation, Be the descending pilot frequency that the antenna j of this communication equipment issues to described second communication equipment, L _DlBe the time delay extension length of down channel, L _UlBe the time delay extension length of up channel, a is the real number greater than zero;

Transmitting element is used for the descending pilot frequency that described descending pilot frequency coding unit generates is sent to described second communication equipment;

Receiving element is used for receiving the described hybrid pilot that is sent by described second communication equipment, and wherein said hybrid pilot is: the descending pilot frequency that is sent by this communication equipment that described second communication equipment receives and the stack of ascending pilot frequency;

The uplink channel estimation unit is used for according to described hybrid pilot, and known ascending pilot frequency, and up channel is estimated, obtains the up channel parameter;

The closed loop channel estimating unit is used for according to the hybrid pilot that receives and known descending pilot frequency, and the closed loop channel is estimated, obtains the closed loop channel parameter;

The down channel estimation unit is used for according to described closed loop channel parameter and described up channel parameter, obtains the down channel parameter.

The communication equipment that the embodiment of the invention provides can comprise:

The descending pilot frequency coding unit is encoded for the descending pilot frequency that subtend second communication equipment issues, and the form of described descending pilot frequency on time domain satisfied:

$\underset{n}{\mathrm{\&Sigma;}}{p_{\mathrm{dl}}^i}^{*}\left(t\right)p_{\mathrm{dl}}^j(n-t)=\left\{\begin{array}{cc}a& n=0\\ 0& 0<n\&le;L_{\mathrm{dl}}\end{array}\right.,$

Wherein said

The descending pilot frequency that issues to this communication equipment for the antenna i of described second communication equipment Conjugation,

Be the descending pilot frequency that the antenna j of described second communication equipment issues to this communication equipment, L _DlBe the time delay extension length of down channel, a is the real number greater than zero,

$\underset{n}{\mathrm{\&Sigma;}}{p_{\mathrm{ul}}^i}^{*}\left(t\right)p_{\mathrm{dl}}^j(n-t)=0$ 　　　　　　0<n≤L _ul，

Wherein, described

Be the ascending pilot frequency of second communication device antenna i to the transmission of this communication equipment

Conjugation,

Be the descending pilot frequency that the antenna j of this communication equipment issues to described second communication equipment, L _DlBe the time delay extension length of down channel, L _UlBe the time delay extension length of up channel, a is the real number greater than zero;

Transmitting element is used for the descending pilot frequency that described descending pilot frequency coding unit generates is sent to described second communication equipment;

Receiving element is used for receiving the described hybrid pilot that is sent by described second communication equipment, and wherein said hybrid pilot is: the descending pilot frequency that is sent by this communication equipment that described second communication equipment receives and the stack of ascending pilot frequency;

The uplink channel estimation unit is used for according to described hybrid pilot, and known ascending pilot frequency, and up channel is estimated, obtains the up channel parameter;

The hybrid pilot recovery unit is used for recovering to obtain the hybrid pilot that described second communication equipment sends according to described up channel parameter and the hybrid pilot that receives;

The down channel estimation unit, the hybrid pilot that is used for sending according to described second communication equipment, known descending pilot frequency and known ascending pilot frequency obtain the down channel parameter.

As can be seen from the above technical solutions, in the technical scheme of the embodiment of the invention, the first communication equipment is behind the descending pilot frequency that reception second communication equipment issues, the descending pilot frequency that receives and the ascending pilot frequency that needs to send out on second communication equipment are superposeed, generate hybrid pilot, hybrid pilot is sent to second communication equipment, so that second communication equipment is after receiving this hybrid pilot, according to this hybrid pilot and known ascending pilot frequency, the parameter that descending pilot frequency estimates to obtain up channel and down channel.Realize that second communication equipment in to uplink channel estimation, also obtains the parameter of down channel.

In addition, in the technical scheme of the embodiment of the invention, the first communication equipment is by sending this hybrid pilot to second communication equipment, and make the second communication equipment can be when estimating to obtain the up channel parameter, obtain the down channel parameter, rather than as described in the prior art after second communication equipment receives descending pilot frequency, to descending pilot frequency estimate accordingly and corresponding precoding after, to estimate that the result who processes returns second communication equipment, makes second communication equipment obtain the parameter of this down channel.As seen, the technical scheme of the embodiment of the invention has reduced signaling consumption with respect to prior art, has saved transfer resource; And with respect to prior art, owing to need not directly to transmit the down channel parameter, effectively avoided parameter owing to the distortion that the decline of transmission channel causes causes second communication equipment can't obtain the problem of correct down channel parameter.

In addition, use the technical scheme of the embodiment of the invention, be conducive to that also the processing such as comparatively complicated down channel estimation, precoding are placed on the second communication equipment side and carry out, its effect in the relatively weak situation of the first communication equipment disposal ability is better significantly.

Description of drawings

Accompanying drawing described herein is used to provide a further understanding of the present invention, consists of the application's a part, does not consist of improper restriction of the present invention.In the accompanying drawings:

Fig. 1 is that typical radio communication emission receives schematic diagram in the prior art;

A kind of schematic flow sheet of in SISO system using the method for obtaining channel information of Fig. 2 for providing in the embodiment of the invention 1;

A kind of schematic flow sheet of in mimo system using the method for obtaining channel information of Fig. 3 for providing in the embodiment of the invention 2;

Fig. 4 is provided in the SISO system for the another kind that provides in the embodiment of the invention 3 by the schematic flow sheet of the method for obtaining channel information;

Fig. 5 is provided in mimo system for the another kind that provides in the embodiment of the invention 4 by the schematic flow sheet of the method for obtaining channel information;

A kind of communication apparatus construction schematic diagram of Fig. 6 for providing in the embodiment of the invention 5;

The another kind of communication apparatus construction schematic diagram of Fig. 7 for providing in the embodiment of the invention 5;

The communication apparatus construction schematic diagram of Fig. 8 for providing in the embodiment of the invention 6;

The communication apparatus construction schematic diagram of Fig. 9 for providing in the embodiment of the invention 7;

The communication apparatus construction schematic diagram of Figure 10 for providing in the embodiment of the invention 8.

Embodiment

Below with reference to the accompanying drawings and in conjunction with the embodiments, describe the present invention in detail.At this, illustrative examples of the present invention and explanation thereof are used for explanation the present invention, but not as a limitation of the invention.

Embodiment 1:

The present embodiment specifically divides explanation take a kind of method of obtaining channel information of using the embodiment of the invention provide in the SISO system as example to the method, and Fig. 2 is the method flow schematic diagram of the present embodiment, and as shown in Figure 2, the method can comprise:

Step 201: second communication equipment issues descending pilot frequency to the first communication equipment.

Second communication equipment carries out the OFDM modulation with descending pilot frequency and downlink data, transmit on adding behind the CP from the transmission antennas transmit to the down channel: the transmission of data is through after the coded modulation, insert descending pilot frequency at the first-class introns carrier wave of frequency domain, through after the OFDM modulation, go out from transmission antennas transmit after adding CP.

In order to make the descending pilot frequency in the hybrid pilot in the present embodiment technical scheme not affect the first communication equipment to the estimation of up channel and closed loop channel, therefore, can set in advance ascending pilot frequency and descending pilot frequency between the first communication equipment and the second communication equipment, make ascending pilot frequency, descending pilot frequency satisfy respectively following condition:

(1) descending pilot frequency that issues to the first communication equipment for second communication equipment can make the convolution results of descending pilot frequency on time domain that issue at the time delay extension length L of up channel _UlTime delay extension length L with down channel _DlBe impulse function in the scope of sum, be that the auto-correlation function of descending pilot frequency on time domain can be expressed as the form shown in the functional expression (1), thereby so that the first communication equipment is after receiving this descending pilot frequency, directly descending pilot frequency and the ascending pilot frequency that receives superposeed, and do not need again the descending pilot frequency that receives to be done extra processing.

$\underset{n}{\mathrm{\&Sigma;}}{p}_{\mathrm{dl}}^{*}\left(t\right)p_{\mathrm{dl}}(n-t)=\left\{\begin{array}{cc}a& n=0\\ 0& 0<n\&le;L_{\mathrm{dl}}+L_{\mathrm{ul}}\end{array}\right.---\left(1\right),$

Wherein

Expression: ascending pilot frequency

Conjugation; L _DlExpression: the time delay extension length of down channel; L _UlExpression: the time delay extension length of up channel; L _Dl+ L _UlExpression: the time delay extension length of closed loop channel; A is the real number greater than zero, is without loss of generality, and a can equal 1.

(2) for ascending pilot frequency, its convolution results on time domain is at the time delay extension length L of up channel _UlBe impulse function in the scope, namely the auto-correlation function of ascending pilot frequency on time domain can be expressed as:

$\underset{n}{\mathrm{\&Sigma;}}{p}_{\mathrm{ul}}^{*}\left(t\right)p_{\mathrm{ul}}(n-t)=\left\{\begin{array}{cc}a& n=0\\ 0& 0<n\&le;L_{\mathrm{ul}}\end{array}\right.---\left(2\right),$

Wherein

Expression: ascending pilot frequency Conjugation, a is the real number greater than zero, is without loss of generality, and can make a equal 1.

(3) for ascending pilot frequency and descending pilot frequency, its both convolution results is at the time delay extension length L of up channel _UlTime delay extension length L with down channel _DlBe zero in the scope of sum.That is:

$\underset{n}{\mathrm{\&Sigma;}}{p}_{\mathrm{ul}}^{*}\left(t\right)p_{\mathrm{dl}}(n-t)=0$ 　 　0≤n≤L _ul+L _dl (3)。

The descending pilot frequency that second communication equipment will satisfy functional expression (1), (3) restriction is sent to the first communication equipment, thereby so that second communication equipment is after receiving this descending pilot frequency, directly descending pilot frequency and the ascending pilot frequency that receives superposeed, and do not need again the descending pilot frequency that receives to be done extra processing.

Step 202: the first communication equipment receives descending pilot frequency, and descending pilot frequency and the ascending pilot frequency stack that receives generated hybrid pilot, and the hybrid pilot after the stack is sent to second communication equipment.

After the first communication equipment receives the signal that second communication equipment issues, to the signal that receives through past Cyclic Prefix (Circle Prefix, be called for short CP), after the OFDM demodulation, with the signal extraction on the corresponding pilot channel out, and with the descending pilot frequency that extracts and ascending pilot frequency to second communication equipment to be sent at the frequency domain generation hybrid pilot that superposes.This hybrid pilot is: the stack of the ascending pilot frequency that the descending pilot frequency that second communication equipment issues to the first communication equipment and the first communication equipment send to second communication equipment.Namely in ofdm system, this hybrid pilot shows as: in a subcarrier of an OFDM symbol, comprising second communication equipment needs the ascending pilot frequency sent out to what the first communication equipment issued via the descending pilot frequency of its down channel and the first communication equipment on second communication equipment.

Wherein the ascending pilot frequency sent out on the second communication equipment of the first communication equipment satisfies restrictive condition represented with the functional expression (2), (3) that set in advance in the step 201.

The first communication equipment when sending out upstream data to second communication equipment, carries out the OFDM modulation with the hybrid pilot after the stack with upstream data after generating hybrid pilot, carry out ul transmissions after adding CP, is sent to second communication equipment.

The first communication equipment can be launched this hybrid pilot with reference to pilot transmission mode of the prior art when launching this hybrid pilot to second communication equipment, make the power of the ascending pilot frequency distributed in this hybrid pilot and descending pilot frequency simply equal.

But, in the system of reality, if in the limited situation of the transmitting power of the first communication equipment, if with descending pilot frequency directly and ascending pilot frequency superpose, will cause the transmitting power needs of the first communication equipment greatly to improve, even may be greater than the upper limit of the transmitting power of the first communication equipment, thereby be unfavorable for realizing.In addition, descending pilot frequency can bring Convolution Noise in the process of returning second communication equipment, because this noise has passed through up channel equally, it is difficult to be eliminated in channel estimation process.Therefore, in embodiments of the present invention, can be with most power division to ascending pilot frequency, and with the power division of fraction to descending pilot frequency, this pilot tone (hybrid pilot) transmitting power that not only can guarantee the first communication equipment is no more than the predetermined emission upper limit, can also so that Convolution Noise suppressed significantly, thereby be conducive to improve the second communication equipment of opposite end to the precision of the estimation of up channel.

When the present embodiment was the first communication equipment emission hybrid pilot, the distribution of the transmitting power of descending pilot frequency, ascending pilot frequency provided two kinds of optional technical schemes:

Scheme one: the constant scheme of gross power

Total transmitting power of the pilot sub-carrier of agreement the first communication equipment (distributing to ascending pilot frequency transmitting power in this subcarrier and the transmitting power sum of descending pilot frequency) is constant in this programme, can after agreement, should notify second communication equipment by total transmitting power steady state value.

Then, definition power division factor-alpha, suppose that here this power division factor-alpha is: the power of distributing to descending pilot frequency accounts for the ratio of the gross power of hybrid pilot, and the hybrid pilot signal of then launching on the ascending pilot channel is: $s_p=\sqrt{\mathrm{\&alpha;}}\&CenterDot;\stackrel{\&prime;}{\mathrm{pdl}}+\sqrt{(1-\mathrm{\&alpha;})}{p}_{\mathrm{ul}}.$

In this scheme, the first communication equipment can carry out value to the power division factor-alpha dynamically according to actual conditions, and when sending hybrid pilot, second communication equipment this power division factor-alpha transferred to second communication equipment, so that can be known the power division situation of the hybrid pilot that receives.

