CN1798424A - Method for setting up parameters in compress mode in CDMA system - Google Patents

Abstract

The method includes following steps: when the system needs to start up the compression mode, defines the sequence numbers required by the compression mode; in term of the network planning parameters, configures the parameters for each compression mode sequence. By using the invention, based on the numbers of neighboring cell having different frequency and different system from the current cell, and the wireless condition of the current cell, configures the compression mode sequence in real time to improve the success rate of starting compression mode.

Description

Compressed mode parameter configuration method in code division multiple access system

technical field

The invention relates to the technical field of mobile communication, in particular to a method for configuring compressed mode parameters in a code division multiple access system, in particular to a method for configuring compressed mode parameters required by UE (user equipment) for hard handover measurement.

Background technique

At present, with the expansion of the network scale and the continuous increase of the number of users, higher requirements are put forward for network optimization and signal quality, and the third-generation mobile communication technology based on the CDMA (Code Division Multiple Access) system has been increasingly widely used. . Since the mobile communication system adopts a cellular structure, the mobile station must perform handover when it crosses a cell divided by space, that is, to complete the transfer of the air interface from the mobile station to the base station, and from the base station to the RNC (radio network controller) and Corresponding transfer from RNC to switching center. The 3G (third generation mobile communication) system will implement soft handover between cells using the same carrier frequency, that is, mobile users can connect to the base stations of two cells at the same time when they cross the area, and only change the spreading code accordingly To the switch function of "connect first, then disconnect", which greatly improves the call quality when switching. However, in order to ensure the seamless coverage of the cell, handover between cells with different carrier frequencies still needs to use hard handover, that is, inter-frequency hard handover; and considering the transition from 2G (second generation mobile communication) to 3G, it is necessary to ensure seamless user services. For gap coverage, it is necessary to realize handover between different systems, that is, handover between CDMA and GSM (Global Mobile Communication) systems.

For inter-frequency hard handover and inter-system handover, it can be divided into blind handover and measurement-based handover in terms of implementation. The blind handover method does not require the terminal to perform measurement, and the RNC (Radio Network Controller) completely decides whether to perform handover. Generally speaking, the RNC will decide whether to perform handover according to the location of the terminal, and handover to other cells according to predetermined settings. This method is simple to implement. But usually there are several GSM cells around a CDMA cell, so it is difficult to determine an appropriate target cell through blind handover, which leads to the inability to perform hard handover to 2G cells through blind handover. Measurement-based handover means that the terminal measures the signals of neighboring cells, reports the test results to the RNC, and the RNC decides whether to perform handover.

For inter-frequency hard handover, FDD (frequency division duplex) to TDD (time division duplex) handover and inter-system handover, it is necessary to measure the target cell of the handover. The frequency of these measurements is usually different from the frequency at which the current UE works, and it needs to be performed Different frequency measurement and different system measurement. Since the FDD mode is characterized in that the system receives and transmits on two separate symmetrical frequency channels, and the guaranteed frequency band is used to separate the receiving and transmitting channels, therefore, in the FDD mode of the CDMA system, if the downlink signal is always occupied in time, then If the UE wants to receive downlink data continuously, its receiver cannot receive signals of other frequencies while receiving the current working frequency signal. At this time, if the UE does not have the condition of dual receivers, it must support compressed mode in order to perform Another carrier frequency measurement.

The compressed mode is a mechanism for generating a certain idle period in a radio frame, through which a UE (user equipment) can perform inter-frequency or inter-system cell measurement. As shown in Figure 1:

In the downlink compression mode, technologies such as code puncturing are used to form a period of transmission data "gap". In this gap, the base station does not transmit any data to the mobile station. The mobile station can use this slot to switch its radio frequency receiver to the target frequency that needs to be monitored and take measurements on the target frequency.

After configuring parameters such as the length and repetition period of the compressed mode GAP (gap) in the wireless frame, a specific compressed mode pattern is generated, and all compressed mode patterns called during multiple measurement processes at the same time form a compressed mode pattern sequence .

The configuration parameters for a compressed mode style are shown in Figure 2:

Include TG pattern1 and TG pattern2 in one cycle, among them, TG pattern2 is optional. TGPL1 (length of transmission slot pattern 1) and TGPL2 (length of transmission slot pattern 2) determine the period length of the compressed mode pattern, TGSN (transmission slot start slot number), TGL1 (length of transmission slot 1), TGL2 (transmission slot The length of the gap 2), TGD (transmission gap interval) determines the position of the GAP. GAP1 and GAP2 are the length of GAP, ranging from 0 to 14 slots (time slots), distributed in 1 to 2 frames. In addition, TGCFN (transmission gap control frame connection frame number) determines the moment when the first compressed mode pattern is started in the compressed mode pattern sequence, and the compression gap activation time offset ΔCFN is relative to the next compressed mode pattern started in the compressed mode pattern The time offset of the previous compressed mode pattern started.

