WO2012130053A1 - Method for implementing link self-adaptation, terminal device and network device - Google Patents

Abstract

Disclosed is a method for implementing link self-adaptation, comprising: a terminal device detecting channel quality, comparing the channel quality with a threshold, and when the channel quality exceeds the threshold, reporting channel quality information CQI; and a network device receiving the CQI information, and selecting a suitable transmission mode for downlink data transmission according to the CQI information. Further disclosed are a terminal device and a network device. By using the method and devices provided in the present invention, the spectrum utilization rate and system performance can be improved.

Description

 The invention provides a method for implementing link adaptation, a terminal device and a network device. The application date is March 31, 2011, and the application number is 201110081285.2. The invention name is "a kind of link based on channel quality indication feedback. The priority of the prior application of the method and system of adaptation, the entire contents of which is hereby incorporated by reference.

 This application claims priority on July 7, 2011, application number 201110188814.9, and the prior invention claims the priority of a method, system and device for implementing link adaptation based on channel quality indication feedback. The entire contents of the prior application have been embodied in this application.

 The application is filed on July 6, 2011, and the application number is 201110188947.6. The title of the invention is "a communication method for implementing multiple input and multiple output, a wireless communication system and a device." The entire contents of the application have been embodied in this application.

 The application is filed on May 19, 2011, the application number is 201110130194.3, the priority of the invention is the priority of the prior application, the entire disclosure of which is hereby incorporated by reference.

 This application claims the filing date of February 10, 2012, the application number is 201210029880.6, and the title of the invention is "a method and device for implementing link adaptation", the priority of the prior application. The content has been embodied in this application. Technical field

 The present invention belongs to the field of wireless communications, and in particular, to a method, a terminal device, and a network device for implementing link adaptation. Background technique

 With the rapid development of wireless communication technology, the serious shortage of spectrum resources has increasingly become a "bottleneck" in the development of wireless communication industry. For wireless communication systems, the most valuable is the spectrum resources, so how to fully exploit and use limited spectrum resources and improve the efficiency of spectrum usage is the key.

 The actual wireless communication channel is the performance of time-varying fading channels (such as throughput). The traditional design uses fixed information transmission parameters such as channel coding modulation and transmission power. Obviously, this cannot adapt to time-varying channels. . Therefore, a link adaptation technique is proposed. The link adaptation technology refers to dynamically adjusting the parameters of the transmission and the receiver according to the change of the wireless channel environment in the wireless communication system, such as the transmission power, the modulation mode, the coding rate, and the weight. The number of transmissions and the length of the data frame, etc., make the use of wireless channel resources to the maximum extent.

The channel quality information (CQI, Channel Quality Information) indicates the channel quality information indication that the estimated size, modulation mode, number of parallel codes, etc. of the transport block can be correctly accepted in the downlink or uplink direction to ensure a reasonable block error rate. . The terminal measures the current wireless receiving environment, estimates the maximum allowed CQI value, and the base station selects an appropriate downlink or uplink channel transmission format according to the CQI recommendation of the terminal, including transmission. The link size is adjusted by the size of the block, the modulation method, the number of parallel codes, the reference power correction value, and so on. With the rapid development of wireless communication technologies, higher requirements are imposed on methods for implementing link adaptation mechanisms. Summary of the invention

 In view of this, the technical problem to be solved by the present invention is to provide a new method for implementing link adaptation. In order to have a basic understanding of some aspects of the disclosed embodiments, a brief summary is given below. This generalization is not a general comment, nor is it intended to identify key/important elements or to describe the scope of protection of these embodiments. Its sole purpose is to present some concepts in a simplified form as a prelude to the detailed description which follows.

 In order to solve the above technical problem, the present invention further provides a method for implementing link adaptation based on channel quality indication feedback, including the following steps:

 The terminal device detects the channel quality. If the threshold is exceeded, the terminal device can actively send the CQI information to the network device.

 After receiving the CQI information fed back by each terminal device, the network device combines the upper layer service information, and determines the transmission parameter in the downlink scheduling of the subsequent terminal device according to the fed back CQI information, and sends the data to the corresponding terminal device.

 The resource acquisition of feedback can include the following three methods:

 The CQI feedback information is directly aggregated with the data and transmitted by using the allocated uplink data resource; or the terminal device carries a resource request reported by the CQI in the uplink data frame, and then the network device allocates the resource, and the terminal device sends the resource to the network device again. CQ I information;

 The terminal device sends an uplink scheduling request code, sends an uplink scheduling request, and requests resource allocation for CQI feedback. Active feedback is calculated based on the channel estimate of the most recently received Physical Layer Transport Unit (PPDU) or the downlink sounding channel.

 The CQI information fed back by the terminal device is encapsulated in the MAC frame layer to form a channel quality feedback frame, including a MAC frame header, a frame body, and an FCS. The frame body part information may be instructed according to the feedback type to feed back CQI information of each working bandwidth.

 The CQI information of the subchannels of each working bandwidth includes: MCS, Nss, coding type, and SNR or SINR.

 The CQI information of the subchannels of each working bandwidth includes: MCS, coding type, and SNR or SINR. In order to solve the above technical problem, the present invention further provides a wireless communication system capable of implementing link adaptation based on channel quality indication feedback, including:

 The terminal device is configured to detect channel quality, and if the threshold is exceeded, the CQI information may be sent to the network device actively;

The network device is configured to: after receiving the CQI information fed back by each terminal device, combine the upper layer service information, and determine the transmission parameter in the downlink scheduling of the subsequent terminal device according to the fed back CQI information, The terminal device should send data.

