CN107949050B - A method for increasing downlink data traffic - Google Patents

Abstract

A method for increasing downlink data flow, comprising the steps of: 1. Counting the resource utilization of a current cell to determine whether the power usage has reached a saturated state; if the resource occupancy ratio exceeds a preset threshold, power backoff needs to be performed; 2. Statistics Obtain a terminal UE group that meets the preset threshold of the modulation and coding format MCS level and transmission scheme; 3. Count the resource occupation of the terminal UE group, and if the resource occupation ratio meets the preset threshold, it is considered that the entire terminal UE group can reduce power; 4. Perform a power back-off operation for the terminal UE group that meets the conditions; 5. The process ends. The present invention accurately controls the power in the EVM-limited state, improves the SNR level of the very close point signal-to-noise ratio, and maximizes the throughput of the system.

Description

A method for increasing downlink data traffic

technical field

The invention belongs to the technical field of communications, and in particular relates to a method for improving downlink data flow through downlink power control.

Background technique

In the field of wireless communication, it is an effective solution to make full use of cell power to improve system throughput. However, when the total output power of the cell reaches the rated transmit power of the RRU, the EVM of the RRU is limited, and the signal-to-noise ratio (SNR) cannot increase linearly, which affects the maximum output signal-to-noise ratio (SNR) of the RRU. of downstream traffic cannot reach peak or greater traffic. At present, in order to support the function of 256QAM, the requirements for EVM are more stringent, which makes the solution to this problem more important and urgent. In order to solve this problem, the base station can perform a certain degree of power backoff to avoid the EVM deterioration caused by peak clipping on the RRU side, improve the output signal-to-noise ratio (SNR) of the RRU, and then improve the throughput rate of the near-point terminal UE. At present, for the terminal UE based on the cell reference signal CRS demodulation, the power reduction measures are mainly completed through PA reconfiguration, but the reconfiguration period is long. Once the reconfiguration, the EVM limited state disappears, which will cause Misjudgment will cause traffic to drop due to power backoff. Since the EVM-limited state changes dynamically, a real-time and fast power back-off technique is required to solve this problem, so as to achieve the best effect, otherwise it is possible to reduce the power in the non-EVM-limited state As a result, the signal-to-noise ratio (SNR) is reduced, and the downlink traffic of the terminal UE is affected.

SUMMARY OF THE INVENTION

The technical problem to be solved by the present invention is to provide a method that can accurately perform power control in the EVM-limited state, so as to improve the SNR level of the extremely close point signal-to-noise ratio, so that the throughput of the system can be improved to the greatest extent, and the downlink can be improved to the greatest extent. method of data flow.

In order to solve the above-mentioned problems, the present invention proposes a method for improving downlink data flow, which consists of the following steps:

Step 1: Count the resource utilization of the current cell, and determine whether the power usage has reached a saturation state according to the resource occupancy ratio; if the resource occupancy ratio is very high at this time and exceeds the preset threshold, it is considered that the power has reached saturation, and a power backoff needs to be performed , go to step 2; otherwise, go to step 5;

There are three types of threshold settings:

(1) The threshold of the resource block RB utilization rate under the single subframe TTI of the terminal UE: RBRatioThr1; the resource block RB utilization rate is to count the resource block RB utilization rate on the scheduling subframe TTI of the terminal UE.

The default threshold for 20M and 15M bandwidth is 0.6, and the threshold for 10M and below 10M is 1 (the threshold value of 1 means that the power is not adjusted), which can be configured, and the value ranges from 0.5 to 1.

(2) The MCS threshold of the scheduling modulation and coding format under the single subframe TTI of the terminal UE: MCSThr2, the default value is 20, can be configured, and the value ranges from 15 to 28.

(3) X: Adjusted power value (dB); the default value is -1dB, which can be configured, and the value range is -3～0Db.

Step 2: For the cells that meet the conditions in Step 1, count the modulation and coding format MCS levels and current transmission modes of all terminal UEs in the cell to determine the user group that needs to perform power backoff. When the scheduling MCS and transmission scheme of the terminal UE meet the preset thresholds, it is considered that the user is limited in traffic due to EVM restrictions and needs to perform power backoff; after statistics, the terminal UE groups that meet the preset thresholds of the MCS level and transmission scheme are obtained and enter the step 3; If there is no terminal UE that needs to perform power backoff, go to step 5.

Step 3: For the terminal UE group determined in step 2 that needs power reduction, count the resource occupation of the terminal UE group. If the resource occupation ratio meets the preset threshold, it is considered that the entire terminal UE group can reduce power, and turn to step 4; Otherwise, go to step 5.

Step 4: Perform a power back-off operation for the terminal UE group that meets the conditions in step 3. For the power back-off method of the terminal UE based on the cell reference signal CRS demodulation, see step 4-1; The power backoff method of the terminal UE is according to step 4-2.

