CN101154969B - Method for confirming actual emission power of transmitter - Google Patents

Method for confirming actual emission power of transmitter Download PDF

Info

Publication number
CN101154969B
CN101154969B CN2006101396637A CN200610139663A CN101154969B CN 101154969 B CN101154969 B CN 101154969B CN 2006101396637 A CN2006101396637 A CN 2006101396637A CN 200610139663 A CN200610139663 A CN 200610139663A CN 101154969 B CN101154969 B CN 101154969B
Authority
CN
China
Prior art keywords
power
transmitter
calculate
emission power
subchannel
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Active
Application number
CN2006101396637A
Other languages
Chinese (zh)
Other versions
CN101154969A (en
Inventor
刘云辉
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Lenovo Beijing Ltd
Original Assignee
Lenovo Beijing Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Lenovo Beijing Ltd filed Critical Lenovo Beijing Ltd
Priority to CN2006101396637A priority Critical patent/CN101154969B/en
Publication of CN101154969A publication Critical patent/CN101154969A/en
Application granted granted Critical
Publication of CN101154969B publication Critical patent/CN101154969B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

Links

Images

Classifications

    • Y02B60/50—

Landscapes

  • Mobile Radio Communication Systems (AREA)
  • Transmitters (AREA)

Abstract

The present invention discloses a method for confirming the actual transmitting power of the transmitter, and the method comprises the following steps: a calculating the saturated transmitting power Pcsi and other maximum transmitting power; b. confirming the least value in other maximum transmitting power and the saturated transmitting power Pcsi, and setting the least value as the actual transmitting power Ptol of the transmitter; c. confirming the final actual transmitting power Pk of each subchannel of the transmitter according to the confirmed actual transmitting power Ptol. The scheme of the invention facilitates that the transmitter does power distribution according to the actual need of each subchannel. The scheme of the invention settles the problem that the saturated transmitting power exists when the CSIT of the transmitter generates error, and the problem that the integral performance of the system deteriorates causing by the continuous increasing of the transmitting power when the target SNR which is corresponding to the set SNR or the supported frequency spectrum efficiency is larger than the saturated SNR that is caused by the CSIT error and is corresponding to the saturated transmitting power.

