WO2011015083A1 - 下行调制编码方式和多输入多输出模式的调整方法及设备 - Google Patents
下行调制编码方式和多输入多输出模式的调整方法及设备 Download PDFInfo
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L1/00—Arrangements for detecting or preventing errors in the information received
- H04L1/0001—Systems modifying transmission characteristics according to link quality, e.g. power backoff
- H04L1/0002—Systems modifying transmission characteristics according to link quality, e.g. power backoff by adapting the transmission rate
- H04L1/0003—Systems modifying transmission characteristics according to link quality, e.g. power backoff by adapting the transmission rate by switching between different modulation schemes
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L1/00—Arrangements for detecting or preventing errors in the information received
- H04L1/0001—Systems modifying transmission characteristics according to link quality, e.g. power backoff
- H04L1/0009—Systems modifying transmission characteristics according to link quality, e.g. power backoff by adapting the channel coding
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L1/00—Arrangements for detecting or preventing errors in the information received
- H04L1/0001—Systems modifying transmission characteristics according to link quality, e.g. power backoff
- H04L1/0023—Systems modifying transmission characteristics according to link quality, e.g. power backoff characterised by the signalling
- H04L1/0026—Transmission of channel quality indication
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L1/00—Arrangements for detecting or preventing errors in the information received
- H04L1/12—Arrangements for detecting or preventing errors in the information received by using return channel
- H04L1/16—Arrangements for detecting or preventing errors in the information received by using return channel in which the return channel carries supervisory signals, e.g. repetition request signals
- H04L1/18—Automatic repetition systems, e.g. Van Duuren systems
- H04L1/1812—Hybrid protocols; Hybrid automatic repeat request [HARQ]
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- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02D—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN INFORMATION AND COMMUNICATION TECHNOLOGIES [ICT], I.E. INFORMATION AND COMMUNICATION TECHNOLOGIES AIMING AT THE REDUCTION OF THEIR OWN ENERGY USE
- Y02D30/00—Reducing energy consumption in communication networks
- Y02D30/50—Reducing energy consumption in communication networks in wire-line communication networks, e.g. low power modes or reduced link rate
Definitions
- the present invention belongs to the field of mobile communications, and in particular, to a downlink modulation and coding method, a method for adjusting a multiple input multiple output mode, and a base station device.
- MIMO technology refers to the technology of transmitting/receiving multiple antennas at the transmitter/receiver. It is a research hotspot of multi-antenna technology in the field of wireless mobile antennas, and is also the next generation mobile communication.
- This technology can resist the various random fading of the channel by using multipath, effectively avoid co-channel interference, change channel quality, and improve network reliability and communication service quality.
- space resources By utilizing space resources, theoretically, no additional air interface can be consumed. Resources (time, frequency) are multiplied to increase system capacity and spectrum efficiency.
- STC Space Time Coding
- SM spatial multiplexing
- Diversity STC technology utilizes both time and space, does not increase system capacity, but improves diversity and coding gain.
- the principle is shown in Figure 1.
- the input characters ie the information source, are divided into two groups, each group being two characters.
- two characters [C1, C2] of each group are sent from two antennas at the same time.
- these two characters are transformed into the form [-C2*, C1*] again.
- Sent from two antennas In this way, the receiving antenna can be greatly improved in a form in which two characters of two characters can be received in two character times, and the bit error rate is lowered, and the reliability of the link is improved.
- the coverage of the signal is increased.
- the diversity gain can also be converted into an increase in the data transmission rate, such as using a higher modulation coding scheme.
- the spatial multiplexing technology utilizes space. As shown in Figure 2, the high-speed data stream is divided into parallel data streams for simultaneous transmission. At this time, the transmission data of each antenna is different, and then performed at the receiving end. Spatial demodulation multiplexing, recombined into high speed serial data streams. With this method, the system transmission rate and throughput can be greatly improved.
- the spatial multiplexing SM technology can improve the channel transmission rate, thereby improving channel throughput. the amount.