Need to prove, the shared expense of transmit power allocation factor-alpha is few in this programme, and for example: the regulation descending pilot frequency accounts for 0.1 or 0.25 two kind of distribution of gross power, only needs the communication of 1 bit.

Scheme two: ascending pilot frequency power invariability scheme

In this scheme, for the power of distributing to ascending pilot frequency, can consult to make the power invariability of distributing to ascending pilot frequency, and notify second communication equipment with the steady state value of this ascending pilot frequency power; For the power of distributing to ascending pilot frequency, can guarantee that total transmitting power be no more than under the prerequisite of predetermined total upper limit of emission power, carry out flexible allocation according to the channel condition (such as CQI) of reality.

In this programme, for down channel, because the power of ascending pilot frequency is known constant, can make the ascending pilot frequency situation of second communication device learns reality, provide primary prerequisite to guaranteeing to the correctness of up channel.For down channel, because descending pilot frequency has been carried out the power adjustment at the first communication equipment place, the down channel and the real channel that therefore estimate can differ a scale factor; But, because second communication equipment obtains the purpose of down channel parameter and is to carry out and processing transmitting, channel is carried out some useful corrections, because signal is constant through keeping power before and after the pretreatment module, therefore, second communication equipment reality does not need to know the down channel of estimation and the scale factor that the actual downstream interchannel differs, and only estimated result need to be carried out normalization, namely can be used for designing pretreatment module, carry out the preliminary treatment such as corresponding preequalization or precoding processing.

As seen, if employing scheme two described power allocation schemes, the first communication equipment does not need to feed back any power allocation information, and therefore, scheme two can further be saved feedback overhead with respect to scheme one.

Step 203: second communication equipment receives the hybrid pilot that the first communication equipment sends.

After second communication equipment receives this signal.Extract hybrid pilot wherein, establishing the signal that is sent by the first communication equipment is L through the time delay extension length _UlUp channel arrive second communication equipment, at second communication equipment, its received hybrid pilot signal can be expressed as:

y _Bp(n)＝diag(Y _up(n)+P(n))F _upH _ul+w _Bp(n) (4)，

Y wherein _BP(n) expression: the hybrid pilot that second communication equipment receives; Y _Up(n) expression: the descending pilot frequency that the first communication equipment receives on frequency domain and its additive noise sum through up channel; P _Ul(n) expression: the ascending pilot frequency that the first communication equipment sends on frequency domain and its additive noise sum through up channel; Diag (Y _Up(n)+P _Ul(n)) expression: Y _Up(n) and P _Ul(n) diagonal matrix of sum formation, F _UpExpression: the matrix of the part formation corresponding with pilot tone in discrete Fourier transform (DFT) (Discrete Fourier Transform the is called for short DFT) matrix for up channel; H _UlExpression: for the convolution matrix of up channel; w _Bp(n) expression: when this hybrid pilot arrives second communication equipment, at the additive noise of receiving terminal stack.

Functional expression (4) can also be write as the convolution form of the time-domain signal shown in functional expression (5):

$y_{\mathrm{Bp}}\left(n\right)=h_{\mathrm{dl}}*h_{\mathrm{ul}}*{\stackrel{\&RightArrow;}{p}}_{\mathrm{dl}}\left(n\right)+h_{\mathrm{ul}}*{\stackrel{\&RightArrow;}{p}}_{\mathrm{ul}}\left(n\right)+h_{\mathrm{ul}}*w_{\mathrm{UP}}\left(n\right)+w_{\mathrm{Bp}}\left(n\right)$

(5)，

${=h}_{\mathrm{dl}}*h_{\mathrm{ul}}*{\stackrel{\&RightArrow;}{p}}_{\mathrm{dl}}\left(n\right)+h_{\mathrm{ul}}*{\stackrel{\&RightArrow;}{p}}_{\mathrm{ul}}\left(n\right)+w\left(n\right)$

H wherein _DlExpression: the forms of time and space of down channel; h _UlExpression: the forms of time and space of up channel;

Expression: the forms of time and space of the ascending pilot frequency in the hybrid pilot that second communication equipment receives;

Expression: the forms of time and space of the ascending pilot frequency in the hybrid pilot that second communication equipment receives; w _Up(n) expression: the forms of time and space of the additive noise that this hybrid pilot superposes in via the up channel process; w _Bp(n) expression: this pilot signal is at the forms of time and space of the additive noise of second communication equipment receiving terminal stack; W (n) expression: total equivalent noise item;

Step 204: second communication equipment is estimated up channel according to the hybrid pilot that receives and known ascending pilot frequency, is obtained the up channel parameter.

After second communication equipment receives the hybrid pilot of the first communication equipment transmission, estimate up channel, the hybrid pilot that specifically can use the known ascending pilot frequency of second communication equipment (this ascending pilot frequency is consulted to determine by this second communication equipment and the first communication equipment in advance) dot product to receive in communication system.Namely be equivalent on time domain, use the forms of time and space of known ascending pilot frequency

Conjugation:

With the hybrid pilot signal y that receives _Bp(n) carry out convolution, have:

${\stackrel{\&RightArrow;}{p}}_{\mathrm{ul}}^{*}\left(n\right)*y_{\mathrm{Bp}}\left(n\right)$

(6)，

$={\stackrel{\&RightArrow;}{p}}_{\mathrm{ul}}^{*}\left(n\right)*h_{\mathrm{dl}}*h_{\mathrm{ul}}*{\stackrel{\&RightArrow;}{p}}_{\mathrm{dl}}\left(n\right)+{\stackrel{\&RightArrow;}{p}}_{\mathrm{ul}}^{*}\left(n\right)h_{\mathrm{ul}}*{\stackrel{\&RightArrow;}{p}}_{\mathrm{ul}}\left(n\right)+{\stackrel{\&RightArrow;}{p}}_{\mathrm{ul}}{\left(n\right)}^{*}w\left(n\right)$

Be without loss of generality, make a in the functional expression (2) equal 1, in functional expression (2), (3) difference substitution functional expressions (6), can obtain functional expression (7):

${\hat{h}}_{\mathrm{ul}}={\stackrel{\&RightArrow;}{p}}_{\mathrm{ul}}^{*}\left(n\right)*y_{\mathrm{Bp}}\left(n\right)=h_{\mathrm{ul}}+{\stackrel{\&RightArrow;}{p}}_{\mathrm{ul}}\left(n\right)*w\left(n\right)---\left(7\right),$

Can calculate the estimated value that gets access to the up channel parameter according to functional expression (7)

Need to prove, if the first communication equipment the emission hybrid pilot, employing be the allocative decision one described power division of transmitting power in the step 202, then corresponding, after second communication equipment receives hybrid pilot, according to the power division factor-alpha that receives, use

In replacement function formula (6), (7)

Can carry out corresponding uplink channel estimation according to the functional expression after replacing; If the first communication equipment is at the emission hybrid pilot, employing be the allocative decision two described power division of the transmitting power in the step 202, then directly utility function formula (6), (7) are calculated and both can.

Step 205: second communication equipment is estimated the closed loop channel according to known descending pilot frequency and the hybrid pilot that receives, is obtained the closed loop channel parameter.

Since descending pilot frequency from second communication equipment via down channel to the first communication equipment, return second communication equipment by the first communication equipment via up channel again, passed through the closed loop channel that is consisted of by up channel and down channel.

Therefore, with to uplink channel estimation in like manner, second communication equipment can with known descending pilot frequency (being the descending pilot frequency that second communication equipment issues to the first communication equipment) hybrid pilot that dot product receives on frequency domain, carry out the closed loop channel estimating.Namely be equivalent on time domain, with the conjugation of the forms of time and space of known descending pilot frequency

With the hybrid pilot signal y that receives _Bp(n) carry out convolution, have:

${\stackrel{\&RightArrow;}{p}}_{\mathrm{dl}}^{*}\left(n\right)*y_{\mathrm{Bp}}\left(n\right)$

(8)，

$={\stackrel{\&RightArrow;}{p}}_{\mathrm{dl}}^{*}\left(n\right)*h_{\mathrm{dl}}*h_{\mathrm{ul}}*{\stackrel{\&RightArrow;}{p}}_{\mathrm{ul}}\left(n\right)+{\stackrel{\&RightArrow;}{p}}_{\mathrm{dl}}^{*}\left(n\right)h_{\mathrm{ul}}*{\stackrel{\&RightArrow;}{p}}_{\mathrm{dl}}\left(n\right)+{\stackrel{\&RightArrow;}{p}}_{\mathrm{dl}}\left(n\right)*w\left(n\right)$

With functional expression (1) substitution functional expression (8), can obtain functional expression (9):

${\hat{h}}_{\mathrm{all}}={\hat{h}}_{\mathrm{dl}}*{\hat{h}}_{\mathrm{ul}}={{\stackrel{\&RightArrow;}{p}}_{\mathrm{dl}}}^{*}\left(n\right)*y_{\mathrm{bp}}\left(n\right)={\hat{h}}_{\mathrm{dl}}*{\hat{h}}_{\mathrm{ul}}+{\stackrel{\&RightArrow;}{p}}_{\mathrm{dl}}\left(n\right)*w\left(n\right)---\left(9\right),$

Can calculate the estimated value of obtaining the closed loop channel parameter according to functional expression (9)

Need to prove, if the first communication equipment is at the emission hybrid pilot, what adopt is the power division of the allocative decision one of descending pilot frequency, the transmitting power between the ascending pilot frequency in the step 202, then corresponding, after second communication equipment receives hybrid pilot, according to the power division factor-alpha that receives, use In replacement function formula (8), (9)

Can estimate the closed loop channel according to the functional expression after replacing; If the first communication equipment is when the emission hybrid pilot, what adopt is the descending pilot frequency in the step 202, the allocative decision two described power division of the transmitting power between the ascending pilot frequency, and then directly utility function formula (8), (9) were both calculated and can be estimated the closed loop channel.

Step 206: second communication equipment obtains the down channel parameter according to closed loop channel parameter and up channel parameter.

The estimated value of the up channel that can calculate according to functional expression (7), and the estimated value of the closed loop channel that calculates of functional expression (9) by de-convolution operation, obtain the estimated value of down channel

Get access to the down channel parameter

In addition, the down channel parameter also can be obtained from frequency domain, supposes certain descending pilot frequency p _iWhen down channel, be positioned at m sub-channels H _m, after the first communication equipment place process and ascending pilot frequency superpose, from up n sub-channels H _nReturn second communication equipment, the frequency domain presentation form of functional expression (7), (9) arranged:

Wherein

Be expression: the frequency domain representation form of down channel parameter;

The frequency domain representation form of expression closed loop channel parameter;

Expression: the frequency domain representation form of up channel parameter.

Need explanation, the second communication equipment in the present embodiment can but be not limited to the base station, the first communication equipment can but be not limited to terminal.

Therefore, use the present embodiment technical scheme the first communication equipment send to second communication equipment the descending pilot frequency that issued by its first received communication equipment, with and the hybrid pilot that consists of of the required ascending pilot frequency stack that sends to second communication equipment, second communication equipment is according to this hybrid pilot, and the ascending pilot frequency of precognition, can estimate up channel; According to this hybrid pilot, and known descending pilot frequency, can estimate the closed loop channel, then in conjunction with ascending pilot frequency and the closed loop pilot estimated, estimate down channel.Realization can be obtained the parameter of down channel when carrying out uplink channel estimation, the present embodiment technical scheme has simultaneously greatly reduced as to make second communication equipment obtain the signaling consumption of the parameter of down channel with respect to prior art.For example: if the power allocation scheme one in the employing step 202, using embodiment of the invention method only needs few signalling power division factor to get final product, if and adopt power allocation scheme two in the step 202, using the needed signaling consumption of embodiment of the invention method is zero.

Embodiment 2:

The present embodiment specifically divides explanation take a kind of method of obtaining channel information of using the embodiment of the invention provide in mimo system as example to the method, the basic procedure of the method as shown in Figure 3, as shown, the method can comprise:

Step 301: second communication equipment issues descending pilot frequency to the first communication equipment.

Step 201 among this step and the embodiment 1 in like manner, but because in mimo system, adopt many antennas transmissions, reception technique, therefore be with 1 difference of embodiment in the present embodiment: each antenna of second communication equipment issues descending pilot frequency to the first communication equipment respectively.

In order to make each descending pilot frequency in the hybrid pilot in the present embodiment technical scheme not affect second communication equipment to the estimation of each up channel and closed loop channel, therefore, can set in advance that the first communication is established and second communication equipment between each ascending pilot frequency, descending pilot frequency, make each ascending pilot frequency, descending pilot frequency satisfy respectively following condition:

(1) descending pilot frequency that issues for second communication equipment each day alignment the first communication equipment can make the convolution results of each descending pilot frequency on time domain at the time delay extension length L of up channel _UlTime delay extension length L with down channel _DlBe impulse function in the scope of sum, namely the auto-correlation function of each descending pilot frequency on time domain can be expressed as:

$\underset{n}{\mathrm{\&Sigma;}}{p_{\mathrm{dl}}^i}^{*}\left(t\right)p_{\mathrm{dl}}^j(n-t)=\left\{\begin{array}{cc}a& n=0\\ 0& 0<n\&le;{L_{\mathrm{dl}}+L}_{\mathrm{ul}}\end{array}\right.---\left(11\right),$

Wherein

Expression: the descending pilot frequency that the antenna i of second communication equipment issues to the first communication equipment

Conjugation;

Expression: the descending pilot frequency that the antenna j of second communication equipment issues to the first communication equipment, a are the real number greater than zero, are without loss of generality, and can make a equal 1.

