CN112087796A - Single subband system downlink transmission control method and system - Google Patents

Abstract

The present application discloses a method and system for controlling downlink transmission in a single-subband system, wherein the method includes: for a UE currently occupying downlink resources, the base station sends the frame number according to the current downlink transmission number of frames and a preset downlink transmission frame number threshold value, Perform switch control on the guard interval mode of the UE, and notify the UE; when the guard interval mode of the UE is in the ON state, at each preset guard interval, skip the guard interval to perform downlink transmission; wherein, The guard interval is set according to a preset guard interval period, and the guard interval in each guard interval period at least partially overlaps with the preset paging period. By adopting the present invention, the enhanced coverage requirement of the terminal can be satisfied, and the influence on the uplink and downlink authorization and downlink traffic channel transmission of other terminals can be effectively reduced.

Description

Single subband system downlink transmission control method and system

technical field

The present invention relates to communication technology, in particular to a method and system for downlink transmission control in a single subband system.

Background technique

For a single-subband wireless private network communication system, the bandwidth of the subband is 25 kHz, the sub-carrier spacing is 2 kHz, and there are 11 sub-carriers in the sub-band. The radio frame period of the system is 25ms, which is divided into 5 subframes, which are sequentially numbered as subframes 0 to 4. Among them, subframe 0 is a downlink subframe, subframe 1 is a special subframe, and the others are uplink subframes. Taking subframe i as an example, the frame structure of the wireless private network is shown in FIG. 1 .

In the wireless private network system, the user searches for paging messages during the period of the subband where the user resides, and if a paging message is found and the current subband is idle, service processing is performed in the subband. In order to enhance the coverage level, the downlink control channel (PDCCH) and downlink shared channel (PDSCH) that carry downlink control information and downlink services transmit data in a time-domain repetition manner.

The period of PDCCH is T=PDCCH-NumRepetitions×PDCCH-StartF, where PDCCH-NumRepetitions is the maximum number of repetitions of PDCCH, in frame units, the values are {1, 2, 4, 8, 16, 32, 64, 128, 256, 512, 1024, 2048}, PDCCH-StartF is the number of frames occupied by the PDCCH for each transmission, and the values are {2, 4, 8, 16, 32, 48, 64}.

According to the downlink control information (DCI) indication of the downlink control channel, the terminal obtains the number of radio frames NF and the number of repetitions N _rep allocated to the PDSCH, and _performs resource allocation in the order of frequency domain first and then time domain. The number of PDSCH transmission frames is N=N _rep N _F . where N _F ={1...8}, N _rep ={1, 2, 4, 8, 16, 32, 64, 128, 192, 256, 384, 512, 768, 1024, 1536, 2048}.

In order to achieve the maximum 20dB coverage improvement requirement of a single subband system, the PDCCH and PDSCH of a UE need to be repeatedly transmitted for thousands of milliseconds. In the process of implementing the present invention, the applicant found that if the terminal of the single-subband communication system needs to enhance the coverage, the uplink and downlink grants and downlink traffic channel transmission of other UEs will be blocked, and the uplink resources will be wasted at the same time. The specific analysis is as follows:

If in the coverage enhancement scenario, the downlink resources will be continuously occupied by one UE. At this time, the downlink service transmission of other terminals, especially the UEs that do not need coverage enhancement, will be blocked, and the uplink grants of other UEs will also be blocked, resulting in uplink resources. of waste. If the terminal traffic is not large, the basic performance can be guaranteed and the coverage and delay requirements can be met. However, when the terminal channel quality is not good, the repetition time increases, which will cause a greater delay and affect the throughput of the system. Figure 2 shows a schematic diagram of PDCCH and PDSCH scheduling with enhanced coverage. It can be seen from Figure 2 that because the DL is occupied by one UE for a long time, the UL scheduling of other terminals cannot be performed, resulting in the UL being vacant for a long time. At the same time, this also makes it impossible to perform DL scheduling of other terminals.

SUMMARY OF THE INVENTION

In view of this, the main purpose of the present invention is to provide a single subband system downlink transmission control method and system, which can not only meet the enhanced coverage requirements of the terminal, but also can effectively reduce the uplink and downlink authorization and downlink traffic channel transmission of the enhanced coverage to other terminals. Impact.