- the use of STC technology or SM technology alone does not maximize the use of limited band resources.
- Adaptive Modulation and Coding is a selective link adaptation method in wireless communications.
- AMC provides mobility to accommodate modulation and coding schemes to achieve an average channel situation for each user. Since the AMC modulation and coding format is changed to match the currently received signal quality or channel conditions.
- the downlink AMC is usually implemented in a space-time coding mode other than MIMO or MIMO.
- the selection process of the downlink modulation coding mode and the MIMO mode in the prior art is as follows:
- the AMC module in the base station determines the downlink modulation coding mode and the hybrid automatic repeat request (HARQ) in the base station by using the downlink carrier to interference and noise ratio (CINR) reported by the terminal.
- the module determines the MIMO mode by using the packet information fed back by the terminal, that is, the downlink modulation coding mode and the downlink MIMO mode are separately determined and adjusted.
- the disadvantages of the prior art are: In the data transmission process, since the selection range of the downlink modulation coding mode and the MIMO mode adjustment is relatively small, link reliability may be ensured, but throughput is not improved, or theoretical throughput The amount is improved, but the link reliability is not guaranteed, and eventually the actual throughput is reduced.
- the technical problem to be solved by the present invention is to provide a downlink modulation coding mode and a multi-input multi-output mode adjustment method and device, so that the current downlink modulation coding mode and the multiple input multiple output mode are suitable for the current channel condition, thereby improving the link. Reliability and system throughput.
- the present invention provides the following technical solutions:
- a method for adjusting a downlink modulation coding mode and a multiple input multiple output mode includes: establishing a correspondence table between a combination of a downlink modulation coding mode and a multiple input multiple output mode and a data transmission rate, and the data transmission in the correspondence relationship table The rates are arranged in ascending order;
- the maximum selectable modulation and coding mode is determined according to the downlink carrier to interference and noise ratio reported by the terminal, and when the currently used downlink modulation and coding mode is greater than the maximum selectable modulation and coding mode, the currently used downlink modulation and coding mode is switched to the maximum selectable modulation mode.
- Encoding mode switching the currently used multiple input multiple output mode to the space time coding mode;
- the step of adjusting the currently used downlink modulation coding mode and the multiple input multiple output mode according to the maximum selectable modulation coding mode and the correspondence table includes: calculating the first handover decision period a ratio of the number of valid data packets to the total number of data packets in each reporting period, to obtain a first ratio;
- the first switching threshold determines that the current downlink modulation coding mode and the multiple input and output mode are not suitable for the current channel condition, and searching for the data transmission rate from the correspondence relationship table is greater than the current data transmission rate, And the downlink modulation and coding mode is not greater than the entry of the maximum selectable modulation and coding mode, and the current downlink modulation coding mode and the multiple input multiple output mode are switched to the downlink modulation coding mode and the multiple input multiple output mode in the first entry found. .
- the step of adjusting the currently used downlink modulation coding mode and the multiple input multiple output mode according to the maximum selectable modulation coding mode and the correspondence table further includes: calculating the second handover decision period a ratio of the number of valid data packets to the total number of data packets in each reporting period, to obtain a second ratio; Counting the number of times that the second ratio is less than the second threshold, obtaining a second number of times; and determining that the current downlink modulation coding mode and the multiple input and output mode are not suitable for the current channel condition when the second number reaches the second handover threshold
- the corresponding relationship table searches for an entry whose data transmission rate is lower than the current data transmission rate and the downlink modulation and
- the step of adjusting the currently used downlink modulation coding mode and the multiple input multiple output mode according to the maximum selectable modulation coding mode and the correspondence table further includes: counting the total number of data packets. The number of consecutive zeros, the third number is obtained;
- the third number reaches the third switching threshold, determining that the current downlink modulation coding mode and the multiple input and output mode are not suitable for the current channel condition, and searching for the data transmission rate from the correspondence relationship table is smaller than the current data transmission rate, and the downlink is performed.
