CN102006636B - Method for controlling speed rate of reverse link based on channel quality - Google Patents

Abstract

The present invention relates to a reverse link rate control method based on channel quality. In a system composed of an access terminal, a wireless access network, a packet core network and an IP network, the active access terminal is divided according to the pilot power level, and introduce a weighting factor method to flexibly adjust the distribution of T2P flows, including the following steps: 1) Preset the system load threshold and calculate the reverse link load factor; 2) Combine the calculated reverse link load factor with The load threshold value is compared to obtain the RAB value; 3) The access terminal adjusts the T2P resource allocation according to the current RAB value and the quality of the reverse channel of the access terminal; 4) The access terminal adjusts the T2P resource allocation according to the allocated T2P resources and data The rate mapping table adjusts the transmission rate. With higher system throughput, lower terminal transmission power and smaller system load, resource utilization is improved; at the same time, it avoids system instability caused by terminals with poor channel quality due to increased transmission power.

Description

A Reverse Link Rate Control Method Based on Channel Quality

technical field

The invention relates to a reverse link rate control method based on channel quality, which is suitable for the third generation mobile communication technology cdma2000 1x EV-DO (Evolution-Data Optimized, standard-data optimized) reverse link rate control.

Background technique

cdma2000 is one of the three mainstream technologies of 3G. With the rapid development of Internet and information technology, people's demand for wireless data services is increasing day by day, and data services are developing rapidly in the direction of diversity, large capacity and asymmetry. The data business capabilities of the company are very limited and cannot meet future business needs. cdma2000 1x EV-DO mainly completes the high-speed data transmission function of the cdma2000 1x system, and can solve the problem of wireless transmission of high-speed asymmetric packet data services. 1x EV-DO is an extension of cdma2000 in the direction of data functions. Its key technology - rate control Technology gets attention.

CDMA is a self-interference system. In order to ensure the successful demodulation of the base station, it is necessary to control the transmission power of all users. Since the transmission power of the 1x EV-DO reverse traffic channel is determined by the transmission rate of the terminal and the power ratio between the traffic channel and the pilot channel determined in advance, the reverse data transmission rate of the terminal has a linear relationship with the corresponding transmission power. Therefore, reverse rate control ensures that the system works properly in reverse. The 1x EV-DO reverse link rate control process is completed by the cooperation between the base station and the terminal. The base station side generates a RAB (ReverseActivity Bit, reverse activation bit) value through reverse link load measurement and overload judgment, and the terminal side performs rate control based on the updated RAB value and the current rate. The control object of the 1xEV-DO RTCMAC subtype 3 rate control algorithm is T2P. The power control of the reverse link ensures that the pilot strength of each terminal arriving at the base station receiver is basically the same, and the transmit power of the terminal is determined by T2P. Using T2P as a control variable can more directly control the reverse transmit power of the terminal, thereby More fine-grained control over reverse loading of sectors. The T2P mechanism takes the sector's long-term load into consideration, not only can keep the reverse load at a high level stably, but also enables the terminal to quickly increase its transmission rate when the system load is light, thereby effectively reducing the delay And improve the throughput of the sector.

Under the T2P token bucket mechanism, the reverse transmission rate of the terminal is affected by the token bucket control functions gu(.) and gd(.). The gu(.) and gd(.) functions are piecewise bilinear interpolation functions, which are related to the values of T2PInflow and FRAB. Therefore, the management of gd(.), gu(.) is the key to channel resource allocation. When the T2PInflow value is determined, gu(.) decreases monotonically with FRAB, and gd(.) increases monotonically with FRAB. When the FRAB value is determined, gd(.)/gu(.) decreases monotonically with T2PInflow. These characteristics cause terminals with different initial T2PInflow values to tend to the same T2PInflow value, and the transmission resources are allocated equally. However, from the point of view of system throughput and power utilization, the equal allocation strategy is not a good strategy.

Therefore, there is still room for further improvement in the prior art.

Contents of the invention

Aiming at the deficiencies in the prior art, the present invention proposes a reverse link rate control method based on channel quality, which solves the problem of unreasonable channel resource allocation and low system efficiency of the rate control algorithm under the cdma2000 1x EV-DO reverse link T2P mechanism question.

