CN106559908B

CN106559908B - Method and device for realizing listen before talk

Info

Publication number: CN106559908B
Application number: CN201510622254.1A
Authority: CN
Inventors: 苟伟; 毕峰; 赵亚军; 杨玲
Original assignee: ZTE Corp
Current assignee: ZTE Corp
Priority date: 2015-09-25
Filing date: 2015-09-25
Publication date: 2021-11-09
Anticipated expiration: 2035-09-25
Also published as: CN112584359A; CN106559908A; WO2017050060A1

Abstract

The invention discloses a method and a device for realizing listening before speaking, which comprises the following steps: the method comprises the steps that a station detects whether an unlicensed carrier is idle in a specified CCA time slot of an initial Clear Channel Assessment (CCA) stage; if not, generating a random backoff value; then the site detects whether the unauthorized carrier is idle in the first delay period, if so, the step of judging whether the random back-off value is equal to 0 is continuously executed; wherein the duration of the first delay period is [16+9 × (n + k) ] μ s, n is an integer greater than or equal to 1, k is an integer greater than or equal to 0, and when n is equal to 1, k is equal to 1. Through the scheme of the invention, the station executes the step of judging whether the random backoff value is equal to 0 or not when detecting that the unauthorized carrier wave is idle in the first delay period, and the first delay period is 34 mus when n is equal to 1, so that the fairness of competition with a WiFi system is improved.

Description

Method and device for realizing listen before talk

Technical Field

The present invention relates to the field of unlicensed carriers, and in particular, to a method and an apparatus for implementing Listen Before Talk (LBT).

Background

Currently, communication networks of Long Term Evolution (LTE) are all deployed in authorized carriers for operation, and with the development of LTE, some companies propose "to suggest research on the subject of LTE deployment in unlicensed carriers", for example, the companies in the united states in high traffic consider that: with the rapid growth of data traffic, licensed carriers will not be able to withstand the enormous amount of data brought about by the rapid traffic growth in the near future. It is considered that data volume pressure caused by service growth can be solved by deploying LTE in an unlicensed carrier so as to share data traffic in a licensed carrier. Meanwhile, the unlicensed carrier has the following characteristics: on one hand, the unauthorized carrier does not need to be purchased, or the carrier resources have zero cost, so the unauthorized carrier is free or low in cost; on the other hand, because individuals and enterprises can participate in deployment and equipment of equipment manufacturers can also be used, the admission requirement of the unauthorized carrier wave is low; furthermore, the unlicensed carrier has sharing property, and when a plurality of different systems are operated in the unlicensed carrier or different operators of the same system operate in the unlicensed carrier, some resource sharing modes can be considered to improve the carrier efficiency.

In summary, although LTE deployment has obvious advantages in unlicensed carriers, problems still exist in the deployment process; the method mainly comprises the following steps: the wireless access technology is multiple (different communication standards are crossed, the cooperation is difficult, the network topology is various) and the wireless access sites are multiple (the number of users is large, the cooperation difficulty is large, and the centralized management overhead is large). Due to the fact that multiple wireless access technologies exist, various wireless systems exist in unauthorized carriers, coordination among the wireless systems is difficult, and interference is serious. Therefore, for LTE deployment in unlicensed carriers, it is still necessary to support regulation of unlicensed carriers, and most countries require systems to support LBT mechanism when deployed in unlicensed carriers. Interference caused by simultaneous use of unlicensed carriers between adjacent systems to each other can be avoided through the LBT mechanism. And further enter a contention backoff mechanism, that is, neighboring system stations (generally, neighboring transmission nodes of the same system) can avoid interference caused when the neighboring transmission nodes of the same system use an unlicensed carrier at the same time through the contention backoff mechanism.

Currently, LTE is studying the deployment of LTE in unlicensed carriers (referred to as LAA systems), where most companies consider LAA systems to employ a contention-based fallback mechanism to enable preemption of the usage rights of unlicensed carriers. However, no method for determining the suitability of LAA system, especially considering the relative fairness of the contention mechanism of WiFi system, is disclosed in the present disclosure, which is a flow chart of the method for implementing LBT as shown in fig. 1, and the method substantially includes:

step 100, the station judges whether data needs to be sent, if so, step 101 is executed, and if not, step 100 is continuously executed.

Step 101, the station detects whether an unlicensed carrier is idle in a designated Clear Channel Assessment (CCA) slot of an initial CCA stage, if so, performs step 102, and if not, performs step 104.

In this step, the time of the designated CCA slot of the initial CCA phase may be 9 microseconds (μ s).

Step 102, the station detects whether the unauthorized carrier is idle in the delay period, if so, the step 103 is executed, and if not, the step 101 is returned to.

In this step, the delay period may be (16+9n) μ s, where n is an integer greater than or equal to 1.

Step 103, the station transmits a data packet and judges whether to continue transmission, if so, step 104 is executed, and if not, step 100 is returned.

Steps 100-103 are initial CCA phases.

And 104, generating a random backoff value N by the station.

In this step, the generated random backoff value N is in the range of [0, q-1 ].

Where q is the length of the contention window.

Wherein q can be adjusted in a dynamic or semi-static manner.

And 105, the station detects whether the unauthorized carrier is idle in the delay period, if so, the step 106 is executed, and if not, the step 105 is continuously executed.

Step 106, the station determines whether N is equal to 0, if yes, the step is returned to step 103, and if not, step 107 is executed.

Step 107, the station performs N-1, or does nothing.

Step 108, not sensing in the extended CCA slot, and executing step 105, or the station detects whether the unlicensed carrier is idle in the extended CCA slot, if so, returning to step 106, and if not, returning to step 105.

Steps 104-108 are extended CCA phases.

Wherein, when neither step 107 nor step 108 performs any action and returns to step 105 directly, a self-delay mechanism is implemented.

In the existing method for implementing LBT, if a station detects that an unlicensed carrier is idle in a CCA slot in an initial CCA stage, the station directly enters an extended CCA stage, if a generated N value is 0 and it is detected that the unlicensed carrier is idle in a delayed CCA period, and when a value of N is 1, the station only detects that 25 μ s is idle and performs data transmission, and a WiFi system needs to detect that 34 μ s is idle and performs data transmission, so the fairness of competition with the WiFi system is low.

Disclosure of Invention

In order to solve the above problems, the present invention provides a method and an apparatus for implementing listen before talk, which can improve the fairness of competition with the WiFi system.

In order to achieve the above object, the present invention provides a method for implementing listen before talk, comprising:

the method comprises the steps that a station detects whether an unauthorized carrier is idle in a specified CCA time slot of an initial CCA stage; if not, generating a random backoff value;

then the site detects whether the unauthorized carrier is idle in the first delay period, if so, the step of judging whether the random back-off value is equal to 0 is continuously executed; wherein the duration of the first delay period is [16+9 × (n + k) ] μ s, n is an integer greater than or equal to 1, k is an integer greater than or equal to 0, and when n is equal to 1, k is equal to 1.

Preferably, when it is detected that the unlicensed carrier is idle in a designated CCA slot of the initial CCA phase, the method further includes:

the station detects whether the unauthorized carrier is idle in a second delay period, if not, the station continues to execute the step of detecting whether the unauthorized carrier is idle in a specified CCA time slot of an initial CCA stage; wherein the duration of the second delay period is (16+9n) mus.

Preferably, when it is detected that the unlicensed carrier is idle for the second delay period, the method further includes:

and the station transmits a data packet and continuously executes the step of judging whether to continuously transmit.

Preferably, when n is greater than 1, k is equal to 0 or 1.

Preferably, the station detecting that the unlicensed carrier is idle in the first delayed CCA period includes:

the station sequentially detects (n + k) times of CCA time slots on the unauthorized carrier, if the (n + k) times of CCA time slots are detected to be idle, and then detects that the unauthorized carrier is idle within 16 mu s;

or, the station detects that the unlicensed carrier is idle within 16 μ s, then sequentially performs (n + k) times of detection of CCA slots on the unlicensed carrier, and if (n + k) times of detection are idle.

The invention also provides a method for realizing listen before talk, which comprises the following steps:

the method comprises the steps that a station detects whether an unlicensed carrier is idle in a specified idle channel assessment CCA time slot of an initial CCA stage; if not, generating a random backoff value;

and then the station detects whether the unauthorized carrier is idle in the CCA time slot, if so, detects whether the unauthorized carrier is idle in a second delay period or a third delay period, and if so, continuously executes the step of judging whether the random backoff value is equal to 0.

Preferably, before the station detects that an unlicensed carrier is idle in a designated CCA slot of an extended CCA phase, the method further includes:

and the station judges whether the random backoff value is equal to 0 or not, and when the random backoff value is judged to be equal to 0.

Preferably, when the station determines that the random backoff value is not equal to 0, the method further includes:

and the station executes the step of detecting whether the unauthorized carrier is idle in a second delay period.

