US20180337764A1 - Rank Indicator Adaptation Based on Downlink Error Rate - Google Patents
Rank Indicator Adaptation Based on Downlink Error Rate Download PDFInfo
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- US20180337764A1 US20180337764A1 US15/686,012 US201715686012A US2018337764A1 US 20180337764 A1 US20180337764 A1 US 20180337764A1 US 201715686012 A US201715686012 A US 201715686012A US 2018337764 A1 US2018337764 A1 US 2018337764A1
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
- H04L5/00—Arrangements affording multiple use of the transmission path
- H04L5/003—Arrangements for allocating sub-channels of the transmission path
- H04L5/0053—Allocation of signaling, i.e. of overhead other than pilot signals
- H04L5/0057—Physical resource allocation for CQI
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
- H04B—TRANSMISSION
- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
- H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
- H04B7/0413—MIMO systems
- H04B7/0456—Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting
- H04B7/0486—Selection of precoding matrices or codebooks, e.g. using matrices antenna weighting taking channel rank into account
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- H—ELECTRICITY
- H04—ELECTRIC COMMUNICATION TECHNIQUE
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- H04B7/00—Radio transmission systems, i.e. using radiation field
- H04B7/02—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas
- H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
- H04B7/06—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station
- H04B7/0613—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission
- H04B7/0615—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission of weighted versions of same signal
- H04B7/0619—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission of weighted versions of same signal using feedback from receiving side
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- H04B7/063—Parameters other than those covered in groups H04B7/0623 - H04B7/0634, e.g. channel matrix rank or transmit mode selection
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- 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
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- H04L1/0009—Systems modifying transmission characteristics according to link quality, e.g. power backoff by adapting the channel coding
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- 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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- H04W72/044—Wireless resource allocation based on the type of the allocated resource
- H04W72/0473—Wireless resource allocation based on the type of the allocated resource the resource being transmission power
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- H04B7/04—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas
- H04B7/06—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station
- H04B7/0613—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission
- H04B7/0615—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission of weighted versions of same signal
- H04B7/0619—Diversity systems; Multi-antenna system, i.e. transmission or reception using multiple antennas using two or more spaced independent antennas at the transmitting station using simultaneous transmission of weighted versions of same signal using feedback from receiving side
- H04B7/0621—Feedback content
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- H04L1/0023—Systems modifying transmission characteristics according to link quality, e.g. power backoff characterised by the signalling
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- H04L1/20—Arrangements for detecting or preventing errors in the information received using signal quality detector
- H04L1/203—Details of error rate determination, e.g. BER, FER or WER
Definitions
- Wireless communication devices are commonly used to browse the Internet, transmit files, stream music and video, and perform other tasks that involve wirelessly receiving data from a network.
- the user experience is improved when such data transmissions occur quickly, and thus network operators and device manufacturers strive to improve data throughput.
- MIMO multiple-input multiple-output
- devices can have multiple transmitting antennas and/or multiple receiving antennas, such that multiple data streams can be sent between the multiple antennas over the same radio channel.
- increasing the number of data streams can accordingly increase the amount of data that can be transmitted, thereby improving throughput.
- FIG. 1 depicts a telecommunication device in wireless communication with a network base station via multiple data streams using multiple-input multiple-output (MIMO) techniques.
- MIMO multiple-input multiple-output
- FIG. 2 depicts a graph in which a measured error rate can be compared to a predefined acceptable error rate and/or an RI increase threshold.
- FIG. 3 depicts an example system architecture for a telecommunication device.
- FIG. 4 depicts a flow chart of a method for increasing throughput to a telecommunication device by inducing a base station to transmit additional data streams using MIMO techniques.
- a network base station can wirelessly transmit data to a telecommunication device.
- the data throughput to the telecommunication device can depend, at least in part, on a Modulation and Coding Scheme (MCS) used by the base station, as well as the number of multiple-input multiple-output (MIMO) data streams sent by the base station to the telecommunication device.
- MCS Modulation and Coding Scheme
- MIMO multiple-input multiple-output
- An MCS can indicate a particular modulation scheme used by a base station, such as a quadrature amplitude modulation (QAM) scheme that increases throughput by combining multiple modulated signals into a single channel.
- QAM quadrature amplitude modulation
- the amount of the throughput increase can depend on the particular QAM scheme. For example, an MCS that uses 256-QAM can lead to a higher throughput that an MCS that uses 64-QAM, because 256-QAM can carry 8 bits per symbol while 64-QAM can carry 6 bits per symbol.
- MIMO techniques can also be used to increase throughput to the telecommunication device when the telecommunication device and base station have multiple transmitting and/or receiving antennas.
- the base station can transmit multiple MIMO data streams using different antennas, and the telecommunication device can receive the transmitted signals and decode them back into the original data streams.
- Each MIMO data stream can have substantially the same data capacity, and accordingly increasing the number of MIMO data streams sent by the base station can increase throughput to the telecommunication device.