Technical scheme of the present invention is as follows:

A reverse link rate control method based on channel quality, in a system composed of an access terminal, a wireless access network, a packet core network and an IP network, by classifying the activated access terminals according to the pilot power, and The method of introducing a weighting factor adjusts the allocation of T2P streams to provide better data transmission space for terminals with better reverse channel quality. The steps include:

1) Preset the system load threshold, measure system parameters, and calculate the reverse link load factor;

2) Compare the calculated reverse link load factor with the load threshold to obtain the RAB value. When the reverse link load factor is greater than or equal to the load threshold, set RAB=1; when the reverse link load factor is less than When the load threshold is reached, set RAB=0;

3) The access terminal adjusts the T2P resource allocation through the current RAB value and the reverse channel quality of the access terminal. The specific steps are:

(1) The access terminal counts the average value of its own transmit pilot power in 4 time slots;

(2) The access terminal compares the above statistical mean value with the pilot threshold, and takes the difference;

(3) Assign a weighting factor m to the difference;

(4) Sum the result of step (3) with the FRAB calculated by the RTCMAC subtype 3 rate control algorithm to jointly generate a new long-term system load reference mFRAB;

When the sum of the result of step (3) and the FRAB calculated by the RTCMAC subtype 3 rate control algorithm is less than -1, the value is -1;

When the sum of the result of step (3) and the FRAB calculated by the RTCMAC subtype 3 rate control algorithm is greater than 1, the value is 1;

(5) Replace the original FRAB with mFRAB as a reference factor for terminal T2P flow adjustment;

(6) After the current round of T2P stream allocation ends, return to step 1) to allocate the next subframe T2P stream;

4) The access terminal adjusts the transmission rate according to the allocated T2P resource and data rate mapping table.

The method for controlling the rate of the reverse link based on channel quality, wherein the system parameters are measured, and the load factor of the reverse link is calculated by the following method: measure at all antennas in the sector or at the M antennas in the sector respectively The pilot energy and noise power spectral density of each chip are measured once per time slot, and combined with the data channel gains corresponding to different rate levels, the corresponding reverse link load factor values at each antenna are calculated, and the maximum value is taken The value is used as the final reverse link load factor value, and M is a natural number greater than 2.

A reverse link rate control method based on channel quality, in a system composed of an access terminal, a wireless access network, a packet core network and an IP network, by classifying the activated access terminals according to the pilot power, and The method of introducing a weighting factor adjusts the allocation of T2P streams to provide better data transmission space for terminals with better reverse channel quality. The steps include:

1) Preset the system load threshold, measure system parameters, and calculate the reverse link load factor;

2) Compare the calculated reverse link load factor with the load threshold to obtain the RAB value. When the reverse link load factor is greater than or equal to the load threshold, set RAB=1; when the reverse link load factor is less than When the load threshold is reached, set RAB=0;

3) The access terminal adjusts the T2P resource allocation according to the current RAB value and the reverse channel quality of the access terminal. The specific steps are: a. Take the RAB statistics of 4 slots to generate QRAB, and take the RAB statistics of 384 slots to generate FRAB;

b. The terminal counts the average value of its own transmit pilot power in 4 time slots;

c. The terminal compares the statistical mean value with the pilot threshold and takes the difference;

d. Assign a weighting factor m to the difference;

f. Sum the obtained result with the FRAB calculated by the RTCMAC subtype 3 rate control algorithm to jointly generate a new long-term system load mFRAB;

When the sum of the obtained result and the FRAB calculated by the RTCMAC subtype 3 rate control algorithm is less than -1, the value is -1;

When the sum of the obtained result and the FRAB calculated by the RTCMAC subtype 3 rate control algorithm is greater than 1, the value is 1;

g. Replace the original FRAB with mFRAB as a reference factor for the terminal T2P flow adjustment;

h. After the current round of T2P flow allocation is completed, return and perform next subframe T2P flow allocation.

并与导频门限P_th进行比较，取其差值，得

In the reverse link rate control method based on channel quality, 1) the access terminal counts the average value of its own transmit pilot power in 4 time slots

And compare it with the pilot threshold P _th , take the difference, get

2) Assign a weighting factor m to the result of step 1) to obtain ΔP(i), and combine it with the QRAB value;

3) Sum the results of step 2) and the FRAB calculated by the RTCMAC subtype 3 rate control algorithm to jointly generate a new long-term system load reference mFRAB;

When the sum of the result of step 2) and the FRAB calculated by the RTCMAC subtype 3 rate control algorithm is less than -1, the value is -1;

When the sum of the result of step 2) and the FRAB calculated by the RTCMAC subtype 3 rate control algorithm is greater than 1, the value is 1;

4) Replace the original FRAB with mFRAB for T2P resource allocation.