(2) for the right ascending pilot frequency of each antenna, its each convolution results on time domain is at the time delay extension length L of up channel _UlBe impulse function in the scope, namely the auto-correlation function of each ascending pilot frequency on time domain can be expressed as:

$\underset{n}{\mathrm{\&Sigma;}}{p_{\mathrm{ul}}^i}^{*}\left(t\right)p_{\mathrm{ul}}^j(n-t)=\left\{\begin{array}{cc}a& n=0\\ 0& 0<n\&le;L_{\mathrm{ul}}\end{array}\right.---\left(16\right),$

Wherein i is the sign of the antenna of the first communication equipment, and j is the sign of the antenna of the first communication equipment;

Expression: ascending pilot frequency

Conjugation; A is the real number greater than zero, is without loss of generality, and can make a equal 1.

(3) for each ascending pilot frequency, descending pilot frequency, the convolution results of arbitrary ascending pilot frequency and arbitrary descending pilot frequency is at the time delay extension length L of up channel _UlTime delay extension length L with down channel _DlBe zero in the scope of sum.That is:

$\underset{n}{\mathrm{\&Sigma;}}{p_{\mathrm{ul}}^i}^{*}\left(t\right)p_{\mathrm{dl}}^j(n-t)=0$ 　 0<n≤L _ul+L _dl (17)，

Wherein

Expression: the ascending pilot frequency that the first communication equipment antenna i sends out on the second communication equipment

Conjugation;

Expression: the ascending pilot frequency that the first communication equipment antenna j sends out on the second communication equipment; I, j are respectively the antenna sign, and i can equal j, and a is the real number greater than zero, is without loss of generality, and can make a equal 1.

The descending pilot frequency that second communication equipment will satisfy the represented restrictive condition of functional expression (11), (17) is sent to the first communication equipment, thereby so that second communication equipment is after receiving this descending pilot frequency, directly descending pilot frequency and the ascending pilot frequency that receives superposeed, and do not need again the descending pilot frequency that receives to be done extra processing.

Step 302: the first communication equipment receives descending pilot frequency, and descending pilot frequency and the ascending pilot frequency stack that receives generated hybrid pilot, and the hybrid pilot after the stack is sent to second communication equipment.

Suppose in the mimo system of the present embodiment, second communication equipment, second communication system all adopt 2 antenna receiving-sendings, second communication equipment issues descending pilot frequency by antenna 1,2 to the first communication equipment respectively, at the first communication equipment place, and the pilot signal that the antenna 1 of the first communication equipment receives

For:

$y_{\mathrm{uP}}^1\left(n\right)=\mathrm{diag}\left(P_{\mathrm{dl}}^1\left(n\right)\right)F_{\mathrm{dp}}{h}_{\mathrm{dl}}^{11}+\mathrm{diag}\left(P_{\mathrm{dl}}^2\left(n\right)\right)F_{\mathrm{dp}}{h}_{\mathrm{dl}}^{12}+w_{\mathrm{Up}}^1\left(n\right)---\left(12\right),$

Wherein

Expression: the descending pilot frequency that the antenna 1 by second communication equipment that the antenna 1 of the first communication equipment receives issues;

Expression: the descending pilot frequency that is issued by second communication device antenna 2 that the antenna 1 of the first communication equipment receives;

Expression: the down channel of the antenna 1 of antenna 1 to first communication equipment of second communication equipment;

Expression: the down channel of the antenna 1 of antenna 2 to first communication equipments of second communication equipment; F _DpExpression: the matrix that the part corresponding with pilot tone consists of in the DFT matrix for down channel.

The pilot signal that the antenna 2 of the first communication equipment receives

For:

$y_{\mathrm{uP}}^2\left(n\right)=\mathrm{diag}\left(P_{\mathrm{dl}}^1\left(n\right)\right)F_{\mathrm{dp}}{h}_{\mathrm{dl}}^{21}+\mathrm{diag}\left(P_{\mathrm{dl}}^2\left(n\right)\right)F_{\mathrm{dp}}{h}_{\mathrm{dl}}^{22}+w_{\mathrm{Up}}^1\left(n\right)---\left(13\right),$

Wherein Expression: the descending pilot frequency that the antenna 1 by second communication equipment that the antenna 2 of the first communication equipment receives issues;

Expression: the descending pilot frequency that is issued by second communication device antenna 2 that the antenna 2 of the first communication equipment receives;

Expression: the down channel of the antenna 2 of antenna 1 to first communication equipment of second communication equipment;

Expression: the down channel of the antenna 2 of antenna 2 to first communication equipments of second communication equipment; F _DpExpression: the matrix that the part corresponding with pilot tone consists of in the DFT matrix for down channel.

At the first communication equipment place, the first communication equipment place with the signal that receives after past CP, OFDM demodulation, down-bound pilot frequency signal on the corresponding pilot channel on each reception antenna is extracted, and with its with this antenna wait that the ascending pilot frequency of sending out carries out corresponding the stack and is created on the hybrid pilot to be sent of each antenna on the first communication equipment.For example: the hybrid pilot x on the antenna 1 of the first communication equipment ₁(n) be:

$x_1\left(n\right)=y_{\mathrm{up}}^1\left(n\right)+P_{\mathrm{ul}}^1\left(n\right)---\left(14\right),$

Wherein

Expression: the ascending pilot frequency that the antenna 1 of the first communication equipment sends to second communication equipment.

Hybrid pilot on the antenna 2 of the first communication equipment is:

$x_2\left(n\right)=y_{\mathrm{up}}^2\left(n\right)+P_{\mathrm{ul}}^2\left(n\right)---\left(15\right).$

Wherein

Expression: the ascending pilot frequency that the antenna 2 of the first communication equipment sends to second communication equipment.

The ascending pilot frequency that the first communication equipment is sent out on the second communication equipment satisfies functional expression (16), (17) the represented restrictive condition in the step 301.

The first communication equipment carries out the OFDM modulation with the hybrid pilot of each antenna in upstream data, adds to carry out up channel behind the CP and transfer to second communication equipment.

The power allocation scheme one, two of this hybrid pilot of the first communication system transmitting in can reference example 1, adopt following power allocation scheme:

Scheme three: the constant scheme of gross power

Identical with the scheme one of step 202 among the embodiment 1 is: the constant situation of total transmitting power (comprising ascending pilot frequency in this subcarrier of emission and the power of descending pilot frequency) of arranging the pilot sub-carrier of the first communication equipment, can be after agreement, with this steady state value notice second communication equipment.

Different from scheme one among the embodiment is: because current system is mimo system, therefore the descending pilot frequency that each antenna that may the first communication equipment receives is respectively from the different antenna of second communication equipment, therefore each antenna on the first communication equipment sends and comprises a plurality of at least ascending pilot frequencies in the hybrid pilot, and this hybrid pilot is: the stack of the required ascending pilot frequency on the second communication equipment of a plurality of descending pilot frequencies and this antenna.Therefore, exist a plurality of power division factors this moment, and the power of distributing to each descending pilot frequency or ascending pilot frequency accounts for the ratio of gross power.

Scheme four: ascending pilot frequency power invariability scheme

Scheme one difference in this programme and embodiment 1 step 202 is, the first communication equipment adopts many antennas to send, each antenna is the upper ascending pilot frequency of sending out separately all, therefore for the first communication breath equipment, total upper ascending pilot frequency can be more than one, therefore, for the power of distributing to the right ascending pilot frequency of each antenna, can consult to make the transmitting power of the ascending pilot frequency of the first communication equipment antenna is steady state value, after agreement with the steady state value notice second communication equipment of this each ascending pilot frequency power.

And for the power of the ascending pilot frequency of each antenna, with scheme two among the embodiment 1 in like manner, can guarantee that total transmitting power is no more than under the prerequisite of predetermined total upper limit of emission power, according to channel condition (such as CQI) flexible allocation.

As seen, if application scheme four described power schemes, the first communication equipment does not need to feed back any power allocation information, and it can further save feedback overhead with respect to scheme three.

Step 303: second communication equipment receives the hybrid pilot that is sent by the first communication equipment.

The hybrid pilot that the first communication equipment sends arrives second communication equipment through behind the up channel.Suppose that second communication equipment adopts 2 antenna receiving-sendings, at second communication equipment place, the hybrid pilot that the antenna 1 of second communication equipment receives is the stack of the hybrid pilot that sends of second communication terminal antenna 1, antenna 2, and the hybrid pilot that the antenna 1 of second communication equipment receives can be expressed as:

$y_{\mathrm{BP}}^1\left(n\right)=\mathrm{diag}(Y_{\mathrm{up}}^1\left(n\right)+P_{\mathrm{ul}}^1\left(n\right))F_{\mathrm{up}}{h}_{\mathrm{ul}}^{11}+\mathrm{diag}(Y_{\mathrm{up}}^2\left(n\right)+P_{\mathrm{ul}}^2\left(n\right))F_{\mathrm{up}}{h}_{\mathrm{ul}}^{12}+w_{\mathrm{Bp}}^1\left(n\right)---\left(18\right),$

Wherein,

Expression: the antenna 1 of the first communication equipment is to the up channel of the antenna 1 of second communication equipment;

Expression: the antenna 2 of the first communication equipment is to the up channel of the antenna 1 of second communication equipment;

Expression: signal is at the additive noise of antenna 1 place of second communication equipment stack; F _UpExpression: the matrix that the part corresponding with pilot tone consists of in the DFT matrix for up channel.

In like manner, the hybrid pilot that receives of the antenna 2 of second communication equipment can be expressed as:

$y_{\mathrm{BP}}^2\left(n\right)=\mathrm{diag}(Y_{\mathrm{up}}^1\left(n\right)+P_{\mathrm{ul}}^1\left(n\right))F_{\mathrm{up}}{h}_{\mathrm{ul}}^{21}+\mathrm{diag}(Y_{\mathrm{up}}^2\left(n\right)+P_{\mathrm{ul}}^2\left(n\right))F_{\mathrm{up}}{h}_{\mathrm{ul}}^{22}+w_{\mathrm{Bp}}^2\left(n\right)---\left(19\right).$

Wherein,

Expression: the antenna 1 of the first communication equipment is to the up channel of the antenna 2 of second communication equipment;

Expression: the antenna 2 of the first communication equipment is to the up channel of the antenna 2 of second communication equipment;

Expression: signal is at the additive noise of antenna 2 places of second communication equipment stack.

Need to prove, the present embodiment all adopts 2 antenna receiving-sendings with the first communication equipment, second communication system, still, is not limited to this, and in addition, the number of the dual-mode antenna of the first communication equipment, second communication system can be not identical.

Step 304: second communication equipment is estimated each up channel according to the hybrid pilot that receives and each known ascending pilot frequency, is obtained each up channel parameter.

For each uplink channel estimation, second communication equipment uses known each ascending pilot frequency hybrid pilot that each antenna reception of dot product arrives on frequency domain.Namely be equivalent on time domain the forms of time and space of the ascending pilot frequency of the antenna i of the first communication equipment that usefulness second communication equipment is known

Conjugation

The hybrid pilot signal that receives with the antenna j of second communication equipment

Carry out convolution, antenna i estimated to the up channel of antenna j,

With

Carrying out convolution can be expressed as:

${\stackrel{\&RightArrow;}{p}}_{\mathrm{ul}}^{*1}\left(n\right)*y_{\mathrm{Bp}}^1\left(n\right)$

$={\stackrel{\&RightArrow;}{p}}_{\mathrm{ul}}^{*1}\left(n\right)*[h_{\mathrm{dl}}^{11}*h_{\mathrm{ul}}^{11}*{\stackrel{\&RightArrow;}{p}}_{\mathrm{dl}}^1\left(n\right)+h_{\mathrm{dl}}^{12}*h_{\mathrm{ul}}^{11}*{\stackrel{\&RightArrow;}{p}}_{\mathrm{dl}}^2\left(n\right)+h_{\mathrm{dl}}^{21}*h_{\mathrm{ul}}^{12}*{\stackrel{\&RightArrow;}{p}}_{\mathrm{dl}}^1\left(n\right)$ (20)。

$+h_{\mathrm{dl}}^{22}*h_{\mathrm{ul}}^{12}*{\stackrel{\&RightArrow;}{h}}_{\mathrm{dl}}^2\left(n\right)+h_{\mathrm{ul}}^{11}*{\stackrel{\&RightArrow;}{p}}_{\mathrm{ul}}^1\left(n\right)+h_{\mathrm{ul}}^{12}*{\stackrel{\&RightArrow;}{p}}_{\mathrm{ul}}^2\left(n\right)+w_{\mathrm{Bp}}^1\left(n\right)]$

With functional expression (16), (17) substitution functional expression (20), can estimate to obtain the antenna i of the first communication equipment to the up channel of the antenna j of second communication equipment

${\hat{h}}_{\mathrm{ul}}^{\mathrm{ij}}={\stackrel{\&RightArrow;}{p}}_{\mathrm{ul}}^{*i}\left(n\right)*y_{\mathrm{Bp}}^j\left(n\right)=h_{\mathrm{ul}}^{\mathrm{ij}}+{\stackrel{\&RightArrow;}{p}}_{\mathrm{ul}}^{*i}\left(n\right)*w_{\mathrm{Bp}}^j\left(n\right)---\left(21\right).$