Usually, there are many kinds of measurements required during handover, which requires configuring multiple TGPS (compressed mode sequences). For example, in the 3GPP (Third Generation Partnership Project) agreement, three types of TGPS for GSM measurement are specified, which are used for: GSM Carrier RSSI (GSM carrier frequency received signal strength indication) measurement, initial BSIC (base station identification code) Confirmation measurement, BSIC reconfirmation measurement. The three compressed mode sequences have different start times, styles, and repetition periods. In order to ensure the channel transmission quality during the start of compressed mode, it is stipulated that no more than two frames in three consecutive frames shall be occupied by GAPs; and the GAPs in compressed mode cannot overlap at any time, otherwise conflicts will occur. The so-called conflict between compressed modes refers to the situation that gaps generated by multiple compressed modes appear in the middle of the same wireless frame. Conflicts are likely to occur when multiple compressed mode sequences exist at the same time.

As shown in FIG. 3 , when two compression modes with the same repetition period exist at the same time, the result of superimposition is that there is a gap between the two compression modes in the same frame, thereby causing conflicts.

Usually, there is no constraint on the repetition period of the compression mode. If the period of two compression modes is different, a conflict may occur in a certain frame after repeated repetitions. As shown in Figure 4, the periods of the two compression modes are 8 and 7 respectively, there is no conflict in the first period of the two compression modes, but a conflict occurs in the third period.

This conflict will lead to unrealizable errors between the various parts of the system cooperating for the compressed mode: the physical layer will not be realized on the network side, and it will not be realized on the mobile station side when there are multiple measurement purposes at the same time.

For the above reasons, avoiding collisions between concurrently existing compressed-mode sequences in a CDMA system will be crucial.

Usually, the configuration of the compression mode is manually pre-configured parameters in the background, for example, several compression mode style parameters that need to be configured in several typical application scenarios are obtained through simulation, and will not be modified during system operation. When inter-frequency measurement or inter-system measurement needs to be started, the RNC (radio network controller) reads these pre-configured parameters and directly sends them to NodeB (base station) and UE (user terminal) through signaling messages. No checking is done for compressed mode sequence parameters.

Using this configuration method, once the wireless environment of the cell changes, these configuration parameters cannot be optimized in real time, and cannot adapt to the change of the wireless environment. If there is a conflict between the compression modes or more than two frames are occupied by the GAP in three consecutive frames, the measurement requirement cannot be met, and the transmission quality of the channel will also be affected.

Contents of the invention

The purpose of the present invention is to provide a method for configuring compressed mode parameters in a code division multiple access system, so as to overcome the disadvantage that the static configuration method in the prior art cannot optimize the compressed mode parameters in real time according to changes in the environment of the cell, so that the compressed mode sequence is more accurate. well meet the system requirements.

For this reason, the present invention provides following technical scheme:

A code division multiple access system compressed mode parameter configuration method, said method comprising steps:

A. When the system needs to start the compressed mode, determine the number of required compressed mode sequences;

B. Configure each compressed mode sequence parameter separately according to the network planning parameters.

Described step B comprises:

B1. Determine the transmission gap length and the transmission gap mode length of the compressed mode style according to the network planning parameters;

B2. Configuring the transmission slot start slot number and transmission slot interval according to the determined transmission slot length and transmission slot pattern length;

B3. When multiple compressed mode sequences are required, respectively configure and adjust the offset ΔCFN of each compressed mode sequence relative to the starting moment of the previously configured compressed mode sequence, so that it meets the valid condition of the compressed mode sequence.

The network planning parameters include:

The number of inter-frequency or inter-system neighboring cells to be measured and the current wireless environment of the system cell.

Said step B1 comprises:

B11. Make the transmission gap length proportional to the number of inter-frequency or inter-system neighboring cells, and proportional to the moving speed of the system cell;

B12. Make the length of the transmission gap pattern inversely proportional to the number of inter-frequency or inter-system neighboring cells, and inversely proportional to the moving speed of the system cell.

Described step B3 comprises:

B31. Select the configured compressed mode sequence respectively, and configure its initial ΔCFN,

B32. Check the validity of the corresponding compressed mode sequence according to the initial ΔCFN;

B33. Adjust the initial ΔCFN according to the inspection result.

Described step B32 comprises:

Determine the check length M=M1+M2+M3 of the compressed mode sequence, where,

M1 is the least common multiple of all compressed mode sequence lengths,

M2 is the deviation of the last compressed mode sequence configured relative to the first compressed mode sequence,

M3 is to check the length margin, M3≥N-1, N means that there are gaps in N consecutive frames;

performing a collision check on the compressed mode sequence within the check length;

Checking the number of frames occupied by continuous gaps on the compressed mode sequence within the checking length;

When the compressed mode sequence has no slot occupancy conflict and the number of consecutive slot occupancy frames is less than the allowed maximum number of consecutive slot occupancy frames, the compressed mode sequence is valid.

The step B33 is specifically:

When the compressed mode sequence selection to be adjusted is invalid, the initial ΔCFN is increased by a predetermined step.

The predetermined step size is 1 frame.