The method for controlling the rate of the reverse link based on channel quality, wherein the system parameters are measured, and the load factor of the reverse link is calculated by the following method: measure at all antennas in the sector or at the M antennas in the sector respectively The pilot energy and noise power spectral density of each chip are measured once per time slot, and combined with the data channel gains corresponding to different rate levels, the corresponding reverse link load factor values at each antenna are calculated, and the maximum value is taken The value is used as the final reverse link load factor value, and M is a natural number greater than 2.

Beneficial positive effect of the present invention:

1. The reverse link rate control method based on channel quality of the present invention has higher system throughput, lower terminal transmission power and smaller system load than the existing reverse link rate control method, and improves resource utilization. utilization rate. The present invention takes into account the self-interference characteristics of the 1x EV-DO reverse link and the influence of power control on terminal transmission power, and the channel resource allocation strategy affects system efficiency and reverse throughput. The relatively few T2P resources of the reverse channel will waste effective data transmission space, which is not conducive to the improvement of system efficiency and reverse throughput; relatively more T2P resources are allocated to terminals with poor reverse channel quality, and the terminal will maintain data transmission. Increase the transmission power due to the increase of transmission rate, which will cause strong interference to the system and affect the stability of system performance. Under the compensation of 1x EV-DO reverse link closed-loop power control, the pilot power of the terminal basically reflects the quality of the channel: lower pilot power corresponds to higher channel quality, and higher pilot power corresponds to lower channel quality. channel quality.

2. The reverse link rate control method based on channel quality of the present invention avoids strong interference to the system caused by terminals with poor reverse channel quality due to increased transmission power, so that the interference of the system is controlled within a certain range . By adopting the above mechanism, the present invention divides the activated terminals into grades according to the pilot power and introduces weighting factors to flexibly adjust the distribution of T2P streams, so that terminals with better reverse channel quality have better data transmission space, and at the same time avoid Terminals with poor reverse channel quality will cause strong interference to the system by increasing the transmit power. The mechanism method can improve system throughput, reduce terminal transmission power and system load. It provides better data transmission space for terminals with better channel quality, and at the same time avoids system instability caused by increasing transmit power for terminals with poor channel quality.

Description of drawings

Fig. 1 is a schematic diagram of a system network structure applying the present invention;

FIG. 2 is a flow chart of the reverse link rate control method based on channel quality in the present invention.

Detailed ways

Embodiment 1: see Fig. 1, Fig. 2. The system network structure of the present invention based on the reverse link rate control method based on channel quality is shown in FIG. The access terminal is a device that provides data connection for users; the wireless access network provides the wireless bearer between the packet core network and the access terminal, and transmits user data and non-access level signaling messages, and the access terminal passes these signaling Messages interact with the packet core network for service information; the packet core network is mainly used to provide access terminals to access the IP network.

The channel quality-based reverse link rate control method of the present invention is mainly used to control the rate of the cdma2000 1x EV-DO reverse link, so that the interference of the system is controlled within a certain range, and the resource utilization rate is effectively improved. It includes the following steps:

A. Measure system parameters and calculate reverse link load factor;

B. Comparing the calculated reverse link load factor with the load threshold to obtain the RAB value;

C. The terminal adjusts the T2P resource allocation according to the current RAB value and the quality of the terminal reverse channel;

D. The terminal adjusts the transmission rate according to the allocated T2P resource and data rate mapping table.

Wherein, the process of measuring system parameters, presetting the system threshold value, and calculating the load factor of the reverse link can be implemented in various ways. For example, by measuring the pilot energy and noise power spectral density per chip at the two antennas of the sector, and combining the data channel gains corresponding to different rate levels, the respective reverse link load factor values can be calculated respectively , taking the maximum value of the two as the final reverse link load factor value. The measurement cycle is every time slot (1.667ms); or, measure the pilot energy and noise power spectral density of each chip at all antennas of the sector, and combine the data channel gains corresponding to different rate levels to calculate the The reverse link load factor value corresponding to the location, take the maximum value as the final reverse link load factor value.

Wherein, the process of comparing the reverse link load factor with the load threshold to obtain the RAB value specifically includes the following steps: when the reverse link load factor is greater than or equal to the load threshold, set RAB=1; when the reverse link When the road load factor is less than the load threshold, set RAB=0.