Preferably, the duration of the second delay period is (16+9n) μ s, n is an integer greater than or equal to 1, and the duration of the third delay period is [16+9 × (n-1) ] μ s

The station detecting that the unlicensed carrier is idle in the second delay period or the third delay period includes:

the station sequentially detects the CCA time slots for n or (n-1) times on the unauthorized carrier, if the CCA time slots are detected for n or (n-1) times, the station detects that the unauthorized carrier is idle within 16 mu s;

or, the station detects that the unlicensed carrier is idle within 16 μ s, then sequentially performs n or (n-1) times of CCA time slot detection on the unlicensed carrier, and if idle is detected n or (n-1) times.

Preferably, when the station detects that the unlicensed carrier is busy in a designated CCA slot of the extended CCA phase, the method further includes:

the station continues to perform the step of detecting whether the unlicensed carrier is idle within a designated CCA slot of an extended CCA phase.

the station detects whether an unauthorized carrier is idle in a specified idle channel assessment CCA time slot of an initial CCA stage, and if not, a random backoff value is generated; wherein, the generated random backoff value is greater than or equal to 1 and less than or equal to q, and q is the size of the contention window;

then the site detects whether the unauthorized carrier is idle in a second delay period, if so, the step of judging whether the random back-off value is equal to 0 is continuously executed; the duration of the second delay period is (16+9n) mu s, and n is an integer greater than or equal to 1.

Preferably, when the station determines to continue to transmit the data packet, the random backoff value is greater than or equal to 0 and less than or equal to (q-1).

the method comprises the steps that a station detects whether an unauthorized carrier is idle in a specified CCA time slot of an initial clear channel assessment CCA stage, and if not, a random backoff value is generated;

the station adds 1 to the random backoff value;

then the site detects whether the unauthorized carrier is idle in a second delay period, if so, the step of judging whether the random backoff value added with 1 is equal to 0 is continuously executed; the duration of the second delay period is (16+9n) mu s, and n is an integer greater than or equal to 1.

and the station detects whether the unauthorized carrier is idle in a second delay period, and if not, the station continues to execute the step of detecting whether the unauthorized carrier is idle in a specified CCA time slot of an initial CCA stage.

and the station transmits a data packet and judges whether to continue transmission, if not, the step of judging whether data needs to be sent is continuously executed.

Preferably, when the station determines to continue transmitting the data packet, the method further includes:

and the site generates the random backoff value, detects that the unauthorized carrier is idle in the second delay period, and continuously executes the step of judging whether the random backoff value is equal to 0.

the station detects whether the unauthorized carrier is idle in a specified CCA time slot of an initial clear channel assessment CCA stage, if so, detects whether the unauthorized carrier is idle in a second delay period, and if not, generates a random backoff value; wherein, the duration of the second delay period is (16+9n) mus, and n is an integer greater than or equal to 1;

and the site detects whether the unauthorized carrier is idle in the second delay period, and if so, the step of judging whether the random backoff value is equal to 0 is continuously executed.

The invention also provides a device for realizing listen before talk, which at least comprises:

a first detecting module, configured to detect whether an unlicensed carrier is idle in a designated CCA slot of an initial clear channel assessment CCA stage, and if not, send a first notification message to a first generating module; detecting whether an unauthorized carrier is idle in a first delay period, if so, sending a second notification message to a first judgment module, wherein the duration of the first delay period is [16+9 × (n + k) ] μ s, n is an integer greater than or equal to 1, k is an integer greater than or equal to 0, and when n is equal to 1, k is equal to 1;

the first generation module is used for receiving the first notification message and generating a random backoff value;

and the first judging module is used for receiving the second notification message and continuously executing the step of judging whether the random backoff value is equal to 0.

Preferably, the first detection module is further configured to:

when detecting that the unlicensed carrier is idle in the designated CCA time slot of the initial CCA stage, detecting whether the unlicensed carrier is idle in a second delay period, and if not, continuing to execute the step of detecting whether the unlicensed carrier is idle in the designated CCA time slot of the initial CCA stage; wherein the duration of the second delay period is (16+9n) mus.

Preferably, the first detection module is further configured to:

when detecting that the unauthorized carrier is idle in the second delay period, sending a third notification message to a first sending module;

further comprising:

the first sending module is used for receiving the third notification message and transmitting a data packet;

the first judging module is further configured to:

and continuing to execute the step of judging whether to continue the transmission.

Preferably, the first detection module is specifically configured to:

the first generation module is used for detecting whether an unlicensed carrier is idle in a specified CCA time slot of an initial CCA stage, and if not, sending a second notification message to the first generation module; sequentially detecting (n + k) times of CCA time slots on the unauthorized carrier, and if the (n + k) times of CCA time slots are detected to be idle, detecting that the unauthorized carrier is idle within 16 mu s; or, the unlicensed carrier is detected to be idle within 16 μ s, then (n + k) times of CCA time slots are sequentially detected for the unlicensed carrier, and if (n + k) times of CCA time slots are detected to be idle, a third notification message is sent to the first determining module.

a second detecting module, configured to detect whether the unlicensed carrier is idle in a specified CCA slot of an initial clear channel assessment CCA stage, and if not, send a sixth notification message to a second generating module; detecting whether the unlicensed carrier is idle in a specified CCA time slot of the extended CCA stage, if so, detecting whether the unlicensed carrier is idle in a second delay period or a third delay period, and if so, sending a seventh notification message to a second judgment module;

the second generation module is used for receiving the sixth notification message and generating a random backoff value;

and the second judging module is used for receiving the seventh notification message and continuously executing the step of judging whether the random backoff value is equal to 0.

Preferably, the second judging module is further configured to:

judging whether the random backoff value is equal to 0, if so, sending an eighth notification message to the second detection module;

the second detection module is specifically configured to:

detecting whether the unlicensed carrier is idle in a specified CCA time slot of an initial CCA stage, and if not, sending a sixth notification message to a second generation module; and receiving a sixth notification message, detecting whether the unlicensed carrier is idle in a specified CCA time slot of the extended CCA stage, if so, detecting whether the unlicensed carrier is idle in a second delay period or a third delay period, and if so, sending a fifth notification message to the second judgment module.

Preferably, the second judging module is further configured to:

judging that the random backoff value is not equal to 0, and sending a seventh notification message to the second detection module;

the second detection module is further configured to:

and receiving the seventh notification message, and executing the step of detecting whether the unlicensed carrier is idle in a second delay period.

Preferably, the second detection module is specifically configured to:

detecting whether the unlicensed carrier is idle in a specified CCA time slot of an initial CCA stage, and if not, sending a fourth notification message to a second generation module; detecting whether an unauthorized carrier is idle in a designated CCA time slot of an extended CCA stage, if so, sequentially detecting the unauthorized carrier for n or (n-1) times of CCA time slots, if both n or (n-1) times of CCA time slots are detected, and then detecting that the unauthorized carrier is idle in 16 mu s; or, detecting that the unlicensed carrier is idle within 16 μ s, then sequentially performing n or (n-1) times of detection of CCA time slots on the unlicensed carrier, and if idle is detected n or (n-1) times, sending a fifth notification message to the second determination module.

Preferably, the second detection module is further configured to:

and detecting that the unlicensed carrier is busy in the specified CCA time slot of the extended CCA stage, and continuously executing the step of detecting whether the unlicensed carrier is idle in the specified CCA time slot of the extended CCA stage.

a third detecting module, configured to detect whether an unlicensed carrier is idle in a specified CCA slot of the initial clear channel assessment CCA stage, and if not, send an eighth notification message to the third generating module; detecting whether the unauthorized carrier is idle in the second delay period, and if so, sending a ninth notification message to a third judgment module; wherein, the duration of the second delay period is (16+9n) mus, and n is an integer greater than or equal to 1;

a third generating module, configured to receive the eighth notification message and generate a random backoff value; wherein, the generated random backoff value is greater than or equal to 1 and less than or equal to q, and q is the size of the contention window;

and the third judging module is used for receiving the ninth notification message and continuously executing the step of judging whether the random backoff value is equal to 0.

a fourth detecting module, configured to detect whether an unlicensed carrier is idle in a specified CCA slot of the initial clear channel assessment CCA stage, and if not, send a tenth notification message to the fourth generating module; detecting whether the unauthorized carrier is idle in a second delay period, and if so, sending an eleventh notification message to a fourth judgment module; wherein, the duration of the second delay period is (16+9n) mus, and n is an integer greater than or equal to 1;

a fourth generating module, configured to receive the tenth notification message and generate a random backoff value;

the calculation module is used for adding 1 to the random backoff value;

and the fourth judging module is used for receiving the eleventh notification message and continuously executing the step of judging whether the random backoff value added with 1 is equal to 0.

a fifth detecting module, configured to detect whether an unlicensed carrier is idle in a specified CCA slot of the initial clear channel assessment CCA stage, if so, detect whether the unlicensed carrier is idle in a second delay period, and if not, send a twelfth notification message to a fifth generating module; wherein, the duration of the second delay period is (16+9n) mus, and n is an integer greater than or equal to 1; detecting whether the unauthorized carrier is idle in a second delay period, if so, sending a thirteenth notification message to a fifth judgment module;

a fifth generating module, configured to receive the twelfth notification message and generate a random backoff value;

and a fifth judging module, configured to receive the thirteenth notification message, and continue to execute the step of judging whether the random backoff value is equal to 0.

calculating measurement quantity according to a detection result of whether the unauthorized carrier is idle in each preset period in the observation window;

and judging that the calculated measurement quantity is larger than a preset threshold, increasing the competition window, and realizing the process of listening before speaking by adopting the increased competition window.