In order to achieve the above object, the technical scheme proposed by the present invention is:

A single-subband system downlink transmission control method, comprising:

For a UE currently occupying downlink resources, the base station performs switch control on the guard interval mode of the UE according to the number of frames currently sent for downlink transmission and the preset number of frames to be sent for downlink transmission, and notifies the UE;

When the guard interval mode of the UE is in the ON state, each preset guard interval is skipped for downlink transmission; wherein, the guard interval is set according to the preset guard interval period, and the guard interval in each guard interval period At least partially overlaps with the preset paging cycle.

Preferably, the switching control of the guard interval mode includes:

If the number of frames to be sent in the current downlink transmission is greater than the threshold value of the number of frames to be sent in the downlink transmission, and the guard interval mode of the UE is in an off state, the guard interval mode of the UE is enabled;

If the number of frames currently sent in downlink transmission is not greater than the threshold value of the number of frames sent in downlink transmission, and the guard interval mode of the UE is in an on state, the guard interval mode of the UE is turned off.

Preferably, the guard interval in each guard interval period completely covers the paging period in this guard interval period.

Preferably, the guard interval in each guard interval period and the paging period in this guard interval period have the same starting position.

Preferably, the guard interval period is an integer multiple of the paging period.

A single-subband system downlink transmission control system, comprising:

The base station, for the UE currently occupying downlink resources, performs switch control on the guard interval mode of the UE according to the current number of transmission frames for downlink transmission and the preset threshold value of the number of transmission frames for downlink transmission, and notifies the UE;

The UE, when the guard interval mode of the UE is in the ON state, skips each preset guard interval to perform downlink transmission; wherein, the guard interval is set according to the preset guard interval period, and the guard interval in each guard interval period The interval overlaps at least partially with the preset paging cycle.

Preferably, the base station performs switch control on the guard interval mode, including:

If the number of frames to be sent in the current downlink transmission is greater than the threshold value of the number of frames to be sent in the downlink transmission, and the guard interval mode of the UE is in an off state, the guard interval mode of the UE is enabled;

If the number of frames currently sent in downlink transmission is not greater than the threshold value of the number of frames sent in downlink transmission, and the guard interval mode of the UE is in an on state, the guard interval mode of the UE is turned off.

Preferably, the guard interval in each guard interval period completely covers the paging period in this guard interval period.

Preferably, the guard interval in each guard interval period and the paging period in this guard interval period have the same starting position.

Preferably, the guard interval period is an integer multiple of the paging period.

To sum up, a method and system for controlling downlink transmission in a single subband system proposed by the present invention, by presetting periodically distributed guard intervals, monitoring downlink transmission volume in real time, and enabling downlink transmission when the downlink transmission volume is large Guard interval mode, when the downlink guard interval mode is turned on, the UE currently occupying downlink transmission resources cannot perform downlink transmission within the downlink guard interval, and other access UEs in the cell except the UE can use the guard interval. The PDCCH search for scheduling grants is performed within the paging cycle time period covered by the interval, which can not only meet the enhanced coverage requirements of the terminal, but also effectively reduce the impact of enhanced coverage on the uplink and downlink grants and downlink traffic channel transmissions of other terminals.

Description of drawings

1 is a schematic diagram of a frame structure of an existing wireless private network, taking subframe i as an example;

FIG. 2 is a schematic diagram of PDCCH and PDSCH scheduling with enhanced coverage;

3 is a schematic flowchart of a method according to an embodiment of the present invention;

FIG. 4 is a schematic diagram of a guard interval configuration in an embodiment of the present invention.

Detailed ways

In order to make the objectives, technical solutions and advantages of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

FIG. 3 is a schematic flowchart of a method according to an embodiment of the present invention. As shown in FIG. 3 , the downlink transmission control method for a single-subband system implemented by this embodiment mainly includes:

Step 301: For a UE currently occupying downlink resources, the base station switches the guard interval mode of the UE according to the number of frames currently sent for downlink transmission and a preset threshold of the number of frames to be sent for downlink transmission, and notifies the UE.

In this step, the difference from the existing random access scheme is that the base station needs to set the guard interval for the UE currently occupying downlink resources according to the number of frames currently sent for downlink transmission and the preset number of frames to be sent for downlink transmission. In order to control the UE not to occupy downlink resources in a certain downlink frame by turning on its guard interval mode when the UE occupies a lot of downlink resources, it can reduce the uplink and downlink authorization and downlink authorization of other terminals for enhanced coverage. The impact of downlink traffic channel transmission.

