Specific embodiment
Below in conjunction with attached drawing, specific embodiments of the present invention will be described in further detail.It should be understood that these embodiments
It is only illustrative of the invention and is not intended to limit the scope of the invention, after reading this disclosure, those skilled in the art are to this
The modification of the various equivalent forms of invention falls within right appended by the present patent application.
Application scenarios: the multi-user downlink system of a single base station, the number of users K serviced, wherein base station section
Point configuration N root transmitting antenna and user node configure single received antenna, and system model figure is referring to Fig. 1.
Optimization aim: single base station to greatest extent transimission power and QoS of customer (quality of service,
QoS it) under the constraint conditions such as demand, maximizes system energy efficiency performance (energy efficiency, EE), i.e. system weighted sum speed
The ratio between rate and total power consumption, mathematic(al) representation are
Wherein,
W=[w1,...,wK],Indicate the beam vector of collaboration user k;
P=[p1,...,pK]T, pkIndicate the downlink power allocation value of collaboration user k;
Indicate the normalization channel coefficients vector between single base station and collaboration user k;
θk,γk,Respectively indicate the rate weighted factor and target Signal to Interference plus Noise Ratio of collaboration user k;
P,PC,P0Respectively indicate single base station transimission power to greatest extent, the fixed circuit-level power consumption of single antenna and
Single base station maintains the base power worked normally consumption;Indicate the poor efficiency of single base station power amplifier.
A kind of extensive MIMO efficiency beam-forming method using statistical channel status information, flow chart referring to fig. 2,
Specific implementation step includes:
Statistical channel status information between step 201, the single base station of acquisition and collaboration user;
Step 202, single base station handle the optimization problem of virtual up-link power distribution using statistical channel status information,
Obtain the virtual up-link power allocation vector of optimization;
Step 203 utilizes at uplink downlink duality according to the virtual up-link power allocation vector of the optimization
The transfer problem for managing uplink downlink power distribution, obtains the downlink power allocation vector of optimization;
Instantaneous channel state information between step 204, the single base station of acquisition and collaboration user;
Step 205 utilizes instantaneous channel state information meter according to the virtual up-link power allocation vector of the optimization
Downlink beamforming vector is calculated, the downlink beamforming vector of optimization is obtained.
It should be noted that step 201 to step 203 is to handle virtual uplink function using statistical channel status information
The optimization problem of rate distribution, and using the transfer problem of uplink downlink duality processing uplink downlink power distribution, it obtains
To the downlink power allocation vector of optimization;Step 204 and step 205 are to calculate downlink chain using instantaneous channel state information
Road beamforming vectors, the downlink beamforming vector optimized.
It will be exemplified below step 202, step 203, the specific feasible implementation method of step 205,
For example, the specific feasible implementation method of step 202, flow chart is referring to Fig. 3, comprising:
Step 301, initialization of virtual up-link power allocation vector;
It specifically can be and minimize power under single base station to greatest extent constraint conditions such as transimission power and QoS demand, i.e.,
It is distributed using the virtual up-link power of minimum power in the prior art (power minimization, PM) algorithm initialization
Vector, to obtain virtual up-link power allocation vector initial value q(0), whereinIt indicates
The virtual up-link power apportioning cost of collaboration user k.
Step 302, external iteration update the power consumption factor;
It specifically can be and determined according to linear search method
Wherein, n indicates external iteration number, initial value
Step 303 updates virtual up-link power allocation vector using statistical channel status information internal layer iteration;
Specific feasible implementation method includes the following steps:
According to the power consumption factor-alpha of current external iteration(n)Initialization of virtual up-link power allocation vector q(m),
In, m indicates internal layer the number of iterations, initial value m=0;
According to the virtual up-link power allocation vector q of current internal layer iteration(m)It calculates
It obtainsWherein, ΘkIndicate the normalization space correlation between single base station and collaboration user k
Matrix;
According to the power consumption factor-alpha of current external iteration(n)Virtual up-link power is updated using broad sense water-filling algorithm
Allocation vector, i.e.,
Alternatively,Search for optimum level of water lineMeet power constraints
Obtain updated virtual up-link power allocation vector q(m+1), wherein
Judge whether to stop internal layer iteration, ifThen the virtual up-link power is distributed
Vector q(m+1)Virtual up-link power allocation vector q as current external iteration*(n), otherwise, return and execute according to current
The virtual up-link power allocation vector of internal layer iteration calculates e, and wherein ζ is a preset threshold.