Preferably, when it is determined that the calculated metric is less than or equal to the preset threshold, the method further includes:

and reducing the contention window or reducing the contention window to the minimum value, and realizing the process of listening before speaking by adopting the reduced contention window.

Preferably, the calculating the metric according to the detection result of whether the unlicensed carrier is idle in each preset period in the observation window includes:

determining the measurement quantity as the number of preset periods with a busy detection result, or the number of CCA time slots with a preset period, or the number of preset periods with a busy detection result and CCA time slots with a preset period, or the accumulated time length with a busy detection result, or the accumulated time length with a free detection result;

or the detection result is the ratio between the number of the preset cycles which are busy and the number of the CCA time slots in the observation window, or the detection result is the ratio between the number of the preset cycles which are busy and are CCA time slots and the number of the CCA time slots in the observation window, or the detection result is the ratio between the accumulated time length which is busy and the time length of the observation window, or the detection result is the ratio between the accumulated time length which is idle and the time length of the observation window.

Preferably, the method further comprises:

determining the priority level of listening before speaking according to the service quality grade of the service, and realizing the process of listening before speaking by adopting the parameters corresponding to the determined priority level;

and judging that the unauthorized carrier is not obtained for k1 times continuously by using the minimum contention window in the parameters corresponding to the determined priority level, or judging that the unauthorized carrier is obtained for k2 times in the initial CCA stage continuously by using the parameters corresponding to the determined priority level, and increasing the priority level of listening before speaking, wherein k1 and k2 are integers greater than or equal to 1.

Preferably, the method further comprises:

and judging the transmission discovery signal DRS, and adjusting the priority level of listening before speaking to the highest priority level.

Preferably, the method further comprises:

and judging that different physical channels are transmitted simultaneously, and adjusting the priority level of listening before speaking to the priority level corresponding to the physical channel with the highest service quality level.

the third calculation module is used for calculating the measurement quantity according to the detection result of whether the unauthorized carrier wave is idle in each preset period in the observation window;

the fifth judging module is used for judging that the calculated measurement quantity is greater than the preset threshold and sending a fifteenth notification message to the adjusting module;

and the adjusting module is used for receiving the fifteenth notification message, increasing the contention window and realizing the process of listening before speaking by adopting the increased contention window.

Preferably, the fifth judging module is further configured to:

judging that the calculated measurement quantity is less than or equal to the preset threshold, and sending a sixteenth notification message to the adjusting module;

the adjustment module is further configured to:

and receiving the sixteenth notification message, reducing the contention window or reducing the contention window to a minimum value, and implementing a listen before talk process by using the reduced contention window.

Preferably, the third computing module is specifically configured to:

Preferably, the method further comprises the following steps:

the determining module is used for determining the priority level of listening before speaking according to the service quality grade of the service and realizing the process of listening before speaking by adopting the parameters corresponding to the determined priority level;

the fifth judging module is further configured to:

judging that the unlicensed carrier is not obtained for k1 times continuously by using the minimum contention window in the parameters corresponding to the determined priority level, or judging that the unlicensed carrier is obtained in the initial CCA stage for k2 times continuously by using the parameters corresponding to the determined priority level, and sending a seventeenth notification message to the adjustment module; wherein k1 and k2 are integers greater than or equal to 1;

the adjustment module is further configured to:

and receiving the seventeenth notification message, and increasing the priority level of listening before speaking.

Preferably, the fifth judging module is further configured to:

judging a transmission discovery signal (DRS), and sending an eighteenth notification message to the adjusting module;

the adjustment module is further configured to:

and receiving the eighteenth notification message, and adjusting the priority level of listening before speaking to the highest priority level.

Preferably, the fifth judging module is further configured to:

judging that different physical channels are transmitted simultaneously, and sending a nineteenth notification message to the adjusting module;

the adjustment module is further configured to:

and receiving the nineteenth notification message, and adjusting the priority level of listening before speaking to the priority level corresponding to the physical channel with the highest service quality level.

judging whether data is to be sent in the buffer area or not, or when unauthorized carrier competition is carried out during multi-carrier aggregation or frequency reuse or uplink multi-user multiplexing, or judging whether a generated random back-off value is larger than or equal to a preset threshold value or whether the data arrives or after a determined time for sending the data is obtained, and allowing a self-delay mechanism to be executed.

Preferably, the number of times of executing the self-delay mechanism is less than or equal to the preset threshold value.

a sixth determining module, configured to determine that there is data to be sent in the buffer, or perform unauthorized carrier contention during multi-carrier aggregation, frequency reuse, or uplink multi-user multiplexing, or determine that a generated random backoff value is greater than or equal to a preset threshold, or determine that data arrives, or obtain a determined time for sending data, and then send a twentieth notification message to the executing module;

and the execution module is used for receiving the twentieth notification message and allowing the self-delay mechanism to be executed.

Compared with the prior art, the technical scheme of the invention comprises the following steps: the station detects whether an unlicensed carrier is idle in a specified CCA time slot of an initial CCA stage; if not, generating a random backoff value; the station detects whether the unauthorized carrier is idle in a first delay period, if so, the step of judging whether the random back-off value is equal to 0 is continuously executed; wherein the duration of the first delay period is [16+9 × (n + k) ] μ s, n is an integer greater than or equal to 1, k is an integer greater than or equal to 0, and when n is equal to 1, k is equal to 1. Through the scheme of the invention, the station executes the step of judging whether the random backoff value is equal to 0 or not when detecting that the unauthorized carrier wave is idle in the first delay period, and the first delay period is 34 mus when n is equal to 1, so that the fairness of competition with a WiFi system is improved.

Drawings

The accompanying drawings in the embodiments of the present invention are described below, and the drawings in the embodiments are provided for further understanding of the present invention, and together with the description serve to explain the present invention without limiting the scope of the present invention.

FIG. 1 is a flow chart of a prior art method of implementing listen before talk;

FIG. 2 is a flow chart of a method of implementing listen before talk in accordance with the present invention;

FIG. 3 is a flowchart of a method for implementing listen before talk according to a first embodiment of the present invention;

FIG. 4 is a flow chart of a method for implementing listen before talk according to a second embodiment of the present invention;

FIG. 5 is a flow chart of a method for implementing listen before talk according to a third embodiment of the present invention;

FIG. 6 is a flow chart of a method for implementing listen before talk according to a fourth embodiment of the present invention;

FIG. 7 is a flow chart of a method for implementing listen before talk in accordance with a fifth embodiment of the present invention;

FIG. 8 is a flowchart of a method for implementing listen before talk according to a sixth embodiment of the present invention;

FIG. 9 is a schematic structural diagram of a first device for implementing listen before talk according to the present invention;

FIG. 10 is a schematic structural diagram of a second device for implementing listen before talk according to the present invention;

FIG. 11 is a schematic structural diagram of a third device for listening before speaking according to the present invention;

FIG. 12 is a schematic diagram of a fourth embodiment of a listen-before-talk apparatus according to the present invention;

fig. 13 is a schematic structural diagram of a fourth device for implementing listen before talk according to the present invention.

Detailed Description

The following further description of the present invention, in order to facilitate understanding of those skilled in the art, is provided in conjunction with the accompanying drawings and is not intended to limit the scope of the present invention. In the present application, the embodiments and various aspects of the embodiments may be combined with each other without conflict.

Referring to fig. 2, the present invention provides a method for implementing LBT, including:

step 200, a station detects whether an unauthorized carrier is idle in a specified CCA time slot of an initial CCA stage; if not, a random backoff value is generated.

In this step, the station may be a device that transmits data using an unlicensed carrier, such as a base station, a mobile terminal, and the like.

In this step, how the station detects whether the unlicensed carrier is idle in the designated CCA slot of the initial CCA stage belongs to the known technology of those skilled in the art, and is not used to limit the protection scope of the present invention, and is not described here again.

In this step, when detecting that the unlicensed carrier is idle in the designated CCA slot of the initial CCA stage, the station detects whether the unlicensed carrier is idle in the second delay period, and if not, continues to perform the step of detecting whether the unlicensed carrier is idle in the designated CCA slot of the initial CCA stage; wherein the duration of the second delay period is (16+9n) mus.

When detecting that the unauthorized carrier is idle in the second delay period, the station transmits a data packet and continues to execute the step of judging whether to continue transmission.