- a base station can combine MIMO techniques and modulation schemes defined by an MCS to adjust the throughput to a telecommunication device. For example, in some situations peak data throughput of over 1 Gigabit per second (Gbps) can be achieved when four data streams can be sent and received in a 4 ⁇ 4 MIMO system using a 256-QAM MCS.
- Gbps Gigabit per second
- the telecommunication device can report information to the base station about the signals it is receiving, such that the base station can adjust how it is sending signals to the telecommunication device based on current radio conditions.
- the report sent by the telecommunication device can include a Rank Indicator (RI) and a Channel Quality Indicator (CQI).
- the RI indicates a MIMO layer associated with a number of MIMO data streams decoded by the telecommunication device.
- the CQI indicates the quality of signals received by the telecommunication device, in some examples and can be based on an error rate measured by the telecommunication device, such as a downlink Block Error Rate (DL BLER).
- DL BLER downlink Block Error Rate
- a telecommunication device can determine the DL BLER of received signals, and report a CQI value to the base station that is associated with an MCS expected to lead to a DL BLER under a predefined acceptable BLER, such as a BLER of 10%.
- the telecommunication device's report can include the measured error rate instead of, or in addition to, the CQI.
- the base station can select the number of MIMO data streams to send based on the reported RI and the MCS to use based on the reported CQI. For example, if the telecommunication device reports an RI value of “3” and a particular CQI value, the base station can follow that information to transmit three MIMO data streams using an MCS associated with the reported CQI value.
- telecommunications devices prioritize sending a CQI value linked to a higher MCS over sending a higher RI value. For example, in tests in which the maximum RI value was four and an acceptable error rate threshold was set at a DL BLER of 10%, when telecommunication devices measured a DL BLER of only 2% or another percentage well below the 10% acceptable BLER threshold, they often reported a high CQI but a lower than maximum RI value of “3.” The difference between the measured error rates and the acceptable error rate threshold in these tests indicates that, as will be discussed below, in some cases the telecommunication device can handle one or more additional MIMO data streams without the measured error rate going over the acceptable error rate threshold. Sending additional MIMO data streams when such capacity exists would lead to increased throughput to the telecommunication device.
- This disclosure describes various systems and processes that can be implemented at telecommunication device to adaptively induce a base station to send one or more additional MIMO data streams in certain situations, in order to increase the data throughput to the telecommunication device.
- the telecommunication device when the telecommunication device measures an RI value that is less than a maximum RI, but it measures an error rate below an acceptable error rate threshold, it can report an inflated RI value to the base station that is higher than the measured RI value. The base station can then follow the reported inflated RI value to send an increased number of MIMO data streams to the telecommunication device.
- FIG. 1 depicts a telecommunication device 102 in wireless communication with a network base station 104 via multiple data streams 106 using multiple-input multiple-output (MIMO) techniques.
- the base station 104 can determine the number of data streams 106 to transmit to the telecommunication device 102 based on a report 108 sent from the telecommunication device 102 to the base station 104 about previous transmissions it has received from the base station 104 .
- the report 108 can include a Rank Indicator (RI) 110 and/or a Channel Quality Indicator (CQI) 112 .
- RI Rank Indicator
- CQI Channel Quality Indicator
- a telecommunication device 102 can be any device that wirelessly connects to a base station 104 , such as a smart phone, a cellular phone, a personal digital assistant (PDA), a personal computer (PC), a laptop, a desktop, a workstation, a media player, a tablet, an electronic book device, a gaming device, a television, a media center, a smart watch, or any other type of computing or communication device.
- a base station 104 such as a smart phone, a cellular phone, a personal digital assistant (PDA), a personal computer (PC), a laptop, a desktop, a workstation, a media player, a tablet, an electronic book device, a gaming device, a television, a media center, a smart watch, or any other type of computing or communication device.
- PDA personal digital assistant
- PC personal computer
- An example telecommunication device 102 is illustrated in greater detail in FIG. 3 and is described in detail below with reference to that figure.
- a base station 104 can be a node or other access point that provides a connected telecommunication device 102 with access to a telecommunications network through a wireless access technology, such as Long Term Evolution (LTE)/LTE Advanced technology, High-Speed Data Packet Access (HSDPA)/Evolved High-Speed Packet Access (HSPA+) technology, Universal Mobile Telecommunications System (UMTS) technology, Code Division Multiple Access (CDMA) technology, Global System for Mobile Communications (GSM) technology, WiMax® technology, and/or WiFi® technology.
- LTE Long Term Evolution
- HSDPA High-Speed Data Packet Access
- HSPA+ High-Speed Packet Access
- UMTS Universal Mobile Telecommunications System
- CDMA Code Division Multiple Access
- GSM Global System for Mobile Communications
- WiMax® Worldwide Interoperability for Mobile Communications
- a telecommunication device 102 and base station 104 can each have multiple antennas 114 for transmitting and/or receiving data, such that they can use MIMO techniques to send and/or receive different data streams 106 with different antennas 114 .