For example: for the estimation to the up channel of the antenna 1 of second communication equipment of the antenna 1 of the first communication equipment, second communication equipment is with the ascending pilot frequency (making an appointment known) of the antenna 1 of the first known communication equipment

Conjugation and the signal that receives of the antenna 1 of second communication equipment

Carry out convolution, can estimate to obtain up channel

${\hat{h}}_{\mathrm{ul}}^{11}={\stackrel{\&RightArrow;}{p}}_{\mathrm{ul}}^{*1}\left(n\right)*y_{\mathrm{Bp}}^1\left(n\right)=h_{\mathrm{ul}}^{11}+{\stackrel{\&RightArrow;}{p}}_{\mathrm{ul}}^{*1}\left(n\right)*w_{\mathrm{Bp}}^1\left(n\right)---\left(22\right),$

In like manner, second communication equipment is with the ascending pilot frequency (making an appointment known) of the antenna 2 of the first known communication equipment

Conjugation and the signal that receives of the antenna 1 of second communication equipment Carry out convolution, can estimate to obtain up channel

${\hat{h}}_{\mathrm{ul}}^{12}={\stackrel{\&RightArrow;}{p}}_{\mathrm{ul}}^{*2}\left(n\right)*y_{\mathrm{Bp}}^1\left(n\right)=h_{\mathrm{ul}}^{12}+{\stackrel{\&RightArrow;}{p}}_{\mathrm{ul}}^{*2}\left(n\right)*w_{\mathrm{Bp}}^1\left(n\right)---\left(23\right),$

In like manner, second communication equipment is with the ascending pilot frequency (making an appointment known) of the antenna 1 of the first known communication equipment

Conjugation and the signal that receives of the antenna 2 of second communication equipment

Carry out convolution, can estimate to obtain up channel

${\hat{h}}_{\mathrm{ul}}^{22}={\stackrel{\&RightArrow;}{p}}_{\mathrm{ul}}^{*1}\left(n\right)*y_{\mathrm{Bp}}^2\left(n\right)=h_{\mathrm{ul}}^{21}+{\stackrel{\&RightArrow;}{p}}_{\mathrm{ul}}^{*1}\left(n\right)*w_{\mathrm{Bp}}^2\left(n\right)---\left(24\right).$

In like manner, second communication equipment is with the ascending pilot frequency (making an appointment known) of the antenna 2 of the first known communication equipment

Conjugation and the signal that receives of the antenna 2 of second communication equipment Carry out convolution, can estimate to obtain up channel

${\hat{h}}_{\mathrm{ul}}^{22}={\stackrel{\&RightArrow;}{p}}_{\mathrm{ul}}^{*2}\left(n\right)*y_{\mathrm{Bp}}^2\left(n\right)=h_{\mathrm{ul}}^{22}+{\stackrel{\&RightArrow;}{p}}_{\mathrm{ul}}^{*2}\left(n\right)*w_{\mathrm{Bp}}^1\left(n\right)---\left(25\right).$

Need to prove, if the first communication equipment in emission during hybrid pilot, employing be scheme three described power division in the step 301, then corresponding, after second communication equipment receives hybrid pilot, account for the ratio of gross power according to this known ascending pilot frequency power: distribution factor α, use

In the corresponding replacement function formula (21)

Can estimate each up channel according to the functional expression after replacing; If the first communication equipment is when the emission hybrid pilot, what adopt is the descending pilot frequency in the step 301, the allocative decision four described power division of the transmitting power between the ascending pilot frequency, and then direct utility function formula (21) is calculated each up channel is estimated to get final product.

Step 305: second communication equipment is estimated each closed loop channel according to each known descending pilot frequency and each hybrid pilot that receives, is obtained each closed loop channel parameter.

Since each descending pilot frequency from second communication equipment via down channel to the first communication equipment, return second communication equipment by the first communication equipment via up channel again, passed through the closed loop channel that is consisted of by up channel and down channel.

Therefore, with in the step 302 to uplink channel estimation in like manner, the hybrid pilot that the descending pilot frequency that second communication equipment can issue with each antenna of this known communication equipment receives with second communication equipment respectively carries out convolution on the time domain or the point multiplication operation on the frequency domain.For example:

On time domain, the forms of time and space of the descending pilot frequency that issues to the first communication equipment with the antenna i of the known second communication equipment of second communication equipment

Conjugation

The hybrid pilot signal y that receives with second communication equipment respectively _BP(n) carry out convolution algorithm, each convolution algorithm formula is carried out equation find the solution, can estimate each closed loop channel, obtain each closed loop channel parameter.

For example: the situation take second communication equipment as 2 antenna receiving-sendings is as example, for the hybrid pilot that second communication device antenna 1 receives, the descending pilot frequency that can use the descending pilot frequency of antenna 1 and antenna 2 carries out convolution on the time domain or the point multiplication operation on the frequency domain to this hybrid pilot respectively; For the hybrid pilot that second communication device antenna 2 receives, the descending pilot frequency that in like manner can use the descending pilot frequency of antenna 1 and antenna 2 carries out convolution on the time domain or the point multiplication operation on the frequency domain to this hybrid pilot respectively.In conjunction with each operation function formula, can obtain the estimated result of closed loop channel again.

Step 306: second communication equipment obtains each down channel parameter according to each closed loop channel parameter and each up channel parameter.

With step 206 among the embodiment 1 in like manner, according to each closed loop channel parameter and each up channel parameter, obtain the right down channel parameter of this antenna.For example:

Down channel is 2 * 2 matrix H _D, up channel is 2 * 2 matrix H _U, wherein:

$H_D=\left[\begin{array}{cc}{h}_d^1& h_d^2\\ h_d^3& h_d^4\end{array}\right]---\left(26\right),$

$H_U=\left[\begin{array}{cc}{h}_u^1& h_u^2\\ h_u^3& h_u^4\end{array}\right]---\left(27\right)$

Then the closed loop channel can be expressed as: H=H _DH _U, namely have:

$H=\left[\begin{array}{cc}{h}_d^1{h}_u^1+h_d^2{h}_u^3& h_d^1{h}_u^2+h_d^2{h}_u^4\\ h_d^3{h}_u^1+h_d^4{h}_u^3& h_d^3{h}_u^2+h_d^4{h}_u^4\end{array}\right]---\left(28\right),$

By functional expression (28) as seen, according to closed loop channel H, each up channel of estimating

Can obtain each down channel $h_d^1,h_d^2,h_d^3,h_d^4.$

Need explanation, the second communication equipment in the present embodiment can but be not limited to the base station, the first communication equipment can but be not limited to terminal.

One of ordinary skill in the art will appreciate that all or part of step that realizes in above-described embodiment method is to come the relevant hardware of instruction to finish by program, described program can be stored in the computer read/write memory medium, this program is when carrying out, can comprise the steps: that second communication equipment receives the descending pilot frequency that the first communication equipment issues, and with the descending pilot frequency and the ascending pilot frequency stack generation hybrid pilot that receive, described hybrid pilot is sent to described the first communication equipment; Described the first communication equipment receives described hybrid pilot, and according to the hybrid pilot that receives and known ascending pilot frequency, up channel is estimated, obtains the up channel parameter; Described the first communication equipment is estimated the closed loop channel according to known descending pilot frequency and the hybrid pilot that receives, is obtained the closed loop channel parameter; Described the first communication equipment obtains the down channel parameter according to described closed loop channel parameter, described up channel parameter.Here alleged storage medium, as: ROM/RAM, magnetic disc, CD etc.

Therefore, each antenna of the first communication equipment of the technical scheme of application the present embodiment is behind the descending pilot frequency that each antenna that receives second communication equipment issues, when each antenna sends ascending pilot frequency, all descending pilot frequencies that this antenna is received and its wait that the superpose hybrid pilot of formation of the ascending pilot frequency of sending out is sent to second communication equipment, second communication equipment is according to this hybrid pilot, and each known ascending pilot frequency, can estimate each up channel; In addition, second communication equipment can also be according to this hybrid pilot, and each known descending pilot frequency, can estimate each closed loop channel, then in conjunction with estimating each ascending pilot frequency and closed loop pilot, estimates each down channel.Realization can be obtained the parameter of each down channel when carrying out each uplink channel estimation, simultaneously, the present embodiment technical scheme has greatly reduced the signaling consumption for the parameter of obtaining down channel with respect to prior art.For example:

If utilize the power allocation scheme three in the step 302, only need few signaling consumption that is used for the transmit power allocation factor both can, and if quote power allocation scheme four in the step 302, needed signaling consumption is zero.

Embodiment 3:

The method that the another kind that the present embodiment provides take the application embodiment of the invention in the SISO system obtains channel information is specifically divided explanation as example to the method, Figure 4 shows that the method flow schematic diagram of the present embodiment, and as shown in Figure 4, the method can comprise:

Step 401: second communication equipment issues descending pilot frequency to the first communication equipment.

Step 201 among this step and the embodiment 1 substantially in like manner, institute's difference is:

In order to make the descending pilot frequency in the hybrid pilot in the technical solution of the present invention not affect the first communication equipment to the estimation of up channel, therefore, can set in advance that the first communication is established and second communication equipment between ascending pilot frequency and descending pilot frequency, make ascending pilot frequency, descending pilot frequency satisfy respectively following condition:

(1) descending pilot frequency that issues to the first communication equipment for second communication equipment can make the convolution results of descending pilot frequency on time domain that issue at the time delay extension length L of up channel _UlScope in be impulse function, namely the auto-correlation function of descending pilot frequency on time domain can be expressed as:

$\underset{n}{\mathrm{\&Sigma;}}{p}_{\mathrm{dl}}^{*}\left(t\right)p_{\mathrm{dl}}(n-t)=\left\{\begin{array}{cc}a& n=0\\ 0& 0<n\&le;L_{\mathrm{dl}}\end{array}\right.---\left(29\right),$

Wherein

Expression: descending pilot frequency

Conjugation; L _DlExpression: the time delay extension length of down channel; A is the real number greater than zero, is without loss of generality, and a can equal 1.

(2) ascending pilot frequency of sending out on the second communication equipment for the first communication equipment, its convolution results on time domain is at the time delay extension length L of up channel _UlBe impulse function in the scope.Be that ascending pilot frequency can be expressed as shown in the functional expression (2) in embodiment 1 step 201 at the auto-correlation function on the time domain.

(3) for ascending pilot frequency and descending pilot frequency, its both convolution results is at the time delay extension length L of up channel _UlScope in be zero.That is:

$\underset{n}{\mathrm{\&Sigma;}}{p}_{\mathrm{ul}}^{*}\left(t\right)p_{\mathrm{dl}}(n-t)=0$ 0≤n≤L _ul (30)，

Need to prove, if descending pilot frequency satisfies such as the represented condition of functional expression (3) among the embodiment 1, then it must satisfy the represented condition of functional expression in the present embodiment (30), namely can be interpreted as: the condition of functional expression (30) restriction is the subset of the condition that limits of functional expression (3).

The descending pilot frequency that second communication equipment will satisfy functional expression (29), (30) restriction is sent to the first communication equipment, thereby so that second communication equipment is after receiving this descending pilot frequency, directly descending pilot frequency and the ascending pilot frequency that receives superposeed, and do not need again the descending pilot frequency that receives to be done extra processing.

Step 402: the first communication equipment receives descending pilot frequency, and descending pilot frequency and the ascending pilot frequency stack that receives generated hybrid pilot, and the hybrid pilot after the stack is sent to second communication equipment.

Step 202 among this step and the embodiment 1 is substantially in like manner: after the first communication equipment receives descending pilot frequency, with the descending pilot frequency that receives and the ascending pilot frequency to be sent generation hybrid pilot that superposes, and this hybrid pilot is sent to second communication equipment.This step and step 202 difference be, the ascending pilot frequency that the first communication equipment is sent out on the second communication equipment satisfies functional expression (2), (30) the represented restrictive condition in the step 401.

After the first communication equipment generates hybrid pilot, when sending out upstream data to second communication equipment, the hybrid pilot after the stack is carried out the OFDM modulation with upstream data, carry out ul transmissions after adding CP, be sent to second communication equipment.

Can adopt scheme one or scheme two described pilot power allocation schemes among the embodiment 1 during the first communication equipment emission hybrid pilot, it specifically sees the associated description among the embodiment 1 for details.Therefore not to repeat here.

Step 403: second communication equipment receives the hybrid pilot that the first communication equipment sends.

Step 203 among this step and the embodiment 1 in like manner.

If the hybrid pilot that the first communication equipment sends is to arrive second communication equipment behind the up channel of Lul through the time delay extension length, the hybrid pilot that receives in second communication equipment place can be expressed as the form shown in the functional expression (2) in embodiment 1 step 201.

Step 404: second communication equipment is estimated up channel according to the hybrid pilot that receives and known ascending pilot frequency, is obtained the up channel parameter.