Step 201, the station detects whether the unauthorized carrier is idle in the first delay period, and if so, continues to execute the step of judging whether the random backoff value is equal to 0.

In this step, the duration of the first delay period is [16+9 × (n + k) ] μ s, n is an integer greater than or equal to 1, k is an integer greater than or equal to 0, and when n is equal to 1, k is equal to 1.

Wherein k is equal to 0 or 1 when n is greater than 1.

The method for detecting that the unlicensed carrier is idle in the first delay period by the station comprises the following steps:

the station sequentially detects (n + k) times of CCA time slots for the unauthorized carrier, if the (n + k) times of CCA time slots are detected to be idle, and then detects that the unauthorized carrier is idle within 16 mu s;

or, the station detects that the unlicensed carrier is idle within 16 μ s, then sequentially performs (n + k) times of detection of the CCA slot on the unlicensed carrier, and if (n + k) times of detection of idle are performed.

That is, the station divides the duration of [16+9 × (n + k) ] μ s into (n + k) CCA slots and 16 μ s for detection, and when it is detected that the unlicensed carrier is busy in any one CCA slot or 16 μ s, the station considers that the unlicensed carrier is busy in the first delay period; the unlicensed carrier is considered to be idle for the first delay period when it is detected that the unlicensed carrier is idle for all CCA slots and 16 μ s.

When the station detects that the unauthorized carrier is busy in the first delay period, the station continues to execute the step of detecting whether the unauthorized carrier is idle in the first delay period.

In the method, the duration of the first delay period is set to [16+9 × (n + k) ] μ s, and when n is equal to 1, k is equal to 1, so that the station can be detected for 34 μ s when n is equal to 1, and the fairness of competition with the WiFi system is improved.

the method comprises the steps that a station detects whether an unauthorized carrier is idle in a specified CCA time slot of an initial CCA stage; if not, generating a random backoff value; and then the station detects whether the unauthorized carrier is idle in the appointed CCA time slot of the extended CCA stage, if so, detects whether the unauthorized carrier is idle in a second delay period or a third delay period, and if so, continuously executes the step of judging whether the random backoff value is equal to 0.

Wherein, the duration of the second delay period is (16+9n) μ s, n is an integer greater than or equal to 1, and the duration of the third delay period is [16+9 × (n-1) ] μ s.

Before the station detects that the unlicensed carrier is idle in the CCA slot, the method further includes:

When the station detects that the unlicensed carrier is busy in the designated CCA slot of the extended CCA phase, the station continues to execute the step of detecting whether the unlicensed carrier is idle in the designated CCA slot of the extended CCA phase.

And when the station judges that the random backoff value is not equal to 0, the station executes a step of detecting whether the unauthorized carrier is idle in a second delay period.

or, the station detects that the unlicensed carrier is idle within 16 μ s, and then sequentially performs n or (n-1) times of detection of the CCA time slots on the unlicensed carrier, if the idle is detected n or (n-1) times.

That is, the station divides the duration of (16+9n) μ s or [16+9 × (n-1) ] μ s into n or (n-1) CCA slots and 16 μ s for detection, and when detecting that the unlicensed carrier is busy in any one CCA slot or 16 μ s, considers that the unlicensed carrier is busy in the second delay period or the third delay period; when it is detected that the unlicensed carrier is idle in all CCA slots and 16 μ s, the unlicensed carrier is considered idle in the second delay period or the third delay period.

the station detects whether an unauthorized carrier is idle in a specified CCA time slot of an initial CCA stage, and if not, a random backoff value is generated; wherein, the generated random backoff value is greater than or equal to 1 and less than or equal to q, and q is the size of the contention window; and then the site detects whether the unauthorized carrier is idle in a second delay period, and if so, the step of judging whether the random backoff value is equal to 0 is continuously executed.

The duration of the second delay period is (16+9n) mu s, and n is an integer greater than or equal to 1.

And when the station judges that the data packet is continuously transmitted, the random back-off value is greater than or equal to 0 and less than or equal to (q-1).

After the method is adopted, the generated random backoff value is not equal to 0, so that the station at least needs to detect that the unauthorized carrier wave is idle in the second delay period and the extended CCA time slot to transmit the data packet, thereby improving the fairness of competition with WiFi.

the station detects whether an unauthorized carrier is idle in a specified CCA time slot of an initial CCA stage, and if not, a random backoff value is generated; the station adds 1 to the random backoff value; then the site detects whether the unauthorized carrier is idle in a second delay period, if so, the step of judging whether the random backoff value added with 1 is equal to 0 is continuously executed; the duration of the second delay period is (16+9n) mu s, and n is an integer greater than or equal to 1.

And if not, continuing to execute the step of detecting whether the unlicensed carrier is idle in the specified CCA time slot of the initial CCA stage.

When detecting that the unauthorized carrier is idle in the second delay period, the station transmits a data packet and judges whether to continue transmission, and if not, the station continues to execute the step of judging whether data needs to be sent.

When the station judges that the data packet is continuously transmitted, the station generates a random backoff value, detects that the unauthorized carrier is idle in the second delay period, and continuously executes the step of judging whether the random backoff value is equal to 0.

After the method is adopted, the generated random backoff value is added with 1 and then is not equal to 0, so that the station at least needs to detect that the unauthorized carrier wave is idle in the second delay period and the extended CCA time slot to transmit the data packet, thereby improving the fairness of competition with WiFi.

the station detects whether the unauthorized carrier is idle in a specified CCA time slot of an initial CCA stage, if so, detects whether the unauthorized carrier is idle in a second delay period, and if not, generates a random backoff value; wherein, the duration of the second delay period is (16+9n) mus, and n is an integer greater than or equal to 1; and the site detects whether the unauthorized carrier is idle in the second delay period, and if so, the step of judging whether the random backoff value is equal to 0 is continuously executed.

By the method, the station can enter the extended CCA stage after executing the detection of the second delay period, so that the process is saved, and the station obtains larger gain when the unauthorized load is heavier.

The process of the invention is illustrated in detail below by means of several specific examples.

First embodiment, referring to fig. 3, the method comprises:

step 300, the station judges whether data needs to be sent, if so, step 301 is executed, and if not, step 300 is continuously executed.

Step 301, the station detects whether an unlicensed carrier is idle in a designated CCA slot of the initial CCA stage, if so, step 302 is executed, and if not, step 304 is executed.

In this step, the duration of the designated CCA slot of the initial CCA stage may be 9 μ s.

Step 302, the station detects whether the unlicensed carrier is idle in the second delay period, if so, step 303 is executed, and if not, step 301 is returned to.

In this step, the second delay period may be (16+9n) μ s, where n is an integer greater than or equal to 1.

Step 303, the station transmits a data packet and determines whether to continue transmission, if so, step 304 is executed, and if not, step 300 is returned.

Steps 300-303 are initial CCA phases.

Step 304, the station generates a random backoff value N.

Where q is the length of the contention window.

Wherein q can be adjusted in a dynamic or semi-static manner.

Step 305, the station detects whether the unlicensed carrier is idle in the first delay period, if so, the step 306 is executed, and if not, the step 305 is continuously executed.

In this step, the duration of the first delay period may be [16+9 × (n + k) ] μ s, n is an integer greater than or equal to 1, k is an integer greater than or equal to 0, and when n is equal to 1, k is equal to 1.

Wherein k is equal to 0 or 1 when n is greater than 1.

Step 306, the station determines whether N is equal to 0, if yes, the process returns to step 303, and if not, step 307 is executed.

Step 307, the station performs N-1, or does nothing.

Step 308, do not sense in the extended CCA slot, and execute step 305, or the station detects whether the unlicensed carrier is idle in the extended CCA slot, if yes, return to step 306, and if not, return to step 305.

Steps 304-308 are extended CCA phases.

In a second embodiment, referring to fig. 4, the method comprises:

step 400, the station judges whether data needs to be sent, if so, step 401 is executed, and if not, step 400 is continuously executed.

Step 401, the station detects whether the unlicensed carrier is idle in a designated CCA slot of the initial CCA stage, if so, step 402 is executed, and if not, step 404 is executed.

In this step, the time of the CCA slot designated by the CCA stage may be 9 microseconds (μ s).

Step 402, the station detects whether the unlicensed carrier is idle in the second delay period, if so, step 403 is executed, and if not, the step 401 is returned to.

Step 403, the station transmits a data packet and determines whether to continue transmission, if so, step 404 is executed, and if not, step 400 is returned.

Steps 400-403 are initial CCA phases.

Step 404, the station generates a random backoff value N.

In this step, the random backoff N generated when entering the extended CCA phase from the initial CCA phase (i.e., entering step 404 from step 402) is within the range of [1, q ], and when entering the extended CCA phase from the non-initial CCA phase (i.e., entering step 404 from step 403), the random backoff N generated is within the range of [0, q-1 ].

Where q is the length of the contention window.