- the arrangement of transmitter antennas 114 and receiver antennas 114 in a MIMO system can be expressed as N ⁇ M, with N indicating the number of transmitter antennas 114 and M indicating the number of receiver antennas 114 .
- devices in a 2 ⁇ 2 MIMO system can have two transmitter antennas 114 and two receiver antennas 114
- devices in a 4 ⁇ 4 MIMO system can have four transmitter antennas 114 and four receiver antennas 114 . While in some examples N can be equal to M, in other examples N and M can be different.
- the base station 104 can split data to be transmitted to the telecommunication device 102 into multiple data streams 106 using multiplexing, such as open-loop or closed-loop spatial multiplexing.
- the base station 104 can transmit each of the multiple data streams 106 with a different transmitting antenna 114 over the same radio channel.
- the signals transmitted from each transmitting antenna 114 can take different paths to the telecommunication device 102 . Accordingly, parts of some or all of the different signals from the different transmitting antennas 114 can be received at multiple receiving antennas 114 at the telecommunication device 102 .
- the telecommunication device 102 can decode the received signals and reconstruct the original data streams 106 .
- Each data stream 106 can have substantially the same data capacity. Accordingly, each additional data stream 106 that can be transmitted from the base station 104 and be received and decoded by the telecommunication device 102 using MIMO techniques can correspondingly increase the data throughput to the telecommunication device 102 .
- the base station 104 can also transmit the data streams 106 to the telecommunication device 102 using a Modulation and Coding Scheme (MCS).
- MCS Modulation and Coding Scheme
- An MCS can define a modulation scheme, code rate, and/or other attributes that the base station 104 can use when sending data transmissions to the telecommunication device 102 , such as a quadrature amplitude modulation (QAM) scheme that can increase throughput by combining multiple modulated signals into a single channel.
- QAM quadrature amplitude modulation
- an MCS can identify a particular modulation scheme, such as 256-QAM, 64-QAM, 16-QAM, or any other modulation scheme.
- the number prefacing “QAM” in these schemes can indicate the number of bits that can be carried per symbol in that scheme. For instance, 256-QAM can carry 8 bits per symbol, while 64-QAM can carry 6 bits per symbol.
- the telecommunication device 102 can send back a report 108 to the base station 104 about how the data streams 106 are being received, including RI 110 and/or CQI 112 values.
- the telecommunication device 102 can send a report 108 periodically at regular intervals, at irregular intervals or predefined times, upon request by the base station 104 , or upon the occurrence of a reporting event.
- the RI 110 in the report 108 can indicate a number of data streams 106 that the telecommunication device 102 is requesting from the base station 104 .
- the telecommunication device 102 can determine the value of the RI 110 based at least in part on the number of data streams 106 it decoded within signals received from the base station 104 . Selection of the RI 110 value will be discussed in more detail below.
- the reported RI 110 can be less than or equal to a maximum RI associated with the MIMO configurations of the telecommunication device 102 and the base station 104 .
- the maximum RI can be the maximum number of MIMO data streams 106 that could be transmitted from the base station 104 to the receiver antennas 114 of the telecommunication device 102 , as limited by the number of transmitter antennas 114 in the base station 104 and the number of receiver antennas 114 in the telecommunication device 102 .
- the maximum RI can be at most the lower of X and Y.
- the maximum RI can be set to four.
- the maximum RI can be set to a higher or lower value determined by the number of receiver antennas 114 in the telecommunication device 102 and/or a maximum number of data streams 106 a base station 104 can send to those receiving antennas 114 using MIMO techniques. For instance, in an 8 ⁇ 8 MIMO configuration, the maximum RI can be set to eight.
- the CQI 112 in the report 108 can be based on an error rate 200 measured by the telecommunication device.
- FIG. 2 depicts a graph in which a measured error rate 200 can be compared to a predefined acceptable error rate 202 and/or an RI increase threshold 204 as will be discussed further below.
- the telecommunication device 102 can include the measured error rate 200 in the report 108 in addition to, or in place of, the CQI 112 .
- an error rate 200 can be a downlink Block Error Rate (DL BLER) determined by the telecommunication device.
- the telecommunication device 102 can use an error detection technique, such as analyzing a cyclic redundancy check (CRC) code in a received data block, to determine when a received data block contains an error.
- the DL BLER can be the percentage of the total number of data blocks that are found to have an error.
- the telecommunication device 102 can thus determine the DL BLER of received signals, and include a CQI 112 in the report 108 that is associated with an MCS expected to lead to a DL BLER under a predefined acceptable error rate 202 , such as a DL BLER of 10%.
- the error rate 200 can be measured as a bit error rate (BER), signal to noise ratio (SNR), or any other measure of errors within received data.
- BER bit error rate
- SNR signal to noise ratio
- the base station 104 When the base station 104 receives a report 108 including an RI 110 and a CQI 112 values from the telecommunication device 102 , it can use those reported values to adjust or select the number of data streams 106 to send to the telecommunication device 102 using MIMO, and/or the MCS to use when sending those data streams 106 . For example, when the reported RI 110 is “3” and the reported CQI 112 is associated with an MCS, the base station 104 can send the telecommunication device 102 three MIMO data streams 106 using that MCS. While the base station 104 may choose to adjust the MCS, it does not attempt to override the reported RI 110 .
