CN101383794B - Method and apparatus lowering peak average ratio - Google Patents

Abstract

The invention provides a method for lowering peak-average ratio, which comprises: conducting spectrum-spreading and scrambling process after conducting code modulation on base-band user signals, and then accomplishing insertion of the training sequence codes; conducting phase rotation based on the time slot on the base-band user signal after inserting the training sequence codes; and conducting multi-user superposition in multi-carrier on the signals whose phases are rotated. The invention also provides a device for lowering peak-average ratio. With the method and the device of the invention, multi-carrier multi-user phase rotation is conducted by taking the user as the smallest rotation unit at the physical layer, and the problem that the TD-SCDMA multi-carrier peak-average ration is over-high; at the same time, the phase rotation conducted at the physical layer has low amount of data and less calculation amount, has rich alternative rotation vectors, and does not need to transfer phase rotation factors to the terminal.

Description

A kind of method and device that reduces peak-to-average force ratio

Technical field

The present invention relates to the mobile communication technology field, relate in particular to a kind of method and device that reduces peak-to-average force ratio.

Background technology

For the TD-SCDMA system, reduce the peak-to-average force ratio in the mobile communication system, use multi-transceiver technology, can make base station equipment can support more customer volume or bigger coverage is provided, improve power system capacity, thereby number of base stations and site are reduced significantly, make system operator reduce investment.

The TD-SCDMA time slot signal totally 848 chip (chip), its structure as shown in Figure 1, wherein, the Midamble (training sequence) at burst middle part is used for carrying out channel estimating, the data block on both sides is used for transmit traffic data.For the same time slot of same sub-district, a given basic intermediate code is as basic code, and different users adopts the channel estimating code of the different cyclic shift version of this identical basic code as it.K the specific intermediate code that derives by same independent basic code; K=1 ..., K constitutes intermediate code sign indicating number collection, abbreviates the sign indicating number collection as.

According to existing TD-SCDMA multi-carrier scheme, a plurality of carrier waves of supporting for same sub-district have following agreement: main carrier uses identical scrambler and basic Midamble (training sequence) sign indicating number with auxilliary carrier wave, for multi-carrier district, and the shared cover transmitter of radio-frequency head.The basic Midamble code position of each carrier wave is a complete matching, and the basic Midamble sign indicating number of each carrier wave all is identical binary sequence vector simultaneously.Because TD-SCDMA is a synchro system, will occur making whole time slot signal peak-to-average force ratio too big owing to the peak-to-peak stack produces stronger bigger peak power in the basic Midamble sign indicating number part of transmitting terminal.

In order to reduce signal peak-to-average ratio, a kind of method that reduces peak-to-average force ratio is arranged in the prior art: in the TD-SCDMA system, each carrier wave base band time slot signal be multiply by a definite phase place deflection factor respectively, and make the phase place deflection factor of each carrier wave correspondence and carrier frequency that unique corresponding relation be arranged, thereby reduced the probability of Midamble sign indicating number place peak-to-peak stack, reduce signal peak-to-average ratio, improved the radio-frequency head emitting performance.But this different carrier multiply by a definite phase place, can not always make Midamble part power fall minimumly, and data division can not reduce its PAR (Peak to Average Ratio, peak-to-average force ratio) especially.Concrete, this technology mainly rotates a certain angle by the Midamble that each carrier wave is identical, is target to realize minimum PAR.Select a carrier wave Rotate 180 ° during three carrier waves, two other carrier wave does not rotate; Two carrier wave Rotate 180s ° during six carrier waves, other four carrier waves do not rotate and make the PAR minimum.Perhaps carry out the phase place rotation according to 90 ° angle precision.Many times this fixing phase place rotation based on carrier wave can not make the power of Midamble sign indicating number fall minimumly, and the while, the design of angle was also more and more difficult along with carrier number increases.In addition, the phase place of data is at random, and the peak-to-average force ratio of data fundamentally also can't improve, so very limited to reducing PAR based on the rotation of the stationary phase of carrier wave in base band.

Also have a kind of intermediate frequency carrier self adaptation phase place that adopts to rotate the method that reduces PAR in the prior art, this method need increase hardware such as FPGA, and amount of calculation is bigger on the one hand, needs to consider problems such as time-delay in addition on the one hand, synchronous bad control acquires a certain degree of difficulty so operate.

Summary of the invention

In view of this, the problem that the present invention solves has provided a kind of method and device that reduces peak-to-average force ratio.

For addressing the above problem, the technical scheme that the present invention proposes is as follows:

A kind of method that reduces peak-to-average force ratio, this method comprises:

The base band subscriber signal is carried out carrying out spectrum-spreading and scrambling process after the coded modulation, finish the insertion of training sequence code then;

After inserting described training sequence code, the base band subscriber signal is carried out timeslot-based phase place rotation;

The multi-user that the postrotational signal of phase place is carried out in the multicarrier superposes.