 In order to solve the above technical problem, the present invention provides a method for implementing link adaptation, including: a terminal device detecting channel quality, and comparing the channel quality with a threshold value, where the channel quality exceeds the The channel quality information CQI information is reported when the threshold is used;

 The network device receives the CQI information and selects a suitable transmission mode for downlink data transmission according to the CQI information.

 In some optional embodiments, the terminal device uses the uplink data transmission resource to report the CQI information.

 In some optional embodiments, the CQI information includes one or more of the following information: a modulation and coding scheme, an MCS, a modulation and coding scheme for identifying a requested frequency band;

 Encoding type, used to identify the encoding method recommended by the STA;

 Signal-to-Noise Ratio (SNR), which is used to identify the average signal-to-noise ratio on the requested bandwidth and spatial stream;

 Subchannel mapping, used to identify the bandwidth of the feedback subchannel and the specific corresponding subchannel number.

 In some optional embodiments, the CQI information includes one or more of the following information: a modulation and coding scheme, an MCS, a modulation and coding scheme for identifying a requested frequency band;

 Encoding type, used to identify the encoding method recommended by the STA;

 The signal to interference and noise ratio SINR is used to identify the average signal to interference and noise ratio on the requested bandwidth and the spatial stream; and, the subchannel mapping is used to identify the bandwidth of the feedback subchannel and the specific corresponding subchannel number.

 In some optional embodiments, the modulation and coding scheme is divided into a first modulation coding mode and a second modulation coding mode.

 In order to solve the above technical problem, the present invention also provides a method for implementing link adaptation, including:

 The terminal device detects channel quality, compares the channel quality with a threshold, and requests resource allocation when the channel quality exceeds the threshold;

 The network device sends a resource indication;

 The terminal device uses the resource to indicate the indicated resource uplink channel quality information CQI information; the network device receives the CQI information, and selects a suitable transmission mode for downlink data transmission according to the CQI information.

 In some optional embodiments, the terminal device carries a resource request when requesting an uplink data frame to request resource allocation.

 In some optional embodiments, the resource request is sent in a manner of being carried in an independent resource request frame, or is sent in an uplink data frame by using a path resource request form.

 In some optional embodiments, the terminal device sends a scheduling request to request resource allocation.

 In some optional embodiments, the terminal device first sends a scheduling request sequence, and then sends a resource request to request resource allocation.

In some optional embodiments, the resource request is sent by means of an independent resource request frame. give away.

 In some optional embodiments, the resource indication specifically includes one or more of the following information: a symbol offset, a duration, a subchannel mapping, and a CQI transmission mode;

 The CQI transmission mode includes a modulation coding mode MCS and a spatial stream number indication Nss.

 In some optional embodiments, the CQI information includes one or more of the following information: a modulation and coding scheme, an MCS, a modulation and coding scheme for identifying a requested frequency band;

 Encoding type, used to identify the encoding method recommended by the STA;

 Signal-to-Noise Ratio (SNR), which is used to identify the average signal-to-noise ratio on the requested bandwidth and spatial stream;

 Subchannel mapping, used to identify the bandwidth of the feedback subchannel and the specific corresponding subchannel number.

 In some optional embodiments, the CQI information includes one or more of the following information: a modulation and coding scheme, an MCS, a modulation and coding scheme for identifying a requested frequency band;

 Encoding type, used to identify the encoding method recommended by the STA;

 The signal to interference and noise ratio SINR is used to identify the average signal to interference and noise ratio on the requested bandwidth and the spatial stream; and, the subchannel mapping is used to identify the bandwidth of the feedback subchannel and the specific corresponding subchannel number.

 In some optional embodiments, the modulation and coding scheme is divided into a first modulation coding mode and a second modulation coding mode.

 In order to solve the above technical problem, the present invention further provides a terminal device, including:

 a detecting unit, configured to detect channel quality;

 a comparing unit, configured to compare the channel quality and a threshold value; and,

 And a reporting unit, configured to report channel quality information CQI information when the channel quality exceeds the threshold. In some optional embodiments, the reporting unit reports the CQI information by using an uplink data transmission resource.

 In some optional embodiments, the CQI information includes one or more of the following information: a modulation and coding scheme, an MCS, a modulation and coding scheme for identifying a requested frequency band;

 Encoding type, used to identify the encoding method recommended by the STA;

 Signal-to-Noise Ratio (SNR), which is used to identify the average signal-to-noise ratio on the requested bandwidth and spatial stream;

 Subchannel mapping, used to identify the bandwidth of the feedback subchannel and the specific corresponding subchannel number.

 In some optional embodiments, the CQI information includes one or more of the following information: a modulation and coding scheme, an MCS, a modulation and coding scheme for identifying a requested frequency band;

 Encoding type, used to identify the encoding method recommended by the STA;

 The signal to interference and noise ratio SINR is used to identify the average signal to interference and noise ratio on the requested bandwidth and the spatial stream; and, the subchannel mapping is used to identify the bandwidth of the feedback subchannel and the specific corresponding subchannel number.

 In some optional embodiments, the modulation and coding scheme is divided into a first modulation coding mode and a second modulation coding mode.

 In order to solve the above technical problem, the present invention further provides a network device, including:

a receiving unit, configured to receive channel quality information CQI information; And a processing unit, configured to select an appropriate transmission mode for downlink data transmission according to the CQI information. In some optional embodiments, the receiving unit is further configured to receive uplink data, where the CQI information is transmitted by using an uplink transmission resource.

