Part decision threshold setting method of the mimo wireless communication based on signal-to-noise ratio (SNR) estimation
Technical field
Portion the present invention relates to multi-antenna wireless communication transmission method, especially mimo wireless communication based on signal-to-noise ratio (SNR) estimation
Divide decision threshold setting method.
Background technique
Currently, the part decision method in patent mimo wireless communication receiver interference cancellation techniques, application number:
The foundation of part judgement in 2012101400375 is threshold value ε, and the value range of the threshold value is 0 < ε < 1, and for
For different modulation systems, threshold value needs are adjusted, meanwhile, for low signal-to-noise ratio and high s/n ratio, threshold value
Also it to be adjusted, threshold value gives range in above-mentioned patent, and specific value is given in specific embodiment, is not given
Out under the conditions of low signal-to-noise ratio and high s/n ratio, how value is carried out to the threshold value.Under actual conditions, high s/n ratio, noise
A possibility that power is small, erroneous judgement is small, and the decision statistics that can carry out hard decision are more, and low signal-to-noise ratio, noise power is big, erroneous judgement
A possibility that it is big, decision statistics are made decisions as little as possible, so, how door obtained according to signal-to-noise ratio and modulation system
The selection principle of limit value is the technical issues that need to address.
Summary of the invention
The purpose of the present invention is to overcome above-mentioned the deficiencies in the prior art, provide a kind of mimo wireless communication to be based on signal-to-noise ratio
The part decision threshold setting method of estimation.
To achieve the above object, the present invention adopts the following technical solutions:
Part decision threshold setting method of the mimo wireless communication based on signal-to-noise ratio (SNR) estimation, this method comprises: according to judgement
The coordinate and constellation coordinate of statistic estimate signal-to-noise ratio;According to the signal-to-noise ratio of estimation and modulation system number to threshold value
Range be configured.
Specifically includes the following steps:
The hard decision region of decision statistics is divided on planisphere in advance, wherein each hard decision region uniquely corresponds to one
A transmitting signal, referred to as constellation point.According to the hard decision region that the system number of QAM modulation divides, each hard decision region is with void
Line or reference axis are boundary, and the black circle in each hard decision region is the corresponding constellation point in hard decision region.Assuming that sentencing
Certainly statistic constellation point in planisphere is mapped as x, and coordinate is (Ix,Qx), the constellation point coordinate in the affiliated hard decision region x is
(ID,QD)。
The signal-to-noise ratio of decision statistics x is estimated in accordance with the following steps in receiving end:
Step 1: determining hard decision region belonging to decision statistics y, and the corresponding constellation point D in the hard decision region is made
For the transmitting signal of estimation;
Step 2: pass through formula (Ix-ID)2+(Qx-QD)2Calculate noise power Pn=(Ix-ID)2+(Qx-QD)2;
Step 3: the power P of the transmitting signal of the estimation is calculateds;
Step 4: it calculatesEstimate the signal-to-noise ratio of decision statistics.
Step 5: modulation system is set using QAM modulation, modulation system number is M, and signal-to-noise ratio is expressed as
It willAs signal-to-noise ratio (SNR) estimation value.
Threshold value set-up mode is as follows:
As SNR >=5log2M-2, corresponding threshold value value range are 0 < ε < 0.5;
As SNR < 5log2M-2, corresponding threshold value value range are 0.5≤ε < 1.
The invention has the advantages that this method according to modulation system system number and by the estimated value to signal-to-noise ratio come pair
Threshold value is divided, and is reasonably divided, is realized to threshold value according to signal-to-noise ratio and modulation system so as to realize
Under the conditions of high s/n ratio, more decision statistics are made decisions, under Low SNR, to less decision statistics into
Row judgement.
Detailed description of the invention
Fig. 1 is part decision threshold setting method flow chart of the mimo wireless communication of the present invention based on signal-to-noise ratio (SNR) estimation;
Fig. 2 is 16QAM modulation constellation.
Specific embodiment
Present invention will be further explained below with reference to the attached drawings and examples.
Part decision threshold setting method of the mimo wireless communication based on signal-to-noise ratio (SNR) estimation, this method comprises: according to judgement
The coordinate and constellation coordinate of statistic estimate signal-to-noise ratio;According to the signal-to-noise ratio of estimation and modulation system number to threshold value
Range be configured.
Specifically includes the following steps:
The hard decision region of decision statistics is divided on planisphere in advance, wherein each hard decision region uniquely corresponds to one
A transmitting signal, referred to as constellation point.For example, Fig. 1 is the hard decision region according to 16QAM model split, each hard decision region
Using dotted line or reference axis as boundary, the black circle in each hard decision region is the corresponding constellation point in hard decision region.It is false
If decision statistics constellation point in planisphere is mapped as y, coordinate is (Ix,Qx), the constellation point coordinate in the affiliated hard decision region y
For (ID,QD)。
As shown in Fig. 2, the signal-to-noise ratio of decision statistics y is estimated in receiving end in accordance with the following steps:
Step 1: determining hard decision region belonging to decision statistics y, and the corresponding constellation point D in the hard decision region is made
For the transmitting signal of estimation;
Step 2: pass through formula (Ix-ID)2+(Qx-QD)2Calculate noise power Pn=(Ix-ID)2+(Qx-QD)2;
Step 3: the power P of the transmitting signal of the estimation is calculateds;
Step 4: it calculatesEstimate the signal-to-noise ratio of decision statistics.
Step 5: modulation system is set using QAM modulation, modulation system number is M, and signal-to-noise ratio is expressed as
Threshold value set-up mode is as follows:
As SNR >=5log2M-2, corresponding threshold value value range are 0 < ε < 0.5;
As SNR < 5log2M-2, corresponding threshold value value range are 0.5≤ε < 1.
Embodiment 1: modulation system is 4QAM modulation, then seeks according to above-mentioned steps one to step 4Numerical value, willEstimated value as Signal to Noise Ratio (SNR);
When SNR >=8, corresponding threshold value value range is 0 < ε < 0.5;
As SNR < 8, corresponding threshold value value range is 0.5≤ε < 1.
Embodiment 2: modulation system is 16QAM modulation, then seeks according to above-mentioned steps one to step 4Numerical value, make
For the estimated value of Signal to Noise Ratio (SNR);
When SNR >=18, corresponding threshold value value range is 0 < ε < 0.5;
As SNR < 18, corresponding threshold value value range is 0.5≤ε < 1.
Embodiment 3: modulation system is 64QAM modulation, then seeks according to above-mentioned steps one to step 4Numerical value, as
The estimated value of Signal to Noise Ratio (SNR);
When SNR >=28, corresponding threshold value value range is 0 < ε < 0.5;
As SNR < 28, corresponding threshold value value range is 0.5≤ε < 1.
The invention has the advantages that this method according to modulation system system number and by the estimated value to signal-to-noise ratio come pair
Threshold value is divided, and is reasonably divided, is realized to threshold value according to signal-to-noise ratio and modulation system so as to realize
Under the conditions of high s/n ratio, more decision statistics are made decisions, under Low SNR, to less decision statistics into
Row judgement.
Above-mentioned, although the foregoing specific embodiments of the present invention is described with reference to the accompanying drawings, not protects model to the present invention
The limitation enclosed, those skilled in the art should understand that, based on the technical solutions of the present invention, those skilled in the art are not
Need to make the creative labor the various modifications or changes that can be made still within protection scope of the present invention.