Description

A kind of method of definite actual emission power of transmitter
Technical field
The present invention relates to wireless communication technology field, specifically relate to a kind of method of definite actual emission power of transmitter.
Background technology
The technology (MIMO) of using many antenna/aerial arrays to launch and/or receive is one of core technology of next generation wireless communication system.The MIMO communication system uses Nt transmitting antenna and Nr reception antenna to carry out transfer of data.The formed Nt of these transmitting antennas and reception antenna * Nr dimension mimo channel can be broken down into the subchannel of L separate space, and wherein (Nt, Nr), and Nt and Nr are respectively and transmit and receive number of antenna elements L＜=min.In this system, can walk abreast on the subchannel of this L separate space sends independent data stream, to increase system spectral efficiency.
In many application, transmitter can pass through feedback channel, measure the channel condition information (CSIT) of the reciprocal attribute acquisition emitting side of channel in inverse channel or time division duplex (TDD) system, and can utilize this CSIT to improve spectrum efficiency and reduction error probability, thereby strengthen the systematic function of MIMO.
Specifically, transmitter just can optimally distribute corresponding transmission power for each subchannel according to the decline situation and the target capabilities of each spatial sub-channel after having obtained CSIT, with the performance of raising subchannel, and then the performance of raising transmitter.Can there be a desired value in the transmitting power of each spatial sub-channel, is referred to as saturation emission power but under many circumstances.Why transmitting power has saturation power, may be because when transmitting power was increased to some value, the error rate of system (BER) had reached our required degree, needn't obtain better BER or performance by increasing transmitting power again; Also may be because the sub-channel spectra efficient that transmitting power caused has reached the maximum spectral efficiency that system can support.Obviously, in these cases, it is also nonsensical to increase transmitting power to subchannel again.And the transmitting power of subchannel is big more, and the interference that other user or other subchannel are brought is also just big more.
But then, the situation of transmitting power under saturation emission power that also may occur other spatial sub-channel in the system, therefore, can consider that the transmission power beyond the saturated power is distributed to the spatial sub-channel of those transmitting powers under saturation power in the subchannel with the transmitting power surplus, to improve the performance of these spatial sub-channels.
Summary of the invention
In view of this, subject matter to be solved by this invention is to provide a kind of method of definite actual emission power of transmitter, reasonably to be transmitter distribution transmitting power.
For overcoming the above problems, the invention provides following technical scheme:
A kind of method of definite actual emission power of transmitter, this method may further comprise the steps:
A. calculate saturation emission power P csi and other maximum transmission power;
B. determine the minimum value among other maximum transmission power and the saturation emission power P csi, and with its actual emission power Ptol as transmitter;
C. determine the final actual emission power P of each subchannel of transmitter according to determined actual emission power Ptol k
Among the described step a, described calculating saturation emission power P csi comprises: the variance of the channel estimation errors of transmitter computes
Figure DEST_PATH_GSB00000398710900011
Utilize formula afterwards
Figure DEST_PATH_GSB00000398710900012
Estimate saturation emission power P csi.
Described transmitter belongs to tdd systems;
Among the step a, the variance of the channel estimation errors of described transmitter computes Comprise: pass through formula
Figure DEST_PATH_GSB00000398710900014
Calculate, wherein, P TBe the training symbol transmitting power; K is the transmitting training number of symbols; Be noise variance; N tBe the transmit antenna elements number.
Described transmitter belongs to frequency division duplex system;
Among the step a, the variance of the channel estimation errors of described transmitter computes
Figure DEST_PATH_GSB00000398710900016
Comprise:
A1. calculate the variance of the channel estimation errors of receiver side by following formula
Figure DEST_PATH_GSB00000398710900017
Obtain corresponding channel estimation errors, and calculating channel state CSI quantization error, calculate afterwards channel estimation errors and CSI quantization error and variance
Figure DEST_PATH_GSB00000398710900018
Wherein, P TBe the training symbol transmitting power; K is the transmitting training number of symbols;
Figure DEST_PATH_GSB000003987109000110
Be noise variance; N tBe the transmit antenna elements number;
A2. calculate channel condition information CSIT and CSI existing coefficient correlation ρ between the CSIT before the feedback delay time τ of current time;
A3. according to obtain and variance
Figure DEST_PATH_GSB000003987109000111
Calculate the variance of the channel estimation errors of transmitter with coefficient correlation ρ
Figure DEST_PATH_GSB000003987109000112
Coefficient correlation ρ among the described step a2 is by formula ρ=J 0(2 π f Dτ) calculate, wherein, J 0(x) expression zeroth order Bessel function of the first kind, f DBe maximum doppler frequency.
Among the described step a, described other maximum transmission power comprises: target transmit power Pset and/or maximum transmission power constraint,
Calculating described target transmit power Pset is: signal to noise ratio snr or systematic function according to target or setting require to calculate;