 In some optional embodiments, the CQI information includes one or more of the following information: a modulation and coding scheme, an MCS, a modulation and coding scheme for identifying a requested frequency band;

 Encoding type, used to identify the encoding method recommended by the STA;

 Signal-to-Noise Ratio (SNR), which is used to identify the average signal-to-noise ratio on the requested bandwidth and spatial stream;

 Subchannel mapping, used to identify the bandwidth of the feedback subchannel and the specific corresponding subchannel number.

 In some optional embodiments, the CQI information includes one or more of the following information: a modulation and coding scheme, an MCS, a modulation and coding scheme for identifying a requested frequency band;

 Encoding type, used to identify the encoding method recommended by the STA;

 The signal to interference and noise ratio SINR is used to identify the average signal to interference and noise ratio on the requested bandwidth and the spatial stream; and, the subchannel mapping is used to identify the bandwidth of the feedback subchannel and the specific corresponding subchannel number.

 In some optional embodiments, the modulation and coding scheme is divided into a first modulation coding mode and a second modulation coding mode.

 In order to solve the above technical problem, the present invention further provides a terminal device, including:

 a detecting unit, configured to detect channel quality;

 a comparing unit, configured to compare the channel quality and a threshold value;

 a resource requesting unit, configured to request resource allocation when the channel quality exceeds the threshold, and receive a resource indication; and,

 And an upper unit, configured to indicate, by using the resource, the channel quality information CQI information indicated by the resource. In some optional embodiments, the resource requesting unit carries a resource request when requesting an uplink data frame to request resource allocation.

 In some optional embodiments, the resource request is sent in a manner of being carried in an independent resource request frame, or is sent in an uplink data frame by using a path resource request form.

 In some optional embodiments, the resource request unit sends a scheduling request to request resource allocation. In some optional embodiments, the resource requesting unit first sends a scheduling request sequence and then sends a resource request to request resource allocation.

 In some optional embodiments, the resource request is sent by being carried in an independent resource request frame.

 In some optional embodiments, the resource indication includes one or more of the following information: a symbol offset, a duration, a subchannel mapping, and a CQI transmission mode;

 The CQI transmission mode includes a modulation coding mode MCS and a spatial stream number indication Nss.

 In some optional embodiments, the CQI information includes one or more of the following information: a modulation and coding scheme, an MCS, a modulation and coding scheme for identifying a requested frequency band;

Encoding type, used to identify the encoding method recommended by the STA; The signal-to-noise ratio SNR is used to identify the average signal-to-noise ratio on the requested bandwidth and the spatial stream; and, the subchannel mapping is used to identify the bandwidth of the feedback subchannel and the specific corresponding subchannel number.

 In some optional embodiments, the CQI information includes one or more of the following information: a modulation and coding scheme, an MCS, a modulation and coding scheme for identifying a requested frequency band;

 Encoding type, used to identify the encoding method recommended by the STA;

 The signal to interference and noise ratio SINR is used to identify the average signal to interference and noise ratio on the requested bandwidth and the spatial stream; and, the subchannel mapping is used to identify the bandwidth of the feedback subchannel and the specific corresponding subchannel number.

 In some optional embodiments, the modulation and coding scheme is divided into a first modulation coding mode and a second modulation coding mode.

 In order to solve the above technical problem, the present invention further provides a network device, including:

 a first receiving unit, configured to receive a resource request;

 a sending unit, configured to send a resource indication;

 a second receiving unit, configured to receive channel quality information CQI information;

 And a processing unit, configured to select an appropriate transmission mode for downlink data transmission according to the CQI information. In some optional embodiments, the first receiving unit receives an uplink data frame, and the uplink data frame carries a resource request message to request resource allocation.

 In some optional embodiments, the first receiving unit receives a scheduling request to request resource allocation. In some optional embodiments, the CQI information includes one or more of the following information: a modulation and coding scheme, an MCS, a modulation and coding scheme for identifying a requested frequency band;

 Encoding type, used to identify the encoding method recommended by the STA;

 Signal to noise ratio SNR, which is used to identify the average signal to noise ratio on the requested bandwidth and spatial stream; and, subchannel mapping, used to identify the bandwidth of the feedback subchannel and the specific corresponding subchannel number.

 In some optional embodiments, the CQI information includes one or more of the following information: a modulation and coding scheme, an MCS, a modulation and coding scheme for identifying a requested frequency band;

 Encoding type, used to identify the encoding method recommended by the STA;

 The signal to interference and noise ratio SINR is used to identify the average signal to interference and noise ratio on the requested bandwidth and the spatial stream; and, the subchannel mapping is used to identify the bandwidth of the feedback subchannel and the specific corresponding subchannel number.

 In some optional embodiments, the modulation and coding scheme is divided into a first modulation coding mode and a second modulation coding mode.

 In summary, the technical solution for implementing uplink and downlink adaptation provided by the present invention can track and reflect channel changes in real time through STA-based active feedback CQI information, thereby effectively reducing system overhead and optimizing system performance; Spectrum resources can be adaptively scheduled to improve spectrum utilization and system performance.