- the telecommunication device 102 can change the data in the report 108 from what it would otherwise include, in order to adaptively induce the base station 104 to increase the number of data streams 106 it sends to the telecommunication device 102 using MIMO. By inducing the base station 104 to transmit an increased number of data streams 106 in these situations, data throughput to the telecommunication device 102 can be increased.
- FIG. 3 depicts an example system architecture for a telecommunication device 102 , in accordance with various examples.
- a telecommunication device 102 can also include a memory 302 that stores modules and data 304 , processor(s) 306 , radio interfaces 308 , a display 310 , output devices 312 , input devices 314 , and/or a drive unit 316 including a machine readable medium 318 .
- memory 302 generally includes both volatile memory and non-volatile memory, such as RAM, ROM, EEPROM, Flash Memory, a hard drive, a memory card, optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium.
- memory 302 can also include a SIM (subscriber identity module) card, which is a removable memory card used to identify a user of the telecommunication device 102 to a telecommunication network.
- SIM subscriber identity module
- Memory 302 can also be described as computer storage media and may include volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information, such as computer readable instructions, data structures, program modules, or other data.
- the modules and data 304 can be utilized by the telecommunication device 102 to perform or enable performing any action taken by the telecommunication device 102 .
- the modules and data 304 can include a telecommunication device platform and applications, and data utilized by the platform and applications.
- the processor(s) 306 is a central processing unit (CPU), a graphics processing unit (GPU), or both CPU and GPU, or any other sort of processing unit.
- CPU central processing unit
- GPU graphics processing unit
- any other sort of processing unit any other sort of processing unit.
- the radio interfaces 308 can include transceivers, modems, interfaces, and/or other components that perform or assist in exchanging radio frequency (RF) communications with a base station 104 via transmitter and receiver antennas 114 .
- a telecommunication device's radio interfaces 308 can include an RF Front End (RFFE) that receives RF signals via four receiving antennas 114 in a 4 ⁇ 4 MIMO configuration, an RFIC (RF Integrated Chip) that decodes the RF signals into four data streams 106 , and a modem that performs other processing operations on the data streams 106 .
- RFFE RF Front End
- RFIC RF Integrated Chip
- a processor 306 , other modules and data 304 , and/or other components of the telecommunication device 102 can perform or assist in transmitting and/or receiving data via the antennas 114 , and/or pre-processing or post-processing of such data.
- the display 310 is a liquid crystal display or any other type of display commonly used in telecommunication devices 102 .
- display 310 may be a touch-sensitive display screen, and can then also act as an input device or keypad, such as for providing a soft-key keyboard, navigation buttons, or any other type of input.
- the output devices 312 can include any sort of output devices known in the art, such as a display 310 , speakers, a vibrating mechanism, and/or a tactile feedback mechanism. Output devices 312 can also include ports for one or more peripheral devices, such as headphones, peripheral speakers, and/or a peripheral display.
- input devices 314 can include any sort of input devices known in the art.
- input devices 314 can include a microphone, a keyboard/keypad, and/or a touch-sensitive display, such as the touch-sensitive display screen described above.
- a keyboard/keypad can be a push button numeric dialing pad, a multi-key keyboard, or one or more other types of keys or buttons, and can also include a joystick-like controller, designated navigation buttons, or any other type of input mechanism.
- the machine readable medium 318 can store one or more sets of instructions, such as software or firmware, that embodies any one or more of the methodologies or functions described herein.
- the instructions can also reside, completely or at least partially, within the memory 302 , processor(s) 306 , and/or radio interface(s) 308 during execution thereof by the telecommunication device 102 .
- the memory 302 and the processor(s) 306 also can constitute machine readable media 322 .
- FIG. 4 depicts a flow chart of a method for increasing throughput to a telecommunication device by inducing a base station 104 to transmit additional data streams 106 using MIMO techniques.
- the telecommunication device 102 can receive RF signals from the base station 104 using multiple receiver antennas 114 .
- the telecommunication device 102 can decode the received RF signals into one or more data streams 106 .
- the telecommunication device 102 can de-multiplex the received RF signals to distinguish different data streams 106 sent over the same radio channel.
- the telecommunication device 102 may not be able to successfully decode all of the data streams 106 sent by the base station 104 , such as when there is noise or interference due to multipath propagation of the MIMO signals, or other issues that affect the signals received by the telecommunication device.
- the telecommunication device 102 can also determine an error rate 200 of the decoded data.
- the error rate 200 can be measured as a downlink Block Error Rate (DL BLER), the percentage of the total number of data blocks that CRC codes indicate have an error.