- the modulation coding mode is not greater than the entry of the maximum selectable modulation coding mode, and the current downlink modulation coding mode and the multiple input multiple output mode are switched to the downlink modulation coding mode and the multiple input multiple output mode in the first entry found.
- the first handover decision period is greater than the second handover decision period.
- the total number of data packets is the number of non-retransmission data packets that the base station counts in one reporting period.
- a base station device includes:
- a correspondence relationship table establishing module configured to establish a correspondence table between a combination of a downlink modulation coding mode and a multiple input multiple output mode and a data transmission rate, and the data transmission rates in the correspondence relationship table are arranged in an order from small to large;
- the adaptive modulation and coding module is configured to determine a maximum selectable modulation and coding mode according to a downlink carrier to interference and noise ratio reported by the terminal, and when the currently used downlink modulation and coding mode is greater than a maximum selectable modulation and coding mode, the currently used downlink is used.
- the modulation and coding mode is switched to the maximum selectable modulation and coding mode, and the currently used multiple input multiple output mode is switched to the space time coding mode;
- a hybrid automatic repeat request module configured to count information on a total number of data packets in each reporting period and a number of valid data packets in the data packet;
- a joint adjustment module configured to determine, according to the total number of data packets and the number of valid data packets, whether the current downlink modulation coding mode and the multiple input/output mode are suitable for the current channel condition, and determine the current downlink modulation coding mode and the multiple input and output mode When it is not suitable for the current channel condition, the currently used downlink modulation coding mode and the multiple input multiple output mode are adjusted according to the maximum selectable modulation coding mode and the correspondence table.
- the joint adjustment module includes:
- a first ratio calculation unit configured to calculate a ratio of the number of valid data packets to the total number of data packets in each reporting period of the first handover decision period, to obtain a first ratio
- a first number of calculation units configured to count the number of times the first ratio is greater than the first threshold, to obtain a first number of times
- a first adjusting unit configured to determine, when the first number of times reaches the first switching threshold, that the current downlink modulation coding mode and the multiple input and output mode are not suitable for the current channel condition, from the correspondence table Finding an entry whose data transmission rate is greater than the current data transmission rate and the downlink modulation and coding mode is not greater than the maximum selectable modulation and coding mode, and switching the current downlink modulation coding mode and the multiple input multiple output mode to the first entry found.
- Downlink modulation coding mode and multiple input multiple output mode configured to determine, when the first number of times reaches the first switching threshold, that the current downlink modulation coding mode and the multiple input and output mode are not suitable for the current channel condition, from the correspondence table Finding an entry whose data transmission rate is greater than the current data transmission rate and the downlink modulation and coding mode is not greater than the maximum selectable modulation and coding mode, and switching the current downlink modulation coding mode and the multiple input multiple output mode to the first entry found.
- the joint adjustment module further includes:
- a second ratio calculating unit configured to calculate a ratio of the number of valid data packets to the total number of data packets in each reporting period of the second handover decision period, to obtain a second ratio
- a second number calculating unit configured to count the number of times the second ratio is less than the second threshold, to obtain a second number of times; and a second adjusting unit configured to determine when the second number reaches the second switching threshold.
- the joint adjustment module further includes:
- a third number of calculation units configured to count the number of times the total number of data packets is continuously zero, and obtain a third number of times
- a third adjusting unit configured to: when the third number reaches the third switching threshold, determine that the current downlink modulation coding mode and the multiple input and output mode are not suitable for the current channel condition, and look up the data transmission rate from the correspondence table. An entry that is smaller than the current data transmission rate and whose downlink modulation and coding mode is not greater than the maximum selectable modulation and coding mode, and switches the current downlink modulation and coding mode and the multiple input multiple output mode to the downlink modulation and coding mode in the first entry that is found. And multiple input multiple output mode.
