CN105163357A - LTE distributed transmission method based on scheduling mode switching - Google Patents

Abstract

The invention provides an LTE distributed transmission method based on scheduling mode switching. The validity of a first distributed transmission scheduling mode is compared with the validity of a second distributed transmission scheduling mode according to reported channel state information, transmission space power negative gain coefficient and mobile frequency offset information, and a distributed transmission scheme adopted for the present transmission is determined according to the result of comparison; due to the switching of a plurality of scheduling modes, the dependency on the ideality of the information state is reduced and the distributed transmission performance of the system is greatly improved.

Description

A kind of LTE distributed transmission method switched based on scheduling mode

Technical field

The present invention relates to wireless communication field, particularly relate to a kind of LTE distributed transmission method switched based on scheduling mode.

Background technology

LTE (Long Term Evolution) is the Long Term Evolution of UMTS (universal mobile telecommunications system) technical standard organized to set up by 3GPP (third generation partner program), in December, 2004 formally sets up the project and starts in the TSGRAN#26 meeting of 3GPP Toronto.LTE system introduces the critical transmissions technology such as OFDM (OFDM) and MIMO (multiple-input and multiple-output), (20M bandwidth 2X2MIMO is in 64QAM situation to significantly increase spectrum efficiency and data transmission bauds, theoretical descending maximum transfer speed is 201Mbps, be probably 140Mbps after removing signaling consumption, but according to actual networking and terminal capability restriction, it is generally acknowledged that down peak magnitude speed is 100Mbps, upper behavior 50Mbps), and support that various bandwidth is distributed: 1.4MHz, 3MHz, 5MHz, 10MHz, 15MHz and 20MHz etc., and support global main flow 2G/3G frequency range and some newly-increased frequency ranges, thus spectrum allocation may is more flexible, power system capacity and covering also significantly promote.The LTE system network architecture more flattening is simplified, and decreases network node and system complexity, thus reduces Time Delay of Systems, also reduce network design and maintenance cost.LTE system is supported and other 3GPP interoperability of system.LTE system has two kinds of standard: FDD-LTE and TDD-LTE, i.e. Frequency Division Duplexing (FDD) LTE system and time division duplex LTE system, and the main distinction of the two technology is in the physical layer of air interface (picture frame structure, time-division design, synchronous etc.).FDD-LTE system downstream transmission of eating dishes without rice or wine adopts UHF band reception and the transmitting data of a pair symmetry, and TDD-LTE system up-downgoing then uses identical frequency range to transmit on different frame slots, and relative to FDD duplex mode, TDD has the higher availability of frequency spectrum.

And in the application of actual LTE system, greatly influential system performance is understood in interference from same community and adjacent cell, therefore need to suppress interference, simultaneously, be in " hunger " state because border cell user usually can not get scheduling, therefore need the distributed transmission considering border cell user.

For participating in the border cell user of distributed transmission, no matter be FDD system or TDD system, all need real-time to provide base station reporting status information of channel or base station to estimate channel condition information according to reciprocity principle to its business.But for community, above-mentioned channel condition information is nonideal channel condition information often, this can cause the performance of distributed transmission significantly to decline.

Summary of the invention

The object of the invention is to be achieved through the following technical solutions.

According to the embodiment of the present invention, propose a kind of LTE distributed transmission method switched based on scheduling mode, described method comprises:

In M service district of S1, statistics participation distributed transmission, the stable translational speed of multiple mobile client, calculates the travel frequency skew of user, according to travel frequency calculations of offset outbound path phase delay parameter;

S2, each service district are chosen a mobile client by round-robin scheduling and are prepared transfer of data, when each transmission starts, first described mobile client calculates self scalar signal to noise ratio (SNR) value, and described scalar SNR is compared with response lag, if described scalar SNR value is less than response lag, then waits for and dispatching next time; If described scalar SNR value is more than or equal to response lag, then described mobile client carries out channel estimating to obtain channel condition information and transmission space power negative gain factor, again according to existing launching code prediction scheme, modulation channel state information, and modulation channel state information and transmission space power negative gain factor are reported corresponding service base station;

S3, described corresponding service base station carry out Usefulness Pair ratio according to the channel condition information reported, transmission space power negative gain factor and travel frequency offset information to the first distributed transmission scheduling mode and the second distributed transmission scheduling mode; And determine according to comparing result the distributed transmission scheme that this transmission adopts;

S4, described corresponding service base station, according to selected distributed transmission scheme, utilize the channel condition information reported to calculate launching code vector, are then modulated by data acquisition launching code vector to be sent, and carry out transfer of data.