Calculating described maximum transmission power is constrained to: calculate the maximum transmission power Pmax of every transmit antennas, calculate total maximum transmission power of all transmitting antennas afterwards again.
Described step c can for: directly actual emission power Ptol is distributed to each subchannel.
Described step c can also for: calculate the actual emission power Ptol that actual emission power Ptol distributes to each subchannel k, and calculate the goal-setting transmitting power Pset of each subchannel k, select the final actual emission power P of the minimum value of two transmitting powers afterwards as subchannel k
Among the described step c, the described goal-setting transmitting power Pset that calculates each subchannel kFor: according to the target or the setting signal to noise ratio snr of k subchannel kOr systematic function requires to calculate.
Among the described step c, describedly calculate the actual emission power Ptol that actual emission power Ptol distributes to each subchannel kFor: utilize the water injection power distribution method described actual emission power Ptol to be distributed to the actual emission power Ptol of each subchannel k
The present invention passes through to calculate saturation emission power P csi and other maximum transmission power, and with the actual emission power Ptol of its minimum value as transmitter, utilizes this actual emission power Ptol to determine the actual emission power P of each subchannel afterwards again kThereby, make transmitter to carry out power division, thereby there is the problem of saturation emission power in the CSIT that has solved transmitter when error occurring according to the actual needs of each subchannel; And when the target SNR of the spectrum efficiency correspondence of signal to noise ratio (snr) of setting or support during greater than the pairing saturated SNR of the saturation emission power that causes owing to the CSIT error, transmitting power continues to increase and the problem of the entire system performance deterioration that causes.
In addition, the present invention program's saturation emission power is calculated at the emission pusher side by transmitter, the problem of spectrum efficiency decline can not occur causing owing to the increase of receiver side feedback information.
And the present invention program's range of application more is close to actual wireless communication environment and condition, because always there is error in the CSI that transmitter obtains, that is to say, always has the saturation emission power P csi that causes owing to the CSIT error.
Description of drawings
When Fig. 1 obtained the CSIT of different accuracy for transmitter, power system capacity was along with the performance curve schematic diagram of transmit power variation;
Fig. 2 is the present invention program's realization flow figure.
Embodiment
For the present invention, want transmitter is carried out rational power division, need at first then to determine a desirable maximum transmission power that i.e. actual emission power Ptol correspondingly determines the actual emission power of this subchannel afterwards again for each subchannel for transmitter.
Before determining actual emission power, at first transmitter is analyzed.
If the CSIT of transmitter is that perfectly then in theory, in the variable range of transmitting power, the mimo system performance of transmitter can improve along with the increase of transmitting power always; If but the CSIT that transmitter obtained has error, then the performance that system obtained does not increase along with the increase of transmitting power always, the transmitting power that this is maximum is called saturation emission power, be designated as Pcsi, the saturation emission power of each subchannel is called Pcsik, wherein, the scope of k is 0～L, and L is the number of separate space subchannel.Figure 1 shows that when transmitter obtains the CSIT of different accuracy power system capacity is along with the performance curve of transmit power variation, the σ among the figure Err 2The variance of expression transmitter CSI error.
Obviously, in the communication environment of reality, transmitter only may obtain to have the CSIT of error, so always there is the saturation emission power P csi that causes owing to the CSIT error in system, and the value of Pcsi reduces along with the increase of CSIT error.
In addition, can also calculate other maximum transmission power of transmitter, this maximum transmission power can be a target transmit power, also can be the maximum transmission power constraint of being determined by the physical condition restriction of transmitting antenna, can certainly comprise this two kinds of power simultaneously.Wherein, target transmit power is designated as Pset, if the actual emission power Ptol of transmitter greater than Pset, the transmitting power that then has more is remaining transmitting power.And because the restriction of the physical condition of transmitting antenna, every transmit antennas also can be subjected to the constraint of maximum transmission power Pmax, it is the constraint that transmitter is subjected to total transmitting power Nt*Pmax, if the actual emission power Ptol of transmitter is greater than Nt*Pmax, the transmitting power that then has more also is remaining transmitting power.
Based on above-mentioned analysis, the present invention program's main thought is: calculate the saturation emission power P csi of transmitter, and other maximum transmission power, afterwards with the actual emission power Ptol of minimum value as this transmitter.
Below in conjunction with drawings and the specific embodiments the present invention program is done and to describe in further detail.
The present invention program's realization flow as shown in Figure 2, corresponding following steps:
Step 201, calculating saturation emission power P csi and other maximum transmission power.