Accordingly, this method further comprises:

Select optimal phase place before the phase place rotation, output is carried out the phase place rotation to the base band subscriber signal more then.

Accordingly, described phase place is selected further to comprise:

Base band subscriber signal behind the insertion training sequence code is divided into identical many groups subsequence, a plurality of users are arranged in every group of subsequence;

Generate and the identical many groups random phase of described many group subsequence numbers the user of each phase place correspondence in every group at random;

According to described random phase the base band subscriber signal in the subsequence is carried out the phase place rotation, and postrotational signal is carried out linear superposition;

Calculate the peak power of each subsequence in the many groups subsequence after the stack, and with largest peaks power points wherein as the peak power point of this group;

Respectively organize peak power point, with this group rotatable phase output of wherein minimum peak power point correspondence.

Accordingly, when the number of users in all carrier waves during, round afterwards as the number of users in the subsequence as quotient with the number of users in all carrier waves and this threshold value greater than the number of users thresholding in the default subsequence;

During number of users thresholding in the number of users in all carrier waves is not more than default subsequence, then has only a user in a subsequence.

Accordingly, after inserting training sequence code, earlier the base band subscriber signal is carried out interpolation filtering and complex modulation.

Accordingly, when the value of handling when interpolation multiple and filter factor and follow-up interpolation filtering is identical, directly enters Digital Up Convert after the multi-user of multicarrier superposes and handle.

Accordingly, this method further comprises:

Store the optimal phase place of choosing, and write down the peak-to-average force ratio of these phase place correspondences.

Accordingly, in multiaerial system, every antenna all rotates with the phase place that described many group random phases are carried out separately.

A kind of device that reduces peak-to-average force ratio, comprise to the base band subscriber signal carry out carrying out after the coded modulation spectrum-spreading and scrambling process modulating unit, the base band subscriber signal after modulation and the spectrum-spreading and scrambling is carried out insertion unit that training sequence code inserts, carries out multi-user's superpositing unit that the multi-user superposes in a plurality of carrier waves, this device further comprises: before the multi-user superposes after inserting training sequence code the base band subscriber signal is carried out the phase place rotary unit that timeslot-based phase place is rotated.

Accordingly, described phase place rotary unit further comprises:

Peak value is optimized the phase place selected cell, is used for selecting before the phase place rotation optimal phase place to export then again the base band subscriber signal is carried out the phase place rotation.

Accordingly, this device further comprises:

Peak value is optimized the phase place selected cell, is used for selecting optimal phase place before the phase place rotary unit carries out the phase place rotation, then the phase place of choosing is exported to the phase place rotary unit.

Accordingly, described peak value optimization phase place selected cell further comprises:

The random phase maker is used for generating at random many group random phases;

Multi-user's phase place rotation and superpositing unit are used to receive the base band subscriber signal that inserts behind the training sequence code, and carry out the phase place rotation according to the subsequence of described random phase after to the grouping of base band subscriber signal, then postrotational signal are carried out linear superposition;

Peak value calculates and comparing unit, be used for calculating the peak power of each subsequence of the many groups subsequence after the stack, and with largest peaks power points wherein as the peak power point of this group, respectively organize peak power point then, with this group rotatable phase output of wherein minimum peak power point correspondence.

Accordingly, described peak value optimization phase place selected cell further comprises:

The intermediate frequency simulation unit is used for earlier the base band subscriber signal being carried out interpolation filtering and complex modulation after inserting training sequence code.

As can be seen, adopt method and apparatus of the present invention,, carry out multicarrier multi-user's phase place rotation, effectively solved the too high problem of TD-SCDMA multicarrier peak-to-average force ratio by being the minimum unit that rotates in physical layer with user; Simultaneously, carry out the phase place rotation in physical layer, data volume is low, and amount of calculation is little, and alternative rotating vector is abundant, and need not to transmit phase rotation coefficient to terminal.

Description of drawings

Fig. 1 is a TD-SCDMA time slot signal structural representation;

Fig. 2 is the flow chart of the inventive method;

Fig. 3 is the schematic flow sheet of the embodiment of the invention 1;

Fig. 4 is the schematic diagram that same user's data and Midamble sign indicating number multiply by same phase rotation coefficient in the embodiment of the invention;

Fig. 5 is the schematic flow sheet of the many antenna phase rotations of the present invention embodiment;

Fig. 6 is the schematic block diagram of apparatus of the present invention;

Fig. 7 is the device schematic diagram of the embodiment of the invention 6;

Fig. 8 is the schematic block diagram that peak value is optimized the phase place selected cell among the present invention;

Fig. 9 is the device schematic diagram of the embodiment of the invention 7;

Figure 10 is many antenna phases choice device schematic diagram among the present invention.