Such as step 204 among the embodiment 1 in like manner, second communication equipment uses the conjugation of the forms of time and space of known ascending pilot frequency on time domain

With the hybrid pilot signal y that receives _Bp(n) carry out convolution, obtain functional expression (6), estimate ascending pilot frequency according to functional expression (6):

${\stackrel{\&RightArrow;}{p}}_{\mathrm{ul}}^{*}\left(n\right)*y_{\mathrm{Bp}}\left(n\right)$

　　　　　　　　　　　　　　　　　　　　　　　　　　　(6)，

$={\stackrel{\&RightArrow;}{p}}_{\mathrm{ul}}^{*}\left(n\right)*h_{\mathrm{dl}}*h_{\mathrm{ul}}*{\stackrel{\&RightArrow;}{p}}_{\mathrm{dl}}\left(n\right)+{\stackrel{\&RightArrow;}{p}}_{\mathrm{ul}}^{*}\left(n\right)h_{\mathrm{ul}}*{\stackrel{\&RightArrow;}{p}}_{\mathrm{ul}}\left(n\right)+{\stackrel{\&RightArrow;}{p}}_{\mathrm{ul}}\left(n\right)*w\left(n\right)$

Can make a in the functional expression (2) equal 1, with functional expression (2), (30) substitution functional expression (6), can obtain functional expression (7):

${\hat{h}}_{\mathrm{ul}}={\stackrel{\&RightArrow;}{p}}_{\mathrm{ul}}^{*}\left(n\right){*y}_{\mathrm{Bp}}\left(n\right)=h_{\mathrm{ul}}+{\stackrel{\&RightArrow;}{p}}_{\mathrm{ul}}\left(n\right)*w\left(n\right)---\left(7\right),$

Can calculate the estimated value that gets access to the up channel parameter according to functional expression (7)

Need to prove, then corresponding if the first communication equipment adopts during hybrid pilot in emission is scheme one described power allocation scheme in the step 202, after second communication equipment receives hybrid pilot, according to the power division factor-alpha that receives, use

In replacement function formula (6), (7)

Can calculate the estimated value of obtaining up channel according to the functional expression after replacing; If what the first communication equipment adopted when the emission hybrid pilot is scheme two described power division in the step 202, then directly utility function formula (6), (7) were both calculated and can be calculated the estimated value of obtaining up channel.

Step 405: second communication equipment recovers to obtain the hybrid pilot that the first communication equipment is launched according to the up channel parameter.

According to the estimated result of up channel, can be to the hybrid pilot y of second communication equipment reception _Bp(n) carry out equilibrium treatment, recover to obtain the signal that this hybrid pilot is located at transmitting terminal (the first communication equipment).Wherein the balanced mode of recovering such as: ZF is balanced, MMSE is balanced etc., for example, uses the ZF equilibrium to obtain:

${\hat{y}}_{\mathrm{ue}}\left(n\right)={\left(\mathrm{diag}\left({\hat{H}}_{\mathrm{ul}}\right)\right)}^{-1}{y}_{\mathrm{Bp}}\left(n\right)---\left(31\right)$

Wherein, Expression: the hybrid pilot that first communication equipment that recover to obtain sends;

Expression: the parameter of the up channel that estimation is obtained; Expression: the diagonal matrix that the up channel parameter that estimation obtains consists of; y _Bp(n) expression: the hybrid pilot that second communication equipment receives,

Expression: right $\left(\mathrm{diag}\left({\hat{H}}_{\mathrm{ul}}\right)\right)$ Matrix is got inverse matrix.

Can calculate according to functional expression (31) and to get access to the signal that this hybrid pilot is located at transmitting terminal (the first communication equipment), be i.e. the hybrid pilot that sends of the first communication equipment.

Step 406: second communication equipment is according to the hybrid pilot that recovers, and known ascending pilot frequency, descending pilot frequency estimate to obtain the down channel parameter.

In the functional expression (31) ${\left(\mathrm{diag}\left({\hat{H}}_{\mathrm{ul}}\right)\right)}^{-1}{y}_{\mathrm{Bp}}\left(n\right)$ Can be expressed as following form:

${\hat{y}}_{\mathrm{ue}}\left(n\right)={\left(\mathrm{diag}\left({\hat{H}}_{\mathrm{ul}}\right)\right)}^{-1}{y}_{\mathrm{Bp}}\left(n\right)$

$=\mathrm{diag}\left(P_{\mathrm{dl}}\left(n\right)\right)F_{\mathrm{dp}}{h}_{\mathrm{dl}}+w_{\mathrm{up}}\left(n\right)+P_{\mathrm{ul}}\left(n\right)+{\left(\mathrm{diag}\left({\hat{H}}_{\mathrm{ul}}\right)\right)}^{-1}{w}_{\mathrm{Bp}}\left(n\right)$ (32)，

$=\mathrm{diag}\left(P_{\mathrm{dl}}\left(n\right)\right)F_{\mathrm{dp}}{h}_{\mathrm{dl}}+P_{\mathrm{ul}}\left(n\right)+w\left(n\right)$

Wherein, P _Dl(n) expression: the frequency domain form of descending pilot frequency; Diag (P _Dl(n)) expression: the diagonal matrix that is consisted of by the pilot tone on the descending frequency domain; F _DpExpression: the IFFT matrix of ascending pilot frequency; h _DlExpression: descending time domain channel vector; w _Up(n) expression: this hybrid pilot is at the additive noise of up channel stack; P _Ul(n) expression: the frequency domain form of ascending pilot frequency; Diag (P _Dl(n)) expression: the diagonal matrix that descending pilot frequency consists of; w _Bp(n) expression: second communication equipment receives the superimposed noise on the mixed pilot tone; W (n) expression: total equivalent noise item.

By functional expression (32) as seen, from this formula, deduct the known ascending pilot frequency P of second communication equipment _Ul(n) (second communication equipment and the first communication equipment are made an appointment) namely can obtain estimated value: diag (P _Dl(n)) F _Dph _Dl+ w (n).

Estimating to obtain estimated value: diag (P _Dl(n)) F _Dph _Dl+ w (n) recycles the descending pilot frequency P that known second communication equipment issues to the first communication equipment afterwards _DlAnd known F (n), _Dp, can estimate to obtain the parameter h of down channel _Dl

Need explanation, the second communication equipment in the present embodiment can but be not limited to the base station, the first communication equipment can but be not limited to terminal.

Therefore, use first communication equipment of technical scheme of the present embodiment after receiving second communication and setting the descending pilot frequency of sending out, when sending out ascending pilot frequency on the second communication equipment again, the descending pilot frequency that receives and ascending pilot frequency to be sent are superposeed, generate hybrid pilot, this hybrid pilot is sent to second communication equipment.After second communication equipment receives this hybrid pilot, according to this hybrid pilot, and known ascending pilot frequency, can estimate up channel; According to the up channel parameter of estimating to obtain, can recover the hybrid pilot that the first communication equipment sends, hybrid pilot according to the first communication equipment transmission that recovers, and the descending pilot frequency that issues to the first communication equipment of this known communication equipment, the ascending pilot frequency that the first communication equipment is sent out on this equipment estimates to obtain the parameter of down channel.Realization can be obtained the parameter of down channel when carrying out uplink channel estimation, the present embodiment technical scheme has simultaneously greatly reduced the signaling consumption for the parameter of obtaining down channel with respect to prior art.

In addition, owing to not needing in the present embodiment to obtain the down channel parameter by calculating the closed loop channel parameter, therefore for ascending pilot frequency and descending pilot frequency, the convolution results between them is at the time delay extension length L of up channel _UlBe zero to get final product (satisfying functional expression (30)), and do not need such as desired its time delay extension length L at the closed loop channel among the embodiment 1 _Ul+ L _DlScope in be zero (satisfying functional expression (3)).Since by functional expression ( ³) the available pilot frequency sequence quantity that obtains of institute's restrictive condition is: N/ (L _Ul+ L _Dl), wherein N is the length of OFDM symbol, and the available pilot frequency sequence quantity that is obtained by functional expression (30) institute restrictive condition is: N/L _UlAs seen: use the technical scheme of the present embodiment with respect to the technical scheme of embodiment 1, can greatly increase the available pilot number in the OFDM symbol, so that pilot-frequency expense further reduces.

Embodiment 4:

The method that the present embodiment obtains channel information take the another kind of using the embodiment of the invention provide in mimo system is specifically divided explanation as example to the method, the basic procedure of the method as shown in Figure 5, as shown, the method can comprise:

Step 501: second communication equipment issues descending pilot frequency to the first communication equipment.

Step 301 among this step and the embodiment 2 in like manner, difference is: do not affect second communication equipment to the estimation of each up channel and closed loop channel in order to make each descending pilot frequency in the hybrid pilot in the technical solution of the present invention, therefore, can set in advance that the first communication is established and second communication equipment between each ascending pilot frequency and descending pilot frequency, make each ascending pilot frequency, descending pilot frequency satisfy respectively following condition:

(1) descending pilot frequency that issues for second communication equipment each day alignment the first communication equipment can make the convolution results of each descending pilot frequency on time domain at the time delay extension length L of up channel _UlScope in be impulse function, namely the auto-correlation function of each descending pilot frequency on time domain can be expressed as:

$\underset{n}{\mathrm{\&Sigma;}}{p_{\mathrm{dl}}^i}^{*}\left(t\right)p_{\mathrm{dl}}^j(n-t)=\left\{\begin{array}{cc}a& n=0\\ 0& 0<n\&le;L_{\mathrm{dl}}\end{array}\right.---\left(33\right),$

Wherein

Expression: the descending pilot frequency that the antenna i of the first communication equipment issues to second communication equipment

Conjugation;

Expression: the descending pilot frequency that the antenna j of the first communication equipment issues to second communication equipment; L _DlTime delay extension length for down channel; I, j are the antenna sign, and i can equal j; A is the real number greater than zero, is without loss of generality, and can make a equal 1.

(2) descending pilot frequency that issues for second communication equipment each day alignment the first communication equipment, its each convolution results on time domain is at the time delay extension length L of up channel _UlBe impulse function in the scope, namely the auto-correlation function of each ascending pilot frequency on time domain can be expressed as:

$\underset{n}{\mathrm{\&Sigma;}}{p_{\mathrm{ul}}^i}^{*}\left(t\right)p_{\mathrm{ul}}^j(n-t)=\left\{\begin{array}{cc}a& n=0\\ 0& 0<n\&le;L_{\mathrm{ul}}\end{array}\right.---\left(39\right),$

Wherein, described Be that the antenna i of the first communication equipment is to the ascending pilot frequency of second communication equipment transmission

Conjugation, Be that the antenna j of the first communication equipment is to the ascending pilot frequency of second communication equipment transmission, L _UlBe the time delay extension length of up channel, a is the real number greater than zero, and i, j are the antenna sign of second communication equipment, and i can equal j.

(2) for each ascending pilot frequency, descending pilot frequency, the convolution results of arbitrary ascending pilot frequency and arbitrary descending pilot frequency is at the time delay extension length L of up channel _UlScope in be zero.That is:

$\underset{n}{\mathrm{\&Sigma;}}{p_{\mathrm{ul}}^i}^{*}\left(t\right)p_{\mathrm{dl}}^j(n-t)=0$ 　　　　　0<n≤L _ul　(34)。

Second communication equipment is sent to the first communication equipment with the descending pilot frequency that second communication equipment will satisfy the represented restrictive condition of functional expression (33), (34), thereby so that second communication equipment is after receiving this descending pilot frequency, directly descending pilot frequency and the ascending pilot frequency that receives superposeed, and do not need again the descending pilot frequency that receives to be done extra processing.

Step 502: the first communication equipment receives descending pilot frequency, and descending pilot frequency and the ascending pilot frequency stack that receives generated hybrid pilot, and the hybrid pilot after the stack is sent to second communication equipment.

Step 302 among this step and the embodiment 2 substantially in like manner, institute's difference is: the ascending pilot frequency that the first communication equipment is sent out on the second communication equipment satisfies functional expression (39), (34) the represented restrictive condition in the step 501.

The first communication equipment carries out the OFDM modulation with the hybrid pilot of each antenna in upstream data, adds to carry out up channel behind the CP and transfer to second communication equipment.

In the present embodiment method, the first communication equipment can adopt scheme three among the embodiment 2 or the hybrid pilot of scheme four described each antenna of pilot power allocation scheme, and it specifically sees the associated description among the embodiment 2 for details.Therefore not to repeat here.

Step 503: second communication equipment receives the hybrid pilot that is sent by the first communication equipment.

Step 303 among this step and the embodiment 2 substantially in like manner.Suppose in the mimo system of the present embodiment, second communication equipment, second communication system all adopt 2 antenna receiving-sendings, with step 303 among the embodiment 2 in like manner, the hybrid pilot that the antenna 1 of second communication equipment receives can be expressed as the form shown in the functional expression (18).The hybrid pilot that the antenna 2 of second communication equipment receives can be expressed as the form shown in the functional expression (19).

Need to prove, the present invention all adopts 2 antenna receiving-sendings with second communication equipment, second communication system, still, is not limited to this, and in addition, the number of the dual-mode antenna of second communication equipment, second communication system can be not identical.

Step 504: second communication equipment is estimated each up channel according to the hybrid pilot that receives and each known ascending pilot frequency, is obtained each up channel parameter.

Among the implementation of this step and the embodiment 2 implementation of step 304 in like manner, therefore not to repeat here.

Step 505: second communication equipment is according to each up channel parameter of estimating to obtain, recovers to obtain the hybrid pilot that each antenna of the first communication equipment is launched.

Second communication equipment is according to each up channel of estimating, to each antenna reception of base station to hybrid pilot carry out equilibrium recovery, obtain it at the signal of second communication equipment transmitting terminal.All adopt 2 antenna receiving-sendings as example take second communication equipment, second communication system: the hybrid pilot that the antenna 1 of second communication equipment is received can be expressed as the form shown in the functional expression (18), and the hybrid pilot that the antenna 2 of second communication equipment receives can be expressed as the form shown in the functional expression (19).Right respectively

Carry out balanced recovery and obtain the hybrid pilot x that the antenna 1 of the first communication equipment sends ₁(n), the hybrid pilot x of antenna 2 transmissions of the first communication equipment ₂(n).Its equalization methods can use ZF equilibrium or MMSE equilibrium etc.

