WO2012024922A1 - Multi-antenna combination method for uplink time advance amount and base station thereof - Google Patents

Abstract

The present invention discloses a multi-antenna combination method for uplink time advance amount, which is applied in a base station having at least two antennas, the method includes that the base station measures the time advance amount Ta value and the carrier to interference and noise ratio CINR value of the uplink channel corresponding to each antenna on the base station respectively, then selects the uplink channel whose channel quality meets the test requirement by comparing each CINR value except for the maximum CINR value among all CINR values with the maximum CINR value among all CINR values, and combines the Ta values of the selected uplink channels whose channel quality meets the test requirement; and the present invention also discloses a base station which can implement the method.

Description

 Multi-antenna combining method for uplink time advance amount and base station

Technical field

 The present invention relates to a measurement technique for time advancement (Ta, T e Advance), and more particularly to an uplink multi-antenna combining method and base station. Background technique

 The LTE project is an evolution of third-generation mobile communication technology (3G, 3rd-generation), which improves and enhances 3G air access technology, using Orthogonal Frequency Division Multiplexing (OFDM) and multiple inputs. Output (MIMO, Multiple-Input Multiple-Out-put) is the only standard for its wireless network evolution.

 The Uplink Physical Uplink Shared Channel (PUSCH) is used to transmit uplink service data sent by the user equipment (UE, User Equipment) to the base station, where one subframe includes two time slots, and each time slot includes one time slot. Pilot symbols known for the channel estimation and measurement known at the receiving end.

The base station performs the Ta measurement by using the uplink pilot symbols of each UE, and reports the measurement result to the media access control (MAC) layer. The MAC layer processes the downlink and sends the downlink to the UE. The Ta value is adjusted by Ta to ensure synchronization with the base station. The uplink synchronization accuracy is 167; (where 7 is the sampling accuracy) and its value is approximately 0.52μ _δ . When the Ta measurement result is not accurate, the UE will always adjust to an optimal transmission time, and the uplink Ta measurement result is not allowed to directly affect the performance of the uplink demodulation algorithm.

In the prior art, a method of averaging Ta values respectively measured using a plurality of antennas is generally employed to obtain a Ta measurement result. However, when the channel conditions are relatively poor, the line loss of one antenna among the plurality of antennas is relatively large, and the reliability of the Ta value measured by the antenna is relatively low. At this time, the average value obtained by using the Ta value measured by the multi-channel antenna is affected by the Ta value measured by the poor antenna, which leads to inaccurate combination result, and the Cyclic Redundancy Check (CRC) It is possible that something went wrong. When one of the antennas is completely broken, the chance of a CRC result error will be greater. Summary of the invention

 The technical problem to be solved by the present invention is to provide an uplink multi-antenna combining method and a base station to overcome the defect that the results obtained by combining the estimated Tas of the antennas when the performance of the plurality of receiving antennas are different are unreliable.

 To solve the above problem, the present invention provides a multi-antenna combining method for uplink time advancement, which is applied to a base station provided with at least two antennas, the method comprising:

 The base station respectively measures the time advance Ta value and the carrier-to-interference and noise ratio CINR value of the uplink channel corresponding to each antenna, and then passes each CINR value except the largest CINR value of all CINR values with all CINR values. The largest CINR value in the value is compared with the uplink channel whose channel quality meets the test requirement, and the Ta value of the uplink channel whose selected channel quality meets the test requirement is combined.

 Further, the step of selecting an uplink channel whose channel quality satisfies the test requirement by comparing each CINR value except the largest CINR value of all CINR values with the largest CINR value of all CINR values includes:

 The uplink channel whose ratio of the CINR value to the largest CINR value of all the CINR values is less than or equal to the preset threshold value is used as the uplink channel whose channel quality meets the test requirement; or the ratio of the CINR value to the largest CINR value among all the CINR values An uplink channel that is greater than or equal to the reciprocal of the preset threshold is used as an uplink channel whose channel quality meets the test requirements.

 Further, the step of combining the Ta values of the uplink channels whose channel quality meets the test requirements includes: performing maximum ratio combining on the Ta values of the uplink channels whose channel quality meets the test requirements.

 Further, the step of performing maximum ratio combining on the Ta value of the uplink channel whose channel quality meets the test requirement includes: the CINR value of the uplink channel that satisfies the test requirement for each channel quality, and the uplink channel of all the channel qualities satisfying the test requirement. The ratio of the sum of the CINR values is used as the weight of the Ta value of the uplink channel, and the weighted addition of the Ta values is performed.