Described step A comprises:

When the target cell of the hard handover is an inter-frequency cell, a compressed mode sequence is required;

When the target cell of the hard handover is a cell of a different system, multiple compressed mode sequences are required.

Said step B also includes:

When the transmission gap of the compressed mode sequence is a single frame mode, the transmission gap is located in the middle of the frame;

When the transmission gap of the compressed mode sequence is a double-frame mode, the transmission gap is located in the middle of the two frames.

As can be seen from the above technical solutions provided by the present invention, the present invention adaptively configures the required compressed mode sequences according to the number of current inter-frequency or inter-system neighboring cells of the cell and the wireless environment of the cell; when multiple compressed mode sequences are required When configuring and adjusting the ΔCFN value of each compressed mode sequence to make the corresponding compressed mode sequence valid, this real-time configuration method can adapt to the needs of different cell environment changes, quickly complete the validity check of the compressed mode sequence, and realize Optimized configuration of the compressed mode sequence, thus improving the success rate of compressed mode startup.

Description of drawings

Fig. 1 is a schematic diagram of a compressed mode style frame structure;

Fig. 2 is a schematic diagram of compression mode style parameters;

FIG. 3 is a schematic diagram of conflicts between compressed mode styles with the same repetition period;

FIG. 4 is a schematic diagram of conflicts between compressed mode styles with different repetition periods;

Fig. 5 is the implementation process of the inventive method;

Fig. 6 is a schematic diagram of a situation in which 3 consecutive frames are occupied in two wireless frames superimposed in compressed mode;

Fig. 7 is a schematic diagram of checking the GAP occupancy rate using the sliding window technique;

Fig. 8 is the check flow of the validity of the compressed mode pattern;

Fig. 9 is a flow chart of multi-sequence compression mode adjustment;

Figure 10 is a simulation relationship diagram of initial BSIC confirmation compressed mode void ratio and measurement maximum time;

Fig. 11 is a simulation relationship diagram of BSIC re-confirmation compression mode void ratio and measurement maximum time.

Detailed ways

The core of the present invention is that when the system needs to start the compressed mode, according to the characteristics of the target cell to be switched, determine the required number of compressed mode sequences, and then, according to some planning parameters of the network, such as the measured inter-frequency or inter-system neighbors The parameters of each compressed mode pattern are adaptively configured according to the number of areas, different wireless environments of the cells, etc. When multiple compressed mode patterns are required, configure and adjust the compression gap activation time offset value of each compressed mode pattern so that the corresponding compressed mode pattern sequence is valid.

In order to enable those skilled in the art to better understand the solution of the present invention, the present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments.

With reference to Fig. 5, Fig. 5 is the realization flowchart of the inventive method:

Step 501: When the system needs to start the compressed mode, determine the required number of compressed mode sequences.

In a CDMA system, usually more than one inter-frequency measurement or inter-system measurement is required for hard handover, so one or more compressed mode sequences are required. For example, if there is only inter-frequency cell measurement, only one compressed mode sequence needs to be configured, and if inter-system cell measurement is required, three compressed mode sequences may need to be configured.

For GSM measurement, it generally includes GSM Carrier RSSI measurement, initial BSIC confirmation measurement, and BSIC re-confirmation measurement, that is, three compressed mode sequences are used. The three compressed mode sequences have different start times, styles, and repetition periods. GAPs in compressed mode cannot overlap at any time, otherwise conflicts will occur; at the same time, in order to ensure the channel transmission quality during the start of compressed mode, it is also stipulated that no more than two frames in three consecutive frames can be occupied by GAPs.

After determining the required number of compressed mode sequences, each compressed mode sequence parameter needs to be configured separately according to network planning parameters. According to the requirements of the compressed mode sequence, the parameters that need to be configured include the transmission gap length TGL, the transmission gap pattern length TGPL, the transmission gap start time slot number TGSN, and the transmission gap interval TGD. If multiple compressed mode sequences are required, each The compression mode style is relative to the ΔCFN parameter of the previous compression mode style, and the compression mode sequences configured according to these parameters will not conflict, and it must be ensured that no more than two frames are occupied by GAP in three consecutive frames.

The specific configuration process is as follows:

Step 502: Determine the transmission gap length TGL and the transmission gap pattern length TGPL of the compressed mode according to network planning parameters. Among them, the network planning parameters include: the number of inter-frequency or inter-system neighboring cells to be measured, and the current wireless environment of the system cells.

In order to have a suitable gap for measurement when different measurement requirements are required, so as to make it sufficient without causing too much waste, it is necessary to consider the impact of the measurement target cell and the environment of the current cell of the system on these parameters.

If there are many inter-frequency or inter-system frequency points to be measured, the gap per unit time needs to be configured larger; if the statistical characteristics of the area covered by the cell is a fast-moving cell, for example, the coverage area of the cell is a road, and fast For measurement, the gap per unit time should be configured larger so that there is enough gap for measurement.

Step 503: Configure TGSN (transmission slot start slot number) and TGD (transmission slot interval) according to the determined TGL and TGPL.