For convenient balanced Recovery processing, functional expression (18), (19) are expressed as following form:

$y_{\mathrm{BP}}^1\left(n\right)=h_{\mathrm{ul}}^{11}{x}_1\left(n\right)+h_{\mathrm{ul}}^{12}{x}_2\left(n\right)---\left(35\right),$

$y_{\mathrm{BP}}^2\left(n\right)=h_{\mathrm{ul}}^{21}{x}_1\left(n\right)+h_{\mathrm{ul}}^{22}{x}_2\left(n\right)---\left(36\right).$

Can be obtained by functional expression (35), (36):

$\left[\begin{array}{c}{y}_{\mathrm{BP}}^1\left(n\right)\\ y_{\mathrm{BP}}^2\left(n\right)\end{array}\right]=\left[\begin{array}{cc}{h}_{\mathrm{ul}}^{11}& h_{\mathrm{ul}}^{12}\\ h_{\mathrm{ul}}^{21}& h_{\mathrm{ul}}^{22}\end{array}\right]\left[\begin{array}{c}{x}_1\left(n\right)\\ x_2\left(n\right)\end{array}\right]=H\left[\begin{array}{c}{x}_1\left(n\right)\\ x_2\left(n\right)\end{array}\right]---\left(37\right),$

According to functional expression (37), have:

$\left[\begin{array}{c}{x}_1\left(n\right)\\ x_2\left(n\right)\end{array}\right]=H^{-1}\left[\begin{array}{c}{y}_{\mathrm{BP}}^1\left(n\right)\\ y_{\mathrm{BP}}^2\left(n\right)\end{array}\right]---\left(38\right)$

Obtain the hybrid pilot that the first communication equipment antenna 1, antenna 2 are launched: x according to functional expression (38) estimation ₁(n), x ₂(n).

Step 506: second communication equipment is according to the hybrid pilot that recovers, and known ascending pilot frequency, descending pilot frequency estimate to obtain each down channel parameter.

Obtain x ₁(n) and x ₂(n) after, therefrom deduct respectively the ascending pilot frequency of known the first communication equipment stack Can obtain descending pilot frequency through the estimated value behind the down channel

Recycle known descending pilot frequency (descending pilot frequency that second communication device antenna 1, antenna 2 issue to the first communication equipment), can recover down channel.

Need explanation, the second communication equipment in the present embodiment can but be not limited to the base station, the first communication equipment can but be not limited to terminal.

One of ordinary skill in the art will appreciate that all or part of step that realizes in above-described embodiment method is to come the relevant hardware of instruction to finish by program, described program can be stored in the computer read/write memory medium, this program is when carrying out, can comprise the steps: that second communication equipment receives the descending pilot frequency that the first communication equipment issues, and with the descending pilot frequency and the ascending pilot frequency stack generation hybrid pilot that receive, described hybrid pilot is sent to described the first communication equipment; Described the first communication equipment receives described hybrid pilot, and according to the hybrid pilot that receives and known ascending pilot frequency, up channel is estimated, obtains the up channel parameter; Described the first communication equipment recovers to obtain the hybrid pilot of described second communication equipment emission according to described up channel parameter; Described the first communication equipment according to the hybrid pilot of described second communication equipment emission, known ascending pilot frequency, known descending pilot frequency, obtain the down channel parameter.Here alleged storage medium, as: ROM/RAM, magnetic disc, CD etc.

Therefore, behind the descending pilot frequency that each antenna of each antenna reception second communication equipment of the first communication equipment of the technical scheme of application the present embodiment issues, all descending pilot frequencies and this antenna that this antenna receives are treated that the ascending pilot frequency of sending out superposes on this second communication equipment, generate hybrid pilot, and this hybrid pilot is sent to second communication equipment.After second communication equipment receives this hybrid pilot, according to this hybrid pilot, and the ascending pilot frequency of precognition, can estimate up channel; According to the up channel parameter of estimating to obtain, can recover the hybrid pilot that the first communication equipment sends, hybrid pilot according to the first communication equipment transmission that recovers to obtain, and the ascending pilot frequency of sending out on the descending pilot frequency that issues of known second communication equipment, known the first communication equipment, can estimate the parameter of down channel.Realization can be obtained the parameter of down channel when carrying out uplink channel estimation, the present embodiment technical scheme has simultaneously greatly reduced the signaling consumption for the parameter of obtaining down channel with respect to prior art.

In addition, owing to not needing to obtain each down channel parameter by calculating each closed loop channel parameter in the present embodiment, therefore for each ascending pilot frequency and each descending pilot frequency, the convolution results between them is at the time delay extension length L of up channel _UlBe zero to get final product (satisfying functional expression (34)), and do not need such as desired its time delay extension length L at the closed loop channel among the embodiment 3 _Ul+ L _DlScope in be zero (satisfying functional expression (17)).Because the available pilot frequency sequence quantity that is obtained by functional expression (17) institute restrictive condition is: N/ (L _Ul+ L _Dl), wherein N is the length of OFDM symbol, and the available pilot frequency sequence quantity that is obtained by functional expression (34) institute restrictive condition is: N/L _UlAs seen: the technical scheme of using the present embodiment can increase the available pilot number in the OFDM symbol greatly with respect to the technical scheme of embodiment 3, further reduces pilot-frequency expense.

Embodiment 5:

The structural representation of a kind of communication equipment that Fig. 6 provides for the present embodiment, as shown, this communication equipment can comprise:

Receiving element 601 is used for receiving the descending pilot frequency that second communication equipment issues, and the descending pilot frequency that wherein receives can the form on time domain satisfy the represented restrictive condition of functional expression among the embodiment (11).

Pilot codes unit 602, the descending pilot frequency and the ascending pilot frequency that are used for receiving superpose, and consist of hybrid pilot.

Pilot codes unit 602 can comprise:

Ascending pilot frequency coding unit 6021, the ascending pilot frequency that is used for sending out on the subtend second communication equipment is encoded, and makes each ascending pilot frequency satisfy functional expression (16), (17) represented restrictive condition among the embodiment 2.

Hybrid pilot coding unit 6022, the descending pilot frequency that the ascending pilot frequency that obtains for ascending pilot frequency coding unit 6021 is encoded and receiving element 601 receive carries out supercomposed coding.

Because, 602 pairs of pilot codes unit are so that the hybrid pilot that generates satisfies functional expression (16), (17) represented restrictive condition simultaneously, after can guaranteeing that second communication equipment receives this hybrid pilot, the impact of the descending pilot frequency that can not be applied the estimation of up channel, closed loop channel.

Coding herein is superposed to: ascending pilot frequency and descending pilot frequency are superimposed upon in the subcarrier of an OFDM symbol.In ofdm system, the hybrid pilot after this stack shows as: in a subcarrier of an OFDM symbol, comprise the descending pilot frequency of the down channel between second communication equipment and the second communication equipment and the ascending pilot frequency of corresponding up channel.

Transmitting element 603 is used for sending described hybrid pilot to second communication equipment, and it is generally transmitting antenna.

Need to prove, if this communication system is supported the MIMO technology, then the hybrid pilot that sends of each antenna is the hybrid pilot of pilot codes unit 602 for needing to send via this antenna, and namely this hybrid pilot is: each descending pilot frequency that each antenna by second communication equipment that this antenna receives issues and this antenna need the stack of the ascending pilot frequency that sends to this second communication equipment.

Communication terminal can generate hybrid pilot with pilot codes unit 602 and be sent to second communication equipment by transmitting element 603.

But, general in conjunction with processing of the prior art, as shown in Figure 7, after pilot codes unit 602 generates hybrid pilot, can use modulating unit 604 that the hybrid pilot that generates is carried out the OFDM modulation with upstream data, then, use CP coding unit 605, ofdm signal after the modulation is added the laggard row of CP carry out ul transmissions by transmitting element 603, be sent to second communication equipment.

The communication equipment of the present embodiment can but be not limited to terminal.

Therefore, the communication equipment that the embodiment of the invention provides, receive the descending pilot frequency that second communication equipment issues by 602 pairs of communication systems in pilot codes unit wherein, and this communication system treats that the ascending pilot frequency of sending out carries out the mixing stack on this second communication equipment, in the transmission ascending pilot frequency, the descending pilot frequency that receives is back to this second communication equipment, so that this second communication equipment can be according to received hybrid pilot, and known ascending pilot frequency, estimate up channel, estimating down channel according to the up channel of estimating in conjunction with known descending pilot frequency, thereby obtain the parameter of down channel, the concrete processing procedure of its second communication equipment sees embodiment 3 for details, associated description in 4, therefore not to repeat here.So that second communication equipment can carry out corresponding preliminary treatment (precoding or preequalization) according to this down channel parameter.

Simultaneously, because this communication system is by transmitting by descending pilot frequency, the hybrid pilot of ascending pilot frequency stack, make second communication equipment obtain the parameter of down channel, rather than as described in the prior artly carry out corresponding down channel at the communication equipment end and estimate, the down channel parameter that again estimation is obtained is with the transmission of ascending pilot frequency, take certain subcarrier in the signal that sends, be passed to second communication equipment, make second communication equipment obtain the parameter of down channel, as seen, using communication equipment of the present invention can either avoid this communication system that down channel is estimated, the processing that precoding etc. are complicated, can also avoid the distortion that produces in the parameter transmission course of down channel, in addition, because the stack of the 602 pairs of ascending pilot frequencies in pilot codes unit and ascending pilot frequency, use that communication equipment of the present invention has greatly reduced in order to reach that second communication equipment obtains the purpose of descending channel information with respect to prior art and the pilot-frequency expense used has been saved the transfer resource cost.

Embodiment 6:

The structural representation of the another kind of communication equipment that Fig. 8 provides for the present embodiment, as shown, the difference of communication equipment shown in Figure 7 is among the communication equipment of the present embodiment and the embodiment 5:

First: the receiving element 801 in the present embodiment has been replaced receiving element 601 among the embodiment 5, receiving element 801 is used for receiving the descending pilot frequency that second communication equipment issues, and the descending pilot frequency that wherein receives can the form on time domain satisfy the represented restrictive condition of functional expression among the embodiment (33).

Second: the second hybrid pilot coding unit 8022 in the pilot codes unit 802 in the present embodiment, ascending pilot frequency coding unit 8021 have been replaced respectively the hybrid pilot coding unit 6022 in the pilot codes unit 602, ascending pilot frequency coding unit 6021 among the embodiment 5.

Ascending pilot frequency coding unit 8021 in the present embodiment, the ascending pilot frequency that is used for sending out on the subtend second communication equipment is encoded, and makes each ascending pilot frequency satisfy functional expression (39), (34) represented restrictive condition among the embodiment 4.

The second hybrid pilot coding unit 8022, the descending pilot frequency that the ascending pilot frequency of determining for ascending pilot frequency coding unit 8021 is encoded and receiving element 801 receive carries out supercomposed coding.

Because, the ascending pilot frequency that generates of ascending pilot frequency coding unit 8021 satisfies functional expression (39), (34) represented restrictive condition simultaneously, after can guaranteeing that second communication equipment receives this hybrid pilot, the impact of the descending pilot frequency that can not be applied the estimation of up channel.

Therefore, the communication equipment that the embodiment of the invention provides, receive the descending pilot frequency that second communication equipment issues by 802 pairs of communication systems in pilot codes unit wherein, and this communication system treats that the ascending pilot frequency of sending out carries out the mixing stack on this second communication equipment, in the transmission ascending pilot frequency, the descending pilot frequency that receives is back to this second communication equipment, so that this second communication equipment can be according to received hybrid pilot, and known ascending pilot frequency is when estimating up channel, and according to the up channel of estimating, the hybrid pilot that can recover to receive is at the channel of pilot transmission end, thereby can be according to the hybrid pilot that recovers, and known descending pilot frequency, ascending pilot frequency, obtain the parameter of down channel, the concrete processing procedure of its second communication equipment sees embodiment 3 for details, associated description in 4, therefore not to repeat here.Thereby can carry out corresponding preliminary treatment (precoding or preequalization) according to this down channel parameter.

Simultaneously, in like manner in embodiment 5, using communication equipment of the present invention can either avoid this communication system to the complicated processing such as down channel estimation, precoding, can also avoid the distortion that produces in the parameter transmission course of down channel, in addition, because the stack of the 802 pairs of ascending pilot frequencies in pilot codes unit and ascending pilot frequency, use that communication equipment of the present invention has greatly reduced in order to reach that second communication equipment obtains the purpose of descending channel information with respect to prior art and the pilot-frequency expense used has been saved the transfer resource cost.

Embodiment 7:

The structural representation of a kind of communication equipment that Fig. 9 provides for the present embodiment, as shown, this communication equipment can comprise:

Descending pilot frequency coding unit 901 is encoded for the descending pilot frequency that subtend second communication equipment issues, and makes described descending pilot frequency satisfy functional expression among the embodiment 2 (11), (17) represented restrictive condition.Wherein, the form of ascending pilot frequency on time domain in functional expression (11), (17) satisfies the represented restrictive condition of functional expression (16).Above-mentioned restrictive condition can so that: second communication equipment is after receiving this descending pilot frequency, hybrid pilot with this descending pilot frequency and ascending pilot frequency stack generation, and after hybrid pilot being sent to the communication equipment of the present embodiment, the impact of the descending pilot frequency that the communication equipment of the present embodiment is not applied the estimation of up channel or closed loop channel according to this hybrid pilot.

