Summary of the invention
Technical problem to be solved by this invention is to provide a kind of channel estimation methods and device of enhancing, improves the accuracy that Real-time Channel is estimated.
In order to solve the problems of the technologies described above, the invention provides a kind of channel estimation methods of enhancing, comprising: the Common Pilot Channel sign computation according to receiving obtains non real-time channel estimation value; Calculate the deviate of this non real-time channel estimation value and the non real-time channel estimation value of history, or calculate the deviate of current Common Pilot Channel value of symbol and history Common Pilot Channel value of symbol; Described non real-time channel estimation value and described deviate are weighted read group total and obtain Real-time Channel estimated value.
Further, said method can also have following characteristics:
After calculating deviate, infinite impulse response digital filtering is carried out to this deviate, then the deviate of carrying out the process of infinite impulse response digital filtering is used for calculating Real-time Channel estimated value.
Further, said method can also have following characteristics:
Calculate Real-time Channel estimated value according to following methods: described deviation is multiplied by after compensating factor with described Non-real time signals estimated value and as live signal estimated value, described compensating factor is a non-zero real being less than or equal to 1.
Further, said method can also have following characteristics:
During calculation deviation value, the discrete time point that non real-time channel estimation value is corresponding with the non real-time channel estimation value of history or the Common Pilot Channel value of symbol discrete time point corresponding with history Common Pilot Channel value of symbol differ X discrete time point, X be less than 5 integer.
In order to solve the problems of the technologies described above, the invention provides a kind of channel estimating apparatus of enhancing, described device is arranged in mobile terminal; Described channel estimating apparatus comprises non real-time channel estimation module, deviate computing module, Real-time Channel estimation module; The output of described non real-time channel estimation module is connected with the input of described deviate computing module; Described non real-time channel estimation module, for obtaining non real-time channel estimation value according to the Common Pilot Channel sign computation received, and exports the non real-time channel estimation value obtained to described deviate computing module and described Real-time Channel estimation module; Described deviate computing module, for calculating the deviate of non real-time the channel estimation module non real-time channel estimation value exported and the non real-time channel estimation value of history deposited, and outputs to Real-time Channel estimation module; Described Real-time Channel estimation module, the deviate for the non real-time channel estimation value of described non real-time channel estimation module output and described deviate computing module being exported is weighted read group total and obtains Real-time Channel estimated value.
Further, said apparatus can also have following characteristics:
Described device also comprises the filtration module be connected between described deviate computing module and described Real-time Channel estimation module; Described filtration module inputs to described Real-time Channel estimation module after being used for carrying out infinite impulse response digital filtering to the deviate that described deviate computing module exports.
Further, said apparatus can also have following characteristics:
Described Real-time Channel estimation module, also for calculating Real-time Channel estimated value according to following methods: described deviation is multiplied by after compensating factor with described Non-real time signals estimated value and as live signal estimated value, described compensating factor is a non-zero real being less than or equal to 1.
In order to solve the problems of the technologies described above, the invention provides a kind of channel estimating apparatus of enhancing, described device is arranged in mobile terminal; Described channel estimating apparatus comprises non real-time channel estimation module, deviate computing module, Real-time Channel estimation module; Described non real-time channel estimation module, for obtaining non real-time channel estimation value according to the Common Pilot Channel sign computation received, and exports the non real-time channel estimation value obtained to described Real-time Channel estimation module; Described deviate computing module, for calculating the deviate of the Common Pilot Channel value of symbol received and the history Common Pilot Channel value of symbol deposited, and outputs to Real-time Channel estimation module; Described Real-time Channel estimation module, the deviate for the non real-time channel estimation value of described non real-time channel estimation module output and described deviate computing module being exported is weighted read group total and obtains Real-time Channel estimated value.
Further, said apparatus can also have following characteristics:
Described device also comprises the filtration module be connected between described deviate computing module and described Real-time Channel estimation module; Described filtration module inputs to described Real-time Channel estimation module after being used for carrying out infinite impulse response digital filtering to the deviate that described deviate computing module exports.