TGSN is the starting time slot number of the first transmission slot in the compressed mode mode in the compressed mode mode, and its value ranges from 0 to 14 slots. Configure the TGSN according to the TGL length configured in step 502 . When setting the TGSN, it is best to make the transmission gap in the single frame mode be located in the middle of a frame; for the transmission gap in the double frame mode, it is best to be located in the middle of two frames. This minimizes the impact of compressed mode on a single frame time.

Suggested values are given below for several typical situations:

(1) When TGL=5slot, set TGSN=5slot;

(2) When TGL=10slot, adopt double frame mode, TGSN=10slot;

(3) When TGL=14slot, adopt double frame mode, TGSN=8slot;

(4) If TGL=7slot, TGSN is preferably set to 4slot or 11slot, and can also be set to 0 or 7slot according to the actual situation.

The protocol stipulates that there can be at most two transmission slots in one compressed mode pattern, and TGD indicates the distance between two transmission slots, that is, the difference between the start time of GAP2 and the start time of GAP1, and the value range is 15 to 269 slots.

According to the TGL configured in step 502, if the TGL is less than or equal to 14 slots and a single hole is used, that is, there is only one transmission slot in the pattern, that is, TGL1, then TGD does not need to be configured. If the TGL is greater than 14slot, use double holes, that is, there are 2 transmission gaps in the pattern: TGL1, TGL2, then you need to configure TGD.

It should be noted that the value of TGD cannot be set too small to avoid overlapping of GAP1 and GAP2.

According to the provisions of the 25.133 protocol, in order to ensure that the transmission gaps of the compressed mode sequence will not overlap, the following principles must be followed:

(1) It is guaranteed that at least one of the three consecutive frames is not compressed.

(2) Ensure that the end time of GAP1 and the start time of GAP2 in two consecutive compressed frames differ by at least 8 time slots.

(3) It is better to configure two GAPs in adjacent radio frames, that is, to configure the value of TGD so that the difference between the start time of GAP2 and the end time of GAP1 is at least 15 time slots.

In order to meet the above conditions, make TGD>TGL1+15 (unit slot) and meet the following conditions:

If TGL2 is a transmission gap in single-frame mode, it is located in the middle of a frame; for a transmission gap in double-frame mode, it is best to be located in the middle of two frames.

Step 504: Determine whether there are multiple compressed mode sequences.

If not, go to step 505: the configuration ends.

If yes, proceed to step 506: respectively configure and adjust the ΔCFN of each compressed mode to meet the valid condition of the compressed mode sequence. Among them, ΔCFN refers to the time deviation of the last compressed mode pattern activated in the compressed mode pattern sequence relative to the activated previous compressed mode pattern, and the first compressed mode pattern does not need to be configured with ΔCFN.

Since more than one type of measurement is required when switching, there are multiple compressed mode patterns in the compressed mode sequence that is started. When entering a wireless frame, the same frame may be occupied by multiple compressed mode GAPs in the wireless frame, that is, the GAPs overlap. 3GPP stipulates that GAPs of compressed mode styles cannot overlap at any time, otherwise, conflicts will occur due to gaps generated by multiple compressed mode styles in the same wireless frame. As shown in FIG. 3 , a conflict occurs between compression modes. At the same time, in order to ensure the channel transmission quality during the start of the compressed mode sequence, 3GPP25.133 stipulates that the maximum number of continuous slots allowed is two frames. As shown in Figure 6, although the two compression mode patterns do not overlap, there are gaps in three consecutive frames.

In order to prevent the above situation, it is necessary to determine the start time of multiple compressed mode sequences, so as to form a complete set of compressed modes. In the present invention, the ΔCFN of each compressed mode sequence is determined by checking the validity of the compressed mode pattern.

The process of checking the validity of the compressed mode style is shown in Figure 8:

Firstly, in step 801, the least common multiple M1 of the lengths of multiple styles is found, and then considering the influence of ΔCFN of each style, taking the first style as the starting point, the deviation of the starting point of the second style relative to the starting point of the first style is ΔCfn1, the deviation between the starting point of the third style and the starting point of the second style is ΔCfn2, M2=ΔCfn1+ΔCfn2, that is, M2 is the deviation of the start time of the last style relative to the first style. The length of the style check is the least common multiple M1 plus M2.

Considering the situation shown in Figure 6: Although the least common multiple of the pattern period and the check length of ΔCFN do not conflict, but after checking the length, 3 consecutive frames are occupied, and the pattern check length needs to be added. A margin M3( M3>=N-1, N means that there cannot be "gap" in consecutive N frames, and M3=N-1 in the best case. For example, N=3 is stipulated in the 3GPP protocol recommendation, that is, it is not allowed to have "gap" in consecutive 3 frames Gap" exists, then M3 can be set to 2).

In this way, the pattern check length M=M1+M2+M3, M1 is the least common multiple of the pattern length, M2 is the deviation of the last pattern from the start time of the first pattern, M3 is to prevent the occurrence of continuous N frames being occupied, M3 >=N-1. Within the scope of the style check length, all conflict possibilities have been traversed, and the check at this time is the most sufficient.