According to the embodiment of the present invention, described first distributed transmission scheduling mode is the continuous transmission means of multiframe time slot.

According to the embodiment of the present invention, described second distributed transmission scheduling mode is single frames time slot hop transmission mode.

According to the embodiment of the present invention, Usefulness Pair ratio is carried out to the first distributed transmission scheduling mode and the second distributed transmission scheduling mode in the corresponding service base station of described step S3, and determines that the distributed transmission scheme that this transmission adopts specifically comprises according to comparing result:

S31, calculate the first distributed transmission scheduling mode under perform the stable transfer data volume peak value SR of distributed transmission ₁;

S32, calculate the second distributed transmission scheduling mode under perform the stable transfer data volume peak value SR of distributed transmission ₂;

S33, to determine time according to the stable transfer data volume peak value under the first calculated distributed transmission scheduling mode and the second distributed transmission scheduling mode the distributed transmission scheme that transmission adopts.

According to the embodiment of the present invention, described S33 to determine time that the distributed transmission scheme that transmission adopts specifically comprises according to the stable transfer data volume peak value under the first calculated distributed transmission scheduling mode and the second distributed transmission scheduling mode:

If meet SR ₁>=SR ₂, then the first distributed transmission scheduling mode is switched to;

If meet SR ₁< SR ₂, then the second distributed transmission scheduling mode is switched to.

The LTE distributed transmission method switched based on scheduling mode of the present invention, according to the channel condition information reported, transmission space power negative gain factor and travel frequency offset information, Usefulness Pair ratio is carried out to the first distributed transmission scheduling mode and the second distributed transmission scheduling mode, and determine according to comparing result the distributed transmission scheme that this transmission adopts, by the switching of multiple scheduling mode, reduce and the desirability of information state is relied on, substantially increase the distributed transmission performance of system.

Accompanying drawing explanation

By reading hereafter detailed description of the preferred embodiment, various other advantage and benefit will become cheer and bright for those of ordinary skill in the art.Accompanying drawing only for illustrating the object of preferred implementation, and does not think limitation of the present invention.And in whole accompanying drawing, represent identical parts by identical reference symbol.In the accompanying drawings:

Figure 1 show the LTE distributed transmission method flow chart switched based on scheduling mode according to embodiment of the present invention.

Embodiment

Below with reference to accompanying drawings illustrative embodiments of the present disclosure is described in more detail.Although show illustrative embodiments of the present disclosure in accompanying drawing, however should be appreciated that can realize the disclosure in a variety of manners and not should limit by the execution mode of setting forth here.On the contrary, provide these execution modes to be in order to more thoroughly the disclosure can be understood, and complete for the scope of the present disclosure can be conveyed to those skilled in the art.

According to the embodiment of the present invention, propose a kind of LTE distributed transmission method switched based on scheduling mode, as shown in Figure 1, described method comprises:

The stable movement speed v of multiple mobile client in M service district of S1, statistics participation distributed transmission, calculates the travel frequency skew f of user _d=f _cv/c, according to travel frequency calculations of offset outbound path phase delay parameter ρ=J ₀(2 π f _dt _s), wherein, c represents the light velocity, f _crepresent mid-band frequency, T _srepresent the cycle span of each symbol, J ₀() represents ordinary differential equation;

S2, each service district are chosen a mobile client by round-robin scheduling and are prepared transfer of data, when each transmission starts, first described mobile client calculates self scalar signal to noise ratio (SNR) value, and described scalar SNR is compared with response lag, if described scalar SNR value is less than response lag, then waits for and dispatching next time; If described scalar SNR value is more than or equal to response lag, then described mobile client carries out channel estimating to obtain channel condition information and transmission space power negative gain factor, again according to existing launching code prediction scheme, modulation channel state information, and modulation channel state information and transmission space power negative gain factor are reported corresponding service base station;

S3, described corresponding service base station carry out Usefulness Pair ratio according to the channel condition information reported, transmission space power negative gain factor and travel frequency offset information to the first distributed transmission scheduling mode and the second distributed transmission scheduling mode; And determine according to comparing result the distributed transmission scheme that this transmission adopts;

S4, described corresponding service base station, according to selected distributed transmission scheme, utilize the channel condition information reported to calculate launching code vector W, are then modulated by data acquisition launching code vector W to be sent, and carry out transfer of data.

According to the embodiment of the present invention, described first distributed transmission scheduling mode is the continuous transmission means of multiframe time slot, namely the data of a dispatching client are transmitted in the base station, multiple service district participating in distributed transmission at continuous multiple frame slot, and utilize the channel condition information obtained to treat that dispatching client performs interference and eliminates to other; Described second distributed transmission scheduling mode is single frames time slot hop transmission mode, namely the data of a dispatching client are transmitted in the base station, multiple service district participating in distributed transmission in a frame slot, and the client different at different frame Slot selection is transmitted.