 Further, the base station measures the Ta value and the CINR value of the uplink channel corresponding to each antenna according to the channel estimation matrix measured by each antenna.

The present invention also provides a base station having at least two antennas disposed thereon, including: Block, screening module and Ta value merge module;

 The measuring module is configured to separately measure a Ta value and a C earning value of an uplink channel corresponding to each antenna on the base station;

 The screening module is configured to select an uplink channel whose channel quality meets the test requirement by comparing each CINR value except the largest CINR value of all CINR values with the largest CINR value of all CINR values, and select the selected channel. The uplink channel Ta value whose quality meets the test requirement is sent to the Ta value merging module;

 The uplink channel whose channel quality meets the test requirement is: an uplink channel whose ratio of the CINR value to the largest CINR value of all CINR values is less than or equal to a preset threshold;

 The Ta value combining module is arranged to merge all received Ta values.

 Further, the screening module is configured to use an uplink channel whose ratio of the CINR value to the maximum CINR value of all CINR values is less than or equal to a preset threshold as an uplink channel whose channel quality meets the test requirement; or, by using a CINR value. The uplink channel with the ratio of the largest CINR value of all CINR values being greater than or equal to the reciprocal of the preset threshold value is used as the uplink channel whose channel quality meets the test requirement.

 Further, the Ta value combining module is configured to perform maximum ratio combining on all received Ta values.

 Further, the Ta value merging module is configured to use, as the Ta value of the uplink channel, a ratio of a CINR value of an uplink channel whose channel quality meets the test requirement to a total of CINR values of uplink channels whose channel qualities meet the test requirements. Weight, the weighted addition of the Ta value.

Further, the measuring module is configured to measure the Ta value and the CINR value of the uplink channel corresponding to each antenna according to the channel estimation matrix measured by each antenna. After adopting the present invention, in a base station provided with at least two antennas, when one antenna and another antenna have a far difference in performance, even if one antenna fails or is broken, the abandonment performance according to a preset threshold is poor or even The estimated Ta value on the faulty or broken antenna improves the reliability of the Ta combined value. Moreover, the accuracy of the Ta estimated combined value is improved by combining the weighted combination of CINR. BRIEF abstract

 1 is a flowchart of a multi-antenna combining method of Ta values according to an embodiment of the present invention;

 FIG. 2 is a schematic structural diagram of a base station according to an embodiment of the present invention. Preferred embodiment of the invention

 The basic idea of the method of the present invention is: the base station separately measures the Ta value and the carrier to interference plus noise ratio (CINR) of the uplink channel corresponding to each antenna, and then satisfies the channel quality. The Ta values of the upstream channels required for the test are combined. The uplink channel whose channel quality meets the test requirement is: the ratio of the maximum CINR value of all the CINR values to the CINR value of the uplink channel is less than or equal to the preset threshold.

 Preferably, the foregoing combining manner may adopt maximum ratio combining, that is, the ratio of the CINR value of the uplink channel whose channel quality satisfies the test requirement to the sum of the CIN values of all the uplink channels whose channel quality meets the test requirement is used as the Ta of the uplink channel. The weight of the value is weighted and added to the Ta value.

 In addition, as an equivalent replacement, the uplink channel that satisfies the test requirement by the channel shield is: an uplink channel whose ratio of the CINR value to the largest CINR value among all the CINR values is greater than or equal to the reciprocal of the preset threshold.

 Specifically, as shown in FIG. 1, the multi-antenna combining method of the Ta value of the present invention includes the following steps: Step 1: The base station performs Ta measurement and CINR measurement according to the channel estimation matrix H measured by each antenna on the antenna;

 The uplink Ta measurement can adopt the time domain or frequency ^ method, and since the measurement can be performed by using the prior art, it will not be described here.

 Step 2: Set a preset threshold of Ta according to the simulation and actual experience, and the base station selects the largest CINR value from all the CIN values measured above;

 Step 3: Calculate the ratio of the maximum CINR value to the CINR value of all other uplink channels, and determine whether there is a ratio greater than the preset threshold. If yes, discard the Ta value of the uplink channel.