Descending pilot frequency coding unit 901 makes the descending pilot frequency that issues satisfy the functional expression shown in functional expression (11), (17), and the second communication equipment of avoiding this descending pilot frequency to arrive is processed it again, and directly itself and ascending pilot frequency stack is got final product.

Transmitting element 902 is used for the descending pilot frequency that descending pilot frequency coding unit 901 generates is sent to second communication equipment.

Receiving element 903 be used for to receive the hybrid pilot that is sent by described second communication equipment, and wherein this hybrid pilot is: the descending pilot frequency that is sent by this communication equipment that described second communication equipment receives and the stack of ascending pilot frequency.

General, transmitting element 902, receiving element 903 can be the antenna of this communication equipment.

Uplink channel estimation unit 904, for the hybrid pilot that receives according to receiving element 903, and known ascending pilot frequency, up channel is estimated, obtain the up channel parameter.Its concrete estimation procedure sees the corresponding description among the embodiment 1,2 for details.

Closed loop channel estimating unit 905 for the hybrid pilot that receives according to receiving element 903 and known descending pilot frequency, is estimated the closed loop channel, obtains the closed loop channel parameter.Its concrete estimation procedure sees the corresponding description among the embodiment 1,2 for details.

Down channel estimation unit 906 is used for estimating that according to closed loop channel estimating unit 905 the closed loop channel parameter that obtains and uplink channel estimation unit 904 estimate the up channel parameter of obtaining, and obtains the down channel parameter.

Need to prove, the communication equipment of the present embodiment can but be not limited to the base station, corresponding, described second communication equipment can but be not limited to terminal.

Therefore the communication equipment that the embodiment of the invention provides can be estimated up channel and closed loop channel according to the hybrid pilot that receives, thereby according to up channel, the closed loop channel estimating down channel estimated, obtains the down channel parameter.Thereby can carry out corresponding preliminary treatment (precoding or preequalization) according to this down channel parameter.

Embodiment 8:

The structural representation of the communication equipment that Figure 10 provides for the present embodiment, as shown, this communication equipment can comprise:

Descending pilot frequency coding unit 1001, encode for the descending pilot frequency that subtend second communication equipment issues, make described descending pilot frequency satisfy functional expression among the embodiment 4 (33), (34) represented restrictive condition, wherein the ascending pilot frequency in functional expression (33), (34) satisfies the represented restrictive condition of functional expression (39).

Above-mentioned restrictive condition can so that: second communication equipment is after receiving this descending pilot frequency, hybrid pilot with this descending pilot frequency and ascending pilot frequency stack generation, and after hybrid pilot being sent to the communication equipment of the present embodiment, the impact of the descending pilot frequency that the communication equipment of the present embodiment is not applied up channel according to this hybrid pilot, and can recover hybrid pilot at the signal at this second communication equipment place according to this descending pilot frequency, thereby estimate to obtain the parameter of up channel.

Transmitting element 1002, receiving element 1003 and uplink channel estimation unit 1004, and they are identical with transmitting element 1002, receiving element 1003, uplink channel estimation unit 904 among the embodiment 7 respectively.

Hybrid pilot recovery unit 1005, be used for estimating the up channel parameter of obtaining and the hybrid pilot that receives according to uplink channel estimation unit 904, the hybrid pilot that second communication equipment sends is obtained in recovery, namely recovers to obtain the hybrid pilot that receives at the signal of transmitting terminal (second communication equipment) end of this hybrid pilot.Its specific works principle sees the associated description among the embodiment 3,4 for details.

Down channel estimation unit 1006 for known descending pilot frequency, the ascending pilot frequency of hybrid pilot, this communication equipment that the second communication equipment of estimating according to hybrid pilot recovery unit 1005 to obtain sends, is estimated down channel, obtains the down channel parameter.Its specific works principle sees the associated description among the embodiment 3,4 for details.

Therefore, the communication equipment that the embodiment of the invention provides can be according to the hybrid pilot that receives, estimate up channel and according to estimated down channel, the signal that the hybrid pilot that recovers to receive is located at this pilot transmission end (second communication equipment), again according to the hybrid pilot of this recovery, in conjunction with known descending pilot frequency, ascending pilot frequency, obtain the down channel parameter.Thereby can carry out corresponding preliminary treatment (precoding or preequalization) according to this down channel parameter.

Need to prove, the communication equipment of the present embodiment both can adopt the form of hardware to realize, also can adopt the form of software function module to realize.The present embodiment device both can be used as independently production marketing or use, also can be stored in the computer read/write memory medium.

Above a kind of method, communication equipment that obtains channel information that the embodiment of the invention is provided is described in detail, used specific case herein principle and the execution mode of the embodiment of the invention are set forth, the explanation of above embodiment just is used for helping to understand method and the principle thereof of the embodiment of the invention; Simultaneously, for one of ordinary skill in the art, the common variation of carrying out in the technical solution of the present invention scope and replacement all should be included in protection scope of the present invention.

Claims (16)

1. a method of obtaining channel information is characterized in that, comprising:

The first communication equipment receives the descending pilot frequency that second communication equipment issues, and descending pilot frequency and the ascending pilot frequency stack that receives generated hybrid pilot, and described hybrid pilot is sent to described second communication equipment;

Described second communication equipment receives described hybrid pilot, and according to the hybrid pilot that receives and known ascending pilot frequency, up channel is estimated, obtains the up channel parameter;

Described second communication equipment is estimated the closed loop channel according to known descending pilot frequency and the hybrid pilot that receives, is obtained the closed loop channel parameter;

Described second communication equipment obtains the down channel parameter according to described closed loop channel parameter, described up channel parameter;

Wherein, described descending pilot frequency and described ascending pilot frequency satisfy following condition:

Described descending pilot frequency is impulse function in the convolution results on the time domain in the scope of the time delay extension length sum of the time delay extension length of up channel and down channel;

Described ascending pilot frequency is impulse function in the time delay extension length scope of the convolution results on the time domain at up channel;

Described ascending pilot frequency and described descending pilot frequency, its both convolution results are zero in the scope of the time delay extension length sum of the time delay extension length of up channel and down channel.

2. the method for obtaining channel information according to claim 1 is characterized in that, the descending pilot frequency that described the first communication equipment receives comprises:

The descending pilot frequency that described the first communication equipment of at least one day alignment of described second communication equipment issues;

Described ascending pilot frequency is:

The ascending pilot frequency that the sky described second communication equipment of alignment of described the first communication equipment sends.

3. the method for obtaining channel information according to claim 1 and 2 is characterized in that, each descending pilot frequency that described the first communication equipment of each day alignment of described second communication equipment issues, and its form on time domain satisfies:

$\underset{n}{\mathrm{\&Sigma;}}{p}_{\mathrm{dl}}^i*\left(t\right)p_{\mathrm{dl}}^j(n-t)=\left\{\begin{array}{cc}a& n=0\\ 0& 0<n\&le;L_{\mathrm{dl}}+L_{\mathrm{ul}}\end{array}\right.,$

Wherein said

The descending pilot frequency that issues to described the first communication equipment for the antenna i of described second communication equipment Conjugation,

Be the descending pilot frequency that the antenna j of described second communication equipment issues to described the first communication equipment, L _DlBe the time delay extension length of down channel, L _UlBe the time delay extension length of up channel, a is the real number greater than zero, and i, j are the antenna sign of second communication equipment;

The ascending pilot frequency of sending out on the described second communication equipment of described first communication equipment each day alignment, its form on time domain satisfies:

$\underset{n}{\mathrm{\&Sigma;}}{p}_{\mathrm{ul}}^i*\left(t\right)p_{\mathrm{ul}}^j(n-t)=\left\{\begin{array}{cc}a& n=0\\ 0& 0<n\&le;L_{\mathrm{ul}}\end{array}\right.,$

Wherein, described

Be that the antenna i of the first communication equipment is to the ascending pilot frequency of described second communication equipment transmission

Conjugation,

Be that the antenna j of the first communication equipment is to the ascending pilot frequency of described second communication equipment transmission, L _UlBe the time delay extension length of up channel, a is the real number greater than zero, and i, j are the antenna sign of the first communication equipment;

Described each ascending pilot frequency and described each descending pilot frequency satisfy:

$\underset{n}{\mathrm{\&Sigma;}}{p}_{\mathrm{ul}}^i*\left(t\right)p_{\mathrm{dl}}^j(n-t)=\mathrm{0,0}<n\&le;L_{\mathrm{ul}}+L_{\mathrm{dl}},$

Wherein said

Be that the antenna i of the first communication equipment is to the ascending pilot frequency of described second communication equipment transmission

Conjugation,

Be the descending pilot frequency that the antenna j of described second communication equipment issues to described the first communication equipment, L _DlBe the time delay extension length of down channel, L _UlBe the time delay extension length of up channel, a is the real number greater than zero, and i, j are respectively the antenna sign of the first communication equipment, second communication equipment.

4. the method for obtaining channel information according to claim 3 is characterized in that, described the first communication equipment is sent to described second communication equipment with described hybrid pilot, comprising:

The transmitting power that described the first communication equipment determines to distribute to described each ascending pilot frequency accounts for the ratio of the constant transmit power of described hybrid pilot, and wherein, the power of the described hybrid pilot of described emission is not more than predetermined hybrid pilot upper limit of emission power;

Described the first communication equipment is launched described hybrid pilot to described second communication equipment, and described each ratio is passed to described second communication equipment according to constant transmit power and described each ratio of described hybrid pilot;

Described second communication equipment is estimated up channel according to the hybrid pilot that receives and known ascending pilot frequency, being comprised:

Described second communication equipment is determined actual ascending pilot frequency according to described each ratio and described known ascending pilot frequency;

Described second communication equipment is estimated described each up channel according to the ascending pilot frequency of described reality, the hybrid pilot that receives.

5. the method for obtaining channel information according to claim 3 is characterized in that, described the first communication equipment is sent to described second communication equipment with described hybrid pilot, comprising:

The transmitting power that described the first communication equipment will be distributed to each ascending pilot frequency is firm power, and each transmitting power of wherein distributing to each ascending pilot frequency is all less than the upper limit of the transmitting power of predetermined described hybrid pilot;

Described the first communication equipment is determined the transmitting power of the described hybrid pilot of emission;

Described the first communication equipment is launched described hybrid pilot according to each transmitting power of described each ascending pilot frequency, the transmitting power of described hybrid pilot to described second communication equipment;

Described second communication equipment is estimated up channel according to the hybrid pilot that receives and known ascending pilot frequency, being comprised:

Described second communication equipment is determined actual ascending pilot frequency according to the transmitting power of known described each ascending pilot frequency;

Described second communication equipment is estimated described each up channel respectively according to the ascending pilot frequency of described reality, the hybrid pilot that receives.

6. a method of obtaining channel information is characterized in that, comprising:

The first communication equipment receives the descending pilot frequency that second communication equipment issues, and descending pilot frequency and the ascending pilot frequency stack that receives generated hybrid pilot, and described hybrid pilot is sent to described second communication equipment;

Described second communication equipment receives described hybrid pilot, and according to the hybrid pilot that receives and known ascending pilot frequency, up channel is estimated, obtains the up channel parameter;

Described second communication equipment recovers to obtain the hybrid pilot of described the first communication equipment emission according to described up channel parameter;

Described second communication equipment according to the hybrid pilot of the first communication equipment emission that recovers to obtain, known ascending pilot frequency, known descending pilot frequency, obtain the down channel parameter;

Wherein, described descending pilot frequency and described ascending pilot frequency satisfy following condition:

Described descending pilot frequency is impulse function in the convolution results on the time domain in the scope of the time delay extension length of down channel;

Described ascending pilot frequency is impulse function in the time delay extension length scope of the convolution results on the time domain at up channel;

Described ascending pilot frequency and described descending pilot frequency, its both convolution results are zero in the scope of the time delay extension length of up channel.

7. the method for obtaining channel information according to claim 6 is characterized in that, the descending pilot frequency that described the first communication equipment receives comprises:

The descending pilot frequency that described the first communication equipment of at least one day alignment of described second communication equipment issues;

Described ascending pilot frequency is:

The ascending pilot frequency that the sky described second communication equipment of alignment of described the first communication equipment sends.