For the above and related purposes, one or more embodiments include the features that are described in detail below and particularly pointed out in the claims. The following description and the annexed drawings are to be considered in a Other benefits and novel features will become apparent from the following detailed description in conjunction with the appended claims. All of these aspects and their equivalents. DRAWINGS

 1 is a schematic flowchart of a method for implementing downlink adaptation based on an active feedback mechanism according to Embodiment 1 of the present invention;

 2 is a schematic structural diagram of a channel quality information feedback frame according to Embodiment 1 of the present invention;

 3 is a schematic structural diagram of a channel quality information feedback frame in a specific scenario according to Embodiment 1 of the present invention;

 4 is a schematic structural diagram of a channel quality information feedback frame in a specific scenario according to Embodiment 1 of the present invention;

 FIG. 5 is a schematic diagram of a frame body portion of a channel quality information feedback frame according to Embodiment 1 of the present invention; FIG. 6 is a schematic diagram of a frame body portion of a channel quality feedback frame according to Embodiment 1 of the present invention; A schematic diagram of a frame body portion of a channel quality feedback frame according to Embodiment 1 of the present invention; FIG. 8 is a schematic structural diagram of a network device according to Embodiment 2 of the present invention;

 9 is a schematic structural diagram of a terminal device according to Embodiment 2 of the present invention;

 10 is a schematic flowchart of a method for implementing downlink adaptation based on an active feedback mechanism according to Embodiment 3 of the present invention;

 11 is a schematic structural diagram of a terminal device according to Embodiment 3 of the present invention;

 FIG. 12 is a schematic flowchart diagram of a method for implementing downlink adaptation based on an active feedback mechanism according to Embodiment 4 of the present invention. detailed description

 The detailed description of the present invention is set forth in the description and drawings in the claims Other embodiments may include structural, logical, electrical, process, and other changes. The examples represent only possible variations. Individual components and functions are optional unless explicitly required, and the order of operations may vary. Portions and features of some embodiments may be included or substituted for parts and features of other embodiments. The scope of the embodiments of the invention includes the full scope of the claims, and all equivalents of the claims. These embodiments of the invention may be referred to herein, individually or collectively, by the term "invention", merely for convenience, and if more than one invention is disclosed, it is not intended to automatically limit the application. The scope is any single invention or inventive concept.

 In view of the deficiencies in the prior art, the present invention proposes a method for implementing uplink and downlink adaptation, which can improve spectrum resource utilization and system performance.

 Link adaptation and other mechanisms, such as beamforming and multi-user MU-MIMO, are inseparable. They are adaptive techniques used to adapt to channel changes, improve link and system capacity, they can share part of the feedback, or the response is calculated at the same time. The present invention only considers a link adaptation implementation method based on channel quality information feedback.

Network devices mentioned in the present invention, such as an access point AP, a central access point CAP, or a base station or other network The device, the terminal device, such as the user station STA, the terminal, or other terminal device, is described below with the network device as the CAP and the terminal device as the STA, but is not limited to the CAP and the STA.

 In the present invention, for a medium and short range wireless communication system, the link adaptation mechanism includes downlink adaptation and uplink adaptation. Among them, downlink adaptation refers to link adaptation in the direction from CAP to STA; uplink adaptation refers to link adaptation in the direction from STA to CAP.

 Downlink adaptation

 In medium and short range wireless communication systems, downlink data transmission supports a link adaptation mechanism. The CAP can adaptively select different physical layer transmission parameters for the STA according to the CQI information fed back by the STA, and the parameters include: MIMO working mode, spatial stream number, coded modulation mode MCS, and transmission power.

 The feedback mechanisms supported by the downlink adaptive support include the following three types: a periodic feedback mechanism, a request-response-based feedback mechanism, and an active response feedback mechanism.

 The present invention mainly describes the feedback mechanism of the active response in detail. Embodiment 1

 Embodiment 1 of the present invention proposes a method for implementing downlink adaptation, which uses an active feedback mechanism, and includes the following steps:

 Step S101: STA channel quality, if the threshold is exceeded, the STA may actively send CQI information to the AP. Wherein, the threshold is preset by the STA.

 Preferably, the STA detects the channel quality of the downlink channel, and compares the channel quality with the threshold. When the channel quality exceeds the threshold, the STA can report the CQI information to the CAP.

 Preferably, the retrieval of the required resources can be obtained in the following three ways:

The first one: the CQI feedback is directly aggregated with the data, and is transmitted by using the allocated uplink data resource. The second type: the STA carries the resource request reported by the corresponding CQI in the uplink data frame, and then the CAP allocates the resource, and the STA then Send CQI information to the AP;

 Third: The STA sends a resource request by sending a scheduling request sequence, and requests resource allocation for CQI feedback. Preferably, the STA requests resource allocation for CQI feedback by first transmitting a scheduling request sequence and then transmitting a resource request.

 Active feedback is calculated based on the channel estimate of the most recently received Physical Layer Transport Unit (PPDU) or the downlink sounding channel.

 Preferably, the CQI information may be encapsulated into a MAC frame to form a channel quality information CQI feedback frame. The CQI feedback frame includes a MAC frame header, a frame body, and an FCS, wherein the frame body part information may include CQI information of each working bandwidth. The CQI information may include one or more of the following information: modulation coding mode (MCS, Modulation and Coding Scheme), space-time stream number (Nss), coding type (LDPC/BCC), and signal-to-noise ratio (ie, signal-to-noise ratio) (SNR, Signal To Noise Ratio) or Signal To Interference Noise Ratio (SINR).

Preferably, for example, as shown in FIG. 2, the CQI information may include: modulation coding mode (MCS), space-time flow number (Nss), coding type (LDPC/BCC), and signal-to-noise ratio (SNR) (or signal to interference and noise ratio (SINR)). Preferably, for example, as shown in FIG. 3, the CQI information may also include an MCS, an encoding type, and an SNR (or SINR), and the modulation and coding scheme (MCS) may include a space-time stream number (Nss). The MCS is used to identify the modulation and coding mode of the requested frequency band. The encoding type is used to identify the encoding method recommended by the terminal. The SNR is used to identify the average signal-to-noise ratio on each spatial stream of the requested channel, and the SINR is used to identify the average signal or interference plus noise ratio on each spatial stream of the requested channel.