- DL BLER downlink Block Error Rate
- the telecommunication device 102 can count the number of data streams 106 that were decoded during block 402 . The telecommunication device 102 can then determine whether the number of different data streams 106 decoded from the received RF signals is equal to a maximum RI for the MIMO arrangement of the telecommunication device 102 and base station 104 .
- the maximum RI can be the maximum number of data streams 106 that could be transmitted from the base station 104 to the telecommunication device 102 , as limited by the number of transmitter antennas 114 in the base station 104 and/or the number of receiver antennas 114 in the telecommunication device 102 .
- the maximum RI can be set to four and the telecommunication device 102 can determine at block 404 whether or not it decoded four data streams 106 from the received RF signals.
- the maximum RI can be set to any other value limited by the number of antennas 114 at the telecommunication device 102 and/or base station 104 , and the telecommunication device 102 can check at block 404 if it decoded a number of data streams 106 equal to that maximum RI.
- the telecommunication device 102 determines at block 404 that it decoded a number of data streams 106 equal to the maximum RI, it can set the value of an RI 110 to the maximum RI at block 406 . For example, if the maximum RI is four and the telecommunication device 102 decoded four data streams 106 , it can set the RI to “4.” The RI 110 can be reported to the base station 104 at block 414 , as will be discussed below.
- the telecommunication device 102 determines that it decoded a number of data streams 106 that is less than the maximum RI, at block 408 it can set the value of the RI 110 to the number of decoded data streams 106 and then move to block 410 . For example, if the maximum RI is four, but the telecommunication device 102 decoded only three data streams, it can set the RI 110 to “3.”
- the telecommunication device 102 can determine if the error rate 200 of the decoded data is below an RI increase threshold 204 .
- the RI increase threshold 204 can be less than or equal to the acceptable error rate 202 .
- the acceptable error rate 202 is set to a DL BLER of 10%
- the RI increase threshold 204 can be set to a DL BLER of 10%, or to any lower percentage, such as 8%.
- the telecommunication device 102 can maintain the value of the RI 110 set during block 408 and move to block 414 to report the RI 110 to the base station 104 .
- the acceptable error rate 202 is a BLER of 10% and the RI increase threshold 204 is set to a BLER of 6%
- the error rate 200 is found to be a BLER of 9% the original RI 110 value can be maintained even though the error rate 200 is below the acceptable error rate 202 .
- the telecommunication device 102 can increase the value of the RI 110 from the value set during block 408 .
- the RI 110 can be increased by any desired amount, up to the maximum RI. For example, if the maximum RI is four but the RI 110 was set to “3” during block 408 because only three data streams were decoded, when the error rate 200 is below the RI increase threshold 204 the RI 110 can be increased to “4” at block 412 .
- the telecommunication device 102 can then report this increased RI 110 to the base station 104 at block 414 .
- the telecommunication device 102 can send a report 108 to the base station 104 that includes the RI 110 set using the process of FIG. 4 .
- the telecommunication device 102 can also include a CQI 112 in the report 108 .
- the telecommunication device 102 can use the measured error rate 200 to also determine the CQI 112 .
- the telecommunication device 102 can determine the DL BLER in received data and then report a CQI 112 value associated with an MCS that is expected to lead to a DL BLER under a predefined acceptable error rate 202 , such as a BLER of 10%.
- the report 108 can include the measured error rate 200 in place of, or in addition to, the CQI 112 .
- the base station 104 can use the reported RI 110 to determine the number of data streams 106 to transmit to the telecommunication device 102 using MIMO techniques during future transmissions.
- the base station 104 can also use the reported CQI 112 and/or error rate 200 to determine an MCS to use when sending data during future transmissions.
- the base station 104 can follow the reported RI 110 and next attempt to send a corresponding number of data streams using MIMO techniques.
- the telecommunication device 102 can thus adaptively induce the base station 104 to send a higher number of data streams 106 than would otherwise be sent, thereby increasing the data throughput to the telecommunication device 102 .
- the reported RI 110 can trigger the base station 104 to begin sending in 4 ⁇ 4 MIMO mode, thereby increasing throughput to the telecommunication device 102 .
- the telecommunication device 110 can also report a high CQI 112 associated with a good MCS that can also increase throughput to the telecommunication device 102 .
- the report 108 can induce the base station 104 to begin sending in 4 ⁇ 4 MIMO mode using 256-QAM, both of which can increase throughput to the telecommunication device 102 .
- Inducing the base station 104 to send additional data streams 106 may result in an increase in the measured error rate 200 .
- the additional data stream 106 can be received and decoded by the telecommunication device 102 without the error rate 200 going over the acceptable error rate 202 .
- the measured error rate 200 is a DL BLER of 2% and the acceptable error rate 202 is a DL BLER of 10%
- increasing the RI 110 to induce the base station 104 to send an additional data stream 106 might result in the error rate 200 increasing to a DL BLER of 8% or other percentage that is still below the acceptable error rate 202 .