8. according to claim 6 or the 7 described methods of obtaining channel information, it is characterized in that each descending pilot frequency that described first communication equipment of each day alignment of described second communication equipment issues, its form on time domain satisfies:

$\underset{n}{\mathrm{\&Sigma;}}{p}_{\mathrm{dl}}^i*\left(t\right)p_{\mathrm{dl}}^j(n-t)=\left\{\begin{array}{cc}a& n=0\\ 0& 0<n\&le;L_{\mathrm{dl}}\end{array}\right.,$

Wherein said

The descending pilot frequency that issues to described the first communication equipment for the antenna i of described second communication equipment

Conjugation,

Be the descending pilot frequency that the antenna j of described second communication equipment issues to described the first communication equipment, L _DlBe the time delay extension length of down channel, a is the real number greater than zero, and i, j are the antenna sign of second communication equipment;

The ascending pilot frequency of sending out on the described second communication equipment of described first communication equipment each day alignment, its form on time domain satisfies:

$\underset{n}{\mathrm{\&Sigma;}}{p}_{\mathrm{ul}}^i*\left(t\right)p_{\mathrm{ul}}^j(n-t)=\left\{\begin{array}{cc}a& n=0\\ 0& 0<n\&le;L_{\mathrm{ul}}\end{array}\right.,$

Wherein, described

Be that the antenna i of the first communication equipment is to the ascending pilot frequency of described second communication equipment transmission

Conjugation,

Be that the antenna j of the first communication equipment is to the ascending pilot frequency of described second communication equipment transmission, L _UlBe the time delay extension length of up channel, a is the real number greater than zero, and i, j are the antenna sign of the first communication equipment;

Described each ascending pilot frequency and described each descending pilot frequency satisfy:

$\underset{n}{\mathrm{\&Sigma;}}{p}_{\mathrm{ul}}^i*\left(t\right)p_{\mathrm{dl}}^j(n-t)=\mathrm{0,0}<n\&le;L_{\mathrm{ul}},$

Wherein said

Be that the antenna i of the first communication equipment is to the ascending pilot frequency of described second communication equipment transmission

Conjugation,

Be the descending pilot frequency that the antenna j of described second communication equipment issues to described the first communication equipment, L _UlBe the time delay extension length of up channel, a is the real number greater than zero, and i, j are respectively the antenna sign of the first communication equipment, second communication equipment.

9. the method for obtaining channel information according to claim 8 is characterized in that, described the first communication equipment is sent to described second communication equipment with described hybrid pilot, comprising:

The transmitting power that described the first communication equipment determines to distribute to described each ascending pilot frequency accounts for the ratio of the constant transmit power of described hybrid pilot, and wherein, the power of the described hybrid pilot of described emission is not more than predetermined hybrid pilot upper limit of emission power;

Described the first communication equipment is launched described hybrid pilot to described second communication equipment, and described each ratio is passed to described second communication equipment according to constant transmit power and described each ratio of described hybrid pilot;

Described second communication equipment is estimated up channel according to the hybrid pilot that receives and known ascending pilot frequency, being comprised:

Described second communication equipment is determined actual ascending pilot frequency according to described each ratio and described known ascending pilot frequency;

Described second communication equipment is estimated described each up channel according to the ascending pilot frequency of described reality, the hybrid pilot that receives.

10. the method for obtaining channel information according to claim 8 is characterized in that, described the first communication equipment is sent to described second communication equipment with described hybrid pilot, comprising:

The transmitting power that described the first communication equipment will be distributed to each ascending pilot frequency is firm power, and each transmitting power of wherein distributing to each ascending pilot frequency is all less than the upper limit of the transmitting power of predetermined described hybrid pilot;

Described the first communication equipment is determined the transmitting power of the described hybrid pilot of emission;

Described the first communication equipment is launched described hybrid pilot according to each transmitting power of described each ascending pilot frequency, the transmitting power of described hybrid pilot to described second communication equipment;

Described second communication equipment is estimated up channel according to the hybrid pilot that receives and known ascending pilot frequency, being comprised:

Described second communication equipment is determined actual ascending pilot frequency according to the transmitting power of known described each ascending pilot frequency;

Described second communication equipment is estimated described each up channel respectively according to the ascending pilot frequency of described reality, the hybrid pilot that receives.

11. a communication equipment is characterized in that, comprising:

Receiving element is used for receiving the descending pilot frequency that second communication equipment issues;

The pilot codes unit, the descending pilot frequency and the ascending pilot frequency that are used for receiving superpose, and consist of hybrid pilot;

Transmitting element, be used for sending described hybrid pilot to described second communication equipment, so that described second communication equipment: according to described hybrid pilot and known ascending pilot frequency, up channel is estimated, obtained the up channel parameter, according to known descending pilot frequency and the hybrid pilot that receives, the closed loop channel is estimated, obtain the closed loop channel parameter, according to described closed loop channel parameter, described up channel parameter, obtain the down channel parameter;

Wherein, described descending pilot frequency and described ascending pilot frequency satisfy following condition:

Described descending pilot frequency is impulse function in the convolution results on the time domain in the scope of the time delay extension length sum of the time delay extension length of up channel and down channel;

Described ascending pilot frequency is impulse function in the time delay extension length scope of the convolution results on the time domain at up channel;

Described ascending pilot frequency and described descending pilot frequency, its both convolution results are zero in the scope of the time delay extension length sum of the time delay extension length of up channel and down channel.

12. communication equipment according to claim 11 is characterized in that, described pilot codes unit comprises:

The ascending pilot frequency coding unit, the ascending pilot frequency that is used for sending out on the subtend second communication equipment is encoded, and the form of each ascending pilot frequency on time domain satisfied:

$\underset{n}{\mathrm{\&Sigma;}}{p}_{\mathrm{ul}}^i*\left(t\right)p_{\mathrm{ul}}^j(n-t)=\left\{\begin{array}{cc}a& n=0\\ 0& 0<n\&le;L_{\mathrm{ul}}\end{array}\right.,$

Wherein, described

The ascending pilot frequency that sends to described second communication equipment for the antenna i of this communication equipment Conjugation,

Be the ascending pilot frequency that the antenna j of this communication equipment sends to described second communication equipment, L _UlBe the time delay extension length of up channel, a is the real number greater than zero, and i, j are the antenna sign of this communication equipment,

$\underset{n}{\mathrm{\&Sigma;}}{p}_{\mathrm{ul}}^i*\left(t\right)p_{\mathrm{dl}}^j(n-t)=\mathrm{0,0}<n\&le;L_{\mathrm{ul}}+L_{\mathrm{dl}},$

Wherein, described

The ascending pilot frequency that sends to described second communication equipment for the antenna i of this communication equipment

Conjugation,

Be the descending pilot frequency that described receiving element antenna j that receive, described second communication equipment issues to this communication equipment, L _DlBe the time delay extension length of down channel, L _UlBe the time delay extension length of up channel, a is the real number greater than zero, and i, j are respectively the antenna sign of this communication equipment, second communication equipment;

The hybrid pilot coding unit, the descending pilot frequency that the ascending pilot frequency of determining for described ascending pilot frequency coding unit is encoded and described receiving element receive carries out supercomposed coding.

13. a communication equipment is characterized in that, comprising:

Receiving element is used for receiving the descending pilot frequency that second communication equipment issues;

The pilot codes unit, the descending pilot frequency and the ascending pilot frequency that are used for receiving superpose, and consist of hybrid pilot;

Transmitting element, be used for sending described hybrid pilot to described second communication equipment, so that described second communication equipment: according to described hybrid pilot and known ascending pilot frequency, up channel is estimated, obtain the up channel parameter, according to described up channel parameter, recover to obtain the hybrid pilot of described the first communication equipment emission, the hybrid pilot that the first communication equipment that recovers to obtain according to institute is launched, known ascending pilot frequency, known descending pilot frequency, obtain the down channel parameter;

Wherein, described descending pilot frequency and described ascending pilot frequency satisfy following condition:

Described descending pilot frequency is impulse function in the convolution results on the time domain in the scope of the time delay extension length of down channel;

Described ascending pilot frequency is impulse function in the time delay extension length scope of the convolution results on the time domain at up channel;

Described ascending pilot frequency and described descending pilot frequency, its both convolution results are zero in the scope of the time delay extension length of up channel.

14. communication equipment according to claim 13 is characterized in that, described pilot codes unit comprises:

The ascending pilot frequency coding unit, the ascending pilot frequency that is used for sending out on the subtend second communication equipment is encoded, and the form of each ascending pilot frequency on time domain satisfied:

$\underset{n}{\mathrm{\&Sigma;}}{p}_{\mathrm{ul}}^i*\left(t\right)p_{\mathrm{ul}}^j(n-t)=\left\{\begin{array}{cc}a& n=0\\ 0& 0<n\&le;L_{\mathrm{ul}}\end{array}\right.,$

Wherein, described

The ascending pilot frequency that sends to described second communication equipment for the antenna i of this communication equipment

Conjugation,

Be the ascending pilot frequency that the antenna j of this communication equipment sends to described second communication equipment, L _UlBe the time delay extension length of up channel, a is the real number greater than zero,

$\underset{n}{\mathrm{\&Sigma;}}{p}_{\mathrm{ul}}^i*\left(t\right)p_{\mathrm{dl}}^j(n-t)=\mathrm{0,0}<n\&le;L_{\mathrm{ul}},$

Wherein said

The ascending pilot frequency that sends to described second communication equipment for the antenna i of this communication equipment

Conjugation,

Be the descending pilot frequency that described receiving element antenna j that receive, described second communication equipment issues to this communication equipment, L _UlBe the time delay extension length of up channel, a is the real number greater than zero;

The second hybrid pilot coding unit, the descending pilot frequency that the ascending pilot frequency of determining for described ascending pilot frequency coding unit is encoded and described receiving element receive carries out supercomposed coding.

15. a communication equipment is characterized in that, comprising:

The descending pilot frequency coding unit is encoded for the descending pilot frequency that subtend second communication equipment issues, and the form of described descending pilot frequency on time domain satisfied:

$\underset{n}{\mathrm{\&Sigma;}}{p}_{\mathrm{dl}}^i*\left(t\right)p_{\mathrm{dl}}^j(n-t)=\left\{\begin{array}{cc}a& n=0\\ 0& 0<n\&le;L_{\mathrm{dl}}+L_{\mathrm{ul}}\end{array}\right.,$

Wherein said

The descending pilot frequency that issues to described second communication equipment for the antenna i of this communication equipment

Conjugation,

Be the descending pilot frequency that the antenna j of this communication equipment issues to described second communication equipment, L _DlBe the time delay extension length of down channel, L _UlBe the time delay extension length of up channel, a is the real number greater than zero,

$\underset{n}{\mathrm{\&Sigma;}}{p}_{\mathrm{ul}}^i*\left(t\right)p_{\mathrm{dl}}^j(n-t)=\mathrm{0,0}<n\&le;L_{\mathrm{ul}}+L_{\mathrm{dl}},$

Wherein, described Be the ascending pilot frequency of second communication device antenna i to the transmission of this communication equipment

Conjugation,

Be the descending pilot frequency that the antenna j of this communication equipment issues to described second communication equipment, L _DlBe the time delay extension length of down channel, L _UlBe the time delay extension length of up channel, a is the real number greater than zero;

Wherein, described ascending pilot frequency is impulse function in the time delay extension length scope of the convolution results on the time domain at up channel;

Transmitting element is used for the descending pilot frequency that described descending pilot frequency coding unit generates is sent to described second communication equipment;

Receiving element is used for receiving the described hybrid pilot that is sent by described second communication equipment, and wherein said hybrid pilot is: the descending pilot frequency that is sent by this communication equipment that described second communication equipment receives and the stack of ascending pilot frequency;

The uplink channel estimation unit is used for according to described hybrid pilot, and known ascending pilot frequency, and up channel is estimated, obtains the up channel parameter;

The closed loop channel estimating unit is used for according to the hybrid pilot that receives and known descending pilot frequency, and the closed loop channel is estimated, obtains the closed loop channel parameter;

The down channel estimation unit is used for according to described closed loop channel parameter and described up channel parameter, obtains the down channel parameter.

16. a communication equipment is characterized in that, comprising:

The descending pilot frequency coding unit is encoded for the descending pilot frequency that subtend second communication equipment issues, and the form of described descending pilot frequency on time domain satisfied:

$\underset{n}{\mathrm{\&Sigma;}}{p}_{\mathrm{dl}}^i*\left(t\right)p_{\mathrm{dl}}^j(n-t)=\left\{\begin{array}{cc}a& n=0\\ 0& 0<n\&le;L_{\mathrm{dl}}\end{array}\right.,$

Wherein said

The descending pilot frequency that issues to described second communication equipment for the antenna i of this communication equipment

Conjugation,

Be the descending pilot frequency that the antenna j of this communication equipment issues to described second communication equipment, L _DlBe the time delay extension length of down channel, a is the real number greater than zero,

$\underset{n}{\mathrm{\&Sigma;}}{p}_{\mathrm{ul}}^i*\left(t\right)p_{\mathrm{dl}}^j(n-t)=\mathrm{0,0}<n\&le;L_{\mathrm{ul}},$

Wherein, described

Be the ascending pilot frequency of second communication device antenna i to the transmission of this communication equipment

Conjugation,

Be the descending pilot frequency that the antenna j of this communication equipment issues to described second communication equipment, L _DlBe the time delay extension length of down channel, L _UlBe the time delay extension length of up channel, a is the real number greater than zero;

Wherein, described ascending pilot frequency is impulse function in the time delay extension length scope of the convolution results on the time domain at up channel;

Transmitting element is used for the descending pilot frequency that described descending pilot frequency coding unit generates is sent to described second communication equipment;

Receiving element is used for receiving the described hybrid pilot that is sent by described second communication equipment, and wherein said hybrid pilot is: the descending pilot frequency that is sent by this communication equipment that described second communication equipment receives and the stack of ascending pilot frequency;

The uplink channel estimation unit is used for according to described hybrid pilot, and known ascending pilot frequency, and up channel is estimated, obtains the up channel parameter;

The hybrid pilot recovery unit is used for recovering to obtain the hybrid pilot that described second communication equipment sends according to described up channel parameter and the hybrid pilot that receives;

The down channel estimation unit, the hybrid pilot that is used for sending according to described second communication equipment, known descending pilot frequency and known ascending pilot frequency obtain the down channel parameter.

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