Step 202, determine the minimum value among other maximum transmission power and the Pcsi, and with the actual emission power Ptol of this minimum value as transmitter.
Step 203, determine the actual emission power P of each subchannel of transmitter according to determined actual emission power Ptol k
By above step, can be embodied as transmitter and determine actual emission power.
In the above-mentioned steps 201, according to the residing system of transmitter difference, saturation emission power P csi has different computational methods.
Want to calculate saturation emission power P csi, then at first want the variance of the channel estimation errors of transmitter computes Utilize again afterwards
Figure DEST_PATH_GSB00000398710900032
Estimation saturation emission power P csi.And Pcsi can calculate by formula (1).
Pcsi = 1 / σ err 2 - - - ( 1 )
If the emission pusher side can obtain perfect CSIT, then
Figure DEST_PATH_GSB00000398710900034
By formula (1) as can be seen, Pcsi → ∞ of this moment that is to say, when the emission pusher side had perfect CSIT, saturation power was non-existent.
Calculating
Figure DEST_PATH_GSB00000398710900035
The time, according to system's difference at transmitter place,
Figure DEST_PATH_GSB00000398710900036
Computational methods also be not quite similar.
Specifically, in time division duplex (TDD) system, transmitter utilizes received signal to estimate reverse channel, directly the estimated value of reverse channel is used as the estimated value of send channel then according to the reciprocal attribute of channel, therefore, can correspondingly determine the variance of channel estimation errors at the employed distinct methods of channel estimating
Figure DEST_PATH_GSB00000398710900037
Such as, if adopt the channel estimation methods of Minimum Mean Square Error (MMSE), then
Figure DEST_PATH_GSB00000398710900038
Can calculate by formula (2).
σ err 2 = 1 1 + P T K / N t σ n 2 - - - ( 2 )
Wherein, P TBe the training symbol transmitting power; K is the transmitting training number of symbols;
Figure DEST_PATH_GSB000003987109000310
Be noise variance;
N tBe the transmit antenna elements number.
If in Frequency Division Duplexing (FDD) (FDD) system, the transmitter signal estimated information that acquisition is received according to feedback channel, the CSIT evaluated error that transmitter obtains comprises channel estimation errors, the CSI quantization error of receiver and the error that feedback delay caused.Specifically, this calculating comprises two steps:
The variances sigma of step a, receiver side channel estimation errors Err 2Can calculate according to formula (2), afterwards again according to this σ Err 2Obtain the channel estimation errors of receiver side, the CSI quantization error then determines according to different quantization methods, calculate again channel estimation errors and CSI quantization error and variance, be designated as σ t 2
Step b, suppose that the CSI feedback delay time is τ, then there is a coefficient correlation ρ in the CSIT of current time and the τ CSIT before constantly, calculates this coefficient correlation ρ.
Such as, if meeting classical Jakes, mimo channel entry of a matrix element distributes (in fact, most mimo channels all satisfy this distribution), then coefficient correlation ρ can estimate according to formula (3).
ρ＝J 0(2πf Dτ)(3)
Wherein, J 0(x) expression zeroth order Bessel function of the first kind, f DBe maximum doppler frequency.
Step c, according to obtain and variances sigma t 2Calculate the variances sigma of the channel estimation errors of transmitter with coefficient correlation ρ Err 2
Above-mentioned steps 201 also need be calculated other maximum transmission power of transmitter.
If this other maximum transmission power comprises target transmit power Pset, then can calculate target transmit power according to the target QoS of system, specifically, does the systematic function of the target SNR of the spectrum efficiency correspondence that can support according to transmitter or the signal to noise ratio snr of setting or QoS and so on require to calculate that (these computational methods are existing methods? as not being please simply to describe).
If this other maximum transmission power comprises maximum transmission power constraint, i.e. Nt*Pmax then can calculate the maximum transmission power Pmax of every transmit antennas earlier, uses the number of transmitting antenna afterwards again, i.e. Nt is with the Pmax acquisition of multiplying each other.
After obtaining actual emission power Ptol, can also obtain the transmitting power of each subchannel by step 203 by above-mentioned steps 202.Such as, can directly distribute this actual emission power Ptol, this Ptol is assigned to each subchannel, obtain the actual emission power Ptol of k subchannel kSpecifically, can be utilize the water injection power distribution method to carry out the power division of subchannel (this water injection power distribution method is existing method? as not being please simply to describe this distribution method).
In addition, the situation of each subchannel has nothing in common with each other usually, such as, the goal-setting transmitting power Pset of each subchannel kJust may vary.In this case, the actual emission power Ptol that utilizes Ptol to calculate then also may appear kGreater than Pset kThereby having wasted number on this subchannel is Ptol k-Pset kThe problem of power resource.Based on this problem, the present invention also provides the implementation method of the final actual emission power Pk that obtains subchannel.This method is: the goal-setting transmitting power Pset that calculates each subchannel k, this Pset kSpecifically can be according to the target or the setting SNR of k subchannel kOr the systematic function of QoS and so on requires to calculate, and selects Ptol kWith Pset kIn minimum value as the final actual emission power P of subchannel k, i.e. P k=min (Pcsi k, Pset k).
The above only is the present invention program's preferred embodiment, not in order to limit protection scope of the present invention.