Then, according to step 802, use a one-dimensional array X _i (i=0, ..., M) (wherein X _i is the value of the member whose subscript is i in the one-dimensional array) to represent the compressed mode sequence, and the subscript of the array is frame Number, mark the frame occupied by GAP, if the frame has GAP, fill in 1, if not, fill in 0.

With the visual representation above in place, checking for overlap is simple.

Starting from the 0 coordinate of the array, fill in the contents of the first style sequence in sequence until the specified length. Then go back to the beginning of the array and fill in the second and third pattern sequences. If a member of the array is found to be assigned a value of 1 twice during the filling process, it means that the GAP has overlapped, and the compression mode pattern is invalid.

That is, step 803: judging whether there is a conflict in the superimposed wireless frames, that is, whether a frame is marked twice or more than twice.

If it is found that a certain array member is assigned a value of 1 twice during the filling process, it means that the GAP has been overlapped, and the compression mode style is invalid. At this time, go to step 804: return failure.

Otherwise, it passes the pattern overlap check, and further checks whether there are consecutive N frames occupied by GAP,

Go to step 805: check whether the continuous GAP occupies more than two frames.

Here, the sliding window technique can be used as follows:

Utilize the formula Y _i =X _i +X _i+1 +...+X _i+N (i=0,...,MN), (wherein X _i is the value of the member whose subscript is i in the above-mentioned one-dimensional array, and M is Check the length, N means that there cannot be "gap" in consecutive N frames), get the second array Y, if the value of any array member in the Y array is greater than or equal to N, it means that there are consecutive N frames occupied by GAP, the The bar compression mode style is invalid, at this time, go to step 804: return failure.

Otherwise, it means that the configuration is successful, and go to step 806: exit the configuration process.

To further understand the sliding window technique, refer to Figure 7:

The wireless frame obtained by superimposing the compressed mode style 1 and the compressed mode style 2 in Figure 6 is shown in Figure 7 after being filled with 0 and 1 marks in an array within the check length 13 frames:

The 1st frame, 4th frame, 5th frame, 9th frame, 11th frame to 13th frame are 1, and the remaining bits are 0. The sliding window first starts from the 0 coordinate of the array, and adds the values of the array members in the window to get the value of the first member of the new data Y as 1, which is not equal to 3; move the window back one bit, and the array members in the window Values are added again, and the second member value of array Y is 1, which is not equal to 3; when it is added to the last array member, the last array member value of Y is 3, indicating that after the compression mode sequence is superimposed If the number of frames occupied by consecutive gaps exceeds two frames, the compression mode pattern sequence in this example is invalid, and the check is completed and exited.

In order to understand the process of checking the validity of the above-mentioned compressed mode pattern, the following describes in detail with reference to the two compressed mode sequences shown in FIG. 6 .

As shown in Figure 6, the two compressed mode sequences are:

Sequence 1: The length of the pattern is 8 frames, the first frame has a compressed gap, expressed as {1, 0, 0, 0, 0, 0, 0, 0}, 0 means no gap, 1 means there is a gap;

Sequence 2: The pattern length is 8 frames, and the 1st, 2nd, and 8th frames have compression gaps, expressed as {1, 1, 0, 0, 0, 0, 0, 1}.

The deviation ΔCFN of the second pattern relative to the first pattern is 3 frames.

First, determine the inspection length. The least common multiple M1 of the length of the two patterns is 8 frames, and the sum of the deviations of the second pattern relative to the first pattern M2 is 3 frames. Assuming that compression gaps are not allowed in consecutive 3 frames, M3 is equal to 2 frames, all style check length M=13 frames;

Then, use a one-dimensional array to mark the compressed mode style sequence, the length of the array X is 12, fill each compressed mode style sequence in the array in turn, and the final result is {1, 0, 0, 1, 1, 0, 0, 0, 1, 0, 1, 1, 1}, the array member has not been assigned multiple times, indicating that there is no GAP overlap, the overlap check of the style is passed, and the next step is checked;

Check whether there are 3 consecutive frames occupied by GAP, use a sliding window, the window size is 3, calculate the array Y={1, 1, 2, 2, 1, 0, 1, 1, 2, 2, 3}, in the array If there is a value greater than or equal to 3, it means that there are 3 consecutive frames occupied by GAP, and the compression mode is invalid.

When there are multiple compression mode sequences, the invalid compression mode styles need to be adjusted so that they can meet the effectiveness after adjustment.

The multi-sequence compression mode adjustment process is shown in Figure 9:

Step 901: Select the compression mode sequence to be adjusted, and configure the initial ΔCFN;

Assume that there are 3 compressed mode style sequences, the first one does not need to be configured with ΔCFN, and the other 2 compressed mode style sequences need to be configured with ΔCFN. The 2nd pattern sequence and the 1st pattern sequence configured first are valid, and then the 3rd pattern and the previous 2 patterns are adjusted to be valid. At the beginning, first adjust the ΔCFN of Article 2, and configure the initial ΔCFN1 to be equal to 1.