Wherein q can be adjusted in a dynamic or semi-static manner.

Step 405, the station detects whether the unlicensed carrier is idle in the second delay period, if so, step 406 is executed, and if not, step 405 is continuously executed.

In step 406, the station determines whether N is equal to 0, and if so, returns to step 403, and if not, executes step 407.

Step 407, the station performs N-1, or does nothing.

Step 408, not sensing in the extended CCA slot, and performing step 405, or the station detects whether the unlicensed carrier is idle in the extended CCA slot, if so, returning to step 406, and if not, returning to step 405.

Steps 404-408 are extended CCA phases.

A third embodiment, see fig. 5, the method comprises:

step 500, the station judges whether there is data to be sent, if yes, step 501 is executed, and if not, step 500 is continuously executed.

Step 501, the station detects whether an unlicensed carrier is idle in a designated CCA slot of the initial CCA stage, if so, step 502 is executed, and if not, step 504 is executed.

Step 502, the station detects whether the unlicensed carrier is idle in the second delay period, if so, step 503 is executed, and if not, step 501 is returned.

Step 503, the station transmits a data packet and determines whether to continue transmission, if so, step 504 is executed, and if not, step 500 is returned.

Steps 500-105 are initial CCA phases.

Step 504, the station generates a random backoff value N and adds 1 to N.

Where q is the length of the contention window.

Wherein q can be adjusted in a dynamic or semi-static manner.

And step 505, the station detects whether the unlicensed carrier is idle in the second delay period, if so, the step 506 is executed, and if not, the step 505 is continuously executed.

Step 506, the station determines whether N is equal to 0, if yes, the step 503 is returned, and if not, the step 507 is executed.

In step 507, the station performs N-1, or does nothing.

Step 508, do not sense in the extended CCA slot, and execute step 505, or the station detects whether the unlicensed carrier is idle in the extended CCA slot, if yes, return to step 506, and if not, return to step 505.

Steps 504-508 are extended CCA phases.

Fourth embodiment, referring to fig. 6, the method comprises:

step 600, the station judges whether data needs to be sent, if so, step 601 is executed, and if not, step 600 is continuously executed.

Step 601, the station detects whether the unlicensed carrier is idle in a designated CCA slot of the initial CCA stage, if so, performs step 602, and if not, performs step 604.

Step 602, the station detects whether the unlicensed carrier is idle in the second delay period, if so, performs step 603, and if not, performs step 604.

Step 603, the station transmits a data packet and determines whether to continue transmission, if so, step 604 is executed, and if not, step 600 is returned.

Steps 600-603 are initial CCA phases.

Step 604, the station generates a random backoff value N.

Where q is the length of the contention window.

Wherein q can be adjusted in a dynamic or semi-static manner.

Step 605, the station detects whether the unlicensed carrier is idle in the second delay period, if so, step 606 is executed, and if not, step 605 is continuously executed.

Step 606, the station determines whether N is equal to 0, if yes, returns to step 603, and if not, executes step 607.

Step 607, the station performs N-1, or does nothing.

Step 608, do not sense in the extended CCA slot, and execute step 605, or the station detects whether the unlicensed carrier is idle in the extended CCA slot, if yes, return to step 606, and if not, return to step 605.

Steps 604-608 are extended CCA phases.

In a fifth embodiment, referring to fig. 7, the method comprises:

step 700, the station determines whether there is data to be sent, if so, step 701 is executed, and if not, step 700 is continuously executed.

Step 701, the station detects whether an unlicensed carrier is idle in a designated CCA slot of the initial CCA stage, if so, performs step 702, and if not, performs step 704.

Step 702, the station detects whether the unlicensed carrier is idle in the second delay period, if so, step 703 is executed, and if not, step 701 is returned to.

And step 703, the station transmits a data packet and judges whether to continue transmission, if so, step 711 or step 704 is executed, and if not, the step 700 is returned.

Steps 700-703 are initial CCA phases.

Step 704, the station generates a random backoff value N.

Where q is the length of the contention window.

Wherein q can be adjusted in a dynamic or semi-static manner.

Step 705, the station determines whether N is equal to 0, if yes, step 706 is executed, and if not, step 707 is executed.

Step 706, the station detects whether the unlicensed carrier is idle in the designated CCA slot of the extended CCA phase, if so, step 707 is executed, and if not, step 706 is continuously executed.

And step 707, the station detects whether the unlicensed carrier is idle within the second delay period, if so, executes step 708, and if not, continues to execute step 707.

Step 708, the station determines whether N is equal to 0, if yes, the step 703 is returned, and if not, step 709 is executed.

Step 709, the station performs N-1, or does nothing.

Step 710, do not sense in the extended CCA slot, and execute step 707, or the station detects whether the unlicensed carrier is idle in the extended CCA slot, if yes, return to step 708, and if not, return to step 707.

Steps 704-710 are extended CCA phases.

In step 711, the station generates a random backoff value N and continues to step 707.

Sixth embodiment, referring to fig. 8, the method comprises:

step 800, the station judges whether data needs to be sent, if so, step 801 is executed, and if not, step 800 is continuously executed.

Step 801, the station detects whether an unlicensed carrier is idle in a designated CCA slot of the initial CCA stage, if so, step 802 is executed, and if not, step 804 is executed.

Step 802, the station detects whether the unlicensed carrier is idle in the second delay period, if so, the step 803 is executed, and if not, the step 801 is returned to.

Step 803, the station transmits a data packet and determines whether to continue transmission, if so, step 810 or step 804 is executed, and if not, step 700 is executed.

Steps 800-803 are initial CCA phases.

And step 804, the station generates a random backoff value N.

Where q is the length of the contention window.

Wherein q can be adjusted in a dynamic or semi-static manner.

Step 805, the station detects whether the unlicensed carrier is idle in the designated CCA slot of the extended CCA phase, if so, executes step 806, and if not, continues executing step 805.

Step 806, the station detects whether the unlicensed carrier is idle in the second delay period, if so, step 807 is executed, and if not, step 806 is continuously executed.

In step 807, the station determines whether N is equal to 0, and if so, returns to step 803, and if not, performs step 808.

Step 808, the station performs N-1, or does nothing.

Step 809, not sensing in the extended CCA slot, and executing step 806, or the station detects whether the unlicensed carrier is idle in the extended CCA slot, if so, returning to step 807, and if not, returning to step 806.

Steps 804 to 809 are extended CCA phases.

In step 810, the station generates a random backoff value N and continues to perform step 806.

The first to sixth embodiments may be used in combination.

Referring to fig. 9, the present invention also provides an apparatus for implementing listen before talk, which at least includes:

a first detecting module, configured to detect whether an unlicensed carrier is idle in a designated CCA slot of an initial CCA stage, and if not, send a first notification message to a first generating module; detecting whether an unauthorized carrier is idle in a first delay period, if so, sending a second notification message to a first judgment module, wherein the duration of the first delay period is [16+9 × (n + k) ] μ s, n is an integer greater than or equal to 1, k is an integer greater than or equal to 0, and when n is equal to 1, k is equal to 1;

The functions of the first determining module, the first detecting module and the first generating module may be implemented by the processor executing the program/instruction stored in the memory, or may be implemented by firmware/logic circuit/integrated circuit.

In the apparatus of the present invention, the first detecting module is further configured to:

detecting whether the unauthorized carrier is idle in a second delay period, if not, continuing to execute the step of detecting whether the unauthorized carrier is idle in a specified CCA time slot of an initial CCA stage; wherein the duration of the second delay period is (16+9n) mus.

further comprising:

the first judging module is further configured to:

In the apparatus of the present invention, the first detection module is specifically configured to:

the first generation module is used for detecting whether an unlicensed carrier is idle in a specified CCA time slot of an initial CCA stage, and if not, sending a second notification message to the first generation module; sequentially detecting (n + k) times of CCA time slots on an unauthorized carrier, if the (n + k) times of CCA time slots are all detected to be idle, and then detecting that the unauthorized carrier is idle within 16 mu s; or, the unlicensed carrier is detected to be idle within 16 μ s, then (n + k) times of detection of CCA time slots are sequentially performed on the unlicensed carrier, and if (n + k) times of detection are idle, a third notification message is sent to the first determining module.

Referring to fig. 10, the present invention also provides an apparatus for implementing listen before talk, which at least includes:

a second detecting module, configured to detect whether an unlicensed carrier is idle in a designated CCA slot in the initial CCA stage, and if not, send a fourth notification message to the second generating module; detecting whether the unauthorized carrier is idle in the extended CCA time slot, if so, detecting whether the unauthorized carrier is idle in a second delay period or a third delay period, and if so, sending a fifth notification message to a second judgment module;

the second generation module is used for receiving the fourth notification message and generating a random backspacing value;

and the second judging module is used for receiving the fifth notification message and continuously executing the step of judging whether the random backoff value is equal to 0.