Embodiment

Basic thought of the present invention is to propose to carry out in physical layer multicarrier multi-user's phase place rotation, and minimum rotation unit is the user, has effectively solved the too high problem of TD-SCDMA multicarrier peak-to-average force ratio.

For this reason, this paper proposes to carry out in physical layer multicarrier multi-user's self adaptation phase place rotation.Multi-user data in a plurality of carrier waves arranges successively, forms the subsequence set of a N*K, with the corresponding phase factor of each user.Because in base band is that least unit is carried out the phase place rotation with user, so sequence number increases greatly, and the increase of subsequence means that the reduction of PAR will be more effective.

In order to make those skilled in the art person understand technical scheme of the present invention better, the present invention is described in further detail below in conjunction with the drawings and specific embodiments.As shown in Figure 2, the inventive method comprises:

Step 201: the base band subscriber signal is carried out carrying out spectrum-spreading and scrambling process after the coded modulation, finish the insertion of training sequence code then;

Step 202: after inserting described training sequence code, the base band subscriber signal is carried out timeslot-based phase place rotation;

Step 203: the multi-user that the postrotational signal of phase place is carried out in the multicarrier superposes.

Based on the basis of prior art, the high-rise Bit data that generates multicarrier sends to physical layer later on, and physical layer generates the baseband signal of each carrier wave, and the insertion that spectrum-spreading and scrambling and Midamble sign indicating number are arranged is handled in the emission of baseband signal; The basic Midamble sign indicating number that each carrier wave uses is the same, and different users produces according to this basic Midamble sign indicating number cyclic shift on the same carrier wave; If the position of the user's cyclic shift like this on the different carrier is the same, the power of Midamble sign indicating number will be the peak-to-peak stack so;

Concrete as embodiment 1, base band data carries out spectrum-spreading and scrambling process after finishing coded modulation, and the Midamble sign indicating number inserts then, and the present invention proposes to carry out at this moment the phase place rotation, specifically as shown in Figure 3;

Being treated to of signal spread-spectrum scrambling: $\underset{\‾}{\mathrm{cd}}\left(\mathrm{kT}\right)=(\underset{k=1}{\overset{K}{\mathrm{\Σ}}}{\mathrm{\λ}}^k\·\underset{n=1}{\overset{N_K}{\mathrm{\Σ}}}{\underset{\‾}{d}}_n^{\left(k\right)}\·\underset{q=1}{\overset{Q_K}{\mathrm{\Σ}}}{S}_{(n-1)\mathrm{Qk}+q}^{\left(k\right)})$ , wherein, λ k represents is the amplitude adjusted factor to k user; d _n ^(k)What represent is k user's n data, and this each data symbol is by the spreading factor S of Q length _{(n-1) Qk+q} ^(k)Spread spectrum; S _{(n+1) Q+q} ^(k)What represent is k user's compound spreading code, and the combination of spreading code and sub-district specific scramble codes can be regarded as the distinctive spreading code of a user and sub-district, is expressed as follows

$S_{(n-1)Q+q}^{\left(k\right)}=c_{1+\left[(q-1)\mathrm{mod}Q\right]}^{\left(k\right)}\·v_{1+(q-1)\mathrm{mod}Q\left]\right],}k=1,...K_{\mathrm{code},}p=1,...\mathrm{NQ}$

Wherein, c _{1+[(q-1) modQ]} ^(k)Be spreading code, from distributing to k user's length Q _k=16 empty sign indicating number $c^{\left(k\right)}=(c_1^{\left(k\right)},c_2^{\left(k\right)},...,c_{Q_k}^{\left(k\right)}),$ v _{1+ (q-1) modQ]]}It is scrambler;

Just can carry out the phase place rotation processing in the data that spectrum-spreading and scrambling is later:

$s_k^{\left(n\right)}\left(t\right)=({\mathrm{cd}}_{k\_r}^{\left(n\right)}\left(t\right)\·{\cos \mathrm{\θ}}_k^{\left(n\right)}-{\mathrm{cd}}_{k\_i}^{\left(n\right)}\·{\sin \mathrm{\θ}}_k^{\left(n\right)})+({\mathrm{cd}}_{k\_i}^{\left(n\right)}\·{\cos \mathrm{\θ}}_n^m+{\mathrm{cd}}_{k\_r}^{\left(n\right)}\left(t\right)\·{\sin \mathrm{\θ}}_n^m)\·j$

1≤k≤K，1≤n≤N

In fact phase place rotation in the present embodiment is exactly to finish complex multiplication one time, and p is set _n ^mBe rotatable phase, to input data c n carrier wave m road user data correspondence _n ^m(kT) carry out the phase place rotation, wherein T is the Signal Processing clock, and the later signal of phase place rotation is cp _n ^m(kT), processing is as follows:

${\mathrm{cp}}_n^m\left(\mathrm{kT}\right)=c_n^m\left(\mathrm{kT}\right)\·p_n^m=(I_n^m\left(\mathrm{kT}\right)+j\·Q_n^m\left(\mathrm{kT}\right))\·\exp \left(j{\mathrm{\θ}}_n^m\right)=$

$(I_n^m\left(\mathrm{kT}\right)+j\·Q_n^m\left(\mathrm{kT}\right))\·({\cos \mathrm{\θ}}_n^m+{j\sin \mathrm{\θ}}_n^m)=$

$(I_n^m\left(\mathrm{kT}\right)\·\cos {\mathrm{\θ}}_n^m-Q_n^m\left(\mathrm{kT}\right)\·{\sin \mathrm{\θ}}_n^m)+(Q_n^m\left(\mathrm{kT}\right)\·{\cos \mathrm{\θ}}_n^m+I_n^m\left(\mathrm{kT}\right)\·{\sin \mathrm{\θ}}_n^m)\·j$

C wherein _n ^m(kT) expression is the user data on n carrier wave m road, p _n ^mThe phase place that the user data at n carrier wave m road of expression rotates, the anglec of rotation is θ _n ^mBecause the data of input are plural numbers, the phase place of rotation also is a plural number, so last output real part and imaginary part all have 2 multiplyings respectively.Certainly, also can adopt additive method of the prior art to realize the rotation of phase place, be not described in detail at this.And after finishing the phase place rotation of a time slot, empty current phase rotation coefficient, wait for the data of next time slot and begin the generation of new phase rotation coefficient.

After each user finishes separately phase place rotation like this, finish all users' stacks in this carrier wave subsequently; After multi-user's stack, carrier signal being carried out the multicarrier stack in finishing multicarrier, if finish after the multicarrier stack, has been the final step of Digital Signal Processing just, will enter Digital Up Convert DAC, finishes analog to digital conversion.

In the said method, can also select optimal phase place to export then before the phase place rotation again signal is carried out the phase place rotation, the concrete embodiment 2 that passes through be described in detail:

In the embodiment of the invention 1 the base band subscriber signal being carried out the phase place rotation is after inserting training sequence code, realizes before multi-user's stack; Select only phase place to carry out before multi-user's stack finishing before the phase place rotation after the insertion training sequence code simultaneously in the present embodiment 2: peak value characteristics, number of users according to the base band subscriber signal after inserting training sequence code carry out selecting of phase place, choose after the only phase place, again these phase place outputs are carried out the phase place of signal is rotated then.

Concrete, receive and insert training sequence code base band subscriber signal afterwards, this signal is distributed into an identical M branch (group) subsequence, NK user arranged in each branch; Generate M branch (group) random phase at random, NK random phase arranged in each branch, so need such random phase to have M*N*K altogether; This M group random phase is modulated corresponding subsequence in the described M group respectively, carries out the phase place rotation; In fact a phase place rotation is exactly to finish complex multiplication operation one time; After finishing the phase place rotation, NK the user's data that M organizes in each group carried out linear superposition, specifically handle as follows:

The phase place exp of Sheng Chenging (j θ at random _n ^m), to the baseband signal signal c of input _n ^m(kT) carry out the phase place rotation, to rotating later signal cp _n ^m(kT) 1≤m≤M finishes NK user's linear superposition, and in fact a phase place rotation is exactly to finish complex multiplication one time, and p is set _n ^mBe the rotatable phase of nth user in m branch, to input data c _n ^m(kT) carry out the phase place rotation, wherein T is the Signal Processing clock, and the later signal of phase place rotation is cp _n ^m(kT), the carrier signal after the stack is CP ^m(kT):

${\mathrm{CP}}^m\left(\mathrm{kT}\right)=\underset{n=1}{\overset{\mathrm{NK}}{\mathrm{\Σ}}}{\mathrm{cp}}_n^m\left(\mathrm{kT}\right)=\underset{n=1}{\overset{\mathrm{NK}}{\mathrm{\Σ}}}{c}_n^m\left(\mathrm{kT}\right)\·p_n^m=\underset{n=1}{\overset{\mathrm{NK}}{\mathrm{\Σ}}}(I_n^m\left(\mathrm{kT}\right)+j\·Q_n^m\left(\mathrm{kT}\right))\·\exp \left({\mathrm{j\θ}}_n^m\right)=$

$\underset{n=1}{\overset{\mathrm{NK}}{\mathrm{\Σ}}}(I_n^m\left(\mathrm{kT}\right)+j\·Q_n^m\left(\mathrm{kT}\right))\·({\cos \mathrm{\θ}}_n^m+{j\sin \mathrm{\θ}}_n^m)=$