Step 4-1: All cell reference signal CRSs in the resource block RB (including PDCCH/PCFICH/PHICH/PBCH/PSS/SSS on symbols occupied by PDCCH/PCFICH/PHICH/PBCH/PSS/SSS) The cell reference signal (CRS) and PDSCH are sent according to the reference signal energy E-RS with reduced power; other REs are sent according to the reference signal energy E-RS without power reduction; for example, PDCCH/PCFICH/PHICH/PBCH/PSS/SSS and The REs occupied by the CSI-RS are all sent according to the reference signal energy E-RS with unreduced power.

Step 4-2: The terminal UE demodulated based on the demodulation reference signal DMRS needs to multiply the existing BF weight of the terminal UE by a weighting factor to realize power reduction transmission; that is, the PDSCH service RE and the demodulation reference signal DMRS are both Reduce power transmission; other RE powers remain unchanged.

Step 5: The process ends.

Step 1 of the present invention is to: count the resource utilization of the current cell, and determine whether the power usage has reached a saturated state according to the resource occupancy ratio; if the resource occupancy ratio exceeds a preset threshold at this time, it is considered that the power has reached saturation, and power recovery needs to be performed. Back off, go to step 2; otherwise, go to step 5.

There are three types of threshold settings:

(1) The threshold of the resource block RB utilization rate under the single subframe TTI of the terminal UE: RBRatioThr1; the resource block RB utilization rate is the statistics of the resource block RB utilization rate on the scheduling subframe TTI of the terminal UE; the default value of the lower threshold of 20M and 15M bandwidth It is 0.6, the threshold value of 10M and below 10M is 1, and the threshold value of 1 means that the power is not adjusted and can be configured. The best value is 0.7.

(2) The MCS threshold for scheduling under the single subframe TTI of the terminal UE: MCSThr2, the default value is 20, which can be configured, and the optimal value is 20.

(3) X: Adjusted power value dB; the default value is -1dB, which can be configured, and the best value is -1dB.

Each downlink scheduling subframe needs to be judged in the above five steps, so that the real-time judgment can more accurately identify the restricted state of the EVM and quickly realize power backoff, so that the downlink traffic can be improved to the greatest extent.

Since the present invention uses each downlink scheduling subframe to perform the above five steps of judgment, the real-time judgment can more accurately identify the restricted state of the EVM and quickly realize power back-off, so that the downlink traffic can be improved to the greatest extent. .

Description of drawings

FIG. 1 is a flowchart of power backoff scheduling.

FIG. 2 is a power allocation diagram of a resource block RB-level downgraded reference signal energy E-RS.

FIG. 3 is a power allocation diagram during user power backoff based on demodulation reference signal DMRS demodulation.

Detailed ways

The present invention is further described in detail below with reference to the accompanying drawings and embodiments, but the present invention is not limited to the following embodiments.

Example 1

Taking a user based on cell reference signal CRS demodulation as an example, the power backoff method in step 4-1 is used, and the power backoff process of the terminal UE is described.

The preset threshold value in step 1 is:

(1) The threshold of the resource block RB utilization rate under the single subframe TTI of the terminal UE: RBRatioThr1; the resource block RB utilization rate is the statistics of the resource block RB utilization rate on the scheduling subframe TTI of the terminal UE; 20M and 15M bandwidth lower thresholds It is 0.6, the threshold value of 10M and below 10M is 1, the threshold value of 1 means that the power is not adjusted, it can be configured, and the value is 0.7.

(2) The MCS threshold for scheduling under the single subframe TTI of the terminal UE is 20.

(3) X: Adjusted power value dB; the value is -1dB.

The resource occupancy ratio of the statistical cell is obtained as a value of 0.7. Since the value exceeds the preset threshold of 0.6, go to step 2.

Step 2: Count the modulation and coding format MCS levels of all terminal UEs in the cell and the transmission mode based on cell reference signal CRS demodulation. If there is a terminal UE that satisfies the minimum value of the two-stream scheduling MCS is greater than or equal to a threshold of 20, start power adjustment, If not satisfied, go to step 5.

Step 3: Count the proportion of resources occupied by the terminal UE group that satisfies the transmission mode based on cell reference signal CRS demodulation in step 2. If the proportion of resources occupied by the group exceeds the preset threshold, go to step 4, otherwise go to step 4 5; The proportion of resources occupied by this group exceeds the preset threshold of 0.6.

Step 4: Perform a power reduction operation for the terminal UE group that meets the power backoff condition in Step 3. Since the current terminal UE is a user based on cell reference signal CRS demodulation, go to step 4-1, based on the demodulation reference signal. The power backoff method for the terminal UE demodulated by the DMRS is implemented according to step 4-2.