- the telecommunication device 102 can monitor the error rate 200 , and then drop the RI 110 back to non-increased levels if the error rate 200 goes over the acceptable error rate 202 . For example, following sending a report 108 with an increased RI 110 at block 414 , the telecommunication device 102 can return to block 400 . If the telecommunication device 102 cannot decode a number of data streams 106 equal to the increased RI 110 at block 404 , the RI 110 can be set to the number of decodable data streams 106 at block 408 . Because the error rate 200 exceeded the RI increase threshold 204 in this example, the telecommunication device 102 would not move to block 412 to increase the RI 110 again, and the lower RI 110 would be reported at block 414 .
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Abstract
Description
- This U.S. patent application claims priority to provisional U.S. Patent Application No. 62/507,006, filed May 16, 2017, the entirety of which is incorporated herein by reference.
- Wireless communication devices are commonly used to browse the Internet, transmit files, stream music and video, and perform other tasks that involve wirelessly receiving data from a network. The user experience is improved when such data transmissions occur quickly, and thus network operators and device manufacturers strive to improve data throughput.
- One technique for improving data throughput between devices uses multiple-input multiple-output (MIMO) technology. In a MIMO configuration, devices can have multiple transmitting antennas and/or multiple receiving antennas, such that multiple data streams can be sent between the multiple antennas over the same radio channel. As each data stream can have substantially the same capacity for transmitting data, increasing the number of data streams can accordingly increase the amount of data that can be transmitted, thereby improving throughput. However, there is a risk that some of the MIMO data streams may not be properly decoded at the receiving device due to interference, noise, or other issues.
- The detailed description is set forth with reference to the accompanying figures. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The use of the same reference numbers in different figures indicates similar or identical items or features.
-
FIG. 1 depicts a telecommunication device in wireless communication with a network base station via multiple data streams using multiple-input multiple-output (MIMO) techniques. -
FIG. 2 depicts a graph in which a measured error rate can be compared to a predefined acceptable error rate and/or an RI increase threshold. -
FIG. 3 depicts an example system architecture for a telecommunication device. -
FIG. 4 depicts a flow chart of a method for increasing throughput to a telecommunication device by inducing a base station to transmit additional data streams using MIMO techniques. - In a radio access network (RAN), a network base station can wirelessly transmit data to a telecommunication device. The data throughput to the telecommunication device can depend, at least in part, on a Modulation and Coding Scheme (MCS) used by the base station, as well as the number of multiple-input multiple-output (MIMO) data streams sent by the base station to the telecommunication device.
- An MCS can indicate a particular modulation scheme used by a base station, such as a quadrature amplitude modulation (QAM) scheme that increases throughput by combining multiple modulated signals into a single channel. The amount of the throughput increase can depend on the particular QAM scheme. For example, an MCS that uses 256-QAM can lead to a higher throughput that an MCS that uses 64-QAM, because 256-QAM can carry 8 bits per symbol while 64-QAM can carry 6 bits per symbol.
- MIMO techniques can also be used to increase throughput to the telecommunication device when the telecommunication device and base station have multiple transmitting and/or receiving antennas. For example, the base station can transmit multiple MIMO data streams using different antennas, and the telecommunication device can receive the transmitted signals and decode them back into the original data streams. Each MIMO data stream can have substantially the same data capacity, and accordingly increasing the number of MIMO data streams sent by the base station can increase throughput to the telecommunication device.
- A base station can combine MIMO techniques and modulation schemes defined by an MCS to adjust the throughput to a telecommunication device. For example, in some situations peak data throughput of over 1 Gigabit per second (Gbps) can be achieved when four data streams can be sent and received in a 4×4 MIMO system using a 256-QAM MCS.
- However, sending the maximum number of data streams using the best MCS is not always possible. Due to the multipath propagation of the MIMO data streams, interference, noise, and/or other issues can make it difficult to decode each of the originally sent data streams. Accordingly, the telecommunication device can report information to the base station about the signals it is receiving, such that the base station can adjust how it is sending signals to the telecommunication device based on current radio conditions.
- The report sent by the telecommunication device can include a Rank Indicator (RI) and a Channel Quality Indicator (CQI). The RI indicates a MIMO layer associated with a number of MIMO data streams decoded by the telecommunication device. The CQI indicates the quality of signals received by the telecommunication device, in some examples and can be based on an error rate measured by the telecommunication device, such as a downlink Block Error Rate (DL BLER). For example, a telecommunication device can determine the DL BLER of received signals, and report a CQI value to the base station that is associated with an MCS expected to lead to a DL BLER under a predefined acceptable BLER, such as a BLER of 10%. In some examples the telecommunication device's report can include the measured error rate instead of, or in addition to, the CQI.
- After receiving reported RI and CQI values from the telecommunication device, the base station can select the number of MIMO data streams to send based on the reported RI and the MCS to use based on the reported CQI. For example, if the telecommunication device reports an RI value of “3” and a particular CQI value, the base station can follow that information to transmit three MIMO data streams using an MCS associated with the reported CQI value.