According to the embodiment of the present invention, Usefulness Pair ratio is carried out to the first distributed transmission scheduling mode and the second distributed transmission scheduling mode in the corresponding service base station of described step S3, and determines that the distributed transmission scheme that this transmission adopts specifically comprises according to comparing result:

S31, calculate the first distributed transmission scheduling mode under perform the stable transfer data volume peak value of distributed transmission;

S32, calculate the second distributed transmission scheduling mode under perform the stable transfer data volume peak value of distributed transmission;

S33, to determine time according to the stable transfer data volume peak value under the first calculated distributed transmission scheduling mode and the second distributed transmission scheduling mode the distributed transmission scheme that transmission adopts;

According to the embodiment of the present invention, the stable transfer data volume peak value SR of distributed transmission is performed under the calculating first distributed transmission scheduling mode of described S31 ₁specifically comprise:

${\mathrm{SR}}_I={\mathrm{Mlog}}_2\left(e\right)\underset{i=0}{\overset{M-2}{\&Sigma;}}\underset{j=1}{\overset{2}{\&Sigma;}}\&lsqb;{\mathrm{\&alpha;}}_i^{\left(j\right)}i!{\left(\frac{{\mathrm{\&mu;}}_1}{{\mathrm{\&mu;}}_2}\right)}^{i+1}I(\frac{1}{{\mathrm{\&mu;}}_1},\frac{{\mathrm{\&mu;}}_1}{{\mathrm{\&mu;}}_2{\mathrm{\&gamma;}}_j},i+1)\&rsqb;$ Formula (1),

In formula, μ ₁=α P/M, μ ₂=β P/M, wherein P represents that the transmitting power that M base station is total, α, β represent that the transmission space power negative gain factor of this community mobile client and other service district mobile clients is arrived in base station respectively, and B represents and reports binary digit, N _trepresent the quantity of transmitting antenna on each base station, N _t≤ 8, ρ represents path phase delay parameter, meanwhile,

${\mathrm{\&alpha;}}_i^{\left(1\right)}=\frac{1}{{\mathrm{\&gamma;}}_1^{i+1}(M-2)!}{\left(\frac{{\mathrm{\&gamma;}}_1}{{\mathrm{\&gamma;}}_1-{\mathrm{\&gamma;}}_2}\right)}^{M-1}\frac{\left(2\right(M-2)-i)!}{i!(M-2-i)!}{\left(\frac{{\mathrm{\&gamma;}}_2}{{\mathrm{\&gamma;}}_2-{\mathrm{\&gamma;}}_1}\right)}^{M-2-i},$

${\mathrm{\&alpha;}}_i^{\left(2\right)}=\frac{1}{{\mathrm{\&gamma;}}_2^{i+1}(M-2)!}{\left(\frac{{\mathrm{\&gamma;}}_2}{{\mathrm{\&gamma;}}_2-{\mathrm{\&gamma;}}_1}\right)}^{M-1}\frac{\left(2\right(M-2)-i)!}{i!(M-2-i)!}{\left(\frac{{\mathrm{\&gamma;}}_1}{{\mathrm{\&gamma;}}_1-{\mathrm{\&gamma;}}_2}\right)}^{M-2-i},$

In formula (1), the account form of I () is provided by following formula:

$I(a,b,m)={(b-1)}^{-m}{I}_0(a,1,1)+\underset{i=1}{\overset{m}{\&Sigma;}}{(-1)}^{i-1}{(1-b)}^{-i}{I}_0(a,b,m-i+1),$

Wherein I ₀() is provided by following formula:

$I_0(a,b,m)=\{\begin{array}{cc}{e}^{ab}{E}_1\left(ab\right)& m=1\\ \frac{{(-a)}^{m-1}}{(m-1)!}{e}^{ab}{E}_1\left(ab\right)+\underset{k=1}{\overset{m-1}{\&Sigma;}}\frac{(k-1)!{(-a)}^{m-k-1}}{(m-1)!b^k}& m\&GreaterEqual;2\end{array},$

In formula it is exponential integral function.