- the embodiment of the present invention uses the HARQ technology to determine whether the current downlink modulation coding mode and the downlink MIMO mode are suitable for the current channel condition, and performs joint adjustment of the downlink modulation coding mode and the downlink MIMO mode according to the determination result, so that the current downlink modulation coding mode and the current
- the input multiple output mode is suitable for current channel conditions, thereby improving link reliability and system throughput.
- Figure 1 is a space-time coding schematic
- Figure 2 is a schematic diagram of spatial multiplexing
- FIG. 3 is a flow chart of a method for adjusting a downlink modulation coding mode and a multiple input multiple output mode according to the present invention
- FIG. 4 is a flow chart of an adjustment method performed in a handover decision period TUP according to the present invention
- FIG. 5 is a flowchart of an adjustment method performed in a handover decision period T DOWN according to the present invention
- FIG. 6 is a schematic structural diagram of a base station device according to an embodiment of the present invention.
- FIG. 7 is a schematic structural diagram of a joint adjustment module in the foregoing base station device. Preferred embodiment of the invention
- Hybrid Hybrid Automatic Repeat Request
- HARQ technology is a physical layer technology developed on the basis of Automatic Repeat Request (ARQ) technology. It combines traditional ARQ technology with Forward Error Correction (FEC) technology and sends by sender. When the information is used, the FEC code is used. When the receiving party receives the information error bit number within the error correction capability, the error can be corrected by itself; when the error is serious and cannot be corrected, the retransmission is requested. Due to the use of multiple retransmissions, HARQ technology can better offset the impact of changes in channel conditions, thereby effectively improving transmission efficiency and reliability.
- ARQ Automatic Repeat Request
- FEC Forward Error Correction
- the retransmission mechanism of HARQ technology reflects to some extent whether the current downlink modulation coding mode and the downlink MIMO mode are suitable for the current wireless channel conditions. If there are a lot of data packets that need to be retransmitted in a certain period of time, or a lot of unsuccessful data packets are transmitted, it indicates that the current downlink modulation coding mode and the downlink MIMO mode are not suitable for the current channel condition; conversely, if within a certain period of time, The packet correct rate is very high, and almost no correction and retransmission are needed. It indicates that the current downlink modulation coding mode and the downlink MIMO mode are suitable for the current channel condition.
- the embodiment of the present invention uses the HARQ technology to determine whether the current downlink modulation coding mode and the downlink MIMO mode are suitable for the current channel condition, and performs joint adjustment of the downlink modulation coding mode and the downlink MIMO mode according to the determination result.
- the downlink modulation coding mode and the multi-input multiple-output mode adjustment method of the present invention mainly include the following steps:
- Step 301 The base station establishes a correspondence table between the combination of the downlink modulation and coding mode and the MIMO mode and the data transmission rate, and the data transmission rate in the correspondence table is in the order of decreasing to large;
- the number of bytes per time slot is also fixed in the case where the modulation coding mode and the MIMO mode are both fixed, the number of bytes on each time slot can be equivalent to the data transmission rate.
- the different modulation and coding modes for example, the downlink interval code value DIUC
- the MIMO mode are combined, and the data transmission rates corresponding to the combination are arranged in the order of small to large, that is, the following correspondence table is obtained:
- Downlink modulation coding eg., the downlink interval code value DIUC
- Step 302 The adaptive modulation and coding (AMC) module in the base station determines the maximum selectable modulation and coding mode according to the downlink CINR reported by the terminal, and when the currently used downlink modulation and coding mode is greater than the maximum selectable modulation and coding mode, the currently used The downlink modulation and coding mode is switched to the maximum selectable modulation and coding mode, and the currently used MIMO mode is switched to the space-time coding mode;
- AMC adaptive modulation and coding
- the size of the modulation and coding mode mentioned in the present invention refers to the size of the data transmission rate corresponding to the modulation and coding mode in the space-time coding mode.
- the size of the modulation and coding mode follows the following rules:
- the modulation coding mode with high coding efficiency is larger than the modulation coding mode with low coding efficiency, for example, 16QAM(CTC)3/4>16QAM(CTC)l/2.