$\underset{n=1}{\overset{\mathrm{NK}}{\mathrm{\Σ}}}(I_n^m\left(\mathrm{kT}\right)\·{\cos \mathrm{\θ}}_n^m-Q_n^m\left(\mathrm{kT}\right)\·{\sin \mathrm{\θ}}_n^m)+(Q_n^m\left(\mathrm{kT}\right)\·{\cos \mathrm{\θ}}_n^m+I_n^m\left(\mathrm{kT}\right)\·{\sin \mathrm{\θ}}_n^m)\·j$

1≤m≤M，1≤n≤NK，

C wherein _n ^m(kT) expression is m user data of n carrier wave, p _n ^mWhat represent is that the anglec of rotation is θ at the phase place of m user's data rotation of n carrier wave _n ^m, the data of input are plural numbers, the phase place of rotation also is a plural number, so last output real part and imaginary part all have 2 multiplyings respectively.Certainly, also can adopt additive method of the prior art to carry out the phase place rotation herein.

After carrier signal stack, calculates the peak power point in each moment of each branch in M the branch, being calculated as follows of any time power:

CP_pow ^m(kT)＝|CP ^m(kT)| ²＝[CPi ^m(kT)] ²+[CPq ^m(kT)] ²

This is the folded kT of a m user rating formula constantly, according to above-mentioned formula calculate finish the power of all sampled points of time slot after, write down the performance number of each branch's maximum in M the branch, in this M road branch, search that branch of the minimum of peak power point then, handle as follows:

${\mathrm{PAR}}_{\mathrm{low}}=\underset{1\&le;m\&le;M}{\mathrm{<figure-callout\; id="1"\; label="min"\; filenames="S2007101214506E00021.png"\; state="\{\{state\}\}">min</figure-callout>}}\left\{{\mathrm{PAR}}_m\right\}$

$=\underset{1\&le;m\&le;M}{\mathrm{<figure-callout\; id="1"\; label="min"\; filenames="S2007101214506E00021.png"\; state="\{\{state\}\}">min</figure-callout>}}\left\{\underset{1\&le;k\&le;K}{\mathrm{<figure-callout\; id="1"\; label="max"\; filenames="S2007101214506E00021.png"\; state="\{\{state\}\}">max</figure-callout>}}\right[\mathrm{cp}\_{\mathrm{pow}}^m\left(\mathrm{kT}\right)\left]\right\}$

If the peak power point minimum of m branch in this M branch, then the phase rotation coefficient optimum on definite this road is exported phase factor exp (the j θ on this road ₁ ^m), exp (j θ ₂ ^m) ... exp (j θ _N ^m), after inserting training sequence code, before multi-user's stack the base band subscriber signal is carried out the phase place rotation with this phase factor, to reach the purpose that reduces PAR.

Present embodiment also proposes at local cache P group phase factor, and writes down the corresponding PAR of this P group.When so each a time slot carries out PAR reduction processing, to use M group phase factor altogether, remove like this outside the P group phase factor of having deposited, simultaneously as long as regeneration M-P organizes new phase rotation coefficient.

Select the original P group of this record to reduce PAR optimum phase twiddle factor, be because the basic Midamble sign indicating number of each base station is unique, the Midamble sign indicating number of each user's correspondence all obtains by basic Midamble sign indicating number cyclic shift, so present certain rules, generally can reduce time of search by the cache optimum phase rotation coefficient, make the more effective reduction of peak power simultaneously.

In addition, because the phase rotation coefficient in every group is in the M group $P^m=[p_1^m,...,p_{\mathrm{NK}}^m],m=\mathrm{1,2},...,M,$ If have only the carrier wave in a group to carry out the phase place rotation, then peak power is Pr{c greater than the probability of average power _KT＞p ₀}=1-(1-exp (p ₀)) ^NK, wherein $p_0=\frac{{\mathrm{<figure-callout\; id="2"\; label="p\; av"\; filenames="S2007101214506E00021.png,S2007101214506E00051.png"\; state="\{\{state\}\}">p</figure-callout>}}_{\mathrm{av}}}{{2\mathrm{\&sigma;}}^2},$ p _AvBe the average power of input signal, σ ²Be the variance of input signal, NK is a number of users; From then on formula finds out that the subsequence number is big more along with the increasing of number of users, and is just big more greater than the probability of average power, so number of users is many more, PAR is just big more.If use the different phase rotation coefficient of M group to carry out the phase place rotation, after then NK carrier wave carries out the phase place rotation, peak power point will reduce greatly greater than the probability of average power, and Pr{c is promptly arranged _KT＞p ₀}=(1-(1-exp (p ₀)) ^NK) ^M, then signal power is just more little greater than the probability of average power after the rotation, and the probability that PAR reduces is just big more.