Step 4-1: Based on the cell reference signal CRS demodulation of all cell reference signal CRS in the resource block RB allocated by the terminal UE (including the cell reference signal CRS on the symbols occupied by PDCCH/PCFICH/PHICH/PBCH/PSS/SSS) ) and PDSCH are sent according to the reference signal energy E-RS with reduced power; other REs are sent according to the reference signal energy E-RS without power reduction. Fig. 2 is a diagram illustrating the power allocation of the reference signal energy E-RS of the resource block RB level reduction; wherein according to FDD, the cell reference signal CRS 2port, 20M, CFI=3 is described, and the reference signal energy E-RS of the power reduction is denoted as The reference signal energy E-RS-new, and the reference signal energy E-RS without power reduction is denoted as the reference signal energy E-RS-old. Since the subframe containing PBCH and synchronization signal has no CSI-RS, the figure does not reflect the power description of CSI-RS.

Under FDD, 20M, cell reference signal CRS2port, CFI=3, the terminal UE is allocated to resource blocks RB#44~#55, a total of 12 resource blocks RB, among which all cell reference signals on resource blocks RB#44~#55 The reference signal energy E-RS power corresponding to the REs of CRS and PDSCH is the reduced reference signal energy E-RS, and the reference signal energy E-RS power corresponding to the REs occupied by PDCCH/PCFICH/PHICH/PBCH/PSS/SSS is the unreduced reference signal energy E-RS power. Reduced reference signal energy E-RS.

Step 4-2: No action.

Go to the next terminal UE to continue step 4.

Step 5: End the process.

Example 2

Taking a user based on cell reference signal CRS demodulation as an example, the power backoff method in step 4-1 is used, and the power backoff process of the terminal UE is described.

In step 1, set the threshold as:

(1) The threshold of the resource block RB utilization rate under the single subframe TTI of the terminal UE: RBRatioThr1; the resource block RB utilization rate is the statistics of the resource block RB utilization rate on the scheduling subframe TTI of the terminal UE; 20M and 15M bandwidth lower thresholds It is 0.6, the threshold value of 10M and below 10M is 1, and the threshold value of 1 means that the power is not adjusted, it can be configured, and the value range is 0.5.

(2) The MCS threshold under the single subframe TTI of the terminal UE: MCSThr2, the value is 15.

(3) X: Adjusted power value dB; the value is -3dB.

Other steps are the same as in Example 1.

Example 3

Taking a user based on cell reference signal CRS demodulation as an example, the power backoff method in step 4-1 is used, and the power backoff process of the terminal UE is described.

In step 1, set the threshold as:

(1) The threshold of the resource block RB utilization rate under the single subframe TTI of the terminal UE: RBRatioThr1; the resource block RB utilization rate is the statistics of the resource block RB utilization rate on the scheduling subframe TTI of the terminal UE; 20M and 15M bandwidth lower thresholds It is 0.6, the threshold value of 10M and below is 1, and the threshold value of 1 means that the power is not adjusted, and the value is 1.

(2) The MCS threshold under the single subframe TTI of the terminal UE: MCSThr2, the value is 28.

(3) X: Adjusted power value dB; the value is 0dB.

Other steps are the same as in Example 1.

Example 4

Taking a user demodulated based on the demodulation reference signal DMRS as an example, the power backoff method in step 4-2 is used, and the power backoff process of the terminal UE is described.

Step 1: Count the resource occupancy ratio of the cell, if it exceeds the preset threshold, go to Step 2, otherwise go to Step 5.

The preset thresholds are:

(1) The threshold of the resource block RB utilization rate under the single subframe subframe TTI of the terminal UE: the lower threshold value of 20M and 15M bandwidth is 0.6, and the threshold value of 10M and below 10M bandwidth is 1.

(2) The MCS threshold under the single subframe TTI of the terminal UE: 20.

(3) X: Adjusted power value, -1dB.

The resource occupation ratio of the cell is counted. Since the value exceeds the preset threshold of 0.6, go to step 2.

Step 2: Count the modulation and coding format MCS levels of all the terminal UEs in the cell and the transmission mode based on the demodulation reference signal DMRS demodulation. If the MCS of the terminal UE is greater than or equal to the threshold of 20, start power adjustment, if not all meet, start the power adjustment. then go to step 5.

Step 3: Count the proportion of resources occupied by the terminal UE group that satisfies the transmission mode based on the demodulation reference signal DMRS demodulation in step 2. If the proportion of resources occupied by the group exceeds the preset threshold, go to step 4, otherwise go to Step 5: The proportion of resources occupied by the group exceeds a preset threshold of 0.6.

Step 4: Perform a power reduction operation for the terminal UE group that meets the power backoff condition in step 3. Since it is assumed that the current terminal UE is a user demodulated based on the demodulation reference signal DMRS, go to step 4-2.

Step 4-1: No action.