According to the embodiment of the present invention, the stable transfer data volume peak value SR of distributed transmission is performed under the calculating second distributed transmission scheduling mode of described S32 ₂specifically comprise:

${\mathrm{SR}}_2={\log }_2\left(\mathrm{\&gamma;}L\right)-\frac{1}{1n}(\frac{1}{L}-\frac{1}{3L^2}-\frac{2}{15L^4})$ Formula (2),

γ and L is provided by following formula:

$\mathrm{\&gamma;}=\frac{A_1}{2A_2},L=\frac{2A_2^2}{A_1},$

In formula,

$A_1=N_t{c}_1^2+c_2^2+(M-1)N_t{c}_3^2+(M-1)c_4^2,$

A ₂＝1+c ₁N _t+c ₂+c ₃(M-1)N _t+c ₄(M-1)，

Wherein c ₁, c ₂, c ₃, and c ₄for corresponding weighted correction parameter, account form is as follows:

$c_1=\frac{\mathrm{\&alpha;}\mathrm{\&xi;}P}{M}{\mathrm{\&rho;}}^2,c_2=\frac{\mathrm{\&alpha;}P}{M}{\mathrm{\&epsiv;}}_e^2,c_3=\frac{\mathrm{\&beta;}\mathrm{\&xi;}P}{M}{P}^2,c_4=\frac{\mathrm{\&beta;}P}{M}{\mathrm{\&epsiv;}}_e^2,$

In formula, $\mathrm{\&xi;}=1-2^B\&CenterDot;\mathrm{\&beta;}(2^B,\frac{N_t}{N_t-1}).$

According to the embodiment of the present invention, described S33 to determine time that the distributed transmission scheme that transmission adopts specifically comprises according to the stable transfer data volume peak value under the first calculated distributed transmission scheduling mode and the second distributed transmission scheduling mode:

If meet SR ₁>=SR ₂, then the first distributed transmission scheduling mode is switched to;

If meet SR ₁< SR ₂, then the second distributed transmission scheduling mode is switched to.

The above; be only the present invention's preferably embodiment, but protection scope of the present invention is not limited thereto, is anyly familiar with those skilled in the art in the technical scope that the present invention discloses; the change that can expect easily or replacement, all should be encompassed within protection scope of the present invention.Therefore, protection scope of the present invention should described be as the criterion with the protection range of claim.

Claims (5)

1., based on the LTE distributed transmission method that scheduling mode switches, described method comprises:

In M service district of S1, statistics participation distributed transmission, the stable translational speed of multiple mobile client, calculates the travel frequency skew of user, according to travel frequency calculations of offset outbound path phase delay parameter;

S2, each service district are chosen a mobile client by round-robin scheduling and are prepared transfer of data, when each transmission starts, first described mobile client calculates self scalar signal to noise ratio (SNR) value, and described scalar SNR is compared with response lag, if described scalar SNR value is less than response lag, then waits for and dispatching next time; If described scalar SNR value is more than or equal to response lag, then described mobile client carries out channel estimating to obtain channel condition information and transmission space power negative gain factor, again according to existing launching code prediction scheme, modulation channel state information, and modulation channel state information and transmission space power negative gain factor are reported corresponding service base station;

S3, described corresponding service base station carry out Usefulness Pair ratio according to the channel condition information reported, transmission space power negative gain factor and travel frequency offset information to the first distributed transmission scheduling mode and the second distributed transmission scheduling mode; And determine according to comparing result the distributed transmission scheme that this transmission adopts;

S4, described corresponding service base station, according to selected distributed transmission scheme, utilize the channel condition information reported to calculate launching code vector, are then modulated by data acquisition launching code vector to be sent, and carry out transfer of data.

2. a method of claim 1, described first distributed transmission scheduling mode is the continuous transmission means of multiframe time slot.

3. a method as claimed in claim 2, described second distributed transmission scheduling mode is single frames time slot hop transmission mode.

4. a method as claimed in claim 3, Usefulness Pair ratio is carried out to the first distributed transmission scheduling mode and the second distributed transmission scheduling mode in the corresponding service base station of described step S3, and determines that the distributed transmission scheme that this transmission adopts specifically comprises according to comparing result:

S31, calculate the first distributed transmission scheduling mode under perform the stable transfer data volume peak value SR of distributed transmission ₁;

S32, calculate the second distributed transmission scheduling mode under perform the stable transfer data volume peak value SR of distributed transmission ₂;

S33, to determine time according to the stable transfer data volume peak value under the first calculated distributed transmission scheduling mode and the second distributed transmission scheduling mode the distributed transmission scheme that transmission adopts.

5. a method as claimed in claim 4, according to the stable transfer data volume peak value under the first calculated distributed transmission scheduling mode and the second distributed transmission scheduling mode, described S33 determines that time distributed transmission scheme of transmission employing specifically comprises:

If meet SR ₁>=SR ₂, then the first distributed transmission scheduling mode is switched to;

If meet SR ₁< SR ₂, then the second distributed transmission scheduling mode is switched to.