The functions of the second judging module, the second detecting module and the second generating module may be implemented by the processor executing the program/instruction stored in the memory, or may be implemented by firmware/logic circuit/integrated circuit.

In the apparatus of the present invention, the second determining module is further configured to:

the second detection module is specifically configured to:

the second detection module is further configured to:

In the apparatus of the present invention, the second detection module is specifically configured to:

detecting whether the unlicensed carrier is idle in a specified CCA time slot of an initial CCA stage, and if not, sending a fourth notification message to a second generation module; detecting whether an unauthorized carrier is idle in a designated CCA time slot of an extended CCA stage, if so, sequentially detecting the CCA time slot of n or (n-1) times for the unauthorized carrier, if both n or (n-1) times detect idle, and then detecting that the unauthorized carrier is idle in 16 mu s; or, the unlicensed carrier is detected to be idle within 16 μ s, then the detection of the CCA time slots is performed n or (n-1) times in sequence on the unlicensed carrier, and if the idle is detected n or (n-1) times, a fifth notification message is sent to the second judgment module.

In the apparatus of the present invention, the second detecting module is further configured to:

Referring to fig. 11, the present invention also provides an apparatus for implementing listen before talk, which at least includes:

a third detecting module, configured to detect whether an unlicensed carrier is idle in a specified CCA slot in the initial CCA stage, and if not, send an eighth notification message to the third generating module; detecting whether the unauthorized carrier is idle in the second delay period, and if so, sending a ninth notification message to a third judgment module; wherein, the duration of the second delay period is (16+9n) mus, and n is an integer greater than or equal to 1;

The functions of the third judging module, the third detecting module and the third generating module may be implemented by the processor executing the program/instruction stored in the memory, or may be implemented by firmware/logic circuit/integrated circuit.

Referring to fig. 12, the present invention also provides an apparatus for implementing listen before talk, which at least includes:

a fourth detecting module, configured to detect whether an unlicensed carrier is idle in a specified CCA slot in the initial CCA stage, and if not, send a tenth notification message to the fourth generating module; detecting whether the unauthorized carrier is idle in a second delay period, and if so, sending an eleventh notification message to a fourth judgment module; wherein, the duration of the second delay period is (16+9n) mus, and n is an integer greater than or equal to 1;

the calculation module is used for adding 1 to the random backoff value;

The functions of the fourth judging module, the fourth detecting module, the fourth generating module and the calculating module can be realized by the processor executing the program/instruction stored in the memory, and can also be realized by firmware/logic circuit/integrated circuit.

Referring to fig. 13, the present invention also provides an apparatus for implementing listen before talk, which at least includes:

a fifth detecting module, configured to detect whether an unlicensed carrier is idle in a specified CCA slot of the initial CCA stage, if so, detect whether the unlicensed carrier is idle in a second delay period, and if not, send a twelfth notification message to a fifth generating module; wherein, the duration of the second delay period is (16+9n) mus, and n is an integer greater than or equal to 1; detecting whether the unauthorized carrier is idle in a second delay period, if so, sending a thirteenth notification message to a fifth judgment module;

The functions of the fifth judging module, the fifth detecting module and the fifth generating module may be implemented by the processor executing the program/instruction stored in the memory, or may be implemented by firmware/logic circuit/integrated circuit.

The invention provides eight ways to implement the process of listening before speaking, which is described in detail below.

Mode 1 concept description

Based on the flowchart illustrated in fig. 1, when the duration of the delay period in the initial CCA stage is set to (16+ n × 9) us, the duration of the delay period in the extended CCA is set to (16+ (n + k) × 9) us (here, the duration is merely shown, and the front and back orders of n CCA slots of 9us and 16-use CCA detection are not distinguished). Wherein n is a positive integer and k is 0 or a positive integer.

For n equal to 1, setting the time length of the delay period in the extended CCA, and setting k to be only 1. This can overcome the requirement in fig. 1 that the idle duration in the unlicensed carrier is not less than 34us before the station sends data for the first time (or before the station obtains the access right of the unlicensed carrier). If not, then in the following case, a situation occurs in which the station does not satisfy the above conditions. For example, N of the delay period is configured to be 1, when the station performs an initial CCA, the CCA detection of one slot is busy, the station enters an extended CCA stage, randomly generates a backoff value N, where N is exactly 0, and then performs the CCA detection of the delay period, where if the CCA detection of the delay period is idle, the station may obtain the usage right of the unlicensed carrier. The total duration of the idle of the unlicensed carriers experienced by the station at this time is the duration of the idle of the delay period, which is (16+1 × 9) us (i.e. 25 us). After the above parameter configuration is adopted, the flow of the station is not changed, but since the duration of the delay period of the extended CCA stage is (16+ (1+1) × 9) us (i.e., 34us), the total duration of the unlicensed carriers experienced by the station at this time is the duration of the idle of the delay period, which is (16+ (1+1) × 9) us (i.e., 34 us). The requirements are met, and therefore the fairness of the LAA system and the wifi system in competition is guaranteed.

The above setting may always exist regardless of whether n is 1.

Or the above setting may be set only for the case where n is 1. Thus, when n is greater than 1, the station allows setting k in the delay period in the extended CCA to 0 or 1.

Mode 2 concept description

The problem to be solved is described in mode 1.

Based on the flowchart 1, when the station performs the extended CCA phase, the generation range of N is limited to [1 to q ]. This avoids the case where N is randomly generated to be 1, and also overcomes the above problem. In order not to affect the effect of entering the extended CCA phase from other entries, it may be that when a station enters the extended CCA phase from the non-initial CCA, the station randomly generates N in the range of [0 to q-1], and the limit N from the initial CCA entering the extended CCA phase generates N in the range of [1 to q ]. Of course, the value range of N may also be limited to [1 to q ] for all entering the extended CCA stage.

Mode 3 concept description

Again based on the flow chart 1. After generating a random backoff N value for a station, the station performs N-N +1 and then uses the new N value as the N value of the random backoff. Likewise, stations are allowed to limit the generation range of N to [ 0-q-1 ] and not to perform N +1 when a station enters the extended CCA phase from a non-initial CCA. Likewise, when the station enters the extended CCA phase from the initial CCA phase, the station limits the generation range of the N value to [0 to q-1], and performs N ═ N + 1.

Description of concept of mode 4

Referring to fig. 6, based on fig. 1, approach 4 is modified for the initial CCA phase in fig. 1.

The station starts with whether or not to transmit a data unit, and if data transmission is required, the station performs a CCA slot detection,

if the detection is idle, entering a delay period CCA detection, and if the delay period CCA detection is idle, starting the station to transmit data; and if the CCA detection in the delay period is busy, the station enters an extended CCA stage.

And when the station is detected to be busy, the station enters an extended CCA stage.

Other flows may refer to fig. 1.

Compared with the existing flow of fig. 1, when one CCA slot detection in the initial CCA stage is idle, in the method 4, the station may enter the extended CCA stage only by performing one CCA slot detection for a delay period, whereas in fig. 1, after the station performs one CCA slot detection for a delay period, it is determined whether the station may enter the extended CCA stage only by performing one CCA slot detection for a delay period. Obviously, the mode 4 is faster, and this characteristic will obtain a larger gain in case of a heavy unauthorized load.

Mode 5 concept description

Still, modifications are made based on the procedure of fig. 1, mainly aiming at the extended CCA phase, to overcome the problem mentioned in mode 1.

Referring to fig. 7, based on the flowchart of fig. 1, when a station enters an extended CCA phase, the station generates a value N of a random backoff, determines whether N is 0,

when N is equal to 0, the station executes CCA time slot (slot) detection, and when the station is detected to be idle, the station enters into the CCA detection of a delay period; and when the detection is busy, the station continues to perform CCA detection of the one time slot.

And when N is not 0, the station enters the CCA detection of the delay period.

The above approach is directed to a station entering an extended CCA phase from an initial CCA. Of course, other ways of entering the extended CCA phase are also applicable. However, for entering the extended CCA phase in other ways, the present application also provides a preferable option that, when the station enters the extended CCA from the non-initial CCA phase, the station directly enters the delay period CCA detection after generating the N value of the random backoff (this procedure is not illustrated in fig. 3).

Other flows may refer to fig. 1.

With this flow, the problem mentioned in the mode 1 can be overcome.

Mode 6 concept description

Referring to fig. 8, based on the flowchart of fig. 1, a station enters an extended CCA phase, the station generates an N value of a random backoff, the station performs a CCA slot detection, and when the station detects idle, the station enters a delayed period CCA detection. When the detection is busy, the station repeatedly performs the detection of the one CCA slot.

The above approach is directed to a station entering an extended CCA phase from an initial CCA. Of course, other ways of entering the extended CCA phase are also applicable. However, for entering the extended CCA phase in other ways, the present application also provides a preferable option that, when the station enters the extended CCA from the non-initial CCA phase, the station directly enters the delay period CCA detection after generating the N value of the random backoff (this procedure is not illustrated in fig. 4).