Embodiment two: see Fig. 1, Fig. 2. The reverse link rate control method based on channel quality in this embodiment is different from Embodiment 1 in that step C specifically includes the following steps:

C1. The terminal counts the average value of its own transmission pilot power in 4 time slots;

C2. The terminal compares the statistical mean value with the pilot threshold, and takes the difference;

C3. Assign a weighting factor m to the difference;

C4. Sum the result of step C3 and the FRAB calculated by the RTCMAC subtype 3 rate control algorithm to jointly generate a new long-term system load reference mFRAB; when the sum of the result of step C3 and the FRAB calculated by the RTCMAC subtype 3 rate control algorithm is less than When -1, the value is -1; when the sum of the result of step C3 and the FRAB calculated by the RTCMAC subtype 3 rate control algorithm is greater than 1, the value is 1;

C5. Replace the original FRAB with mFRAB as a reference factor for the terminal T2P flow adjustment amount;

C6. After the current round of T2P flow allocation ends, return to step C1 to perform next subframe T2P flow allocation.

Embodiment three: see Fig. 1, Fig. 2. The reverse link rate control method based on channel quality in this embodiment is slightly different from Embodiment 2, and specifically includes the following steps:

1. Preset the system load threshold and the value of the weighting factor m;

2. Measure the pilot energy and noise power spectral density of each chip at all antennas of the sector, and measure once for each time slot. Combining the data channel gains corresponding to different rate levels, calculate the corresponding reverse link load factor value at each antenna, and take the maximum value as the final reverse link load factor value;

3. Comparing the reverse link load factor with the load threshold to obtain the RAB value;

4. Take the RAB statistics of 4 time slots to generate QRAB, and take the RAB statistics of 384 time slots to generate FRAB;

5. The terminal counts the average value of its own transmission pilot power in 4 time slots;

6. The terminal compares the above statistical mean with the pilot threshold, and takes the difference;

7. Assign a weighting factor m to the difference;

8. Sum the result of step C3 and the FRAB calculated by the RTCMAC subtype 3 rate control algorithm to jointly generate a new long-term system load reference mFRAB;

9. Replace the original FRAB with mFRAB as a reference factor for terminal T2P flow adjustment;

10. After the current round of T2P stream allocation ends, return to step C1 to allocate the next subframe T2P stream.

In the above steps, step 8: when the sum of the result of step 7 and the FRAB calculated by the RTCMAC subtype 3 rate control algorithm is less than -1, the value is -1; when the result of step 7 and the FRAB calculated by the RTCMAC subtype 3 rate control algorithm When the sum of the output FRAB is greater than 1, the value is 1.

Embodiment four: this embodiment further describes in detail the process that the present invention carries out rate control in the cdma2000 1x EV-DO reverse link in conjunction with Fig. 2:

Step 201: First, measure pilot energy and noise power spectral density per chip at all antennas of the sector, and measure once per time slot. Combining the data channel gains corresponding to different rate levels, calculate the corresponding reverse link load factor value at each antenna, and take the maximum value as the final reverse link load factor value;

Step 202: Second, compare the reverse link load factor with a load threshold. If the reverse link load factor determined in step 202 is greater than or equal to the load threshold, set RAB=1. If the reverse link load factor determined in step 202 is less than the load threshold, then set RAB=0;

Step 203: take 4 time slot RAB statistical values to generate QRAB, and take 384 time slot RAB statistical values to generate FRAB;

并与导频门限P_th进行比较，取其差值，得 Step 204: The access terminal counts the mean value of its own transmit pilot power in 4 time slots

And compare it with the pilot threshold P _th , take the difference, get

Step 205: assign a weighting factor m to the result of step 204 to obtain ΔP(i), and combine it with the QRAB value;

Step 206: Summing the result of step 205 and the FRAB calculated by the RTCMAC subtype 3 rate control algorithm to jointly generate a new long-term system load reference mFRAB;

In step 206, when the sum of the FRAB calculated by the step 205 result and the RTCMAC subtype 3 rate control algorithm is less than -1, the value is -1; when the step 205 result and the FRAB calculated by the RTCMAC subtype 3 rate control algorithm When the sum is greater than 1, the value is 1;

Step 207: Replace the original FRAB with mFRAB as a reference factor for the T2P flow adjustment of the terminal, and perform T2P resource allocation.

Claims (5)

1. reverse link rate control method based on channel quality; By access terminal, in the system that wireless access network, packet-based core networks and IP network are formed; Through with activated access terminal according to the pilot power divided rank, and introduce the method for weighted factor, the distribution of adjustment T2P stream; For reverse channel quality provides better transfer of data space in the terminal preferably, its step comprises:

1) predetermined system load-threshold value, the measuring system parameter is calculated the reverse link loading factor;

2) the reverse link loading factor and the load-threshold value that calculate are compared, draw the RAB value,, establish RAB=1 when the reverse link loading factor during more than or equal to load-threshold; When the reverse link loading factor during, establish RAB=0 less than load-threshold;