Preferably, the base station can use the strategy of enabling the downlink guard interval mode when the current UE's downlink transmission volume is relatively large, and perform switch control on the guard interval mode. Specifically, the following method can be used to perform switch control on the guard interval mode:

If the number of frames to be sent in the current downlink transmission is greater than the threshold value of the number of frames to be sent in the downlink transmission, and the guard interval mode of the UE is in an off state, the guard interval mode of the UE is enabled;

If the number of frames currently sent in downlink transmission is not greater than the threshold value of the number of frames sent in downlink transmission, and the guard interval mode of the UE is in an on state, the guard interval mode of the UE is turned off.

In the above switch control method, when the number of frames sent by the current downlink transmission is greater than the threshold value of the number of frames sent by the downlink transmission, it means that the amount of data transmitted by the UE currently occupying the downlink resources is large, which will seriously affect the data of other terminals. For uplink and downlink grants and downlink traffic channel transmission, it is necessary to enable the guard interval mode of the UE currently occupying downlink resources to reduce its impact on other UEs.

When the number of frames sent in the current downlink transmission is not greater than the threshold of the number of frames sent in the downlink transmission, it means that the amount of data transmitted by the UE currently occupying the downlink resources is not large, and the uplink and downlink authorization of other terminals will not be seriously affected at this time. and downlink traffic channel transmission, therefore, it is necessary to turn off the guard interval mode of the UE currently occupying downlink resources, so as to better meet the enhanced coverage requirement of the terminal.

In practical applications, the threshold value of the number of frames for downlink transmission can be set appropriately by those skilled in the art according to actual needs, as long as it can better reflect the impact of the amount of data transmitted by the UE currently occupying the downlink resources on other in the cell The degree of influence of the UE is sufficient to enable the guard interval mode of the UE in time to obtain the effect of reducing the influence of enhanced coverage on other UEs.

It should be noted here that when the guard interval mode of the UE is turned off, the downlink control is not performed on the UE currently occupying downlink resources, that is, the existing enhanced coverage mode may be used for normal transmission.

Step 302: When the guard interval mode of the UE is in an on state, skip each preset guard interval for downlink transmission; wherein, the guard interval is set according to a preset guard interval period, and in each guard interval period The guard interval at least partially overlaps with the preset paging cycle.

Here, when the guard interval mode of the UE is on, the UE needs to skip each preset guard interval for downlink transmission, that is to say, the UE will consider the guard interval in the guard interval period as an invalid frame and cannot Perform downlink transmission, so that the UE will give up the occupation of the guard interval, so that other UEs can use the time period overlapping the paging cycle in the guard interval to perform uplink and downlink authorization and downlink traffic channel transmission, that is, other UEs can The PDCCH search for the scheduling grant is performed within the paging cycle time period covered by the guard interval.

In this step, by making the guard interval in each guard interval period at least partially overlap with the preset paging period, it can be ensured that when the guard interval mode of the UE is in the ON state, other UEs can use the guard interval to communicate with the paging period. Uplink and downlink grants and downlink traffic channel transmissions are performed in overlapping time periods to reduce the impact of enhanced coverage on other accessed UEs.

In practical applications, those skilled in the art can set the length of the guard interval period and the relationship between the guard interval and the paging period in each interval period according to actual needs.

Preferably, in order to minimize the impact of enhanced coverage on other accessed UEs, the guard interval in each guard interval period may completely cover the paging period in this guard interval period.

Preferably, the guard interval in each guard interval period and the paging period in this guard interval period have the same starting position.

Further, in order to fully utilize the guard interval resources in each guard interval period, the guard interval in each guard interval period may be completely overlapped with the paging period in this guard interval period.

Preferably, the guard interval period may be an integer multiple of the paging period.

For example, the configuration shown in FIG. 4 may be adopted, the period of the guard interval is 4 times of the paging period, and the length of the guard interval is the length of one paging period.