- the AMC module determines whether the currently used downlink modulation and coding mode is greater than the maximum selectable modulation and coding mode, and if so, switches the currently used downlink modulation and coding mode to the maximum selectable modulation and coding mode, and The currently used MIMO mode is switched to the space-time coding mode, otherwise, the current downlink modulation coding mode and the MIMO mode are maintained.
- Step 303 The hybrid automatic repeat request (HQ) module in the base station collects the total number of data packets in each reporting period and the number of valid data packets therein. Since the channel conditions between different users and base stations may be different, in this step, the HARQ module separately performs the statistics for each user separately. In order to prevent the base station from frequently performing statistics, the resource occupancy rate is too high, and a reporting period TH is set. After the reporting period TH arrives, the HARQ module counts the packet information in the period: the total number of packets M, and the number of packets N successfully transmitted in the M packets, and the successfully transmitted packets are referred to in the present invention. A valid packet.
- HQ hybrid automatic repeat request
- the number of data packets transmitted for the first time may be counted, the number of the first transmitted data packets is taken as the total number of the data packets M, and the M data packets are transmitted without being retransmitted.
- the number of successful valid packets N may be used to determine the number of successful valid packets.
- Step 304 The base station determines, according to the total number of data packets and the number of valid data packets, whether the current downlink modulation and coding mode and the MIMO mode are suitable for the current channel condition, and when determining that the current downlink modulation and coding mode and the MIMO mode are not suitable for the current channel condition, Adjusting the currently used downlink modulation coding mode and MIMO mode according to the maximum selectable modulation coding mode and the correspondence table.
- two handover decision periods are set: a first handover decision period (TUP) and a second handover decision period.
- T DOWM two switching thresholds are also set: a first switching threshold (THUP ) and a second switching threshold (TH DO wM ).
- THUP first switching threshold
- TH DO wM second switching threshold
- Step 401 When each reporting period TH arrives, the HARQ module in the base station counts data packets in the reporting period TH. The total number M and the number of valid data packets N therein;
- Step 402 Calculate a ratio of the number N of valid data packets in the reporting period TH to the total number M of the data packets, to obtain a first ratio
- Steps 403 ⁇ 404 determining whether the first ratio is greater than the first threshold (m%), and if so, adding the first number of times NUP, otherwise, proceeds to step 406;
- the first threshold m% can be flexibly set according to a specific communication environment, and the first number of times NUP is initially 0.
- Step 405 determining whether the first number of times NUP reaches the first handover threshold THUP, if yes, indicating that the current downlink modulation coding mode and the MIMO mode are not suitable for the current channel condition, proceeding to step 407, otherwise, proceeding to step 406;
- Step 406 Determine whether the first handover decision period TUP arrives, and if yes, proceed to step 408, otherwise, return to step 401;
- Step 407 Adjust the currently used downlink modulation coding mode and the MIMO mode according to the maximum selectable modulation coding mode and the correspondence relationship table, thereby adjusting the data transmission rate; specifically, from the correspondence table ( Table 1)
- the entry in the downward looking data transmission rate is greater than the current data transmission rate, and the downlink modulation coding mode is not greater than the maximum selectable modulation coding mode, and the current downlink modulation coding mode and the MIMO mode are switched to the first one found.
- the downlink modulation coding mode and MIMO mode in the entry is not greater than the maximum selectable modulation coding mode
- Step 408 All statistics are cleared to the next handover decision cycle.
- FIG. 5 is a flowchart of an adjustment method performed in a handover decision period T DOWN according to the present invention, which mainly includes the following steps:
- Step 501 When each reporting period TH arrives, the HARQ module in the base station counts the total number of data packets M in the reporting period TH and the number of valid data packets N therein;
- Step 502 Calculate a ratio of the number N of valid data packets in the reporting period TH to the total number M of the data packets, to obtain a second ratio;
- Steps 503 to 504 determining whether the second ratio is less than a second threshold ( ⁇ %), and if so, adding a second number of times N DO WN to 1, otherwise, proceeding to step 506;
- the second threshold n% can be flexibly set according to a specific communication environment, and the second number N DO WN is initially 0.