Step 4: Perform maximum ratio combining on the Ta values of the uplink channel of the remaining Ta value and the maximum CINR value to obtain an uplink Ta measurement value. After the above method is used, it is found that when the uplink configuration is two antennas receiving and one antenna is unplugged at the same time (corresponding to the case where the analog antenna is broken), the measured Ta value is wrong at all. In the merger, because the CIN value of the broken one is very low, it is discarded, and the correct value of Ta is directly used. At this time, the CRC result is completely correct.

The invention will be further illustrated by two application examples below.

 Application example 1: When the number of uplink receiving antennas of the base station is 2, and the preset threshold value of the preset CINR ratio is 3, the multi-antenna combining method of the Ta value of the present invention includes the following steps:

 Step 1: Perform CIN measurement and Ta measurement on the signals received by antenna 0 and antenna 1, respectively, and obtain the CINR result and the Ta result of the uplink channel corresponding to antenna 0 are CINR0 and TaO, respectively, and the CINR result of the uplink channel corresponding to antenna 1 and The Ta results are CINR1 and Tal, respectively;

 Step 2: Determine whether the CINR ratios CI R1/CIK 0 and CIN 0/CINR1 calculated on the two antennas are greater than the preset threshold value 3, and if there is a threshold greater than the preset threshold, the quality of the two signals is far apart. , directly discarding Ta of one signal with poor signal quality, and using the Ta value of one signal with good signal quality as the final Ta measurement result;

 Step 3: If the CINR ratio of the two signals does not exceed the threshold, the Ta value of the two signals is subjected to maximum ratio combining (MRC, Maximum Ratio Combination), that is:

τ CINRO _τ CINRl _τ .

 Ta xTaO + xTal

 CINRO + CINRl CINRO + CINRl

 Application example 2: When the number of uplink receiving antennas of the base station is 4, and the preset threshold of the CINR ratio is 2, the multi-antenna combining method of the Ta value of the present invention includes the following steps:

 Step 1: Perform CINR measurement and Ta measurement on the received signals on antenna 0, antenna 1, antenna 2, and antenna 3, respectively, and obtain CINR measurement results and Ta measurement results on antenna 0 as CIN 0 and TaO, respectively. The CINR measurement result and the Ta measurement result are CINR1 and Tal, respectively, the CINR measurement result and the Ta measurement result on the antenna 2 are CINR2 and Ta2, respectively, and the CINR measurement result and the Ta measurement result on the antenna 3 are CINR3 and Ta3, respectively;

Step 2: Find the maximum value of the CINR value on the above four antennas CINR_Max; Step 3: Determine whether the calculated CINR ratio CINR_Max/CINRx on the CINR-Max and other antennas is greater than the preset threshold 2. If there is a threshold greater than the preset threshold, the signal with the best signal quality is much better than the other signal. , directly discarding Ta of one signal with poor signal quality;

 Step 4: Perform MRC merge on the remaining Ta value and the maximum CINR value of the Ta value.

In addition, the base station of the present invention, as shown in FIG. 2, includes: a measurement module, a screening module, and a Ta value combining module, wherein the base station is provided with at least two antennas;

 The measurement module is configured to separately measure a Ta value and a CINR value of an uplink channel corresponding to each antenna.

 Preferably, the measuring module can measure the Ta value and the CINR value of each corresponding uplink channel according to the channel estimation matrix measured by each antenna.

 The screening module is configured to send the Ta value of the uplink channel whose selected channel quality meets the test requirement to the Ta value combining module.

 The uplink channel whose channel quality meets the test requirement is an uplink channel whose ratio of the CINR to the CINR with the largest median value of all the CINRs is less than or equal to the preset threshold.

 Further, the uplink channel whose channel quality meets the test requirement may also be an uplink channel whose ratio of the CINR to the CINR of all the median CINR is greater than or equal to the reciprocal of the preset threshold.

 The Ta value combining module is arranged to merge all received Ta values.

 Preferably, the Ta value merging module may be configured to perform maximum ratio combining on all received Ta values: that is, the Ta value merging module is configured to set the CINR value of the uplink channel whose channel quality meets the test requirement to all channel qualities. The ratio of the sum of the CINR values of the uplink channels satisfying the test requirement is used as the weight of the Ta value of the uplink channel, and the weighted addition of the Ta values is performed.