Step 902: Check the validity of the compressed mode pattern, and the specific checking process is shown in FIG. 5 .

Step 903: judging whether the current compression mode is valid;

If it is valid, enter step 905: judge whether all compressed mode pattern sequences have been adjusted;

If the adjustment is completed, go to step 906: end; otherwise, return to step 901, select the remaining compressed mode pattern sequence to be adjusted, and configure the initial ΔCFN.

If invalid, go to step 904: adjust ΔCFN, generally the adjustment step is 1 frame, ie ΔCFN=ΔCFN+1, of course, ΔCFN=ΔCFN+2 can also be set according to the actual situation.

Then, return to step 902: check the validity of the compressed mode pattern again.

Considering the usual GSM measurement, it is necessary to start three compressed mode sequences, which are respectively used to measure GSMCarrier RSSI, initial BSIC confirmation, and BSIC reconfirmation. Therefore, the following three compressed mode sequences are used as an example to describe in detail the TGL and TGL in the method of the present invention. The configuration process of these two parameters of TGPL.

The 25.133 agreement stipulates that the measurement period of GSM Carrier RSSI is 480ms, and requires that the RSSI value of each carrier frequency be sampled at least 3 times within the measurement period. If the UE cannot complete the sampling of all required GSM carrier frequencies within a measurement period of 480ms, the UE will measure as many GSM carrier frequencies as possible and ensure that each carrier frequency is sampled at least three times. Incomplete carrier frequency measurements will be completed in subsequent measurement cycles. This means that the period for the physical layer to report to the RRC (Radio Resource Control) layer may be a multiple of the measurement period of 480ms.

In order to be able to achieve the desired GSM RSSI measurement requirements, the effective measurement time available to the UE is equal to the length of the GAP minus the maximum allowable delay for the UE to switch from FDD frequency to GSM frequency and from GSM frequency back to FDD frequency and an additional margin.

The number of RSSI samples that the UE can perform during the transmission gap length TGL is shown in Table 1 below:

Table 1: TGL (time slot) Number of GSM carrier RSSI samples in each GAP 3 1 4 2 5 3 7 6 10 10 14 15

The TGL in the 3GPP protocol ranges from 1 to 14 time slots. The 25.133 protocol recommends that the TGL of the RSSI measurement compressed mode sequence can be 3, 4, 5, 7, 10, or 14 time slots, but no specific pattern has been determined. Since each carrier frequency needs to be sampled at least 3 times, it is not necessary to select a pattern in which TGL is equal to 3 or 4 time slots.

When TGL is equal to 5 or 7 time slots, only 1 carrier frequency can be measured (7 time slots can theoretically be sampled 6 times, assuming that each carrier frequency is sampled 3 times, then a maximum of 2 carrier frequencies can be measured, but due to compression There is a switching process between the uncompressed and uncompressed time slots, resulting in less than 7 actually measurable time slots).

If the pattern length TGPL is set to 3 frames, then (48/3)*1=16 carrier frequencies can be measured within the 480ms measurement period, that is, within 48 frames;

If TGPL is set to 8 frames, then (48/8)*1=6 carrier frequencies can be measured within a 480ms measurement period;

Assuming that the TGPL is 12 frames, then (48/12)*1=4 carrier frequencies can be measured within a 480 ms measurement period.

From the above analysis, it can be concluded that the relationship between TGL, TGPL and the number of measurement frequency points N of RSSI measurement compressed mode sequence is:

48/TGPL*F(TGL)＝3N (1)

Among them, F(TGL) is the relationship function of the measurable frequency point sampling number corresponding to TGL, see Table 1.

It can be seen from formula (1) that the number of measurable frequency points is directly proportional to TGL and inversely proportional to TGPL.

Therefore, the corresponding TGPL and TGL values can be configured according to the number of frequency points to be measured.

For the configuration of initial BSIC confirmation and BSIC re-confirmation compressed mode sequence, since the BSIC decoding is performed on several cells with the best RSSI, the cell environment can be mainly considered. For cells with statistical characteristics of slow movement, there are more For time measurement, a compressed mode sequence with a relatively short gap per unit time can be used. For a cell whose statistical characteristics are fast-moving, fast measurement is required, and a compressed mode sequence with a relatively large gap per unit time is required. The gap ratio refers to (TGL1+TGL2)/TGPL1, that is, the ratio of all transmission gap lengths within a transmission gap pattern length to the transmission gap pattern length.

Refer to the initial BSIC shown in Figure 10 to confirm the compressed mode void ratio and the simulation relationship diagram of the maximum measurement time:

It can be seen that the gap ratio is inversely proportional to the maximum measurement time, that is, the smaller the gap ratio, the less time for measurement and the longer the maximum time required for measurement, that is to say, it can only be used for slow moving users.

The compressed mode is configured according to the cells with different statistical characteristics. For example, the statistical characteristics of the cells can be divided into high speed, medium speed, and low speed according to the user speed characteristics of the cell coverage area. Of course, it can also be divided into multiple levels according to needs.