3) access terminal through the current RAB value and the reverse channel quality that accesses terminal, adjustment T2P resource allocation, concrete steps are: (1) accesses terminal and adds up the average of 4 time slots self emission pilot power;

(2) access terminal above-mentioned average statistical and pilot threshold are compared, get its difference;

(3) give weighted factor for this difference m

(4) FRAB that step (3) result and RTCMAC subtype 3 rate control algorithms is calculated get with, generate new long-term system load jointly with reference to mFRAB;

The FRAB sum that calculates when step (3) result and RTCMAC subtype 3 rate control algorithms is less than-1 the time, and value is-1;

The FRAB sum that calculates when step (3) result and RTCMAC subtype 3 rate control algorithms is greater than 1 the time, and value is 1;

(5) mFRAB is replaced former FRAB, as the reference factor of terminal T2P stream adjustment amount;

(6) after epicycle T2P flow distribution finishes, turn back to step 1), carry out next subframe T2P flow distribution;

4) access terminal according to the mapping table adjustment transmission rate of T2P resource of distributing and data rate.

2. the reverse link rate control method based on channel quality according to claim 1; It is characterized in that: measuring system parameter wherein; Calculate that the reverse link loading factor is concrete to adopt following method to realize: at all antenna places of sector or M wherein antenna place measure the pilot energy and the noise power spectral density of every chip respectively; Every time slot is measured once, and combines the corresponding data channel gain of different rates grade, calculates the corresponding reverse link loading factor values in each antenna place respectively; Get wherein maximum as final reverse link loading factor values, M is the natural number greater than 2.

3. reverse link rate control method based on channel quality; By access terminal, in the system that wireless access network, packet-based core networks and IP network are formed; Through with activated access terminal according to the pilot power divided rank, and introduce the method for weighted factor, the distribution of adjustment T2P stream; For reverse channel quality provides better transfer of data space in the terminal preferably, its step comprises:

1) predetermined system load-threshold value, the measuring system parameter is calculated the reverse link loading factor;

2) the reverse link loading factor and the load-threshold value that calculate are compared, draw the RAB value,, establish RAB=1 when the reverse link loading factor during more than or equal to load-threshold; When the reverse link loading factor during, establish RAB=0 less than load-threshold;

3) access terminal through the current RAB value and the reverse channel quality that accesses terminal, adjustment T2P resource allocation, concrete steps are: a, get 4 time slot RAB statistical values and generate QRAB, get 384 time slot RAB statistical values and generate FRAB;

The average of 4 time slots self emission pilot power is added up at b, terminal;

C, terminal compare above-mentioned average statistical and pilot threshold, get its difference;

D, give weighted factor for this difference m

F, the FRAB that gained result and RTCMAC subtype 3 rate control algorithms are calculated get and, generate new long-term system load mFRAB jointly;

The FRAB sum that calculates when gained result and RTCMAC subtype 3 rate control algorithms is less than-1 the time, and value is-1;

The FRAB sum that calculates when gained result and RTCMAC subtype 3 rate control algorithms is greater than 1 the time, and value is 1;

G, mFRAB is replaced former FRAB, as the reference factor of terminal T2P stream adjustment amount;

After h, epicycle T2P flow distribution finish, return, carry out next subframe T2P flow distribution.

4. the reverse link rate control method based on channel quality according to claim 3 is characterized in that:

1) the access terminal average of statistics 4 time slots self emission pilot power; And compare with pilot threshold

; Get its difference, get

;

2), get Δ P (i), and combine with the QRAB value for the step 1) result gives weighted factor m;

3) with step 2) FRAB that calculates of result and RTCMAC subtype 3 rate control algorithms get with, generate new long-term system load jointly with reference to mFRAB;

When step 2) the FRAB sum that calculates of result and RTCMAC subtype 3 rate control algorithms is less than-1 the time, and value is-1;

When step 2) the FRAB sum that calculates of result and RTCMAC subtype 3 rate control algorithms is greater than 1 the time, and value is 1;

4) mFRAB is replaced former FRAB, carry out the T2P resource allocation.

5. according to claim 3 or 4 described reverse link rate control methods based on channel quality; It is characterized in that: measuring system parameter wherein; Calculate that the reverse link loading factor is concrete to adopt following method to realize: at all antenna places of sector or M wherein antenna place measure the pilot energy and the noise power spectral density of every chip respectively; Every time slot is measured once, and combines the corresponding data channel gain of different rates grade, calculates the corresponding reverse link loading factor values in each antenna place respectively; Get wherein maximum as final reverse link loading factor values, M is the natural number greater than 2.

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