Other flows may refer to fig. 1.

In the method 6, the station detection time can be shortened compared to the method 1. For example, in fig. 1, after the station generates the random backoff N value, the station directly performs CCA detection for a delay period, where the duration of one delay period is (16+ N × 9) us, and the station needs to detect the longest (16+ N × 9) us before obtaining whether to be idle, or at least needs to perform detection of 16us before obtaining to obtain whether to be idle, so as to determine whether to enter the next link. In the method 6, only one CCA slot (9us) needs to be detected to determine whether the CCA slot is idle, so as to determine whether to perform the next procedure. Obviously, the method 6 can lead the conclusion whether to enter the next link or not in advance, so that the whole detection time can be shortened, and the spectrum efficiency is indirectly improved.

Mode 6 can also overcome the problem mentioned in mode 1.

Mode 7 concept description

Conventionally, according to the flowchart 1, the duration of the delay period CCA in the extended CCA is (16+ n × 9) us. As for the mode 7, based on the flow structure of the mode 6 (fig. 4), the station configuration in the mode 7 reduces the CCA duration of the delay period by one 9us CCA slot, and at this time, the reduced 9us CCA slot may be regarded as a CCA slot placed before the delay period instead of the CCA slot.

The mode 7 has a feature that the mode 6 shortens the detection time.

Other flows may refer to fig. 1.

Mode 8 concept description

The delay period in the extended CCA is defined as (n x 9+16) us, where 9 represents one CCA slot and 16 represents one 16us CCA detection. Thus, the delayed period CCA detection in extended CCA becomes: executing n CCA slots, if all the CCA slots are idle, then executing a CCA detection of 16us, if the CCA slots are idle, the CCA detection in the whole delay period is idle. If any CCA slot is detected to be busy, the CCA slot can be considered to be busy in the delay period.

Mode 8 directly employs the flow of fig. 1. In this way, mode 8 can also achieve efficiency in shortening the detection time.

The above-described modes 1 to 8 can be used in combination without conflict.

Example 1

A structure of delay period. The structure consists of n consecutive 9us CCA slots followed by a 16us CCA detection.

When the station detects that n slots are idle and that 16us CCA detects idle, the CCA detection in the delay period is idle. And when the station detects that any CCA slot is busy, the station considers that the CCA detection in the delay period is busy. At which point the station may immediately begin the next CCA slot detection. That is, when a station can determine that a CCA slot being detected is busy, the station will immediately perform the next CCA slot detection, thereby shortening the time.

Example 2

Based on the existing flowchart 1, the configuration in the delay period of the extended CCA stage and the delay period of the initial CCA stage are both performed according to the structure of 16us + n × 9 us. In this embodiment, it is proposed to modify the inside of the delay period of the extended CCA phase. For example, the arrangement of the delay periods in this case is performed in a structure of n × 9us +16 us. The remaining unexhausted flows still use scheme 1. Where n × 9us denotes that there are n CCA slots of 9us, and 16us denotes that a CCA detection of 16us duration is performed.

Thus, the method 8 is realized, the whole detection time of listening before speaking is favorably shortened, the saved time can be used for transmitting data, and the frequency spectrum efficiency is improved.

Example 3

Based on the existing flowchart 1, when a station configures/selects CCA detection with a delay cycle duration of an initial CCA stage of 16us +9us, then the station correspondingly configures/selects a CCA detection with a delay cycle duration of an extended CCA stage of 16us +9us +9 us. And may be used only when the value N randomly generated for the station is 0 (other values of N may be used, and it is most efficient when N is 0). The remaining steps still follow the flow chart of fig. 1.

If the time length of the delay period of the station configuration/selection initial CCA phase is 16us +9us +9us, the time length of the delay period of the station configuration/selection extended CCA phase is 16us +9us +9us (since n is not 1, the time length equal to the delay period of the initial CCA phase may be configured) or 16us +9us +9us +9us (this always remains 9us longer than the delay period of the initial CCA phase).

Thus, the object of embodiment 1 can be achieved.

The application also provides a counting rule for adaptively adjusting the size of the LBT contention window.

The basic idea is that during LBT, when a time slot is not observed, the station is not idle (i.e. busy) for the time slot according to the unlicensed carrier in the time slot.

When the station calculates the parameter for adjusting the size of the LBT contention window, the busy status of the timeslot is not used as the basis for increasing or decreasing the parameter.

Wherein the parameters are: the number of busy slots, or the number of busy cycles.

Further, the busy period is defined as: the total amount of time between two free slots that an unlicensed carrier is detected to be busy (The total amount of time between two free slots that The unlicensed carrier decreases while The medium is determined to be busy), or an equivalent definition: a set of CCA slots that are continuously busy.

Further, when the station calculates a parameter for adjusting the size of the LBT contention window, the busy state of the timeslot is not used as a basis for increasing or decreasing the parameter, and specifically includes: for the number of time slots with the parameter busy, the time slot is not counted as busy time slot, and the number of busy time slots is not increased or decreased. For the number of cycles for which the parameter is busy, the slot is not counted as a busy cycle or a fraction of a busy cycle.

Further, the timeslot exists as a CCA timeslot in the station observation window, and is counted in the number of CCA timeslots. Or the time slot is not taken as a CCA time slot in the observation window, and the number of the CCA time slots is not counted. Or the time duration of the time slot is not part of the time duration of the observation window.

Further, the calculation formula for calculating the contention backoff window size includes:

mode 1: the measurement amount is the number of busy periods;

mode 2: the measurement quantity is the number of busy periods/the number of CCA time slots;

mode 3: measuring the quantity as the number of busy time slots;

mode 4: the metric is the number of busy slots/the number of CCA slots.

Mode 5: metric is the number of time slots.

Mode 6: measuring the amount of the busy accumulated time length;

mode 7: measuring the quantity which is the busy accumulated time length/the time length of the observation window;

mode 8: measuring the amount as idle accumulated time length;

mode 9: the metric is the accumulated duration of idle/duration of the observation window.

The cumulative duration of busy may comprise an accumulation of times during which the unlicensed carrier is busy for a specified period of time. The time slots that are not observed but considered busy are not accumulated at this time.

The accumulated duration of idle includes an accumulation of times during which the unlicensed carrier is idle during the execution period.

The metric is a predetermined threshold, is constant, or is related to the random backoff N value, or is related to the current contention window length. And when the measurement quantity is larger than the threshold value, the competition window is increased. When the measurement quantity is smaller than the threshold value, the contention window is reduced or restored to the original contention window size.

After the station determines the priority corresponding to the LBT according to the QoS class of the service, if the station uses the parameter corresponding to the priority, for example, the minimum contention backoff window does not obtain the usage right of the unlicensed carrier for k consecutive times, the station may use the LBT priority parameter of the higher level to contend for the usage right of the next unlicensed carrier. The preferred value of k is 3.

After the station determines the priority corresponding to the LBT according to the QoS class of the service, if the station uses the priority to obtain the usage right of the unlicensed carrier for k times, and each time the usage right is obtained, the initial CCA stage (based on the cat4 type) directly obtains the usage right of the unlicensed carrier. The station may use the higher LBT priority parameter to contend for the next unlicensed carrier. The preferred value of k is 2.

When a station transmits a discovery signal (DRS) and simultaneously transmits a PDSCH, the station should select a parameter corresponding to a priority of the highest LBT in a data burst (burst) to perform a listen-before-talk mechanism. For example, the DRS and the PDSCH are included in the burst scheduled for transmission by the station, and then the station selects the LBT priority corresponding to the highest QoS of the DRS and the PDSCH to preempt the unlicensed carrier. For example, when the subframe in which the DRS is located also needs to transmit partial control information or PDSCH, the station selects the corresponding parameter with the highest LBT priority to perform LBT.

When a transmission burst comprises different physical channels, a station selects a parameter of an LBT priority corresponding to the physical channel with the highest QoS to execute LBT; or the station selects the parameter of the corresponding highest LBT priority in different physical channels to perform LBT.

A self-delay processing mechanism in LBT flow is used for improving the existing flow.

In the flowchart 1, in the extended CCA stage, there is a "do nothing" (do nothing) process, and in conjunction with the flowchart 1, it can be found that the main feature is that the station performs CCA slot detection, and when the detection result is idle, the N value of the random backoff is not decremented. This approach may present the following risks or problems.

The station always keeps performing the flow of fig. 1 to contend for the unlicensed carrier, but always performs do nothing when the random backoff value N is decremented to a small certain value, for example, N is 1, until data arrives to continue to perform the decrement of N, thereby achieving the purpose of quickly and highly probabilistically obtaining the usage right of the unlicensed carrier to transmit the data. It is conceivable, however, that all stations obtain the use right of the unlicensed carrier in the above-described manner if the do nothing process is not restricted in use. It is inevitable to cause a contention conflict between stations, that is, a plurality of neighboring stations simultaneously obtain the use right, and interfere with each other. This has some conflict with the goal of introducing listen-before-talk for a random backoff mechanism. To overcome or mitigate the above problems, the following method may be used.