Step 303 it can be appreciated that if external iteration frequency n=0 when, according to the power consumption of current external iteration
The factorUsing statistical channel status information internal layer iteration update virtual up-link power distribute to
Amount, obtains the virtual up-link power allocation vector of current external iteration, is denoted asOtherwise, root
According to the power consumption factor of current external iterationIt is updated on virtual using statistical channel status information internal layer iteration
Uplink power allocation vector obtains the virtual up-link power allocation vector of current external iteration, is denoted as
Step 304 calculates efficiency optimization target values, and shortens the region of search using section elimination approach;
If specifically can be external iteration frequency n=0, according to the power consumption factor of current external iterationWith the virtual up-link power allocation vector of current external iteration
The efficiency optimization target values for calculating current external iteration, are denoted asOtherwise, according to current outer
The power consumption factor in stacking generationWith the virtual up-link power allocation vector of current external iterationThe efficiency optimization target values for calculating current external iteration, are denoted asWherein, efficiency optimizes mesh
The calculation formula of scale value is
Shorten the region of search using section elimination approach, ifThen Otherwise,
Step 305 judges whether to meet external iteration stop condition, ifThen follow the steps 306, it is no
Then return to step 302;
Step 306 is incited somebody to actionOrVirtual up-link power allocation vector q as optimization**。
In another example the specific feasible implementation method of step 203 includes the following steps:
According to the virtual up-link power allocation vector q of optimization**Uplink and downlink chain is handled using uplink downlink duality
The transfer problem of road power distribution, i.e. p=(Ao)-11, obtain the downlink power allocation vector p of optimization**, wherein 1 indicates
All elements are all 1 K dimensional vector,
Wherein,
Enable e'=[e'1,...,e'K]T, e'm=[e'1,m,...,e'K,m]T, then e'=(IK-J)-1V, e'm=(IK-J)- 1vm,
Wherein,
For another example the specific feasible implementation method of step 205 includes the following steps:
It specifically can be the virtual up-link power allocation vector q according to optimization**Utilize instantaneous channel state information meter
Downlink beamforming vector is calculated, the downlink beamforming vector W of optimization is obtained**, wherein calculation formula is as follows:
It should be noted that single base stations and multiuser MIMO efficiency beam-forming method that the prior art proposes is using instantaneous
Channel state information updates downlink power allocation vector sum downlink beamforming vector simultaneously, and what is once updated holds
Continuous time interval is τ.However, a kind of extensive MIMO efficiency beam forming using statistical channel status information proposed in this paper
Method is single base station using statistical channel state information updating downlink power allocation vector and utilizes instantaneous channel state
Information update downlink beamforming vector, the duration time interval that downlink power allocation vector once updates are T,
The duration time interval that downlink beamforming vector once updates is τ, wherein T > > τ.It is also understood that continuing
In time interval T, the method mentioned herein only needs to update a downlink power allocation vector, and the prior art needs more
New τ downlink power allocation vector of T/, that is, illustrate the mentioned method of this paper can be substantially reduced downlink power allocation to
The renewal frequency of amount, to further decrease computation complexity.
Below a kind of the extensive of statistical channel status information will be utilized by the way that MATLAB simulating, verifying is proposed by the present invention
The performance of MIMO efficiency beam-forming method.