In the above-described embodiments, the next user of the situation of system default is the subsequence of a phase place rotation, but along with number of users increases, even if use the phase place recursive search algorithm, amount of calculation is also bigger, and multiplication computation amount is W*NK.So it is L that a subsequence upper limit is set.If NK is greater than L, then the user's number that comprises in subsequence is

A plurality of like this users participate in the phase place rotation as same subsequence.If NK is smaller or equal to L, then NumofSC=1 has only a user profile in the subsequence.

In addition, different users has the detection that different phase places is rotated does not influence the terminal use, and is as shown in Figure 4 concrete;

Each user rotates by after the aerial transmission through phase place, receives the channel impulse response that obtains and is H "=IDFT ( G ^-1DFT ( e _m)), wherein, e _mBe back 128 chips of Midamble section in the received signal, GBe diagonal matrix, its diagonal entry vector is g=DFT ( m _P). wherein, mP=( m ₁, m ₂..., m _P) be the plural basic Midamble sign indicating number after the modulation, so have H " _(k)= h _(k) exp (j θ _k).Therefore, owing to used identical phase rotation coefficient to rotate as a user's information after Midamble sign indicating number and the data cascade, so the terminal use need not know phase rotation coefficient, just can carry out correct demodulation, therefore also need not to transmit the deterioration that side information does not have EVM yet signal.

In addition, the embodiment of the invention 3 also proposes before inserting training sequence code phase place selection afterwards the base band subscriber signal to be carried out interpolation filtering and complex modulation processing; Carry out the rotation of the laggard line phase of interpolation filtering complex modulation in base band at each user, K user data after the phase place rotation in N carrier wave carries out the multi-user together and superposes; Simultaneously, for the real intermediate frequency process of the emulation of maximum, the interpolation multiple with filter coefficient during all with normal process the interpolation multiple of intermediate frequency identical with filter coefficient, interpolation multiple L=60 for example, data volume has just improved 60 times, and the multiple of Filtering Processing also be when the K of pre-treatment doubly, like this, superimposed data just can directly enter DAC and handle.

Below, specifically describe method of the present invention by specific embodiment 4.

For TD-SCDMA multi-antenna multi-carrier-wave base station, owing to adopted intelligent antenna technology, and intelligent antenna array is made up of N antenna element, the corresponding feeder line of N root and radio frequency part N relevant RF (Radio Frequency, radio frequency) transceiver.When the signal of the UE (User Equipment, subscriber equipment) in this Node B coverage arrived, each antenna element and RF receiver all can receive this signal.Because the position difference at different antennae place, the signal phase that they receive are also different, after the despreading processing through DSP (Digital Signal Processor, digital signal processor), just the reception data of each code channel can have been obtained.Have different phase places and amplitude owing to arrive the received signal of each root antenna, down beam shaping utilizes the space reception result of Node B, therefore be that the wave beam forming factor on each root antenna is also with difference, different antennae is except wave beam forming factor difference, and primary signal all is the same.

Data on each root antenna are distributed different by the PAR of signal after the figuration, so the optimum phase twiddle factor of different antennae is also with difference in theory, different phase rotation coefficients will make that the purpose of wave beam forming is destroyed.But propose still to use M group phase place in the present embodiment, each group phase place all is applied on the Ka root antenna, then largest peaks power: PAR on the calculating K a root antenna _m=Max (MaxPowe_1_m, MaxPowe_2_m ... MaxPow_Ka_m), 1≤m≤M after M group phase calculation is finished, selects the minimum peak power points ${\mathrm{PAR}}_{\mathrm{low}}=\underset{1\&le;m\&le;M}{\mathrm{<figure-callout\; id="1"\; label="min"\; filenames="S2007101214506E00021.png"\; state="\{\{state\}\}">min</figure-callout>}}\left\{{\mathrm{PAR}}_m\right\},$ If the peak power point minimum of m branch in this M branch, then the phase rotation coefficient optimum on definite this road is exported phase factor exp (the j θ on this road ₁ ^m), exp (j θ ₂ ^m) ... exp (j θ _NK ^m), this group phase rotation coefficient is sent to subscriber signal on all antennas, the subscriber signal on the Ka root antenna carries out same phase place rotation, specifically as shown in Figure 5.Multiple user signals on the different antennae is rotated according to same group of phase place, has so both reduced each root antenna upward peak power, has avoided the destruction of phase place rotation to wave beam forming simultaneously again.