- However, test results have shown that telecommunications devices prioritize sending a CQI value linked to a higher MCS over sending a higher RI value. For example, in tests in which the maximum RI value was four and an acceptable error rate threshold was set at a DL BLER of 10%, when telecommunication devices measured a DL BLER of only 2% or another percentage well below the 10% acceptable BLER threshold, they often reported a high CQI but a lower than maximum RI value of “3.” The difference between the measured error rates and the acceptable error rate threshold in these tests indicates that, as will be discussed below, in some cases the telecommunication device can handle one or more additional MIMO data streams without the measured error rate going over the acceptable error rate threshold. Sending additional MIMO data streams when such capacity exists would lead to increased throughput to the telecommunication device.
- This disclosure describes various systems and processes that can be implemented at telecommunication device to adaptively induce a base station to send one or more additional MIMO data streams in certain situations, in order to increase the data throughput to the telecommunication device. As described herein, when the telecommunication device measures an RI value that is less than a maximum RI, but it measures an error rate below an acceptable error rate threshold, it can report an inflated RI value to the base station that is higher than the measured RI value. The base station can then follow the reported inflated RI value to send an increased number of MIMO data streams to the telecommunication device.
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FIG. 1 depicts atelecommunication device 102 in wireless communication with anetwork base station 104 viamultiple data streams 106 using multiple-input multiple-output (MIMO) techniques. As will be described below, thebase station 104 can determine the number ofdata streams 106 to transmit to thetelecommunication device 102 based on areport 108 sent from thetelecommunication device 102 to thebase station 104 about previous transmissions it has received from thebase station 104. Thereport 108 can include a Rank Indicator (RI) 110 and/or a Channel Quality Indicator (CQI) 112. - A
telecommunication device 102 can be any device that wirelessly connects to abase station 104, such as a smart phone, a cellular phone, a personal digital assistant (PDA), a personal computer (PC), a laptop, a desktop, a workstation, a media player, a tablet, an electronic book device, a gaming device, a television, a media center, a smart watch, or any other type of computing or communication device. Anexample telecommunication device 102 is illustrated in greater detail inFIG. 3 and is described in detail below with reference to that figure. - A
base station 104 can be a node or other access point that provides a connectedtelecommunication device 102 with access to a telecommunications network through a wireless access technology, such as Long Term Evolution (LTE)/LTE Advanced technology, High-Speed Data Packet Access (HSDPA)/Evolved High-Speed Packet Access (HSPA+) technology, Universal Mobile Telecommunications System (UMTS) technology, Code Division Multiple Access (CDMA) technology, Global System for Mobile Communications (GSM) technology, WiMax® technology, and/or WiFi® technology. For example, in an LTE network abase station 104 can be an eNode B. - A
telecommunication device 102 andbase station 104 can each havemultiple antennas 114 for transmitting and/or receiving data, such that they can use MIMO techniques to send and/or receivedifferent data streams 106 withdifferent antennas 114. In general, the arrangement oftransmitter antennas 114 andreceiver antennas 114 in a MIMO system can be expressed as N×M, with N indicating the number oftransmitter antennas 114 and M indicating the number ofreceiver antennas 114. For example, devices in a 2×2 MIMO system can have twotransmitter antennas 114 and tworeceiver antennas 114, while devices in a 4×4 MIMO system can have fourtransmitter antennas 114 and fourreceiver antennas 114. While in some examples N can be equal to M, in other examples N and M can be different. - Using MIMO, the
base station 104 can split data to be transmitted to thetelecommunication device 102 intomultiple data streams 106 using multiplexing, such as open-loop or closed-loop spatial multiplexing. Thebase station 104 can transmit each of themultiple data streams 106 with a different transmittingantenna 114 over the same radio channel. The signals transmitted from each transmittingantenna 114 can take different paths to thetelecommunication device 102. Accordingly, parts of some or all of the different signals from thedifferent transmitting antennas 114 can be received atmultiple receiving antennas 114 at thetelecommunication device 102. Thetelecommunication device 102 can decode the received signals and reconstruct theoriginal data streams 106. - Each
data stream 106 can have substantially the same data capacity. Accordingly, eachadditional data stream 106 that can be transmitted from thebase station 104 and be received and decoded by thetelecommunication device 102 using MIMO techniques can correspondingly increase the data throughput to thetelecommunication device 102. - The
base station 104 can also transmit thedata streams 106 to thetelecommunication device 102 using a Modulation and Coding Scheme (MCS). An MCS can define a modulation scheme, code rate, and/or other attributes that thebase station 104 can use when sending data transmissions to thetelecommunication device 102, such as a quadrature amplitude modulation (QAM) scheme that can increase throughput by combining multiple modulated signals into a single channel. For example, an MCS can identify a particular modulation scheme, such as 256-QAM, 64-QAM, 16-QAM, or any other modulation scheme. The number prefacing “QAM” in these schemes can indicate the number of bits that can be carried per symbol in that scheme. For instance, 256-QAM can carry 8 bits per symbol, while 64-QAM can carry 6 bits per symbol. - As mentioned above, the