One of ordinary skill in the art will appreciate that all or a portion of the above steps may be performed by a program to instruct the associated hardware, such as a read only memory, a magnetic disk, or an optical disk. Alternatively, all or part of the steps of the above embodiments may also be implemented using one or more integrated circuits. Correspondingly, each module/unit in the above embodiment can be used The form of hardware implementation can also be implemented in the form of software function modules. The invention is not limited to any specific form of combination of hardware and software. Industrial applicability

 After adopting the present invention, in a base station provided with at least two antennas, when one antenna and another antenna have a far difference in performance, even if one antenna fails or is broken, the abandonment performance according to a preset threshold is poor or even The estimated Ta value on the faulty or broken antenna improves the reliability of the Ta combined value. Moreover, by combining the weighted combination of CINR, the accuracy of the estimated value of Ta estimation is improved, and it has good industrial applicability.

Claims

Claim  A multi-antenna combining method for uplink time advancement, which is applied to a base station provided with at least two antennas, the method comprising:  The base station separately measures the time advance Ta value of the uplink channel corresponding to each antenna and the carrier and the interference and noise ratio CINR value, and then passes each CINR value except the largest CINR value among all the CINR values. The largest CINR value in the CINR value is compared with the uplink channel whose channel quality meets the test requirement, and the Ta value of the uplink channel whose selected channel quality meets the test requirement is combined.  2. The method according to claim 1, wherein: selecting an uplink channel whose channel quality meets the test requirement by comparing each CINR value except the largest CINR value among all CINR values with the largest CINR value among all CINR values The step of the disc includes:  The uplink channel whose ratio of the CINR value to the largest CINR value of all the CINR values is less than or equal to the preset threshold value is used as the uplink channel whose channel quality meets the test requirement; or the ratio of the CINR value to the largest CINR value among all the CINR values An uplink channel that is greater than or equal to the reciprocal of the preset threshold is used as an uplink channel whose channel quality meets the test requirements.  3. The method of claim 1 or 2, wherein:  The step of combining the Ta values of the uplink channels whose channel quality meets the test requirements includes: performing maximum ratio combining on the Ta values of the uplink channels whose channel quality meets the test requirements.  4. The method of claim 3, wherein:  The step of performing maximum ratio combining on the Ta value of the uplink channel whose channel quality meets the test requirement includes: CINR value of the uplink channel whose channel quality meets the test requirement is occupied by the CINR value of the uplink channel whose channel quality meets the test requirement. The ratio of the sum is used as the weight of the Ta value of the upstream channel, and the weighted addition of the Ta values is performed.  5. The method of claim 1 wherein:  The base station measures the Ta value and the CINR value of the uplink channel corresponding to each antenna according to the channel estimation matrix measured by each antenna. 6. A base station, configured with at least two antennas, including: a measurement module, a screening module, and a Ta value combining module; The measuring module is configured to separately measure a Ta value and a CINR value of an uplink channel corresponding to each antenna on the base station;  The screening module is configured to select an uplink channel whose channel quality meets the test requirement by comparing each CINR value except the largest CINR value of all CINR values with the largest CINR value of all CINR values, and select the selected channel. The uplink channel Ta value whose quality meets the test requirement is sent to the Ta value merging module;  The uplink channel whose channel quality meets the test requirement is: an uplink channel whose ratio of the CINR value to the largest CINR value of all CINR values is less than or equal to a preset threshold;  The Ta value combining module is arranged to merge all received Ta values.  7. The base station according to claim 6, wherein: the screening module is configured to satisfy a test requirement by using an uplink channel having a ratio of a CINR value to a maximum CINR value of all CIN values that is less than or equal to a preset threshold as a channel quality. Or an uplink channel that satisfies the test requirement by using an uplink channel whose ratio of the CINR value to the largest CINR value of all CINR values is greater than or equal to the reciprocal of the preset threshold.  8. The base station according to claim 6 or 7, wherein:  The Ta value combining module is configured to perform maximum ratio combining on all received Ta values.  9. The base station according to claim 8, wherein:  The Ta value merging module is configured to use, as the weight of the Ta value of the uplink channel, the ratio of the CINR value of the uplink channel whose channel quality meets the test requirement to the sum of the CINR values of the uplink channels whose channel qualities meet the test requirements. A weighted addition of the Ta values is performed.  10. The base station of claim 6, wherein:  The measurement module is configured to measure a Ta value and a CINR value of an uplink channel corresponding to each antenna according to a channel estimation matrix measured by each antenna.