Based on said method, see embodiment 5 the present invention for details a kind of device that reduces peak-to-average force ratio also is provided, as shown in Figure 6, this device comprises: modulating unit 51, insertion unit 52, multi-user's superpositing unit 53 and phase place rotary unit 54;

Described modulating unit 51 is used for the base band subscriber signal is carried out carrying out spectrum-spreading and scrambling process after the coded modulation;

Described insertion unit 52 is used for that the base band subscriber signal after modulation and the spectrum-spreading and scrambling is carried out training sequence code and inserts;

Described phase place rotary unit 54 is used for after inserting unit 52 to finish the insertion of training sequence code the base band subscriber signal being carried out timeslot-based phase place rotation, and after finishing the phase place rotation of a time slot, empty current phase rotation coefficient, wait for the data of next time slot and begin the generation of new phase rotation coefficient; In fact this phase place rotation is exactly to finish complex multiplication one time, and as above embodiment 1 is described for concrete processing procedure, is not described in detail in this.

Described multi-user's superpositing unit 53 is used for after phase place rotary unit 54 is finished the phase place rotation multi-user in a plurality of carrier waves being superposeed.

In addition, embodiment 6 as shown in Figure 7, described phase place rotary unit 54 can comprise that also peak value optimizes phase place selected cell 541, is used for selecting before the phase place rotation optimal phase place to export then again signal being carried out phase place rotating.

Concrete, base band subscriber signal behind the insertion training sequence code is input to peak value optimizes phase place selected cell 541, peak value characteristics, number of users according to input signal are carried out selecting of phase place, choose after the only phase place, again these phase place outputs are carried out the phase place rotation to signal.Rotate later base band subscriber signal and finish the stack of multi-user in the multicarrier, through finishing the stack of multicarrier after intermediate frequency filtering and the complex modulation, export to DAC at last then.

More specifically, as shown in Figure 8, this peak value is optimized phase place selected cell 541 and also can be comprised: random phase maker 5411, the rotation of multi-user's phase place and superpositing unit 5412 and peak value calculate and comparing unit 5413;

Behind the base band subscriber signal that peak value optimization phase place selected cell 541 receives after inserting training sequence code, be distributed to different rotation of multi-user's phase place and superpositing unit 5412 (unit 1 is to unit M), be about to the base band subscriber signal and be divided into identical M branch subsequence, comprise NK user in each branch; Random phase maker 5411 generates many group random phases simultaneously, and there be NK random phase in this each branch (group), has M branch altogether, so the random phase that needs has N*K*M altogether.This M group random phase is modulated the subsequence in this M group respectively, realizes the phase place rotation; After finishing the phase place rotation, each organizes NK user's data linear superposition, exporting to peak value then calculates and comparing unit 5413, this element at first calculates the peak power point of each branch, with largest peaks power points in a plurality of subsequences in each branch as the peak power point of this branch, in this M branch, select the branch of peak power point minimum then, determine that then the random phase factor that maximum peak power point is corresponding in this branch is optimum, export this group random phase factor in this branch then.

Specific embodiment 7, in the above-described embodiments, peak value is optimized phase place selected cell 541 also can be in phase place rotary unit 54 inside, but in phase place rotary unit 54 outsides, be used for before phase place rotary unit 54 carries out the phase place rotation, selecting optimal phase place, then the phase place of choosing is exported to phase place rotary unit 54, as shown in Figure 9.

Concrete, after inserting training sequence code, baseband user data is sent to peak value optimize phase place selected cell 5411, optimize execution and above-mentioned same step in the phase place selected cell 5411 at peak value, and calculate the different peak power point of each user on the Ka root antenna, with the user data peak power point of maximum maximum peak power, select the minimum peak power points as this antenna ${\mathrm{PAR}}_{\mathrm{low}}=\underset{1\&le;m\&le;M}{\mathrm{<figure-callout\; id="1"\; label="min"\; filenames="S2007101214506E00021.png"\; state="\{\{state\}\}">min</figure-callout>}}\left\{{\mathrm{PAR}}_m\right\},$ If the peak power point minimum of m branch in this M branch, then the phase rotation coefficient optimum on definite this road is exported phase factor exp (the j θ on this road ₁ ^m), exp (j θ ₂ ^m) ... exp (j θ _N ^M), this group phase rotation coefficient is sent to phase place rotary unit on all antennas, again the subscriber signal on the Ka root antenna is carried out same phase place rotation, as shown in figure 10.Though the multiple user signals on the different antennae is rotated according to same group of phase place, so both reduced each root antenna upward peak power, avoided the destruction of phase place rotation simultaneously again to wave beam forming.