Step 4-2: The terminal UE demodulated based on the demodulation reference signal DMRS needs to multiply a weighting factor on the basis of the existing BF weight of the terminal UE to realize power reduction transmission; It can be seen that under TDD, 20M, cell reference signal CRS2port, demodulation reference signal DMRS2port, CFI=3, the terminal UE is allocated to resource blocks RB#0~#11, a total of 12 resource blocks RB, among which, as shown in the figure , only the power of the REs occupied by the PDSCH and the demodulation reference signal DMRS is reduced for transmission (it needs to be multiplied by the power backoff factor), and the powers of other REs remain unchanged.

Go to the next terminal UE to continue step 4.

Step 5: End the process.

The working principle of the present invention has been described in detail above, but this is only a visual example for the convenience of understanding, and should not be regarded as a limitation on the scope of the present invention. Likewise, according to the description of the technical solutions of the present invention and the preferred embodiments thereof, various possible equivalent changes or substitutions can be made, and all these changes or substitutions should belong to the protection scope of the claims of the present invention.

Claims (2)

1. a method for improving downlink data flow is characterized in that being made up of the following steps: Step 1: Count the resource utilization of the current cell, and determine whether the power usage has reached a saturated state according to the resource occupancy ratio; if the resource occupancy ratio exceeds the preset threshold at this time, it is considered that the power has reached saturation, and a power backoff needs to be performed, and enter the step 2; otherwise, go to step 5; There are three types of threshold settings: (1) The threshold of the resource block RB utilization rate under the single subframe TTI of the terminal UE: RBRatioThr1; the resource block RB utilization rate is the statistics of the resource block RB utilization rate on the scheduling subframe TTI of the terminal UE; the default value of the lower threshold of 20M and 15M bandwidth It is 0.6, the threshold value of 10M and below 10M is 1, the threshold value of 1 means that the power is not adjusted, it can be configured, and the value range is 0.5 to 1; (2) MCS threshold for scheduling under the single subframe TTI of the terminal UE: MCSThr2, the default value is 20, which can be configured, and the value ranges from 15 to 28; (3) X: Adjusted power value dB; the default value is -1dB, which can be configured, and the value range is -3~0dB; Step 2: Count the modulation and coding format MCS levels of all terminal UEs in the cell and the transmission mode based on cell reference signal CRS demodulation. If there is a terminal UE that satisfies the minimum value of the two-stream scheduling MCS is greater than or equal to a threshold of 20, start power adjustment, If not satisfied, go to step 5; Step 3: For the terminal UE group determined in step 2 that needs power reduction, count the resource occupation of the terminal UE group. If the resource occupation ratio meets the preset threshold, it is considered that the entire terminal UE group can reduce power, and turn to step 4; Otherwise, go to step 5; Step 4: Perform a power back-off operation for the terminal UE group that meets the conditions in step 3, and the power back-off method for terminal UE based on cell reference signal CRS demodulation is implemented according to step 4-1; The power backoff method of the terminal UE is implemented according to step 4-2; Step 4-1: All cell reference signal CRS in the resource block RB allocated by the terminal UE based on the cell reference signal CRS demodulation that needs to be reduced in power, including the symbols occupied by PDCCH/PCFICH/PHICH/PBCH/PSS/SSS. The cell reference signal CRS and PDSCH are sent according to the reference signal energy E-RS with reduced power; other REs are sent according to the reference signal energy E-RS without power reduction; Step 4-2: The terminal UE demodulated based on the demodulation reference signal DMRS needs to multiply the existing BF weight of the terminal UE by a weighting factor to realize power reduction transmission; that is, the PDSCH service RE and the demodulation reference signal DMRS are both Reduce power transmission; other RE powers remain unchanged; Step 5: The process ends. 2. the method for improving downlink data flow according to claim 1, is characterized in that described step 1 is: the resource utilization situation of current cell is counted, and according to resource occupancy ratio, judge whether power usage has reached saturation state; When the resource occupancy ratio exceeds the preset threshold, it is considered that the power is saturated, and a power backoff needs to be performed, and go to step 2; otherwise, go to step 5; There are three types of threshold settings: (1) The threshold of the resource block RB utilization rate under the single subframe TTI of the terminal UE: RBRatioThr1; the resource block RB utilization rate is the statistics of the resource block RB utilization rate on the scheduling subframe TTI of the terminal UE; the default value of the lower threshold of 20M and 15M bandwidth It is 0.6, the threshold value of 10M and below 10M is 1, the threshold value of 1 means that the power is not adjusted, it can be configured, and the value is 0.7; (2) MCS threshold for scheduling under the single subframe TTI of the terminal UE: MCSThr2, the default value is 20, which can be configured, and the value is 20; (3) X: Adjusted power value dB; the default value is -1dB, which can be configured, and the value is -1dB.

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