- Step 505 Determine whether the second number N DOWN reaches the second handover threshold TH DOWN , and if yes, indicating that the current downlink modulation coding mode and the MIMO mode are not suitable for the current channel condition, proceed to step 507, otherwise, proceed to step 506;
- Step 506 Determine whether the second handover decision period T DOWN arrives, and if yes, proceed to step 508. Otherwise, return to step 501;
- Step 507 Adjust the currently used downlink modulation and coding mode and the MIMO mode according to the maximum selectable modulation and coding mode and the corresponding relationship table, thereby reducing the data transmission rate; specifically, from the correspondence table ( Table 1) Looking up the entry in which the data transmission rate is lower than the current data transmission rate and the downlink modulation coding mode is not greater than the maximum selectable modulation coding mode, and switching the current downlink modulation coding mode and the MIMO mode to the first entry found.
- the downlink modulation coding mode and the MIMO mode is the correspondence table
- Step 508 All statistics are cleared to the next handover decision period.
- the method includes: collecting a number of times that the total number of data packets is consecutively zero, and obtaining a third number of times; when the third number of times reaches a third switching threshold, searching for the data transmission rate from the correspondence relationship table is smaller than a current data transmission rate.
- the downlink modulation and coding scheme is not greater than the entry of the maximum selectable modulation and coding scheme, and the current downlink modulation and coding scheme and the MIMO mode are switched to the downlink modulation and coding scheme and the MIMO mode in the first entry that is found.
- a base station device that implements the above method is given below.
- the base station device 60 of the embodiment of the present invention includes:
- the correspondence relationship table establishing module 61 is configured to establish a correspondence table between the combination of the downlink modulation coding mode and the multiple MIMO mode and the data transmission rate, and the data transmission rates in the correspondence relationship table are arranged in descending order.
- the number of bytes per time slot is also fixed in the case where the modulation coding mode and the MIMO mode are both fixed, the number of bytes on each time slot can be equivalent to the data transmission rate.
- the different modulation and coding modes are combined with the MIMO mode, and the data transmission rates corresponding to the combination are arranged in ascending order to obtain a correspondence table as shown in Table 1.
- the adaptive modulation and coding module 62 is configured to determine a maximum selectable modulation and coding mode according to the downlink CINR reported by the terminal, and to use the currently used downlink modulation and coding mode when the currently used downlink modulation and coding mode is greater than the maximum selectable modulation and coding mode. Switch to the maximum optional modulation and coding mode, Switch the currently used MIMO mode to the space-time coding mode.
- the hybrid automatic repeat request module 63 is arranged to count information on the total number of packets in each reporting period and the number of valid packets in the packet.
- the hybrid automatic repeat request module 63 Since the channel conditions between different users and base stations may be different, the hybrid automatic repeat request module 63 separately performs the statistics for each user separately. In order to avoid frequent statistics, the resource occupancy rate is too high, and a reporting period TH is set. After the reporting period TH arrives, the hybrid automatic repeat request module 63 counts the total number M of packets in the period, and the number of valid packets N in the M packets. The successfully transmitted data packet is referred to in the present invention. A valid packet. .
- the number of data packets transmitted for the first time may be counted, the number of the first transmitted data packets is taken as the total number of the data packets M, and the M data packets are transmitted without being retransmitted.
- the number of successful valid packets N may be used to determine the number of successful valid packets.
- the joint adjustment module 64 is configured to determine, according to the total number of data packets and the number of valid data packets, whether the current downlink modulation and coding mode and the MIMO mode are suitable for the current channel condition, and determine that the current downlink modulation and coding mode and the MIMO mode are not suitable for the current In the channel condition, the currently used downlink modulation and coding mode and the MIMO mode are adjusted according to the maximum selectable modulation and coding scheme and the correspondence table.