For example, according to the maximum measurement time division, set two thresholds: the high-speed threshold Tfast1 and the low-speed threshold Tslow1, as shown in Table 2 below:

Table 2: Measure the maximum time range Cell Speed Characteristics Compressed Mode Void Ratio >Tslow1 slow <Pslow1 >Tfast1 and <=Tslow1 medium speed <Pfast1 and >=Pslow1 <= Tfast1 fast ＞＝Pfast1

Tfast1 and Tslow1 are configurable. For cells with statistical characteristics of fast movement, the configured air gap ratio in compressed mode >= Pfast1; for cells with statistical characteristics of medium-speed movement, configured compressed mode air ratio For a cell characterized by slow movement, the configured air gap ratio in compressed mode is < Pslow1.

For example, Tfast1 can be set to 2 seconds, and Tslow1 can be set to 4 seconds. From Figure 10, it can be obtained that Pfast1 is 1.75, and Pslow1 is 0.85. That is, the compressed mode air gap ratio configured for a cell whose statistical characteristic is fast moving is greater than or equal to 1.75 time slots/frame, and the compressed mode air ratio configured for a cell whose statistical characteristic is slow moving is less than 0.85 time slot/frame. The compressed mode gap ratio configured for cells moving at a medium speed is between 1.75 and 0.85 slots/frame.

Refer to the BSIC re-confirmation compression mode void ratio and the simulation relationship diagram of the maximum measurement time shown in Figure 11:

It can also be seen that the gap ratio is inversely proportional to the maximum measurement time, that is, the smaller the gap ratio, the less time for measurement and the longer the maximum measurement time, which can only be used for slow moving users.

The compression mode is configured according to cells with different statistical characteristics. For example, the statistical characteristics of cells can be divided into high speed, medium speed, and low speed according to the user speed characteristics of the cell coverage area. Of course, it can be divided into multiple levels according to needs.

For example, according to the division of the maximum measurement time, set two thresholds: the high-speed threshold Tfast2 and the low-speed threshold Tslow2, as shown in Table 3 below:

table 3: Measure the maximum time range Cell Speed Characteristics Compressed Mode Void Ratio >Tslow2 slow <Pslow2 >Tfast2 and <=Tslow2 medium speed <Pfast2 and >=Pslow2 <= Tfast2 fast ＞＝Pfast2

Tfast2 and Tslow2 are configurable. For cells with statistical characteristics of fast movement, the configured air gap ratio in compressed mode >= Pfast2. For cells with statistical characteristics of medium-speed movement, the configured compressed mode air ratio For a cell characterized by slow movement, the configured air gap ratio in compressed mode is < Pslow2.

For example, Tfast2 can be set to 2 seconds, and Tslow2 can be set to 5 seconds. From Figure 10, it can be obtained that Pfast2 is 0.71 and Pslow2 is 1.4. That is, the compressed mode air gap ratio configured for a cell whose statistical characteristic is fast moving is greater than or equal to 1.4 time slots/frame, and the compressed mode air ratio configured for a cell whose statistical characteristic is slow moving is less than 0.71 time slot/frame. The compressed mode gap ratio configured for cells moving at a medium speed is between 1.4 and 0.71 slots/frame.

The configuration process of the above TGL and TGPL will be further explained through specific application examples below:

Assuming that GSM measurement needs to be started, there are 16 GSM neighbors in the current cell, and the statistical characteristics of the cell are medium-speed mobile cells. Three compressed mode patterns are used to measure GSM Carrer RSSI, initial BSIC confirmation, and BSIC reconfirmation.

First configure the compressed mode styles TGL1 and TGPL1 for measuring GSM Carrier RSSI:

According to formula (1), draw TGPL1=F(TGL1), although the protocol scope of TGPL1 is 1～144 frames, according to table 1, select TGPL1 to be equal to 15 frames, so TGL1 is equal to 14slots (time slot).

Then configure the compressed mode styles TGL2 and TGPL2 to measure the initial BSIC confirmation:

For the case of using multiple compressed mode sequences, try to make the TGPL of each compressed mode style equal, which can simplify the later configuration. For this example, the statistical characteristic of the cell is a medium-speed mobile cell, and the configured compressed mode air gap ratio is between 1.75 and 0.85 slots/frame. The maximum measurement time can be taken as an intermediate value of 3 seconds. According to Figure 10, the configured compressed mode air gap ratio is equal to 0.96 time slots/frame, then measure TGL2=0.96TGPL2 of the compressed mode style confirmed by the initial BSIC, and TGPL2=15 frames, then TGL2=0.96*15=14.4, the range of TGL is 3, 4, 5, 7, 10, or 14 time slots recommended by the protocol, and TGL2 is rounded to 14 time slots.