Further, said apparatus can also have following characteristics:
Described Real-time Channel estimation module, also for calculating Real-time Channel estimated value according to following methods: described deviation is multiplied by after compensating factor with described Non-real time signals estimated value and as live signal estimated value, described compensating factor is a non-zero real being less than or equal to 1.
The present invention is when calculating the estimated value of Real-time Channel, with reference to the history value of non real-time channel estimation value or the history value of Common Pilot Channel symbol, thus improve the accuracy of Real-time Channel estimation, effectively improve the demodulation performance of channel, and less to the consumption of hardware resource, realize simple.
Embodiment
As shown in Figure 1, the channel estimating apparatus being arranged in the enhancing of mobile terminal in embodiment one comprises non real-time channel estimation module, deviate computing module, Real-time Channel estimation module.The output of non real-time channel estimation module is connected with the input of described deviate computing module.
The Common Pilot Channel sign computation that described non real-time channel estimation module is used for according to receiving obtains non real-time channel estimation value, and exports the non real-time channel estimation value obtained to described deviate computing module and described Real-time Channel estimation module.
Described deviate computing module for the deviate of the calculate non real-time channel estimation module non real-time channel estimation value exported and the non real-time channel estimation value of history to have deposited, and outputs to Real-time Channel estimation module.
Described Real-time Channel estimation module is used for that the deviate that the non real-time channel estimation value of described non real-time channel estimation module output and described deviate computing module export is weighted read group total and obtains Real-time Channel estimated value.
As shown in Figure 2, the channel estimating apparatus being arranged in the enhancing of mobile terminal in embodiment one comprises non real-time channel estimation module, deviate computing module, Real-time Channel estimation module.
The Common Pilot Channel sign computation that described non real-time channel estimation module is used for according to receiving obtains non real-time channel estimation value, and exports the non real-time channel estimation value obtained to described Real-time Channel estimation module.
Described deviate computing module for calculating the deviate of the Common Pilot Channel value of symbol received and the history Common Pilot Channel value of symbol deposited, and outputs to Real-time Channel estimation module.
Described Real-time Channel estimation module is used for that the deviate that the non real-time channel estimation value of described non real-time channel estimation module output and described deviate computing module export is weighted read group total and obtains Real-time Channel estimated value.
The filtration module be connected between deviate computing module and Real-time Channel estimation module can also be comprised in device shown in above-mentioned two embodiments.This filtration module inputs to Real-time Channel estimation module after being used for carrying out infinite impulse response digital filtering to the deviate that deviate computing module exports.The filter function of this filtration module assists in removing noise.
In above-mentioned two embodiments, Real-time Channel estimation module calculate Real-time Channel estimated value time can adopt following methods: described deviation is multiplied by after compensating factor with described Non-real time signals estimated value and as live signal estimated value, described compensating factor is a non-zero real being less than or equal to 1.
Specific embodiment one:
In the specific embodiment one of embodiment one correspondence, channel estimating apparatus is as shown in Figure 3, and channel estimation methods comprises following content:
One, current C PICH symbol is obtained
Obtaining the CPICH symbol that current CPICH symbol comprises each footpath of reception, is that after completing the descrambling and de-spreading of CPICH channel via descrambling and de-spreading module, Symbol division module carries out the CPICH symbol after separating treatment to the frequency pilot sign of CPICH.
Two, non real-time channel estimating
Non real-time channel estimation module adopts conventional filtering method, such as multiple frequency pilot sign moving average method when carrying out channel estimating to the CPICH symbol received.If the current CPICH symbol received is for being expressed as x (n), then non real-time channel estimating export that y (n-1) is x (n), x (n-1), x (n-2) and x's (n-3) and mean value.Namely non real-time channel estimating exports and meets following formula description:
The cumulative symbolic number of N in formula, value can be 4 or 8.This non real-time channel estimation module adopts non-causal filter, and use following CPICH symbol as the input of non real-time filter, the offset data that the channel estimation value of current output is corresponding will do time delay N/2-1 process.
