CN1155179C - Fast Cell Selection Method Based on Quality of Service Judgment Criterion - Google Patents

Abstract

A fast cell selection method based on the quality of service judgment criterion: When the UE measures each cell in the effective set, it measures the SNR of the common pilot channel, and selects a target value that satisfies the given common pilot channel SNR and has the minimum emission. The cell with the highest power is used as the preferred cell. If there is no cell that meets the requirements, increase the number of serving cells according to the signal-to-noise ratio of the common pilot channel received by the cell until the combined received common pilot channel meets the minimum signal-to-noise ratio of all common pilot channels Until the target value, the selected cells serve the UE together through their respective high-speed shared channels. The invention can achieve the purpose of reducing system downlink interference and increasing system capacity.

Description

Fast Cell Selection Method Based on Quality of Service Judgment Criterion

technical field

The invention relates to a fast cell selection method, in particular to a fast cell selection method based on service quality judgment criteria.

Background technique

"Transmission power control method in CDMA system and mobile station using the method" disclosed by Chinese invention patent application publication number CN1115555A is to compare the transmission power control bit from the old base station with the transmission from the new base station during soft handover power control bits and selects the transmission power control bit indicating a lower transmission power for the mobile station which determines its transmission power. In addition, the mobile station determines the transmission power control bit of the base station during soft handover by comparing the SIR (Signal to Interference Ratio) received from the old base station with the SIR received from the new base station and selecting the larger received SIR. This makes it possible to reduce the transmission power of the base station and increase the capacity of the number of users.

The high-speed data transmission in the wireless mobile communication system includes the HSDPA (High Speed Downlink Packet Access) technology of WCDMA and the 1xEV-DV (1x EVolution Data and Voice, the 1x evolution of cdma2000 - data and voice version) technology, all use fast cell selection technology to replace traditional soft handover.

In the current fast cell selection method, UE (User Equipmennt, user equipment) measures the RSCP (Rdceived Signal Code Power, received signal code power) strength or SNR (signal-to-noise ratio) of all cells in the effective set in each frame. , select the cell with the highest strength as the best cell (preferred cell), instruct this cell to serve it through uplink signaling, and receive data from this cell through a high-speed shared channel. At any time, only one best cell serves the UE via the high-speed shared channel.

Since the UE selects the cell with the largest effective centralized measurement value as the best cell in each frame, and receives the service of the best cell through the high-speed shared channel, it does not consider the service quality of the high-speed shared channel of the traffic channel. If the corresponding user service quality of the high-speed shared channel from the serving cell to the UE exceeds the QoS (Quality of Service) target value, system power resources will be wasted, system downlink interference will be increased, and system capacity will be reduced; if the service quality does not reach the target value, then Can not meet the needs of the business.

Contents of the invention

The purpose of the present invention is to provide a fast cell selection method based on service quality judgment criterion, so as to reduce system downlink interference and increase system capacity.

In order to achieve the above purpose, the present invention provides a fast cell selection method based on the quality of service judgment criterion: when the UE measures the cells in the effective set, it measures the signal-to-noise ratio of the common pilot channel, and selects a cell that satisfies the given common pilot channel. The target value of channel signal-to-noise ratio and the cell with the minimum transmit power are used as the preferred cell, and the cell serves the user equipment through the high-speed shared channel; if there is no cell that meets the requirements, the cell receives the signal-to-noise ratio of the common pilot channel , increasing the number of serving cells until the combined received common pilot channels meet the minimum signal-to-noise ratio target value among all common pilot channels, then the selected cells serve the UE together through their respective high-speed shared channels.

In the above-mentioned fast cell selection method based on the quality of service judgment criterion, when measuring each cell in the effective concentration, first set the signal-to-noise ratio target value of the common pilot channel according to the service quality requirements of the high-speed shared channel, and measure the common pilot channel The signal-to-noise ratio is compared with the target value of the common pilot channel signal-to-noise ratio to find a cell that meets the service quality of the high-speed shared channel.

In the above-mentioned fast cell selection method based on the quality of service judgment criterion, the method of setting the signal-to-noise ratio target value of the common pilot channel according to the high-speed shared channel service quality requirement is, according to the received and FCS (Fast cell selection, fast cell selection) Cell selection) related system information to calculate the signal-to-noise ratio target value of the common pilot channel of each cell of the user, and the target value also includes the service quality requirement of the user on the high-speed shared channel.

By adopting the above-mentioned technical solution, when selecting a fast cell, the service quality of the high-speed shared channel is considered, and the SNR target value of the common pilot channel of each cell is calculated through certain system information. In this way, the present invention is based on the QoS judging criterion of the traffic channel, while measuring the signal-to-noise ratio of the common pilot channel to perform fast cell selection, it can take into account the service quality requirement of the high-speed shared channel. In addition, the measurement of each frame of the UE selects the cell that satisfies the SNR target value of the given common pilot channel and has the minimum transmit power as the preferred cell, or merges the cells so that the SNR of the combined common pilot channel can meet the requirements. Therefore, system downlink interference can be reduced and system capacity can be increased.