Claims (10)

1. the method for a definite actual emission power of transmitter is characterized in that, this method may further comprise the steps:
A. calculate saturation emission power P csi and other maximum transmission power, wherein, described saturation emission power is that error is arranged for the channel condition information that obtains at transmitter, under the situation that the performance that system obtained does not increase along with the increase of transmitting power always, and maximum transmitting power;
B. determine the minimum value among other maximum transmission power and the saturation emission power P csi, and with its actual emission power Ptol as transmitter;
C. determine the final actual emission power P of each subchannel of transmitter according to determined actual emission power Ptol k
2. method according to claim 1 is characterized in that, among the described step a, described calculating saturation emission power P csi comprises: the variance of the channel estimation errors of transmitter computes
Figure FSB00000524093800011
Utilize formula afterwards
Figure FSB00000524093800012
Estimate saturation emission power P csi.
3. method according to claim 2 is characterized in that described transmitter belongs to tdd systems;
Among the step a, the variance of the channel estimation errors of described transmitter computes
Figure FSB00000524093800013
Comprise: pass through formula
Figure FSB00000524093800014
Calculate, wherein, P TBe the training symbol transmitting power; K is the transmitting training number of symbols; Be noise variance; N tBe the transmit antenna elements number.
4. method according to claim 2 is characterized in that described transmitter belongs to frequency division duplex system;
Among the step a, the variance of the channel estimation errors of described transmitter computes
Figure FSB00000524093800016
Comprise:
A1. calculate the variance of the channel estimation errors of receiver side by following formula
Figure FSB00000524093800017
, obtain corresponding channel estimation errors, and calculating channel state CSI quantization error, calculate afterwards channel estimation errors and CSI quantization error and variance
Figure FSB00000524093800019
Wherein, P TBe the training symbol transmitting power; K is the transmitting training number of symbols;
Figure FSB000005240938000110
Be noise variance; N tBe the transmit antenna elements number;
A2. calculate channel condition information CSIT and CSI existing coefficient correlation ρ between the CSIT before the feedback delay time τ of current time;
A3. according to obtain and variance
Figure FSB00000524093800021
Calculate the variance of the channel estimation errors of transmitter with coefficient correlation ρ
Figure FSB00000524093800022
5. method according to claim 4 is characterized in that, the coefficient correlation ρ among the described step a2 is by formula ρ=J 0(2 π f Dτ) calculate, wherein, J 0(x) expression zeroth order Bessel function of the first kind, f DBe maximum doppler frequency.
6. method according to claim 1 is characterized in that, among the described step a, described other maximum transmission power comprises: target transmit power Pset and/or maximum transmission power constraint,
Calculating described target transmit power Pset is: signal to noise ratio snr or systematic function according to target or setting require to calculate;
Calculating described maximum transmission power is constrained to: calculate the maximum transmission power Pmax of every transmit antennas, calculate total maximum transmission power of all transmitting antennas afterwards again.
7. method according to claim 1 is characterized in that, described step c is: directly actual emission power Ptol is distributed to each subchannel.
8. method according to claim 1 is characterized in that, described step c is: calculate the actual emission power Ptol that actual emission power Ptol distributes to each subchannel k, and calculate the goal-setting transmitting power Pset of each subchannel k, select the final actual emission power P of the minimum value of two transmitting powers afterwards as subchannel k
9. method according to claim 8 is characterized in that, among the described step c, and the described goal-setting transmitting power Pset that calculates each subchannel kFor: according to the target or the setting signal to noise ratio snr of k subchannel kOr systematic function requires to calculate.
10. method according to claim 7, it is characterized in that, among the described step c, describedly directly actual emission power Ptol is distributed to each subchannel and be: utilize the water injection power distribution method described actual emission power Ptol to be distributed to the actual emission power Ptol of each subchannel k
CN2006101396637A 2006-09-28 2006-09-28 Method for confirming actual emission power of transmitter Active CN101154969B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN2006101396637A CN101154969B (en) 2006-09-28 2006-09-28 Method for confirming actual emission power of transmitter