 Preferably, for example, as shown in FIG. 4, the CQI information may further include a subchannel mapping for identifying a bandwidth of the feedback subchannel and a specific corresponding subchannel number.

 Preferably, if the system supports 8 spatial stream transmissions, and one MCS supports up to 4 spatial stream transmissions, two MCSs are needed. As shown in FIG. 6, the MCS can also be divided into two, that is, the first modulation and coding manner. MCS1 represents the MCS of the request channel codeword 1, and the second modulation coding mode MCS2 represents the MCS of the request channel codeword 2. Preferably, the CQI information may include subchannel mapping, MCS1, MCS2, coding type, and SINR. The contents of the CQI information are shown in Table 1:

 Table 1

When the system operates at 20 MHz, the frame body portion of the channel quality feedback frame is as shown in FIG. 3 or 4 or 5. When the system operates in 40 MHz aggregation mode 1, the frame body portion of the channel quality feedback frame is as shown in FIG. 6. When the system works in 80MHz aggregation mode 1, the CQI_FB frame body part is shown in Figure 7.

 When the system is operating in 40MHz aggregation mode 2, the CQI_FB frame body is shown in Figure 5.

 When the 80MHz system operates at 40MHz, the CQI_FB frame body is shown in Figure 6. When the system is operating at a continuous 80MHz, the CQI_FB frame body is shown in Figure 5.

 Regarding the aggregation mode mentioned above, the following is described in detail:

 Spectrum aggregation

 This part uses 20MHz as the basic channel bandwidth, and can support 40MHz and 80MHz spectrum continuous or non-continuous bandwidth through spectrum aggregation.

 Aggregation mode 1: Each 20MHz subchannel is an independent channel, and 20MHz, 40MHz and 80MHz STAs can be scheduled to be transmitted independently on one or more 20MHz subchannels;

 Aggregation Mode 2: Multiple consecutive 20MHz subchannel aggregations, 40MHz and 80MHz STAs can be continuously transmitted in the frequency domain on the aggregate channel.

 20MHz STA can only select aggregation mode 1 , 40MHz and 80MHz STA can choose aggregation mode 1 or 2.

 Step S102: After receiving the CQI information fed back by each STA, the CAP selects an appropriate transmission mode for downlink data transmission according to the CQI information.

 Preferably, after receiving the CQI information fed back by each STA, the CAP combines the upper layer service information, and according to the fed back CQI information, determines the transmission parameter in the downlink scheduling of the subsequent STA, and sends the data to the corresponding STA.

 In order to implement the foregoing method, the first embodiment of the present invention further provides a system for implementing link adaptation, including:

 The user site STA is configured to detect channel quality. If the threshold is exceeded, the STA may actively send CQI information to the AP.

 The central access point CAP is configured to: after receiving the CQI information fed back by each STA, combine the upper layer service information, and determine the transmission parameter in the downlink scheduling of the subsequent STA according to the fed back CQI information, and send the data to the corresponding STA. .

 The system for implementing link adaptation according to the first embodiment of the present invention has the same working principle and related operational procedures as those in the foregoing method embodiments, and details are not described herein again.

 The technical solution for implementing downlink adaptation provided by the first embodiment of the present invention can track the channel change in real time through the STA based on the threshold-based active feedback CQI information, thereby effectively reducing system overhead and optimizing system performance; Adaptively schedule spectrum resources to improve spectrum utilization and system performance.

 Specifically, the three methods are described in detail by the following three embodiments. Embodiment 2

A second embodiment of the present invention provides a method for implementing downlink adaptation, which uses an active feedback mechanism, as shown in FIG. 1, and includes the following steps: Step S201: The STA detects the channel quality, compares the channel quality with a preset threshold, and reports the CQI information when the channel quality exceeds the threshold. The threshold is preset by the STA.

 Preferably, the STA detects the channel quality of the downlink channel.

 Preferably, the STA can directly aggregate the CQI information with the uplink data and report the CQI information. Preferably, the CQI information is reported by using the allocated uplink data resource.

 In the second embodiment, when the CAP has allocated uplink data resources to the STA in advance, the STA transmits the uplink data to the CAP.

 The description of the CQI information is the same as that in the first embodiment, and details are not described herein again.

 Step S202: After receiving the CQI information fed back by each STA, the CAP feeds back according to the terminal device.

CQI information, select the appropriate transmission mode for downlink data transmission.

 In order to implement the foregoing method for implementing link adaptation, the second embodiment of the present invention further provides a network device, as shown in FIG. 8, including:

 The receiving unit 11 is configured to receive uplink data and channel quality information CQI information;

 The processing unit 12 is configured to select an appropriate transmission mode for downlink data transmission according to the CQI information. Preferably, the receiving unit 11 receives uplink data, and the uplink data is aggregated with channel quality information CQI information.

 In order to implement the foregoing method for implementing link adaptation, the second embodiment of the present invention further provides a terminal device, as shown in FIG. 9, including:

 a detecting unit 21, configured to detect channel quality;

 Comparing unit 22, configured to compare channel quality with a threshold value; and,

 The reporting unit 23 is configured to report CQI information when the channel quality exceeds the threshold.

 Preferably, the reporting unit 23 can aggregate the CQI information and the uplink data to report the CQI information. In order to implement the foregoing method for implementing link adaptation, the second embodiment of the present invention further provides a system for implementing link adaptation, including the network device and the terminal device according to the second embodiment.

 The system, the network device, and the terminal device for implementing link adaptation provided by the second embodiment of the present invention, the working principle and related operation procedure, and the foregoing method for implementing downlink adaptation based on the periodic feedback mechanism are basically The same, will not be described here.

 The technical solution for implementing downlink adaptation provided by the second embodiment of the present invention can track the channel change in real time through the STA based on the threshold-based active feedback CQI information, thereby effectively reducing system overhead and optimizing system performance; Adaptively schedule spectrum resources to improve spectrum utilization and system performance. Embodiment 3

 The third embodiment of the present invention proposes a method for implementing downlink adaptation, which uses an active feedback mechanism. As shown in FIG. 10, the following steps are included:

Step S301: The STA detects the channel quality, compares the channel quality with the threshold, and requests resource allocation when the channel quality exceeds the threshold. Preferably, the STA detects the channel quality of the downlink channel. Where the threshold The value is preset by the STA.

 Preferably, the STA carries the resource request for reporting the CQI in the uplink data frame sent to the CAP by using the allocated resource to request the resource allocation. Preferably, the resource request can be carried in the independent resource request frame manner. Send, or send in the form of an upstream data frame by means of the associated resource request form.

 Step S302: The CAP sends a resource indication to the STA, that is, allocates resources to the STA.

 Preferably, the resource indication specifically includes one or more of the following information: symbol offset, duration, subchannel mapping, and CQI transmission mode; wherein, the CQI transmission mode includes a modulation coding mode MCS and a spatial stream number indication Nss.

 Step S303: The STA receives the resource indication, and reports the CQI information by using the resource indicated by the resource indication. The description of the CQI information is the same as that in the first embodiment, and details are not described herein again.

 In the third embodiment, when the CAP has allocated uplink data resources to the STA in advance, the STA transmits the uplink data to the CAP.

 Step S304: After receiving the CQI information fed back by each STA, the CAP selects an appropriate transmission mode for downlink data transmission according to the CQI information.

 To implement the foregoing method for implementing link adaptation, the third embodiment of the present invention further provides a network device. As shown in FIG. 11, the method includes:

 a first receiving unit 31, configured to receive a resource request;

 a sending unit 32, configured to send a resource indication;

 a second receiving unit 33, configured to receive channel quality information CQI information;

 The processing unit 34 is configured to select an appropriate transmission mode for downlink data transmission according to the CQI information.

 Preferably, the first receiving unit 31 receives an uplink data frame, where the uplink data frame carries a resource request message to request resource allocation.

 In order to implement the foregoing method for implementing link adaptation, the third embodiment of the present invention further provides a terminal device, as shown in FIG. 12, including:

 a detecting unit 41, configured to detect channel quality;

 a comparing unit 42 , configured to compare channel quality and a threshold value;

 The resource requesting unit 43 is configured to request resource allocation when the channel quality exceeds the threshold, and receive the resource indication and,

 The upper unit 44 is configured to use the resource indication to indicate the CQI information on the resource.

 Preferably, the resource requesting unit 43 carries a resource request message when transmitting the uplink data frame to request resource allocation.

 In order to implement the foregoing method for implementing link adaptation, the third embodiment of the present invention further provides a system for implementing link adaptation, including the network device and the terminal device according to the third embodiment.

The system, the network device, and the terminal device for implementing link adaptation provided by the third embodiment of the present invention, the working principle and related operation procedure, and the foregoing method for implementing downlink adaptation based on the periodic feedback mechanism are basically implemented. The same, will not be described here. The technical solution for implementing downlink adaptation provided by the third embodiment of the present invention can track the channel change in real time through the STA based on the threshold-based active feedback CQI information, thereby effectively reducing system overhead and optimizing system performance; Adaptively schedule spectrum resources to improve spectrum utilization and system performance. Embodiment 4

 A fourth embodiment of the present invention proposes a method for implementing downlink adaptation, which uses an active feedback mechanism. As shown in FIG. 10, the following steps are included:

 Step S301: The STA detects the channel quality, compares the channel quality with the threshold, and requests resource allocation when the channel quality exceeds the threshold. Preferably, the STA detects the channel quality of the downlink sounding channel.

 Preferably, the STA sends a scheduling request to the CAP to request resource allocation. Preferably, the STA may request a resource allocation for the CQI feedback by first sending a scheduling request sequence and then sending a resource request. Preferably, the resource request is sent by being carried in an uplink data frame.

 Step S402: The CAP sends a resource indication to the STA, that is, allocates resources to the STA.

 Preferably, the resource indication specifically includes one or more of the following information: symbol offset, duration, subchannel mapping, and CQI transmission mode; wherein, the CQI transmission mode includes a modulation coding mode MCS and a spatial stream number indication Nss.

 Step S303: The STA receives the resource indication, and reports the CQI information by using the resource indicated by the resource indication. The description of the CQI information is the same as that in the first embodiment, and details are not described herein again.

 In the fourth embodiment, in the case that the CAP has allocated uplink data resources to the STA in advance, the STA transmits the uplink data to the CAP.

 Step S304: After receiving the CQI information fed back by each STA, the CAP selects an appropriate transmission mode for downlink data transmission according to the CQI information.

 To implement the foregoing method for implementing link adaptation, the third embodiment of the present invention further provides a network device. As shown in FIG. 11, the method includes:

 a first receiving unit 31, configured to receive a resource request;

 a sending unit 32, configured to send a resource indication;

 a second receiving unit 33, configured to receive channel quality information CQI information;

 The processing unit 34 is configured to select an appropriate transmission mode for downlink data transmission according to the CQI information.

 Preferably, the first receiving unit 31 receives a scheduling request for requesting resource allocation. Preferably, the first receiving unit 31 first receives the scheduling request sequence, and then receives a resource request, where the resource request is used to request resource allocation for CQI feedback.

 In order to implement the foregoing method for implementing link adaptation, the fourth embodiment of the present invention further provides a terminal device, as shown in FIG. 12, including:

 a detecting unit 41, configured to detect channel quality;

 a comparing unit 42 , configured to compare channel quality and a threshold value;

The resource requesting unit 43 is configured to request resource allocation when the channel quality exceeds a threshold, and receive the resource indicator Show and,

 The upper unit 44 is configured to use the resource indication to indicate the CQI information on the resource.

 Preferably, the resource requesting unit 43 sends a scheduling request to request resource allocation. Preferably, the resource requesting unit 43 may request a resource allocation for the CQI feedback by first sending a scheduling request sequence and then sending a resource request.

 In order to implement the foregoing method for implementing link adaptation, the fourth embodiment of the present invention further provides a system for implementing link adaptation, including the network device and the terminal device according to the fourth embodiment.

 The system, the network device, and the terminal device for implementing link adaptation provided by Embodiment 4 of the present invention, the working principle and related operation procedure, and the foregoing method for implementing downlink adaptation based on the periodic feedback mechanism are basically The same, will not be described here.

 The technical solution for implementing downlink adaptation provided by the fourth embodiment of the present invention can adaptively schedule spectrum resources and improve spectrum utilization and system performance through STA active feedback CQI information.

 The embodiment of the present invention is described by taking only the medium and short distance communication system as an example, but is not limited to the medium and short distance communication system, and other systems implemented by the method of the present invention are all within the protection scope.

 In summary, the technical solution for implementing downlink adaptation provided by the present invention can track and reflect channel changes in real time through STA-based active feedback CQI information, thereby effectively reducing system overhead and optimizing system performance; Adaptively schedule spectrum resources to improve spectrum utilization and system performance.

 It will be understood that the specific order or hierarchy of steps in the process disclosed is an example of an exemplary method. Based on a design preference, it is understood that the specific order or hierarchy of steps in the process can be rearranged without departing from the scope of the disclosure. The appended method claims set forth the elements of the various steps in the exemplary order and are not intended to

 In the above Detailed Description, various features are grouped together in a single embodiment to simplify the present disclosure. This method of disclosure should not be interpreted as reflecting the intention that the embodiments of the claimed subject matter require more features than those recited in the claims. Rather, as the following claims reflect, the invention is in a <RTIgt; less</RTI> <RTIgt; Therefore, the following claims are hereby expressly incorporated in the claims

 The above description includes examples of one or more embodiments. Of course, it is not possible to describe all possible combinations of components or methods for the purposes of describing the above-described embodiments, but one of ordinary skill in the art will recognize that the various embodiments can be further combined and arranged. Accordingly, the embodiments described herein are intended to cover all such modifications, modifications, and variations in the scope of the appended claims. Furthermore, the term "comprising", as used in the specification or the claims, is intended to be inclusive of the term "comprising" as used in the claims. Further, any of the terms "or" used in the specification of the claims is intended to mean "non-exclusive or".

Claims

Claim

A method for implementing link adaptation, comprising:

 The terminal device detects channel quality, compares the channel quality with a threshold, and reports channel quality information CQI information when the channel quality exceeds the threshold;

 The network device receives the CQI information and selects a suitable transmission mode for downlink data transmission according to the CQI information.

 The method according to claim 1, wherein the terminal device reports the CQI information by using an uplink data transmission resource.

 3. The method according to claim 1, wherein the CQI information comprises one or more of the following information:

 Modulation coding mode MCS, used to identify the modulation and coding mode of the requested frequency band;

 Encoding type, used to identify the encoding method recommended by the STA;

 The signal to interference and noise ratio SINR is used to identify the average signal to interference and noise ratio on the requested bandwidth and the spatial stream; and, the subchannel mapping is used to identify the bandwidth of the feedback subchannel and the specific corresponding subchannel number.

 The method according to claim 3, wherein the modulation and coding mode is divided into a first modulation coding mode and a second modulation coding mode.

 A method for implementing link adaptation, comprising:

 The terminal device detects channel quality, compares the channel quality with a threshold, and requests resource allocation when the channel quality exceeds the threshold;

 The network device sends a resource indication;

 The terminal device uses the resource to indicate the indicated resource uplink channel quality information CQI information; the network device receives the CQI information, and selects a suitable transmission mode for downlink data transmission according to the CQI information.

 The method according to claim 5, wherein the terminal device carries a resource request when requesting an uplink data frame to request resource allocation.

 The method according to claim 6, wherein the resource request is sent by being carried in an independent resource request frame, or is sent in an uplink data frame by using a path resource request form.

 The method according to claim 5, wherein the terminal device sends a scheduling request to request resource allocation.

The method according to claim 8, wherein the terminal device first sends a scheduling request sequence, Resend the resource request to request resource allocation.

 The method according to claim 9, wherein the resource request is sent by being carried in an independent resource request frame.