Corresponding to the above method, an embodiment of the present invention further provides a single-subband system downlink transmission control system, including:

The base station, for the UE currently occupying downlink resources, performs switch control on the guard interval mode of the UE according to the current number of transmission frames for downlink transmission and the preset threshold value of the number of transmission frames for downlink transmission, and notifies the UE;

The UE, when the guard interval mode of the UE is in the ON state, skips each preset guard interval to perform downlink transmission; wherein, the guard interval is set according to the preset guard interval period, and the guard interval in each guard interval period The interval overlaps at least partially with the preset paging cycle.

Preferably, the base station performs switch control on the guard interval mode, including:

If the number of frames to be sent in the current downlink transmission is greater than the threshold value of the number of frames to be sent in the downlink transmission, and the guard interval mode of the UE is in an off state, the guard interval mode of the UE is enabled;

If the number of frames currently sent in downlink transmission is not greater than the threshold value of the number of frames sent in downlink transmission, and the guard interval mode of the UE is in an on state, the guard interval mode of the UE is turned off.

Preferably, the guard interval in each guard interval period completely covers the paging period in this guard interval period.

Preferably, the guard interval in each guard interval period and the paging period in this guard interval period have the same starting position.

Preferably, the guard interval period is an integer multiple of the paging period.

It can be seen from the above embodiments that the downlink transmission control method and system for a single-subband system proposed by the embodiments of the present invention pre-set periodically distributed guard intervals and monitor the downlink transmission volume in real time. When it is larger, the downlink guard interval mode is turned on. When the downlink guard interval mode is turned on, the UE currently occupying the downlink transmission resources cannot perform downlink transmission within the downlink guard interval. In this way, other UEs in the cell can perform normal operation within the downlink guard interval. Downlink paging space search and/or PDCCH search for scheduling grants can not only meet the enhanced coverage requirements of the terminal, but also effectively reduce the impact of enhanced coverage on uplink and downlink grants and downlink traffic channel transmissions of other terminals.

To sum up, the above are only preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included within the protection scope of the present invention.

Claims (10)

1. A downlink transmission control method of a single subband system is characterized by comprising the following steps:

for UE occupying downlink resources currently, a base station performs on-off control on a protection interval mode of the UE according to a sending frame number of current downlink transmission and a preset threshold value of the sending frame number of the downlink transmission, and notifies the UE;

skipping each preset guard interval to perform downlink transmission when the guard interval mode of the UE is in an open state; the guard interval is set according to a preset guard interval period, and the guard interval in each guard interval period is at least partially overlapped with a preset paging period.

2. The method of claim 1, wherein the switching the guard interval mode comprises:

if the sending frame number of the current downlink transmission is larger than the threshold value of the sending frame number of the downlink transmission and the protection interval mode of the UE is in a closed state, the protection interval mode of the UE is started;

and if the sending frame number of the current downlink transmission is not greater than the threshold value of the downlink transmission sending frame number and the protection interval mode of the UE is in an open state, closing the protection interval mode of the UE.

3. The method of claim 1, wherein a guard interval in each guard interval period completely covers a paging period in the guard interval period.

4. The method of claim 1 or 3, wherein the guard interval in each guard interval period and the paging period in the guard interval period have the same starting position.

5. The method of claim 1, wherein the guard interval period is an integer multiple of the paging period.

6. A downlink transmission control system for a single subband system, comprising:

the base station carries out on-off control on the protection interval mode of the UE according to the sending frame number of the current downlink transmission and a preset threshold value of the sending frame number of the downlink transmission for the UE occupying the downlink resource currently, and informs the UE;

the UE skips each preset guard interval to carry out downlink transmission when the guard interval mode of the UE is in an open state; the guard interval is set according to a preset guard interval period, and the guard interval in each guard interval period is at least partially overlapped with a preset paging period.

7. The system of claim 6, wherein the base station performs switching control on the guard interval mode, comprising:

if the sending frame number of the current downlink transmission is larger than the threshold value of the sending frame number of the downlink transmission and the protection interval mode of the UE is in a closed state, the protection interval mode of the UE is started;

and if the sending frame number of the current downlink transmission is not greater than the threshold value of the downlink transmission sending frame number and the protection interval mode of the UE is in an open state, closing the protection interval mode of the UE.

8. The system of claim 6, wherein the guard interval in each guard interval period completely covers the paging period in the guard interval period.

9. The system according to claim 6 or 8, wherein the guard interval in each guard interval period and the paging period in the guard interval period have the same starting position.

10. The system of claim 6, wherein the guard interval period is an integer multiple of the paging period.

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