In addition, in the foregoing description 6 or 7, described peak value is optimized phase place selected cell 5411 also can further comprise the intermediate frequency simulation unit that is used for earlier the base band subscriber signal being carried out interpolation filtering and complex modulation after inserting training sequence code;

Concrete, described intermediate frequency simulation unit is carried out interpolation filtering and complex modulation in base band at each user; Simultaneously, for the real intermediate frequency process of the emulation of maximum, the interpolation multiple with filter coefficient during all with normal process the interpolation multiple of intermediate frequency identical with filter coefficient, interpolation multiple L=60 for example, data volume has just improved 60 times, and the multiple of Filtering Processing also be when the K of pre-treatment doubly, like this, superimposed data just can directly enter DAC and handle.

As can be seen, adopt method and apparatus of the present invention, effectively solved the too high problem of TD-SCDMA multicarrier peak-to-average force ratio, and data volume is low, amount of calculation is little, and alternative rotating vector is abundant, also need not to transmit simultaneously phase rotation coefficient and gives terminal, therefore need not to transmit the further deterioration that side information has not just had EVM yet.

The above only is preferred embodiment of the present invention, and is in order to restriction the present invention, within the spirit and principles in the present invention not all, any modification of being done, is equal to replacement, improvement etc., all should be included within protection scope of the present invention.

Claims (8)

1. a method that reduces peak-to-average force ratio is characterized in that, this method comprises:

The base band subscriber signal is carried out carrying out spectrum-spreading and scrambling process after the coded modulation, finish the insertion of training sequence code then;

After inserting described training sequence code, select optimal phase place output that the base band subscriber signal is carried out timeslot-based phase place rotation; Described phase place is selected further to comprise:

Base band subscriber signal behind the insertion training sequence code is divided into identical many groups subsequence, a plurality of users are arranged in every group of subsequence; Generate and the identical many groups random phase of many group subsequence numbers the user of each phase place correspondence in every group at random; According to described random phase the base band subscriber signal in the subsequence is carried out the phase place rotation, and postrotational signal is carried out linear superposition; Calculate the peak power of each subsequence in the many groups subsequence after the stack, and with largest peaks power points wherein as the peak power point of this group; Respectively organize peak power point, with this group rotatable phase output of wherein minimum peak power point correspondence;

The multi-user that the postrotational signal of phase place is carried out in the multicarrier superposes.

2. method according to claim 1 is characterized in that:

When the number of users in all carrier waves during, round afterwards as the number of users in the subsequence as quotient with the number of users in all carrier waves and this threshold value greater than the number of users thresholding in the default subsequence;

During number of users thresholding in the number of users in all carrier waves is not more than default subsequence, then has only a user in a subsequence.

3. method according to claim 1 is characterized in that:

After inserting training sequence code, earlier the base band subscriber signal is carried out interpolation filtering and complex modulation.

4. method according to claim 3 is characterized in that:

When the value of handling when interpolation multiple and filter factor and follow-up interpolation filtering is identical, directly enters Digital Up Convert after the multi-user of multicarrier superposes and handle.

5. according to any described method of claim 1 to 4, it is characterized in that this method further comprises:

Store the optimal phase place of choosing, and write down the peak-to-average force ratio of these phase place correspondences.

6. according to any described method of claim 1 to 4, it is characterized in that:

In multiaerial system, every antenna all rotates with the phase place that described many group random phases are carried out separately.

7. device that reduces peak-to-average force ratio, comprise to the base band subscriber signal carry out carrying out after the coded modulation spectrum-spreading and scrambling process modulating unit, the base band subscriber signal after modulation and the spectrum-spreading and scrambling is carried out insertion unit that training sequence code inserts, carries out multi-user's superpositing unit that the multi-user superposes in a plurality of carrier waves, it is characterized in that this device further comprises: the phase place rotary unit that after inserting training sequence code, before multi-user's stack the base band subscriber signal is carried out timeslot-based phase place rotation;

This device further comprises:

Peak value is optimized the phase place selected cell, is used for selecting optimal phase place before the phase place rotary unit carries out the phase place rotation, then the phase place of choosing is exported to the phase place rotary unit; Described peak value is optimized the phase place selected cell and is further comprised:

The random phase maker is used for generating at random many group random phases;

Multi-user's phase place rotation and superpositing unit are used to receive the base band subscriber signal that inserts behind the training sequence code, and carry out the phase place rotation according to the subsequence of described random phase after to the grouping of base band subscriber signal, then postrotational signal are carried out linear superposition;

Peak value calculates and comparing unit, be used for calculating the peak power of each subsequence of the many groups subsequence after the stack, and with largest peaks power points wherein as the peak power point of this group, respectively organize peak power point then, with this group rotatable phase output of wherein minimum peak power point correspondence.

8. device according to claim 7 is characterized in that, described peak value is optimized the phase place selected cell and further comprised:

The intermediate frequency simulation unit is used for earlier the base band subscriber signal being carried out interpolation filtering and complex modulation after inserting training sequence code.

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