Adjust the method and apparatus of the step-length of regularly following the tracks of
Technical field
The present invention relates to adjust the method and apparatus of the step-length of regularly following the tracks of in a kind of TD-SCDMA system.
Background technology
In portable terminal, power consumption is an important performance parameter of terminal.How to reduce the importance that to consider when power consumption is Terminal Design with the stand-by time that increases portable terminal and air time.Terminal reduces power consumption in the standby process method mainly is by in the paging receiving information process, between adjacent paging indication, does province's electric treatment.Comprising: radio-frequency module, Analog Baseband module, digital baseband part.The analog baseband section branch comprises that falling voltage handles; Digital baseband part comprises that falling voltage handles and down conversion process.
For the battery saving mode in the paging, need guarantee the correctness of terminal when receiving the paging indication.For the TD-SCDMA system terminal, mean and to guarantee the correct of System Frame Number and frame timing.For portable terminal, after entering the sound sleep pattern, generally the master clock of system is turned off.This moment, the timing of system was kept by a low-frequency clock.The frequency of this low-frequency clock is uncertain, must be through calibration carry out the timing maintenance with this clock before.
After low-frequency clock is calibrated, owing to still have error after the low-frequency clock calibration, and there is the temperature drift phenomenon in low-frequency clock, make system by the sound sleep mode switch behind normal mode, regularly trail-and-error can take place when adopting traditional timing track algorithm.
(so-called " robustness " is meant that control system in the parameter perturbation of certain (structure, size) down, keeps the characteristic of some performance to traditional timing tracking method for the robustness that guarantees to follow the tracks of.) and the track algorithm of employing fixed step size.The timing error that the timing track algorithm of this fixed step size can be followed the tracks of in the regular hour is limited.When terminal when deep sleep mode switches to normal mode owing to have calibration error and temperature drift phenomenon, make timing position drift about.When adopting the timing track algorithm of fixed step size, may cause that timing position can not recover before the paging receiving indication, thereby cause receiving mission failure.
Summary of the invention
The purpose of this invention is to provide a kind of method and apparatus of adjusting the step-length of regularly following the tracks of, when terminal when deep sleep mode switches to normal mode, the step-length that can regularly follow the tracks of according to system's current state adjustment, thus avoid receiving mission failure.
The objective of the invention is to be achieved through the following technical solutions:
A kind of method of adjusting the step-length of regularly following the tracks of, when terminal when deep sleep mode switches to normal mode, judge at first whether timing position is lost, recomputate the step-length of regularly following the tracks of if timing position is lost.
Utilize following method to judge whether timing position is lost: at first, to measure the signal to noise ratio x on the PCCPCH of current subframe
SIRJudge whether to satisfy first condition, that is, and x
SIR-x
SIR_AVE〉=T
SIR, wherein, T
SIRBe a predefined threshold value, x
SIR_AVEIt is average signal-to-noise ratio; Judge whether second condition is set up, i.e. x
SIR〉=T
SIR_Min, T
SIR_MinIt is the lowest signal-to-noise threshold value; When one of them is false when above-mentioned first, second condition, assert that then timing position loses.
When timing position is lost, and Δ<Δ
Max, then calculate the step-length of regularly following the tracks of according to following method:
Δ=Δ+0.5chip,
Wherein, Δ is the step-length of current timing track algorithm, Δ
MaxFor regularly following the tracks of the maximum step value that allows, chip is a chip, and unit is the time.
When timing position is not lost, judge whether the step-length that current timing is followed the tracks of is initial value, if not initial value, then at Δ>Δ
MinThe time, method is calculated the step-length of regularly following the tracks of below utilizing:
Δ=Δ-0.5chip,
Wherein, Δ is the step-length of current timing track algorithm, Δ
MinFor regularly following the tracks of the minimum step value that allows, chip is a chip, and unit is the time;
The step-length that current timing is followed the tracks of is that the words of initial value then keep the step-length of regularly tracking constant.
When terminal is from the sound sleep mode switch to normal mode at every turn, the step-length of regularly following the tracks of is resetted, that is:
Δ=Δ
min。
Only work as x
SIR〉=T
SIR_MinThe time just upgrade x
SIR_AVEValue.
x
SIR_AVEObtain by following method: x
SIR_AVE=(1-α) x
SIR+ α x
SIR_AVE',
α is the parameter that is used to control signal to noise ratio mean value renewal speed, wherein an x
SIR_AVE' be the average signal-to-noise ratio of previous frame.
A kind of equipment of adjusting the step-length of regularly following the tracks of comprises:
A timing position judgment means, when terminal when deep sleep mode switches to normal mode, judge at first whether timing position is lost;
One first timing tracing step calculation element, it recomputates the step-length of regularly following the tracks of when timing position is lost.
This timing position judgment means comprises:
The snr measurement unit, it measures the signal to noise ratio x on the PCCPCH of current subframe
SIR
First judging unit, it judges whether first condition is set up, that is, and x
SIR-x
SIR_AVE〉=T
SIR, wherein, T
SIRBe a predefined threshold value, x
SIR_AVEIt is average signal-to-noise ratio;
Second judging unit, it judges whether second condition is set up, that is, and x
SIR〉=T
SIR_Min, T
SIR_MinIt is the lowest signal-to-noise threshold value.
In this first timing tracing step calculation element, when Δ<Δ
MaxThe time, calculate the step-length of regularly following the tracks of according to following method:
Δ=Δ+0.5chip,
Wherein, Δ is the step-length of current timing track algorithm, Δ
MaxFor regularly following the tracks of the maximum step value that allows, chip is a chip, and unit is the time.
This equipment also comprises one second regularly tracing step calculation element, when it is not lost at timing position, judges whether the step-length that current timing is followed the tracks of is initial value, if not initial value, then at Δ>Δ
MinThe time, method is calculated the step-length of regularly following the tracks of below utilizing,
Δ=Δ-0.5chip,
Wherein, Δ is the step-length of current timing track algorithm, Δ
MinFor regularly following the tracks of the minimum step value that allows, chip is a chip, and unit is the time.
This equipment also comprises a regularly tracing step resetting means, and it, resets the step-length of regularly following the tracks of, that is: during at every turn from the sound sleep mode switch to normal mode in terminal
Δ=Δ
min。
This equipment also comprises an average signal-to-noise ratio updating device, and it only works as x
SIR〉=T
SIR_MinThe time, just upgrade x
SIR_AVEValue.
Method was upgraded average signal-to-noise ratio x below this average signal-to-noise ratio updating device utilized
SIR_AVE:
x
SIR_AVE=(1-α)x
SIR+αx
SIR_AVE′,
α is the parameter that is used to control signal to noise ratio mean value renewal speed, wherein an x
SIR_AVE' be the average signal-to-noise ratio of previous frame.
Positive progressive effect of the present invention is: terminal by the sound sleep mode switch behind normal mode, reduced the error rate of regularly following the tracks of, thereby improved the accuracy of paging receiving indication.
Description of drawings
Fig. 1 adjusts the flow chart of the method for the step-length of regularly following the tracks of for the present invention.
Fig. 2 adjusts the block diagram of the equipment of the step-length of regularly following the tracks of for the present invention.
Embodiment
Below in conjunction with Fig. 1 and Fig. 2, provide preferred embodiment of the present invention, to describe characteristics of the present invention and effect in detail.
As shown in Figure 1, a kind of method of adjusting the step-length of regularly following the tracks of, when terminal when deep sleep mode switches to normal mode, judge at first whether timing position is lost.
Can utilize following method to judge whether timing position is lost:
Step 100 is measured the signal to noise ratio x on the PCCPCH of current subframe
SIR
Step 110 judges whether to satisfy first condition, that is, and and x
SIR-x
SIR_AVE〉=T
SIR, wherein, T
SIRBe a predefined threshold value, x
SIR_AVEIt is average signal-to-noise ratio;
If above-mentioned condition is set up, judge then whether second condition sets up (step 120), i.e. x
SIR〉=T
SIR_Min, T
SIR_MinIt is the lowest signal-to-noise threshold value;
When one of them is false when above-mentioned first, second condition, assert that then timing position loses.
Step 130, when timing position is lost, then calculate the step-length of regularly following the tracks of according to following method:
Δ=Δ+0.5chip,
Wherein, Δ is the step-length of current timing track algorithm, and chip is a chip, and unit is the time.
Because regularly the step-length of tracking can not be unconfined big, after being increased to maximum, step-length just no longer increased the step-length of regularly tracking, so when needs increase step-length, judge Δ<Δ
MaxWhether set up,, then increase step-length, otherwise then what is not done, Δ if set up
MaxFor regularly following the tracks of the maximum step value that allows.
When timing position is not lost, judge whether the step-length that current timing is followed the tracks of is the initial value Δ
Min,, promptly judge Δ=Δ as step 140
MinWhether set up, if set up then keep Δ constant.
If not initial value, method is calculated the step-length of regularly following the tracks of below then utilizing, as step 150,
Δ=Δ-0.5chip,
Wherein, Δ is the step-length of current timing track algorithm, and chip is a chip, and unit is the time.
Similarly, regularly the step-length of following the tracks of can not be unconfined little, just no longer reduced the step-length of regularly tracking after step-length reduces minimum value, thereby, when needs reduce step-length, judge Δ>Δ
MinWhether set up,, then reduce step-length, otherwise what is not done, Δ if set up
MinFor regularly following the tracks of the minimum step value that allows.
Wherein, x
SIR_AVEObtain by following method:
x
SIR_AVE=(1-α)x
SIR+αx
SIR_AVE′,
α is the parameter that is used to control signal to noise ratio mean value renewal speed, wherein an x
SIR_AVE' be the average signal-to-noise ratio of previous frame.
In the method, only work as x
SIR〉=T
SIR_MinThe time just upgrade x
SIR_AVEValue.
In addition, when terminal is from the sound sleep mode switch to normal mode at every turn, the step-length of regularly following the tracks of is resetted, that is:
Δ=Δ
min,
Δ
MinFor regularly following the tracks of the minimum step value that allows.
As shown in Figure 2, a kind of equipment of adjusting the step-length of regularly following the tracks of comprises:
A timing position judgment means 1, when terminal when deep sleep mode switches to normal mode, judge at first whether timing position is lost;
One first timing tracing step calculation element 2, it recomputates the step-length of regularly following the tracks of when timing position is lost.
This timing position judgment means 1 comprises:
Snr measurement unit 11, it measures the signal to noise ratio x on the PCCPCH of current subframe
SIR
First judging unit 12, it judges whether first condition is set up, that is, and x
SIR-x
SIR_AVE〉=T
SIR, wherein, T
SIRBe a predefined threshold value, x
SIR_AVEIt is average signal-to-noise ratio;
Second judging unit 13, it judges whether second condition is set up, that is, and x
SIR〉=T
SIR_Min, T
SIR_MinIt is the lowest signal-to-noise threshold value.
In this first timing tracing step calculation element 2, when Δ<Δ
MaxThe time, calculate the step-length of regularly following the tracks of according to following method:
Δ=Δ+0.5chip,
Wherein, Δ is the step-length of current timing track algorithm, and chip is a chip, and unit is the time, Δ
MaxFor regularly following the tracks of the maximum step value that allows.
This equipment also comprises one second regularly tracing step calculation element 3, when it is not lost at timing position, judges whether the step-length that current timing is followed the tracks of is initial value, if not initial value, i.e. and Δ>Δ
Min, method is calculated the step-length of regularly following the tracks of below then utilizing,
Δ=Δ-0.5chip,
Wherein, Δ is the step-length of current timing track algorithm, and chip is a chip, and unit is the time, Δ
MinFor regularly following the tracks of the minimum step value that allows.
Further, this equipment also comprises a regularly tracing step resetting means 4, and it, resets the step-length of regularly following the tracks of, that is: during at every turn from the sound sleep mode switch to normal mode in terminal
Δ=Δ
min,
Δ
MinFor regularly following the tracks of the minimum step value that allows.
In addition, this equipment also comprises an average signal-to-noise ratio updating device 5, and it only works as x
SIR〉=T
SIR_MinThe time, just upgrade x
SIR_AVEValue.
Wherein, method was upgraded average signal-to-noise ratio x below this average signal-to-noise ratio updating device 5 utilized
SIR_AVE:
x
SIR_AVE=(1-α)x
SIR+αx
SIR_AVE′,
α is the parameter that is used to control signal to noise ratio mean value renewal speed, wherein an x
SIR_AVE' be the average signal-to-noise ratio of previous frame.