Finally configure the compressed mode styles TGL3 and TGPL3 to measure BSIC reconfirmation:

For this example, the statistical characteristic of the cell is a medium-speed mobile cell. For a cell with a statistical characteristic of medium-speed mobile, the compressed mode air gap ratio is between 1.4 and 0.71 slot/frame, and the maximum measurement time can be taken as the median 3.5 seconds, according to Figure 11, the configured compressed mode air gap ratio is equal to 0.85 time slot/frame, then measure the TGL3 of the compressed mode pattern confirmed by the initial BSIC=0.85TGPL3, TGPL3 is preferably 15 frames, then TGL3=0.85*15= 12.75, the TGL range is 3, 4, 5, 7, 10, or 14 time slots recommended by the protocol, and TGL3 is rounded to 14 time slots.

Of course, the present invention is not limited to the configuration of the above three compressed mode sequence parameters, and the configuration process when multiple compressed mode sequences are required is similar to the above process, and will not be repeated here.

For the TGL and TGPL configured by the above-mentioned application example, TGPL1=15, TGL1=14, TGPL2=15, TGL2=14, TGPL3=15, TGL3=14 of three compressed mode styles are obtained, then according to the configuration principle in step 503, TGSN1, TGSN2, and TGSN3 can be configured as 8 slots.

If the TGL is less than or equal to 14 slots and a single hole is used, that is, there is only one transmission slot in the pattern, that is, TGL1, then TGD does not need to be configured. If the TGL is greater than 14slot, use double holes, that is, there are 2 transmission gaps in the pattern: TGL1, TGL2, then you need to configure TGD.

When multiple compressed mode sequences are required, configure and adjust the ΔCFN corresponding to each compressed mode sequence to make all the sequences valid. In this way, the RNC (Radio Network Controller) can send these real-time configured compressed mode parameters to the base station and UE through signaling messages, so that they can use these compressed mode sequences to complete inter-frequency measurement or inter-system measurement, and switch according to the measurement results to the appropriate target area.

While the invention has been described by way of example, those skilled in the art will appreciate that there are many variations and changes to the invention without departing from the spirit of the invention, and it is intended that the appended claims cover such variations and changes without departing from the spirit of the invention.

Claims (10)

1, a kind of code division multiple access system compressed mode parameter configuration method, it is characterized in that, described method comprises steps: A. When the system needs to start the compressed mode, determine the number of required compressed mode sequences; B. Configure each compressed mode sequence parameter separately according to the network planning parameters. 2. The method according to claim 1, wherein said step B comprises: B1. Determine the transmission gap length and the transmission gap mode length of the compressed mode style according to the network planning parameters; B2. Configuring the transmission slot start slot number and transmission slot interval according to the determined transmission slot length and transmission slot pattern length; B3. When multiple compressed mode sequences are required, respectively configure and adjust the offset ΔCFN of each compressed mode sequence relative to the starting moment of the previously configured compressed mode sequence, so that it meets the valid condition of the compressed mode sequence. 3. The method according to claim 2, wherein the network planning parameters include: The number of inter-frequency or inter-system neighboring cells to be measured and the current wireless environment of the system cell. 4. The method according to claim 3, characterized in that the step B1 comprises: B11. Make the transmission gap length proportional to the number of inter-frequency or inter-system neighboring cells, and proportional to the moving speed of the system cell; B12. Make the length of the transmission gap pattern inversely proportional to the number of inter-frequency or inter-system neighboring cells, and inversely proportional to the moving speed of the system cell. 5. The method according to claim 2, characterized in that the step B3 comprises: B31. Select the configured compressed mode sequence respectively, and configure its initial ΔCFN, B32. Check the validity of the corresponding compressed mode sequence according to the initial ΔCFN; B33. Adjust the initial ΔCFN according to the inspection result. 6. The method according to claim 5, characterized in that the step B32 comprises: Determine the check length M=M1+M2+M3 of the compressed mode sequence, where, M1 is the least common multiple of all compressed mode sequence lengths, M2 is the deviation of the last compressed mode sequence configured relative to the first compressed mode sequence, M3 is to check the length margin, M3≥N-1, N means that there are gaps in N consecutive frames; performing a collision check on the compressed mode sequence within the check length; Checking the number of frames occupied by continuous gaps on the compressed mode sequence within the checking length; When the compressed mode sequence has no slot occupancy conflict and the number of consecutive slot occupancy frames is less than the allowed maximum number of consecutive slot occupancy frames, the compressed mode sequence is valid. 7. The method according to claim 5, characterized in that, the step B33 is specifically: When the compressed mode sequence selection to be adjusted is invalid, the initial ΔCFN is increased by a predetermined step. 8. The method according to claim 7, wherein the predetermined step size is 1 frame. 9. The method according to claim 1, wherein said step A comprises: When the target cell of the hard handover is an inter-frequency cell, a compressed mode sequence is required; When the target cell of the hard handover is a cell of a different system, multiple compressed mode sequences are required. 10. The method according to claim 2, wherein said step B further comprises: When the transmission gap of the compressed mode sequence is a single frame mode, the transmission gap is located in the middle of the frame; When the transmission gap of the compressed mode sequence is a double-frame mode, the transmission gap is located in the middle of the two frames.

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