- two handover decision periods are set: a first handover decision period (TUP) and a second handover decision period.
- T DOWM two switching thresholds are also set: a first switching threshold (THUP) and a second switching threshold (TH DO wM ).
- THUP first switching threshold
- TH DO wM second switching threshold
- the joint adjustment module 64 specifically includes:
- a first ratio calculating unit 71 configured to calculate a ratio of the number of valid data packets to the total number of data packets in each reporting period of the first switching decision period, to obtain a first ratio
- a first number calculation unit 72 configured to count the number of times the first ratio is greater than the first threshold, to obtain a first number of times
- the first adjusting unit 73 is configured to: when the first number of times reaches the first switching threshold, determine that the current downlink modulation and coding mode and the MIMO mode are not suitable for the current channel condition, and search for the data transmission from the correspondence table. An entry whose rate is greater than the current data transmission rate and whose downlink modulation and coding mode is not greater than the maximum selectable modulation and coding mode, and switches the current downlink modulation and coding mode and the MIMO mode to the downlink modulation coding mode and MIMO in the first entry found. mode;
- a second ratio calculating unit 74 configured to calculate a ratio of the number of valid data packets to the total number of data packets in each reporting period of the second switching decision period, to obtain a second ratio
- a second number calculating unit 75 configured to count the number of times the second ratio is less than the second threshold to obtain a second number of times; and a second adjusting unit 76 configured to when the second number reaches the second switching threshold Determining that the current downlink modulation coding mode and the MIMO mode are not suitable for the current channel condition, and searching for an entry in the correspondence relationship table that the data transmission rate is smaller than the current data transmission rate, and the downlink modulation coding mode is not greater than the maximum selectable modulation coding mode, The current downlink modulation coding mode and the MIMO mode are switched to the downlink modulation coding mode and the MIMO mode in the first entry found.
- the joint adjustment module 64 may further include:
- a third number of calculation units (not shown), configured to count the number of times the total number of data packets is continuously zero, to obtain a third number of times;
- a third adjusting unit (not shown), configured to: when the third number reaches the third switching threshold, the upward looking data transmission rate is lower than the current data transmission rate, and the downlink modulation and coding mode is not An entry larger than the maximum selectable modulation coding mode switches the current downlink modulation coding mode and the MIMO mode to the downlink modulation coding mode and the MIMO mode in the first entry found.
- Table 1 is instantiated to obtain the following Table 2: Downlink modulation coding mode Number of bytes per time slot
- the current downlink modulation and coding mode is: 16 QAM (CTC) 1/2
- the downlink MIMO mode is: SM mode
- the downlink CINR reported by the terminal does not change. If the download performance of the terminal is not good at this time, the data transmission rate needs to be lowered.
- the current downlink modulation and coding mode 16QAM (CTC) 1/2 is maintained, and the downlink MIMO mode is adjusted to: STC mode.
- the technical solution of the present invention will look up from the current entry of Table 2 (16QAM (CTC) 1/2, SM), and the data transmission rate is lower than the current data transmission rate (24), and the downlink modulation coding mode is not greater than the maximum.
- the search result is: QPSK (CTC) 3/4, SM, and switch the current downlink modulation and coding mode and MIMO mode to: QPSK (CTC) ) 3/4, SM.
- the HARQ technique is used to judge whether the current downlink modulation coding mode and the downlink MIMO mode are suitable for the current channel condition.
- the present invention can effectively improve the data transmission rate and spectrum utilization, thereby improving the reliability of the link and the throughput of the system.
- the downlink modulation coding method, the multi-input multiple-output mode adjustment method, and the base station apparatus provided by the present invention use HARQ technology to determine whether the current downlink modulation coding mode and the downlink MIMO mode are suitable for the current channel condition, and perform downlink according to the determination result.
- the joint adjustment of the modulation coding mode and the downlink MIMO mode effectively improves the reliability of the link and the throughput of the system.