Mode 1: when there is data to be sent in the buffer area (buffer) of the station, and the station executes the flow of fig. 1, the station allows the self-delay mechanism to be executed.

Mode 2: when the single-time execution of the LBT mechanism in the flowchart 1 is to compete for the usage right of the unlicensed carrier, the number of times of performing the self-delay processing cannot exceed the predetermined threshold. The predetermined threshold is an N value randomly generated when LBT is performed; or a function of the value of N, such as N/2, N/3 (rounded when not an integer), etc.; or the size of the contention window L when performing LBT, or a function of the value of L, e.g., L/2, L/3 (rounded when not integer), etc.

Mode 3: the self-delay processing is only used when the station is in multi-carrier aggregation, the frequency reuse purpose and the unauthorized carrier competition during uplink multi-user multiplexing.

Mode 4: when the station executes LBT, the generated random back-off N value is larger than a preset threshold value, and self-delay processing is allowed to be used. The predetermined threshold is a constant value, or the predetermined threshold is a function of the value of the size L of the contention window when performing LBT, such as L/2, L/3 (rounded when not an integer), and so on.

Mode 5: the station can perform listen before talk mechanism to compete for the unlicensed carrier only when data arrives (there is data in the buffer). Further, the station determines that the behavior of data in the buffer is as follows: the Mac layer informs/triggers the physical layer that data arrives and the time point is t 0. The physical layer starts to perform the LBT procedure from the time point of t0 or t0+ t 1. Referring to fig. 1, for example, if the starting point is t0, the time position of the first CCA slot is t0+9us (t0 is the starting point, and the duration is 9us), and if idle is detected, the time position of the delay period is t0+9us + (16+ n × 9) us (t0+9us is the starting point, and (16+ n × 9) us is the duration). The time position of each CCA slot or delay period may be predetermined, whether the detection result is busy or idle. The time position of the subsequent CCA slot or delay period and so on.

Mode 6: when the station (UE side) obtains a certain scheduled transmission time, the station can perform the process shown in fig. 1 as contention for the unlicensed carrier. For example, after receiving the uplink grant information of the base station, the UE may determine a transmission time point of the uplink data according to the received uplink grant information, and then the UE may execute a listen-before-talk mechanism after receiving the uplink grant information, and allow the self-delay function to be executed before the data transmission time point.

calculating measurement quantity according to a detection result of whether the unauthorized carrier is idle in each preset period in the observation window; and judging that the calculated measurement quantity is larger than a preset threshold, increasing the competition window, and realizing the process of listening before speaking by adopting the increased competition window.

Wherein, the adjustment of the contention window may be, but not limited to, doubling, or exponentially increasing, or linearly increasing, etc.

When the calculated measurement quantity is judged to be less than or equal to the preset threshold, the contention window is reduced or the contention window is reduced to the minimum value, and the process of listening before speaking is realized by adopting the reduced contention window.

The contention window may be adjusted to be smaller by, but not limited to, doubling, exponentially decreasing, linearly decreasing, or the like.

Wherein, calculating the metric according to the detection result of whether the unauthorized carrier is idle in each preset period in the observation window comprises:

or the detection result is the ratio between the number of the preset cycles which are busy and the number of the CCA time slots in the observation window, or the detection result is the ratio between the number of the preset cycles which are busy and the CCA time slots in the observation window, or the detection result is the ratio between the accumulated time length which is busy and the time length of the observation window, or the detection result is the ratio between the accumulated time length which is idle and the time length of the observation window.

The preset period in which the detection result is busy may be a time of 16 μ s and/or each of adjacent CCA slots in which the detection result is busy.

The accumulated time length with the busy detection result refers to the accumulated time length with the busy detection result in the observation window, and the accumulated time length with the idle detection result refers to the accumulated time length with the idle detection result in the observation window.

Wherein, the observation window refers to the time that the station starts to compete to the unlicensed carrier.

Furthermore, the priority level of listening before speaking can be determined according to the service quality level of the service, and the process of listening before speaking is realized by adopting the parameters corresponding to the determined priority level; and judging that the unauthorized carrier is not obtained for k1 times continuously by using the minimum contention window in the parameters corresponding to the determined priority level, or judging that the unauthorized carrier is obtained for k2 times in the initial CCA stage continuously by using the parameters corresponding to the determined priority level, and increasing the priority level of listening before speaking, wherein k1 and k2 are integers which are more than or equal to 1.

Wherein a listen before talk priority level may be, but is not limited to, determined as a quality of service level of the traffic.

The parameters corresponding to the listen-before-talk priority level include the maximum value of the contention window, the minimum value of the contention window, and n.

Further, it is also possible to determine the transmission discovery signal DRS and adjust the listening-before-speaking priority level to the highest priority level.

Furthermore, it can also be determined that different physical channels are transmitted simultaneously, and the priority level of listening before speaking is adjusted to the priority level corresponding to the physical channel with the highest quality of service level.

The invention also provides a device for realizing listen before talk, which is characterized by at least comprising:

The functions of the third calculating module, the fifth judging module and the adjusting module can be realized by the processor executing the program/instruction stored in the memory, and can also be realized by firmware/logic circuit/integrated circuit.

In the apparatus of the present invention, the fifth determining module is further configured to:

judging that the calculated measurement quantity is less than or equal to a preset threshold, and sending a sixteenth notification message to the adjusting module;

the adjustment module is further configured to:

and receiving the sixteenth notification message, reducing the contention window or reducing the contention window to the minimum value, and realizing the listening-before-speaking process by adopting the reduced contention window.

In the apparatus of the present invention, the third calculating module is specifically configured to:

The apparatus of the present invention further comprises:

the fifth judging module is further configured to:

judging that the unauthorized carrier is not obtained for k1 times continuously by using the minimum contention window in the parameters corresponding to the determined priority level, or judging that the unauthorized carrier is obtained for k2 times continuously by using the parameters corresponding to the determined priority level in the initial CCA stage, and sending a seventeenth notification message to the adjusting module; wherein k1 and k2 are integers greater than or equal to 1;

the adjustment module is further configured to:

and receiving a seventeenth notification message, and increasing the priority level of listening before speaking.

The functions of the determining module may be implemented by the processor executing the programs/instructions stored in the memory, or may be implemented by firmware/logic/integrated circuit.

judging a transmission discovery signal DRS, and sending an eighteenth notification message to the adjusting module;

the adjustment module is further configured to:

receiving the eighteenth notification message, and adjusting the listen-before-talk priority level to the highest priority level.

the adjustment module is further configured to:

How to determine whether there is data to be sent in the buffer area belongs to the known technology of those skilled in the art, and is not used to limit the protection scope of the present invention, and is not described herein again.

The method includes that whether data arrives or not can be judged by a mode that a Media Access Control (MAC) layer sends a notification message to a physical layer, when the physical layer receives the notification message, the data arrives are judged, and when the physical layer does not receive the notification message, the data does not arrive are judged.

The base station may send the sending time of the data to the terminal through the uplink grant information.

The number of times of executing the self-delay mechanism may be limited to be less than or equal to a preset threshold value.

The preset threshold may be a generated random backoff value, or a function of the random backoff value (e.g., N/2, N/3, etc.), or a size q of the contention window, or a function of the size of the contention window (e.g., q/2, q/3, etc.).

The self-delay mechanism means that in step 107 and step 108 in fig. 1, after N is equal to 1, the value of N is not subtracted by 1, and no detection is performed, that is, nothing is done.

By the method, the probability of competition conflict among the stations is reduced by limiting the times of executing the self-delay mechanism by each station.

The functions of the sixth judging module and the executing module may be implemented by the processor executing the program/instruction stored in the memory, or may be implemented by firmware/logic circuit/integrated circuit.

It should be noted that the above-mentioned embodiments are only for facilitating the understanding of those skilled in the art, and are not intended to limit the scope of the present invention, and any obvious substitutions, modifications, etc. made by those skilled in the art without departing from the inventive concept of the present invention are within the scope of the present invention.

Claims

1. A method for implementing listen before talk, comprising:

2. The method of claim 1, wherein when it is detected that the unlicensed carrier is idle in a designated CCA slot of the initial CCA phase, the method further comprises:

3. The method as claimed in claim 2, wherein when it is detected that the unlicensed carrier is idle for the second delay period, the method further comprises:

4. The method of claim 1, wherein k is equal to 0 or 1 when n is greater than 1.

5. The method of claim 1, wherein the station detecting that an unlicensed carrier is idle for a first delayed CCA period comprises:

6. An apparatus for enabling listen before talk, comprising at least:

7. The apparatus of claim 6, wherein the first detection module is further configured to:

8. The apparatus of claim 7, wherein the first detection module is further configured to:

further comprising:

the first judging module is further configured to:

9. The apparatus of claim 6, wherein the first detection module is specifically configured to: