CN102281087B - Communication method, carrier wave dispatching method, base station and terminal - Google Patents

Abstract

The present application provides a communication method and a carrier scheduling method, as well as corresponding base stations and terminals. The communication method performed by the terminal includes: detecting the downlink channel quality of each subcarrier; selecting a subcarrier according to the detected downlink channel quality; and sending a Sounding sequence on the selected subcarrier. The carrier scheduling method performed by the base station includes: receiving a Sounding sequence; identifying a terminal that has sent a Sounding sequence on each subcarrier; and for each subcarrier, allowing a terminal identified as having sent a Sounding sequence to participate in its scheduling competition .

Description

Communication method, carrier scheduling method, base station and terminal

technical field

The present application relates to wireless communication technology, and more specifically, to a communication method and a carrier scheduling method in a wireless communication system, as well as corresponding base stations and terminals.

Background technique

In a wireless communication system such as a TDD-LTE system, in order to perform downlink beamforming processing by the base station, a known sequence (ie, Sounding sequence) is usually sent by the user terminal, and the base station detects the sequence and utilizes the uplink and downlink of the channel The characteristic of row symmetry obtains downlink channel information. The sending of the Sounding sequence can be configured in three ways: frequency division, time division and code division. Frequency division means that each terminal can send the Sounding sequence on consecutive different subcarriers; time division means that the terminal can send the Sounding sequence on the last symbol of different downlink time slots; code division means that the terminals can use mutually orthogonal The codeword sequence sends the Sounding sequence.

For this existing system, the main purpose of the Sounding sequence is to enable the base station to obtain downlink channel information, so as to use the EBB beamforming method for data transmission. Because the terminal does not know which subcarriers will be scheduled when sending the Sounding sequence, it usually needs to send the Sounding sequence on the full bandwidth, otherwise, the subcarriers that do not send the Sounding sequence cannot be scheduled, thus losing the frequency selective scheduling gain . However, when the system uses a large bandwidth (for example, 20 MHz), it is difficult to transmit the Sounding sequence with sufficient power over the full bandwidth because the terminal transmits power is limited.

Contents of the invention

The purpose of this application is that, for a wireless communication system using a large bandwidth, the user terminal in the system can have enough power to send the Sounding sequence, and can not lose or lose frequency selective scheduling gain as little as possible.

To this end, the present application proposes a communication method, including: detecting the downlink channel quality of each subcarrier; selecting a subcarrier according to the detected downlink channel quality; and sending a Sounding sequence on the selected subcarrier.

The present application also proposes a terminal, including: a detection module, which detects the downlink channel quality of each subcarrier; a selection module, which selects a subcarrier according to the detected downlink channel quality; and a sending module, which sends Sounding on the selected subcarrier sequence.

The present application also proposes a carrier scheduling method, including: receiving a Sounding sequence; identifying a terminal that has sent a Sounding sequence on each subcarrier; and for each subcarrier, allowing a terminal identified as having sent a Sounding sequence to participate in the Its scheduling contention.

The present application also proposes a base station, including: a receiving module, which receives the Sounding sequence; an identification module, which identifies the terminal that has sent the Sounding sequence on each subcarrier; and a scheduling module, which allows each subcarrier to be identified as being on the The terminal that sent the Sounding sequence participates in its scheduling competition.

According to the embodiment of the present application, the terminal only sends the Sounding sequence on some subcarriers with better downlink channel quality, thereby ensuring that the terminal has sufficient transmit power to send the Sounding sequence in the case of a large bandwidth. At the same time, since the terminal sends the Sounding sequence on the subcarrier with better downlink channel quality, the frequency selective scheduling gain will not be lost. In addition, since all user terminals transmit the Sounding sequences on corresponding partial subcarriers, the interference between the Sounding sequences is also reduced, and the detection accuracy of the Sounding by the base station is further improved.

Description of drawings

FIG. 1 exemplarily shows a flow chart of an embodiment of a terminal communication method according to the present application;

Fig. 2 exemplarily shows the flowchart of the detection step in Fig. 1;

FIG. 3 exemplarily shows a flow chart of an embodiment of a carrier scheduling method according to the present application;

FIG. 4 exemplarily shows a flow chart of another embodiment of the carrier scheduling method according to the present application;

FIG. 5 exemplarily shows a structural diagram of a terminal according to the present application; and

Fig. 6 exemplarily shows a structural diagram of a base station according to the present application.

Detailed ways

Hereinafter, exemplary embodiments of the present application will be described in detail with reference to the accompanying drawings.

Fig. 1 exemplarily shows a flow chart of a terminal communication method 100 according to an embodiment of the present application. This method is especially suitable for TDD-LTE system. As shown in the figure, in step S101, the terminal detects the downlink channel quality of each available subcarrier in the system. In one embodiment, the terminal detects the downlink channel quality of each available subcarrier by detecting the downlink signal quality. In this case, the downlink channel quality can be characterized by, for example, the received signal-to-noise ratio of CRS (Common Reference Signal). As shown in Figure 2, when the downlink channel quality is represented by the received signal-to-noise ratio of CRS, the step S101 of detecting the downlink channel quality may further include: receiving the downlink CRS on each subcarrier in step S1011; and in step S1012 , based on the received CRS and the known standard CRS, calculate the received signal-to-noise ratio of the CRS on each subcarrier.

In step S102, based on the detected downlink channel quality of each sub-carrier, a sub-carrier for sending the Sounding sequence is selected. For example, subcarriers whose downlink channel quality is greater than a predetermined threshold may be selected; or a predetermined number of subcarriers with the best downlink channel quality may be selected. Taking the above-mentioned CRS detection as an example, in step S102, a subcarrier with a CRS receiving signal-to-noise ratio greater than a preset threshold value can be selected as the subcarrier for sending the Sounding sequence; or, a predetermined number of subcarriers with the maximum CRS receiving One or more subcarriers of the signal-to-noise ratio are used as subcarriers for sending the Sounding sequence. Specifically, the measured CRS signal-to-noise ratios may be sorted according to their magnitudes, and among them, three or five subcarriers with the highest CRS signal-to-noise ratios, for example, are selected. Then, in step S103, the Sounding sequence is sent on the selected subcarrier.

In this way, the terminal only sends the Sounding sequence on some subcarriers with better downlink channel quality, instead of sending the Sounding sequence on the full bandwidth, thus ensuring that the terminal has sufficient transmit power to send the Sounding sequence in the case of a large bandwidth. sequence, thus further ensuring the correct detection of the Sounding sequence at the base station. At the same time, because the terminal sends the Sounding sequence on the subcarrier with better downlink channel quality, and the subcarrier with better downlink channel quality is the subcarrier most likely to be scheduled for the terminal, therefore, frequency selective scheduling will not be lost gain. In addition, since all user terminals transmit Sounding sequences on corresponding partial subcarriers, the interference between Sounding sequences can also be reduced, and the detection accuracy of Sounding can be further improved.

The aforementioned Sounding sequence sent is received by the base station. Fig. 3 shows a flowchart of an exemplary implementation 300 of a method for a base station to perform carrier scheduling based on a received Sounding sequence.

Referring to FIG. 3, in step S301, the base station receives the Sounding sequence sent by the terminal. As mentioned above, each terminal only sends the Sounding sequence on some subcarriers. Then, in step S302, the base station identifies the terminal that sent the Sounding sequence on each subcarrier according to the received Sounding sequence. In step S303, for each subcarrier, the base station allows the terminal identified as having sent the Sounding sequence on the subcarrier to participate in its scheduling competition. For example, these terminals can be scheduled through an existing scheduling algorithm, and the time slots occupying the carrier can be allocated to these terminals. A terminal that does not send a Sounding sequence on the subcarrier does not participate in the scheduling competition of the subcarrier.

In one embodiment, if the terminal sends the Sounding sequence sent on the subcarrier a long time ago, it determines whether the user participates in the scheduling competition of the subcarrier according to the length of time. This is because, if the time for receiving the Sounding sequence is too long, the message containing the Sounding sequence has lost effectiveness, so the user no longer participates in the scheduling competition of the subcarrier.

Fig. 4 exemplarily shows a carrier scheduling method 400 in this case. Steps S401-S403 in FIG. 4 are the same as steps S301-S303 in the embodiment shown in FIG. 3, so the description will not be repeated here. As shown in the figure, the carrier scheduling method 400 further includes steps S404 and S405. In step S404, determine whether the Sounding sequence sent on each subcarrier has expired, for example, determine whether the time from receiving the Sounding sequence to the current moment has exceeded a predetermined value, and if so, determine that it has expired. When it is determined that the Sounding sequence sent by a certain terminal on the carrier has expired, in step S405, the terminal is prohibited from continuing to participate in the scheduling competition of the subcarrier, and then, returning to step S403, for the carrier, the corresponding subcarrier after the terminal is allowed to be removed. The terminal participates in its scheduling competition; otherwise, directly return to step S403.

The above describes the terminal communication method and the carrier scheduling method according to the present application. Although the above method is particularly applicable to the TDD-LTE system, those skilled in the art should understand that the solution of the present application is not limited to the TDD-LTE system, for example, it may also be applicable to other OFDMA systems.

In the following, the terminal and the base station that execute the above methods are described respectively.

Referring to FIG. 5 , a terminal 500 according to the present application may include a detection module 501 , a selection module 502 and a sending module 503 . The detection module 501 detects the downlink channel quality of each subcarrier. The selection module 502 selects subcarriers according to downlink channel quality. The sending module 503 sends the Sounding sequence on the selected subcarrier.

The downlink channel quality can be characterized by, for example, the received signal-to-noise ratio of the common reference signal. In this case, the detection module 501 may further include a receiving unit 5011 and a computing unit 5012 . The receiving unit 5011 receives the downlink common reference signal on each subcarrier. The calculation unit 5012 calculates the received signal-to-noise ratio of the common reference signal on each subcarrier based on the received common reference signal and the known standard common reference signal. The selection module 502 selects subcarriers according to the detected downlink channel quality. For example, the selection module 502 may select subcarriers whose downlink channel quality is greater than a predetermined threshold; or select a predetermined number of subcarriers with the best downlink channel quality.

Referring to FIG. 6 , a base station 600 according to the present application may include a receiving module 601 , an identification module 602 and a scheduling module 603 . The receiving module 601 receives the Sounding sequence. The identification module 602 identifies the terminal that has sent the Sounding sequence on each subcarrier. For each subcarrier, the scheduling module 603 allows the terminal identified as having sent the Sounding sequence on it to participate in its scheduling competition.

In one embodiment, the base station 600 may further include a determining module 604, configured to determine whether the Sounding sequence sent on each subcarrier has expired. For example, the determination module 604 may determine whether the time from receiving the Sounding sequence to the current moment has exceeded a predetermined value, and if so, determine that it has expired. When the determining module 604 determines that the Sounding sequence sent by a certain terminal on the carrier has expired, the scheduling module 603 prohibits the terminal from continuing to participate in the scheduling competition of the subcarrier.

The present application has been described above with reference to exemplary embodiments, and it should be understood that the above embodiments should not be regarded as limiting the scope of the present application. Those skilled in the art can make various modifications and variations to the above-mentioned embodiments without departing from the spirit and scope of the present application. The protection scope of the application is defined by the claims.

Claims (8)

1. a communication means, comprising:

The down channel quality of available each subcarrier in detection system;

According to detected down channel quality chooser carrier wave; And

On selected subcarrier, send Sounding sequence,

Wherein, the step that detects the down channel quality of each subcarrier available in described system comprises:

Receive the descending public reference signal on each subcarrier; And

Public reference signal based on receiving and known standard public reference signal, calculate the received signal to noise ratio of the public reference signal on each subcarrier.

2. the method for claim 1, wherein according to the step of detected down channel quality chooser carrier wave, comprise:

Select down channel quality to be greater than the subcarrier of predetermined threshold; Or

Select subcarrier predetermined quantity, that there is best down channel quality.

3. method as claimed in claim 1 or 2, wherein, described down channel quality is characterized by the received signal to noise ratio of public reference signal.

4. a terminal, comprising:

Detection module, detects the down channel quality of each subcarrier;

Select module, according to detected down channel quality chooser carrier wave; And

Sending module sends Sounding sequence on selected subcarrier,

Wherein, described detection module comprises:

Receiving element, receives the descending public reference signal on each subcarrier; And

Computing unit, the public reference signal based on receiving and known standard public reference signal, calculate the received signal to noise ratio of the public reference signal on each subcarrier.

5. terminal as claimed in claim 4, wherein, described selection module selects down channel quality to be greater than the subcarrier of predetermined threshold; Or selection subcarrier predetermined quantity, that there is best down channel quality.

6. the terminal as described in claim 4 or 5, wherein, described down channel quality is characterized by the received signal to noise ratio of public reference signal.

7. a carrier scheduling method, comprising:

Receive Sounding sequence;

Be identified in the terminal that has sent Sounding sequence on each subcarrier; And

For each subcarrier, the terminal that allows to be identified as sending Sounding sequence thereon participates in its scheduling competition,

Determine that whether the Sounding sequence sending is expired on each subcarrier; And

When determining that the Sounding sequence that sends of certain terminal is expired on this subcarrier, forbid that this terminal continues to participate in the scheduling competition of this subcarrier.

8. a base station, comprising:

Receiver module, receives Sounding sequence;

Identification module, is identified in the terminal that has sent Sounding sequence on each subcarrier; And

Scheduler module, for each subcarrier, the terminal that allows to be identified as sending Sounding sequence thereon participates in its scheduling competition,

Determination module, determines that whether the Sounding sequence sending on each subcarrier is expired; And

When described determination module determines that Sounding sequence that certain terminal sends on this subcarrier is expired, described scheduler module forbids that this terminal continues to participate in the scheduling competition of this subcarrier.

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