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Priority Applications (2)
Application Number | Priority Date | Filing Date | Title |
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JP2012520895A JP2012533947A (ja) | 2009-08-04 | 2010-06-11 | ダウンリンク変調符号化方式及びマルチ入力マルチ出力モードの調整方法、並びに設備 |
US13/383,280 US20120120840A1 (en) | 2009-08-04 | 2010-06-11 | Adjusting Method for Downlink Modulation Coding Mode and Multiple-Input-Multiple-Output Mode and Device |
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CN200910090269.2 | 2009-08-04 | ||
CN2009100902692A CN101990315B (zh) | 2009-08-04 | 2009-08-04 | 下行调制编码方式和多输入多输出模式的调整方法及设备 |
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CN102761387B (zh) * | 2011-04-26 | 2015-06-03 | 中兴通讯股份有限公司 | 自适应调制与编码方法及装置 |
CN102833034B (zh) * | 2011-06-16 | 2017-03-15 | 中兴通讯股份有限公司 | 确定调制编码方式的方法及装置 |
CN102916764B (zh) * | 2011-08-03 | 2017-08-25 | 中兴通讯股份有限公司 | 一种升阶周期的调整方法及系统 |
US9036608B2 (en) * | 2012-11-09 | 2015-05-19 | Telefonaktiebolaget L M Ericsson (Publ) | Adaptive transmission mode switching |
JP6440176B2 (ja) | 2014-07-07 | 2018-12-19 | 華為技術有限公司Huawei Technologies Co.,Ltd. | ワイヤレスフィディリティ技術の帯域幅選択方法およびアクセスポイントap |
KR20170128019A (ko) * | 2016-05-13 | 2017-11-22 | 삼성전자주식회사 | 전자 장치 및 전자 장치에서의 무선 통신 방법 |
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CN1567759A (zh) * | 2003-06-27 | 2005-01-19 | 上海贝尔阿尔卡特股份有限公司 | 一种自适应正交频分复用(ofdm)系统中的反馈信息传输方法 |
CN101039164A (zh) * | 2006-03-14 | 2007-09-19 | 华为技术有限公司 | 多输入输出系统下行链路数据处理方法和模块 |
CN101478364A (zh) * | 2008-01-02 | 2009-07-08 | 中国移动通信集团上海有限公司 | 用于wcdma网络高速下行分组接入的自适应调制编码方法 |
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US7706347B2 (en) * | 2003-05-15 | 2010-04-27 | Lg Electronics Inc. | Signal processing apparatus and method using multi-output mobile communication system |
US7843887B2 (en) * | 2004-11-02 | 2010-11-30 | Panasonic Corporation | Mobile station device and communication partner selection method |
CN101375523B (zh) * | 2005-01-12 | 2012-12-12 | 高通创锐讯有限公司 | 在mimo系统中选择mcs的方法 |
CN101030833B (zh) * | 2006-03-01 | 2012-09-05 | 株式会社Ntt都科摩 | 自适应空时编码调制方法及使用其的发射机 |
JP5388529B2 (ja) * | 2008-09-30 | 2014-01-15 | 株式会社日立国際電気 | 無線通信装置 |
US8107888B2 (en) * | 2009-03-04 | 2012-01-31 | Clearwire IP Holdings, LLC | Communication operating mode selection based on multi-path signal power measurement |
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CN1567759A (zh) * | 2003-06-27 | 2005-01-19 | 上海贝尔阿尔卡特股份有限公司 | 一种自适应正交频分复用(ofdm)系统中的反馈信息传输方法 |
CN101039164A (zh) * | 2006-03-14 | 2007-09-19 | 华为技术有限公司 | 多输入输出系统下行链路数据处理方法和模块 |
CN101478364A (zh) * | 2008-01-02 | 2009-07-08 | 中国移动通信集团上海有限公司 | 用于wcdma网络高速下行分组接入的自适应调制编码方法 |
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JP2012533947A (ja) | 2012-12-27 |
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