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN2006101396637A CN101154969B (en) 2006-09-28 2006-09-28 Method for confirming actual emission power of transmitter

Publications (2)

Publication Number Publication Date
CN101154969A CN101154969A (en) 2008-04-02
CN101154969B true CN101154969B (en) 2011-11-02

Family

ID=39256443

Family Applications (1)

Application Number Title Priority Date Filing Date
CN2006101396637A Active CN101154969B (en) 2006-09-28 2006-09-28 Method for confirming actual emission power of transmitter

Country Status (1)

Country Link
CN (1) CN101154969B (en)

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN102487300B (en) * 2010-12-03 2015-01-28 中兴通讯股份有限公司 Method and system for testing maximum transmitting power of multi-antenna user device
CN102761947B (en) * 2011-04-25 2017-05-03 中兴通讯股份有限公司 Method and system for coordinating same frequency interference based on power control

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1315788A (en) * 2000-03-23 2001-10-03 华为技术有限公司 Forward power saturation protecting method and power controller for CDMA communication system
CN1815913A (en) * 2004-12-29 2006-08-09 朗迅科技公司 Scheduling calls in downlink transmissions

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN1315788A (en) * 2000-03-23 2001-10-03 华为技术有限公司 Forward power saturation protecting method and power controller for CDMA communication system
CN1815913A (en) * 2004-12-29 2006-08-09 朗迅科技公司 Scheduling calls in downlink transmissions

Also Published As

Publication number Publication date
CN101154969A (en) 2008-04-02

Similar Documents

Publication Publication Date Title
CN101252417B (en) Method and system for sending information in wireless communicating system
CN102804660B (en) The link circuit self-adapting of the coordinated multi-point downlink transmission centered by network
CN102035615B (en) MIMO-based downlink data transmission method, device and system
CN101517922B (en) Beamforming method, system and device
CN101741508B (en) Method for obtaining and using CQI in LTE transmission mode 7
JP2012531132A (en) Method and related apparatus for transmitting signals in a time division multiple access MIMO system
CN102415002A (en) Channel state information reconstruction from sparse data
CN104702390A (en) Pilot frequency distribution method in distributed compressive sensing (DCS) channel estimation
CN101388752A (en) Uplink transmission method, terminal and base station based on time division duplexing system
CN101686500B (en) Method and user terminal for determining correlation parameters, and signal forming method and base station
CN101304301A (en) Orthogonal air time precoding transmission method based on distributed antenna system
CN106941688B (en) PDMA system power distribution method based on historical information
CN101174924A (en) Method and system for measuring space channel order
CN102148663A (en) Method for realizing adaptive transmission by comprehensively utilizing long-time and short-time channel state information
CN103023619B (en) Wireless communication system link self-adaption transmission method
CN102752037B (en) Multi-antenna relay pre-code robust construction method under delayed feedback
US20040132494A1 (en) Communication method
CN102474318A (en) Method of PCI and CQI estimation in CDMA systems
CN101154969B (en) Method for confirming actual emission power of transmitter
CN101227444A (en) Method and device for selecting precoding weight vectors
CN104901732A (en) Pilot frequency multiplexing method in dense node configuration system
CN102547953B (en) Method for obtaining beam forming gain
CN105227222B (en) A kind of extensive MIMO beam-forming method of high energy efficiency using statistical channel status information
CN101834652B (en) Downlink transmission method based on MIMO-OFDM (Multiple Input Multiple Output-Orthogonal Frequency Division Multiplexing) time domain feedback
CN105656535B (en) Downlink correction method and device in Massive MIMO system

Legal Events

Date Code Title Description
C06 Publication
PB01 Publication
C10 Entry into substantive examination
SE01 Entry into force of request for substantive examination
C14 Grant of patent or utility model
GR01 Patent grant