Simulated environment parameter setting is as follows, and the number of users K of single base station service, base-station node configures N root transmitting antenna, uses
Family node configures single received antenna.Coverage radius of cell 500m, user's random distribution and with the distance between base station at least
35m.Using the flat fading model under the suburb non line of sight scene in 3GPP, path loss 38log10(d)+34.5,
Shadow fading obeys the logarithm normal distribution of zero-mean standard deviation 8dB and multipath fading coefficient obeys zero mean unit
The multiple Gauss random distribution of variance.The fixed circuit-level power consumption of single antenna is PC=30dBm, single base station maintain normal work
The base power consumption of work is P0=40dBm, and transmission power is P to greatest extent for single base station.Signal bandwidth W=10MHz is used
Family receiving end noise coefficient is 9dB, the poor efficiency of base station power amplifierAnd user rate weighted factor is set as θk=
1,Meanwhile having the method for a kind of united beam forming and power control in the prior art, beam forming uses high specific
(maximum ratio transmission, the MRT) technology of transmission, power control uses mean allocation strategy, by the method phase
The user's Signal to Interference plus Noise Ratio answered is as ownership goal Signal to Interference plus Noise Ratio γk,
Fig. 3 is that single base station is asked using the virtual up-link power distribution optimization of statistical channel status information processing in the present invention
The graph of relation of efficiency optimization target values and the power consumption factor involved in inscribing, according to different power consumption factor-alpha ∈
[0,1] virtual up-link power allocation vector is updated using statistical channel status information iteration, to obtain corresponding virtual
Up-link power allocation vector and calculate its efficiency optimization target values, wherein community user number K=2, Base Transmitter day
Line number mesh N=16.(a), (b), (c), (d) are single base station transmission power P=26dBm, P=34dBm to greatest extent respectively in figure,
Realize that the efficiency optimization target values under (H1, H2, H3, H4) disappear with power in four accidental channels when P=42dBm, P=46dBm
Consume the graph of relation of the factor.Simulation result shows when transmission power region is 26dBm≤P < 42dBm to greatest extent, most
The corresponding optimal power consumption factor-alpha of efficiency optimization target values greatly*=1, it also means that and makes full use of transimission powerWhen transmission power region is 42dBm≤P≤46dBm to greatest extent, efficiency optimization target values and power consumption
The factor (0≤α≤1) presentation first increases the relationship reduced afterwards.In this way, there are a 0≤α of the optimal power consumption factor*≤ 1 makes
Efficiency optimization target values are maximum, therefore can find α using linear search method*, then obtain the virtual uplink function of optimization
Rate allocation vector.
Fig. 5 is the graph of relation of the system energy efficiency performance and single Base Transmitter number of antennas of the mentioned method of the present invention,
In, community user number K=4, Dan Jizhan transmission power P=46dBm to greatest extent." instantaneous CSI " curve refers to use in figure
Single base stations and multiuser MIMO efficiency beam-forming method in the prior art using instantaneous channel state information, 1000 times with
The relation curve of average system performance efficiency and single Base Transmitter number of antennas under the realization of machine channel;" statistical CSI " is bent in figure
Line, which refers to, uses a kind of extensive MIMO efficiency beam-forming method using statistical channel status information proposed by the present invention,
The relation curve of average system performance efficiency and single Base Transmitter number of antennas under 1000 accidental channel realizations;" hundred in figure
Point ratio " curve refers to the ratio and list Base Transmitter number of antennas of both " statistical CSI " and " instantaneous CSI " average system efficiency
Relation curve.Simulation result shows that single base station user number is fixed (K=4), either utilizes instantaneous CSI or statistical CSI
All there is optimal antenna for base station configuration (N in efficiency beam-forming method*=8).When antenna for base station number N=5, " statistics
The ratio of both CSI " and " instantaneous CSI " average system efficiency is 89.46%;It is both above-mentioned when antenna for base station number N=64
Average system efficiency ratio be 98.68%.Also mean that the wave using statistical channel status information that the present invention is mentioned
Its system energy efficiency performance of beam forming method close in the prior art utilize instantaneous channel state information beam-forming method its
System energy efficiency performance, almost can achieve 90% or more.
In conclusion a kind of extensive MIMO efficiency beam forming using statistical channel status information proposed by the present invention
Method, its main feature is that the optimization problem of virtual up-link power distribution is handled first with statistical channel status information, and
Using the transfer problem of uplink downlink duality processing uplink downlink power distribution, to obtain the downlink function of optimization
Rate allocation vector;Secondly, downlink beamforming vector is calculated using instantaneous channel state information, to obtain under optimization
Downlink beam shapes vector.The advantage of the mentioned method of the present invention is, replaces transient channel using statistical channel status information
Status information handles the optimization problem of downlink power allocation vector, reduces and updates a downlink power allocation vector
Operand can simultaneously be effectively avoids downlink power allocation vector renewal frequency excessively high, to further decrease calculating
Complexity.In addition, its system energy efficiency performance of the method using statistical channel status information for being mentioned of the present invention is close to existing skill
Its system energy efficiency performance of the method for instantaneous channel state information is utilized in art.Therefore, a kind of utilize proposed by the present invention counts letter
The extensive MIMO efficiency beam-forming method of channel state information can weigh system energy efficiency performance and computation complexity.