 The method according to claim 5, wherein the resource indication specifically includes one or more of the following information: a symbol offset, a duration, a subchannel mapping, and a CQI transmission mode;

 The CQI transmission mode includes a modulation coding mode MCS and a spatial stream number indication Nss.

 12. The method according to claim 5, wherein the CQI information comprises one or more of the following information:

 Modulation coding mode MCS, used to identify the modulation and coding mode of the requested frequency band;

 Encoding type, used to identify the encoding method recommended by the STA;

 The signal to interference and noise ratio SINR is used to identify the average signal to interference and noise ratio on the requested bandwidth and the spatial stream; and, the subchannel mapping is used to identify the bandwidth of the feedback subchannel and the specific corresponding subchannel number.

 The method according to claim 12, wherein the modulation and coding mode is divided into a first modulation coding mode and a second modulation coding mode.

 A terminal device, comprising:

 a detecting unit, configured to detect channel quality;

 a comparing unit, configured to compare the channel quality and a threshold value; and,

 And a reporting unit, configured to report channel quality information CQI information when the channel quality exceeds the threshold.

The terminal device according to claim 14, wherein the reporting unit reports the CQI information by using an uplink data transmission resource.

 16. The terminal device according to claim 14, wherein the CQI information comprises one or more of the following information:

 Modulation coding mode MCS, used to identify the modulation and coding mode of the requested frequency band;

 Encoding type, used to identify the encoding method recommended by the STA;

 The signal to interference and noise ratio SINR is used to identify the average signal to interference and noise ratio on the requested bandwidth and the spatial stream; and, the subchannel mapping is used to identify the bandwidth of the feedback subchannel and the specific corresponding subchannel number.

 The terminal device according to claim 16, wherein the modulation and coding scheme is divided into a first modulation and coding scheme and a second modulation and coding scheme.

 A network device, comprising:

 a receiving unit, configured to receive channel quality information CQI information;

And a processing unit, configured to select an appropriate transmission mode for downlink data transmission according to the CQI information.

The network device according to claim 18, wherein the receiving unit is further configured to receive uplink data, where the CQI information is transmitted by using an uplink transmission resource.

 20. The network device according to claim 18, wherein the CQI information comprises one or more of the following information:

 Modulation coding mode MCS, used to identify the modulation and coding mode of the requested frequency band;

 Encoding type, used to identify the encoding method recommended by the STA;

 The signal to interference and noise ratio SINR is used to identify the average signal to interference and noise ratio on the requested bandwidth and the spatial stream; and, the subchannel mapping is used to identify the bandwidth of the feedback subchannel and the specific corresponding subchannel number.

 A terminal device, comprising:

 a detecting unit, configured to detect channel quality;

 a comparing unit, configured to compare the channel quality and a threshold value;

 a resource requesting unit, configured to request resource allocation when the channel quality exceeds the threshold, and receive a resource indication; and,

 And an upper unit, configured to indicate, by using the resource, the channel quality information CQI information indicated by the resource.

The terminal device according to claim 21, wherein the resource requesting unit carries a resource request when requesting the uplink data frame to request resource allocation.

 The terminal device according to claim 22, wherein the resource request is sent by being carried in an independent resource request frame, or is sent in an uplink data frame by using a path resource request form.

 24. The terminal device according to claim 21, wherein the resource requesting unit sends a scheduling request to request resource allocation.

 The terminal device according to claim 24, wherein the resource requesting unit first sends a scheduling request sequence, and then sends a resource request to request resource allocation.

 The terminal device according to claim 25, wherein the resource request is transmitted by being carried in an independent resource request frame.

 The terminal device according to claim 21, wherein the resource indication comprises one or more of the following information: a symbol offset, a duration, a subchannel mapping, and a CQI transmission mode;

 The CQI transmission mode includes a modulation coding mode MCS and a spatial stream number indication Nss.

 The terminal device according to claim 21, wherein the CQI information comprises one or more of the following information:

a modulation and coding mode MCS, which is used to identify a modulation and coding mode of the requested frequency band; Encoding type, used to identify the encoding method recommended by the STA;

 The signal to interference and noise ratio SINR is used to identify the average signal to interference and noise ratio on the requested bandwidth and the spatial stream; and, the subchannel mapping is used to identify the bandwidth of the feedback subchannel and the specific corresponding subchannel number.

 The terminal device according to claim 28, wherein the modulation and coding scheme is divided into a first modulation and coding scheme and a second modulation and coding scheme.

 30. A network device, comprising:

 a first receiving unit, configured to receive a resource request;

 a sending unit, configured to send a resource indication;

 a second receiving unit, configured to receive channel quality information CQI information;

 And a processing unit, configured to select an appropriate transmission mode for downlink data transmission according to the CQI information.

The network device according to claim 30, wherein the first receiving unit receives an uplink data frame, where the uplink data frame carries a resource request, and the resource request is used to request resource allocation.

 The network device according to claim 30, wherein the first receiving unit receives a scheduling request, and the scheduling request is used to request resource allocation.

 33. The network device according to claim 32, wherein the first receiving unit first receives a scheduling request sequence, and then receives a resource request, where the request is used to request resource allocation.

 34. The network device of claim 30, wherein the CQI information comprises one or more of the following information:

 Modulation coding mode MCS, used to identify the modulation and coding mode of the requested frequency band;

 Encoding type, used to identify the encoding method recommended by the STA;

 The signal to interference and noise ratio SINR is used to identify the average signal to interference and noise ratio on the requested bandwidth and the spatial stream; and, the subchannel mapping is used to identify the bandwidth of the feedback subchannel and the specific corresponding subchannel number.