CN1885754A - Closed-loop power control method for reverse supplementary channel - Google Patents

Abstract

The invention relates to a closed-loop power control method of a reverse supplementary channel. The method mainly includes: making statistics on the frame quality combinations of R-SCH (reverse supplementary channel) and R-FCH (reverse fundamental channel); Adjust the R-SCH power according to the above statistical results. By using the method of the present invention, it can be ensured that when the bit error rate of R-FCH converges to the target bit error rate, the independent closed-loop power control of R-SCH can be realized, so that the bit error rate of R-SCH can also converge well to the target error rate. code rate.

Description

Closed-loop power control method for reverse supplementary channel

technical field

The invention relates to the field of wireless communication, in particular to a closed-loop power control method of a reverse supplementary channel.

Background technique

Wireless communication will play an increasingly important role in future communication, and CDMA (Code Division Multiple Access) will become the main wireless access technology of the third generation mobile communication system. At present, the international common CDMA standard is mainly developed and promulgated by the American National Standards Committee. IS2000 is one of the standards of the third generation mobile communication system.

In the RCLPC (reverse closed-loop power control) function of the reverse traffic channel of the third-generation mobile communication system applying the IS2000 standard, the power control of the reverse traffic channel is completed through the R-PILOT (reverse pilot channel). The BSC (Base Station Controller) adjusts the R-PILOT power at a rate of 800 Hz with the reverse power control bit. However, the power offsets of R-FCH (reverse fundamental channel), R-SCH (reverse supplementary channel) and R-PILOT are relatively fixed, as shown in Figure 1. Therefore, the power of R-FCH and R-SCH varies with R -Varies with changes in PILOT power.

The purpose of RCLPC is to maximize the reverse capacity of traffic channels while ensuring the target FER (bit error rate) of one or more traffic channels. When only one traffic channel (such as R-FCH) is activated, the algorithm of RCLPC is relatively simple: BSC adjusts the power of R-FCH by adjusting the power of R-PILOT according to the received R-FCH frame quality. But when multiple traffic channels (such as R-FCH, R-SCH) are activated, it is more difficult to realize the RCLPC function. At this time, the RCLPC function must not only ensure the power control of the R-FCH according to the quality of the R-FCH frame, but also independently control the power of the R-SCH according to the quality of the R-SCH frame. In addition, when the base station CSM5000 chip distinguishes between SCH error frames and SCH DTX (discontinuous transmission) frames, there is a misjudgment situation. This also brings difficulties to the realization of the RCLPC function.

A schematic diagram of a method for realizing the RCLPC (reverse closed-loop power control) function of the reverse traffic channel in the prior art is shown in FIG. 2 .

In this method, R-FCH closed-loop power control and R-SCH closed-loop power control are superimposed together. In the power control outer loop part of the BSC, the reverse closed-loop power control algorithm combines the frame quality of R-FCH and R-SCH to generate an outer loop setting value. According to the outer loop setting value, a control channel is used to The reverse power control bit adjusts the power of R-PILOT, and controls the power of R-FCH and R-SCH synchronously.

The disadvantage of this method is: in this method, the power offset of R-SCH and R-FCH relative to R-PILOT is fixed, and the power difference between R-SCH and R-FCH is also kept unchanged. The closed-loop power control of R-SCH and R-FCH cannot be performed independently, and when the wireless characteristics of these two traffic channels are different, their power cannot be adjusted separately. The bit error rates of R-SCH and R-FCH cannot converge to the target bit error rate at the same time.

A schematic diagram of another method for realizing the RCLPC (reverse closed-loop power control) function of the reverse traffic channel in the prior art is shown in FIG. 3 .

In this method, the power control operation of R-FCH and R-SCH includes two parts. According to the frame quality of R-FCH, control the R-PILOT through the power control bit, and indirectly adjust the power of R-FCH and R-SCH; at the same time, according to the frame quality of R-SCH, change the R-SCH through layer 3 messages The power offset G _{R_SCH} between R-PILOT and R-PILOT adjusts the power of R-SCH.

The disadvantage of this method is: in this method, the R-SCH power is acted on simultaneously by two different power control operations, and the two different power control operations are superimposed together without coordination. Therefore, the R-SCH bit error rate cannot be guaranteed to converge to the target bit error rate.

Contents of the invention

In view of the problems existing in the above-mentioned prior art, the purpose of the present invention is to provide a closed-loop power control method for the reverse supplementary channel, so as to ensure that the bit error rate of R-FCH converges to the target bit error rate, and realize the control of R-FCH The independent closed-loop power control of SCH makes the bit error rate of R-SCH well converge to the target bit error rate.

The purpose of the present invention is achieved through the following technical solutions:

A closed-loop power control method for a reverse supplementary channel, comprising:

A, carry out statistics on the frame quality combination situation of reverse supplementary channel R-SCH and reverse fundamental channel R-FCH;

B. Adjust the R-SCH power according to the statistics result.

Described step A specifically comprises:

The R-SCH and R-FCH are combined according to the quality of good frames and bad frames respectively, and frame statistics are performed for each combination.

Described step A also includes:

Combine R-SCH and R-SCH discontinuous transmission DTX according to two quality conditions of good frame and bad frame respectively, and perform frame statistics for each combination condition.

Described step A also includes:

Count sporadic and discontinuous DTX frames according to R-SCH bad frames.

Described step A specifically comprises:

A1, set an observation window;

A2. Count the total number of frames in each combination within the observation window.

Described step B specifically comprises:

B1. Calculate the GR- _SCH adjustment amount for adjusting the power deviation GR- _SCH between the R-SCH and the reverse pilot channel R-PILOT according to the statistical results;

B2. Adjust the _{R-SCH power according to the GR-SCH} adjustment amount.

Described step B1 specifically comprises:

B11. Calculate the GR _-SCH adjustment amount for adjusting the _GR- SCH in each combination according to the statistical results;

B12. Obtain the final GR _-SCH adjustment amount according to the calculated GR _-SCH adjustment amount in each case.

Described step B1 specifically comprises:

The calculation of the _GR-SCH adjustment amount can be carried out by using a fixed-period or variable-period method.

Described step B2 specifically comprises:

B21. The base station sends an air interface message to the mobile station, and transmits the _GR-SCH adjustment amount to the mobile station;

B22. The mobile station adjusts _{the GR-SCH} and adjusts the _R-SCH power according to the received GR-SCH adjustment amount.

Described step B2 specifically comprises:

The adjustment to GR _-SCH can be accomplished through the power composition factor Reverse_Channel_Adjustment_Gain of the reverse traffic channel.

The R-SCH and the R-SCH may be the R-SCH and the R-SCH in the code division multiple access CDMA system applying the IS2000 standard.

As can be seen from the technical solution provided by the present invention, the present invention has the following advantages compared with the prior art: the present invention calculates the _GR-SCH adjustment amount by comprehensively counting the frame quality of R-FCH and R-SCH, It can not only make the R-SCH power can be adjusted independently, but also ensure that the power adjustment of the R-SCH is not coupled with the power adjustment of the R-FCH. While ensuring the convergence of the bit error rate of R-FCH, the independent closed-loop power control of R-SCH is realized, so that the bit error rate of R-SCH is also well converged to the target bit error rate; the present invention treats R-SCH DTX differently , reducing the influence of the base station on the power control caused by misjudgment of the R-SCH frame quality.

Description of drawings

Figure 1 is a schematic diagram of the power relationship between R-FCH, R-SCH and R-PILOT;

Fig. 2 is a schematic diagram of a method for realizing the RCLPC function of the reverse traffic channel in the prior art;

Fig. 3 is another schematic diagram of the method for realizing the RCLPC function of the reverse traffic channel in the prior art;

Fig. 4 is a schematic diagram of the method of the present invention;

Fig. 5 is a specific processing flowchart of the method of the present invention.

Detailed ways

The invention provides a closed-loop power control method for a reverse supplementary channel. The core of the present invention is: by comprehensively counting the quality of R-FCH and R-SCH frames, calculating the adjustment amount of R-SCH relative to the power offset G _R-SCH of R-PILOT, so as to realize the adjustment of R-SCH power independent adjustments.

The present invention will be described in detail below in conjunction with the accompanying drawings. The principle diagram of the method of the present invention is shown in FIG. 4 . The principle is: apply the R-SCH closed-loop power control to the "R-FCH closed-loop power control". "R-FCH closed-loop power control" completes the high-frequency and fine control of R-FCH and R-SCH, and "R-SCH closed-loop power control" completes the separate supplementary control of R-SCH.

According to the frame quality of R-FCH and R-SCH, when it is determined that R-FCH converges to the target FER, but R-SCH does not converge to the target FER, a mathematical model is established through the R-SCH closed-loop power control algorithm, and G _R is derived - Calculation formula of _SCH adjustment amount, and determine the value of GR _-SCH adjustment amount. Then, the power offset _GR-SCH is adjusted according to the _GR- SCH adjustment amount, so that the R-SCH reaches the target FER.

When the R-FCH does not converge to the target FER, it means that the R-PILOT power is not suitable and needs to be adjusted, and the R-SCH closed-loop power control loses the adjustment benchmark. At this time, the power offset G _R-SCH cannot be adjusted, and the R-SCH closed-loop power control cannot be performed, otherwise, the R-SCH power will be repeatedly adjusted to form a coupling with the R-FCH power adjustment.

The specific processing flow of the method of the present invention is shown in FIG. 5 . Including the following steps:

Step 5-1. Set an observation window in the reverse traffic channel.

The present invention first needs to set an observation window in the reverse traffic channel, and the size of the observation window can be preset according to actual needs, such as W frame.

Step 5-2: Start the observation window to make statistics on the frame quality combinations of R-SCH and R-FCH.

When it is necessary to perform closed-loop power control on the R-SCH, start the set observation window, and make statistics on the frame quality combinations of the R-SCH and R-FCH. The present invention divides R-FCH and R-SCH into two situations of good frame and bad frame respectively, and combines them to obtain four kinds of combination situations. Then, analyze the situation of the four combinations respectively to determine whether it is necessary to increase or decrease the GR-SCH adjustment, or not to adjust.

Table 1 shows the relationship between the frame quality combination of R-SCH and R-FCH and the adjustment of GR-SCH.

Table 1: The frame quality combination of R-SCH and R-FCH and the corresponding relationship between GR-SCH adjustment Condition R-FCH R-SCH Situation analysis G _R-SCH adjustment A good frame good frame It cannot be judged whether the power of R-PILOT is too high or the power bias of GR-SCH is too high. not adjusted B good frame bad frame It means that the power of the R-FCH is sufficient, but the power of the R-SCH is not enough, and the power can be increased to offset the GR-SCH. improve C bad frame bad frame It cannot be judged whether the R-PILOT power is too low or the power bias GR-SCH is too low. not adjusted D. bad frame good frame It means that the power of R-FCH is not enough, but the power of R-SCH is enough, and the power can be reduced to offset GR-SCH. reduce

The present invention needs to count how many frames the frame quality combinations of R-SCH and R-FCH in one observation window belong to the four situations A, B, C and D shown in Table 1 respectively.

In addition to the four cases shown in Table 1 for the frame combination of R-SCH and R-FCH, two cases of combining R-SCHDTX with good and bad R-SCH frames can also be added.

In order to reduce the influence of the base station on the power control caused by misjudgment of R-SCH frame quality, the present invention treats sporadic and discontinuous DTX frames as "SCH misjudgments as DTX frames", and classifies the DTX frames as R-SCH bad frame to calculate.

For example, in an observation window with a size of W frames, the combination of R-SCH and R-FCH has frame a in case A, frame b in case B, frame c in case C, and frame c in case D. d frame.

Then a+b+c+d=W.

Step 5-3: Calculate the _GR-SCH adjustment amount according to the statistics.

Assuming that the R-SCH and R-FCH in the observation window have reached FER convergence, the following formula is given:

a+b+c+d=W;

(b+c)/W=FER_SCH (bit error rate of R-SCH frame);

(d+c)/W=FER_FCH (bit error rate of R_FCH frame).

According to the above formula, the relationship between the ascending and descending steps can be deduced.

When the observation window ends, the _GR-SCH adjustment amount can be calculated by integrating the quantitative relationships of the four situations A, B, C, and D. And limit the _GR-SCH adjustment amount between the maximum value and the minimum value.

In addition to the fixed-period method, the present invention can also adopt the variable-period method to calculate the GR _-SCH adjustment amount.

Step 5-4: Send the calculated GR _-SCH adjustment amount to the mobile station through an air interface message.

After calculating _{the GR-SCH} adjustment amount, the present invention provides an independent control channel for the R-SCH closed-loop power control, and sends an air interface message to the mobile station through the independent control channel, and transmits the calculated _GR-SCH adjustment amount to mobile station.

Step 5-5, the mobile station adjusts the power of the _{R-SCH according to the GR-SCH} adjustment amount.

The mobile station adjusts the power deviation GR-SCH between R-SCH and R-PILOT according to the received GR- _SCH adjustment amount, and the adjustment to _{GR-SCH can} be completed through Reverse_Channel_Adjustment_Gain (reverse traffic channel power composition factor) , the purpose of adjusting the R-SCH power is achieved by adjusting the G _R-SCH , so that the R-SCH bit error rate reaches the target bit error rate.

The above is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed in the present invention can easily think of changes or Replacement should be covered within the protection scope of the present invention. Therefore, the protection scope of the present invention should be determined by the protection scope of the claims.

Claims (11)

1. A closed-loop power control method for a reverse supplementary channel, characterized in that, comprising: A, carry out statistics on the frame quality combination situation of reverse supplementary channel R-SCH and reverse fundamental channel R-FCH; B. Adjust the R-SCH power according to the statistics result. 2. A closed-loop power control method for a reverse supplementary channel according to claim 1, wherein said step A specifically includes: The R-SCH and R-FCH are combined according to the quality of good frames and bad frames respectively, and frame statistics are performed for each combination. 3. A closed-loop power control method for a reverse supplementary channel according to claim 2, wherein said step A further comprises: Combine R-SCH and R-SCH discontinuous transmission DTX according to two quality conditions of good frame and bad frame respectively, and perform frame statistics for each combination condition. 4. A closed-loop power control method for a reverse supplementary channel according to claim 3, wherein said step A further comprises: Count sporadic and discontinuous DTX frames according to R-SCH bad frames. 5. A closed-loop power control method for a reverse supplementary channel according to claim 1, 2 or 3, wherein said step A specifically includes: A1, set an observation window; A2. Count the total number of frames in each combination within the observation window. 6. A closed-loop power control method for a reverse supplementary channel according to claim 1, wherein said step B specifically includes: B1. Calculate the GR- _SCH adjustment amount for adjusting the power deviation GR- _SCH between the R-SCH and the reverse pilot channel R-PILOT according to the statistical results; B2. Adjust the _{R-SCH power according to the GR-SCH} adjustment amount. 7. A closed-loop power control method for a reverse supplementary channel according to claim 6, wherein said step B1 specifically includes: B11. Calculate the GR _{- SCH adjustment amount for adjusting the GR-} SCH in each combination according to the statistical results; B12. Obtain the final GR _-SCH adjustment amount according to the calculated GR _-SCH adjustment amount in each case. 8. A closed-loop power control method for a reverse supplementary channel according to claim 6 or 7, wherein said step B1 specifically includes: The calculation of the _GR-SCH adjustment amount can be carried out by using a fixed-period or variable-period method. 9. A closed-loop power control method for a reverse supplementary channel according to claim 6, wherein said step B2 specifically comprises: B21. The base station sends an air interface message to the mobile station, and transmits the _GR-SCH adjustment amount to the mobile station; B22. The mobile station adjusts _{the GR-SCH} and adjusts the _R-SCH power according to the received GR-SCH adjustment amount. 10. A closed-loop power control method for a reverse supplementary channel according to claim 6 or 9, wherein said step B2 specifically includes: The adjustment to GR _-SCH can be accomplished through the power composition factor Reverse_Channel_Adjustment_Gain of the reverse traffic channel. 11. A closed-loop power control method for a reverse supplementary channel according to claim 1, characterized in that said R-SCH and R-SCH can be R-SCH in a code division multiple access CDMA system applying the IS2000 standard SCH and R-SCH.