Description of drawings

Fig. 1 is an algorithm flow chart of the present invention.

Detailed ways

As shown in Figure 1, during the measurement process of each frame, the UE receives the common pilot channel transmitted by each cell in the effective set, and also receives some system information related to FCS, such as the transmission of the common pilot channel of each cell Power, power offset information of the common pilot channel and high-speed shared channel of each cell, etc. Among them, the power offset information between the common pilot channel and the high-speed shared channel can be used to calculate the SNR target value of the common pilot channel, and the transmission power of the common pilot channel can be used to judge whether the SNR of the common pilot channel is satisfied. The target value is required and the cell with the minimum transmit power.

Then, the UE calculates the SNR target value of the common pilot channel of each cell according to the received common pilot channel signal and the system information related to the FCS, as shown in step 2 in the figure. For example, the service QoS of a certain user on the downlink shared channel requires that the downlink shared channel must meet a certain signal-to-noise ratio. According to the power offset between the downlink shared channel and the common pilot channel, the user's public The required signal-to-noise ratio target value of the pilot channel. Next, the UE measures the current SNR of the common pilot channel, as shown in step 3 in the figure.

The UE judges whether there is a SNR measurement value of the common pilot channel in the measurement cell that is greater than or equal to the SNR target value of the common pilot channel in the cell, as shown in step 4 in the figure. If the judgment result of step 4 is that there is a SNR measurement value of the common pilot channel greater than or equal to the SNR target value of the common pilot channel in the cell, then the SNR measurement value of the common pilot channel is greater than or equal to the cell Among the cells with the SNR target value of the common pilot channel, select the cell with the minimum transmission power as the best cell (serving cell), as shown in steps 5 and 6 in the figure. After determining the serving cell, the UE instructs the serving cell to serve it through uplink signaling, as shown in step 7 in the figure.

If the judgment result of step 4 is that the SNR measurement value of the common pilot channel of none of the sub-districts is greater than or equal to the SNR target value of the common pilot channel of the sub-district, then first initialize the counter i, make i=0, as shown in the steps 8. Then, as shown in step 9 of the figure, the i+2 common pilot channels with the largest SNR measurement value are combined. Next, judge whether the SNR of the combined common pilot channel is greater than or equal to the minimum common pilot channel SNR target value in the effective set, as shown in figure step 10, if the judgment result of step 10 is greater than or equal to, then as As shown in step 11, the cell incorporating the common pilot channel is selected as the serving cell. If the judgment result of step 10 is less than, then proceed to step 13 first to judge whether there are unmerged sub-districts, that is, to judge whether i is less than N-2, and N is the number of sub-districts in the effective concentration, because at this time i+ has been merged The common pilot channel of 2 cells is gone. If the judgment result of step 13 is less than, the combination can be continued. At this time, go to step 12, add 1 to the counter, and then go to step 9, combine the common pilot channels of the i+2 cells. Then follow step 10 to continue until the merge is complete. If the judging result in step 13 is greater than or equal to, stop combining, go to step 11, select the cell combining the common pilot channel as the serving cell. After determining the serving cell, the UE instructs the serving cell to serve it through uplink signaling, as shown in step 7 in the figure.

Claims (3)

1. A fast cell selection method based on quality of service judgment criteria, characterized in that, when the user equipment measures each cell in the effective concentration, it measures the signal-to-noise ratio of the common pilot channel, and selects a signal-to-noise ratio that satisfies the given common pilot channel signal-to-noise ratio. The cell with the minimum transmit power than the target value is used as the preferred cell, and the cell serves the user equipment through the high-speed shared channel; if there is no cell that meets the requirements, the serving cell is increased according to the signal-to-noise ratio of the common pilot channel received by the cell until the combined received common pilot channels meet the minimum signal-to-noise ratio target value among all common pilot channels, then the selected cells serve the user equipment together through their respective high-speed shared channels. 2. A kind of fast cell selection method based on quality of service judgment criterion according to claim 1, it is characterized in that, when each sub-district in effective concentration is measured, at first according to high-speed shared channel service quality requirement, set the common pilot channel The SNR target value measures the SNR of the common pilot channel, compares it with the target value of the SNR of the common pilot channel, and finds a cell that meets the service quality of the high-speed shared channel. 3. a kind of fast cell selection method based on quality of service judgment criterion according to claim 2, it is characterized in that, described according to the method for the signal-to-noise ratio target value of setting common pilot channel according to the service quality requirement of high-speed shared channel Yes, calculate the SNR target value of the common pilot channel of each cell of the user according to the received system information related to fast cell selection, and the target value also includes the user's service quality requirements on the high-speed shared channel.