Three, non real-time channel estimation bias value is predicted
Utilizing nearest non-causal filter to export the approximate deviation causing channel estimating as channel estimation value to overcome, using current non real-time channel estimation value and the non real-time channel estimation value of history to dope non real-time channel estimation bias value here.If not the output of Real-time Channel estimated value is y (n-1), then shown in the deviate now obtained for Real-time Channel estimation prediction is calculated as follows:
δ(n)=y(n-1)-y(n-3)
δ
f(n)=(1-α)·δ
f(n-1)+α·δ(n)
In order to the impact of noise decrease interference, be employed herein first order IIR filtering device and carry out filtering process.In formula, α is iir filter coefficient, generally can value 1/4, can add computing realize by displacement.
Four, Real-time Channel is estimated
The non real-time channel of current output is exported y (n-1) and is weighted with prediction deviation offset the estimated value that summation just obtains Real-time Channel
namely
In formula, β is the compensating factor that Real-time Channel exports, and this compensating factor is a non-zero real being less than or equal to 1, generally can value 1/2 or 5/8.
Specific embodiment two:
In the specific embodiment two of embodiment two correspondence, channel estimating apparatus is as shown in Figure 4, and channel estimation methods comprises following content:
It is identical with specific embodiment one with the content of Part II and non real-time channel estimating that namely Part I obtains current C PICH symbol.
Three, non real-time channel estimation bias value is predicted
If the CPICH symbol of current acquisition is x (n), then the CPICH deviate calculated is:
δ(n)=x(n)-x(n-2)
δ
f(n)=(1-α)·δ
f(n-1)+α·δ(n)
Here have employed first order IIR filtering device equally and carry out filtering process.α is iir filter coefficient, generally can value 1/4.
Four, Real-time Channel is estimated
The estimated value of Real-time Channel can be weighted addition by CPICH symbol deviate and now non real-time filter output and obtain, and is calculated as follows:
In formula, β is the compensating factor that Real-time Channel exports, and this compensating factor is a non-zero real being less than or equal to 1, generally can value 1/2 or 5/8.
As shown in Figure 5, corresponding to said apparatus, the channel estimation methods of enhancing comprises: the Common Pilot Channel sign computation according to receiving obtains non real-time channel estimation value; Calculate the deviate of this non real-time channel estimation value and the non real-time channel estimation value of history, or calculate the deviate of current Common Pilot Channel value of symbol and history Common Pilot Channel value of symbol; Described non real-time channel estimation value and described deviate are weighted read group total and obtain Real-time Channel estimated value.
After calculating deviate, infinite impulse response digital filtering is carried out to this deviate, then the deviate of carrying out the process of infinite impulse response digital filtering is used for calculating Real-time Channel estimated value.
Calculate Real-time Channel estimated value according to following methods: described deviation is multiplied by after compensating factor with described Non-real time signals estimated value and as live signal estimated value, described compensating factor is a non-zero real being less than or equal to 1.
During calculation deviation value, the discrete time point that non real-time channel estimation value is corresponding with the non real-time channel estimation value of history or the Common Pilot Channel value of symbol discrete time point corresponding with history Common Pilot Channel value of symbol differ X discrete time point, X be less than 5 integer.
The present invention, when calculating the estimated value of Real-time Channel, with reference to the history value of non real-time channel estimation value or the history value of Common Pilot Channel symbol, thus improves the accuracy of Real-time Channel estimation, effectively improves the demodulation performance of channel.
Certainly; the present invention also can have other various embodiments; when not deviating from the present invention's spirit and essence thereof; those of ordinary skill in the art are when making various corresponding change and distortion according to the present invention, but these change accordingly and are out of shape the protection range that all should belong to the claim appended by the present invention.
The all or part of step that one of ordinary skill in the art will appreciate that in said method is carried out instruction related hardware by program and is completed, and described program can be stored in computer-readable recording medium, as read-only memory, disk or CD etc.Alternatively, all or part of step of above-described embodiment also can use one or more integrated circuit to realize.Correspondingly, each module/unit in above-described embodiment can adopt the form of hardware to realize, and the form of software function module also can be adopted to realize.The present invention is not restricted to the combination of the hardware and software of any particular form.