telecommunication device 102 can send back areport 108 to thebase station 104 about how the data streams 106 are being received, includingRI 110 and/orCQI 112 values. In various examples, thetelecommunication device 102 can send areport 108 periodically at regular intervals, at irregular intervals or predefined times, upon request by thebase station 104, or upon the occurrence of a reporting event. - The
RI 110 in thereport 108 can indicate a number of data streams 106 that thetelecommunication device 102 is requesting from thebase station 104. Thetelecommunication device 102 can determine the value of theRI 110 based at least in part on the number ofdata streams 106 it decoded within signals received from thebase station 104. Selection of theRI 110 value will be discussed in more detail below. - The reported
RI 110 can be less than or equal to a maximum RI associated with the MIMO configurations of thetelecommunication device 102 and thebase station 104. The maximum RI can be the maximum number of MIMO data streams 106 that could be transmitted from thebase station 104 to thereceiver antennas 114 of thetelecommunication device 102, as limited by the number oftransmitter antennas 114 in thebase station 104 and the number ofreceiver antennas 114 in thetelecommunication device 102. As such, when thebase station 104 hasX transmitter antennas 114 and thetelecommunication device 102 hasY receiver antennas 114, the maximum RI can be at most the lower of X and Y. - For example, if the
telecommunication device 102 has fourreceiver antennas 114 and abase station 104 is capable of sending fourdata streams 106 to those four receivingantennas 114 in a 4×4 MIMO configuration, the maximum RI can be set to four. In other examples the maximum RI can be set to a higher or lower value determined by the number ofreceiver antennas 114 in thetelecommunication device 102 and/or a maximum number of data streams 106 abase station 104 can send to those receivingantennas 114 using MIMO techniques. For instance, in an 8×8 MIMO configuration, the maximum RI can be set to eight. - The
CQI 112 in thereport 108 can be based on anerror rate 200 measured by the telecommunication device.FIG. 2 depicts a graph in which a measurederror rate 200 can be compared to a predefinedacceptable error rate 202 and/or an RI increase threshold 204 as will be discussed further below. In some examples thetelecommunication device 102 can include the measurederror rate 200 in thereport 108 in addition to, or in place of, theCQI 112. - In some examples an
error rate 200 can be a downlink Block Error Rate (DL BLER) determined by the telecommunication device. Thetelecommunication device 102 can use an error detection technique, such as analyzing a cyclic redundancy check (CRC) code in a received data block, to determine when a received data block contains an error. The DL BLER can be the percentage of the total number of data blocks that are found to have an error. Thetelecommunication device 102 can thus determine the DL BLER of received signals, and include aCQI 112 in thereport 108 that is associated with an MCS expected to lead to a DL BLER under a predefinedacceptable error rate 202, such as a DL BLER of 10%. In other examples theerror rate 200 can be measured as a bit error rate (BER), signal to noise ratio (SNR), or any other measure of errors within received data. - When the
base station 104 receives areport 108 including anRI 110 and aCQI 112 values from thetelecommunication device 102, it can use those reported values to adjust or select the number ofdata streams 106 to send to thetelecommunication device 102 using MIMO, and/or the MCS to use when sending those data streams 106. For example, when the reportedRI 110 is “3” and the reportedCQI 112 is associated with an MCS, thebase station 104 can send thetelecommunication device 102 three MIMO data streams 106 using that MCS. While thebase station 104 may choose to adjust the MCS, it does not attempt to override the reportedRI 110. - As will be discussed below, in some situations the
telecommunication device 102 can change the data in thereport 108 from what it would otherwise include, in order to adaptively induce thebase station 104 to increase the number ofdata streams 106 it sends to thetelecommunication device 102 using MIMO. By inducing thebase station 104 to transmit an increased number ofdata streams 106 in these situations, data throughput to thetelecommunication device 102 can be increased. -
FIG. 3 depicts an example system architecture for atelecommunication device 102, in accordance with various examples. As shown, in addition to theantennas 114 discussed above, atelecommunication device 102 can also include amemory 302 that stores modules anddata 304, processor(s) 306,radio interfaces 308, adisplay 310,output devices 312,input devices 314, and/or adrive unit 316 including a machinereadable medium 318. - In various examples,
memory 302 generally includes both volatile memory and non-volatile memory, such as RAM, ROM, EEPROM, Flash Memory, a hard drive, a memory card, optical storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other medium. In someexamples memory 302 can also include a SIM (subscriber identity module) card, which is a removable memory card used to identify a user of thetelecommunication device 102 to a telecommunication network.Memory 302 can also be described as computer storage media and may include volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information, such as computer readable instructions, data structures, program modules, or other data. - The modules and
data 304 can be utilized by thetelecommunication device 102 to perform or enable performing any action taken by thetelecommunication device 102. The modules anddata 304 can include a telecommunication device platform and applications, and data utilized by the platform and applications. - In some examples, the processor(s) 306 is a central processing unit (CPU), a graphics processing unit (GPU), or both CPU and GPU, or any other sort of processing unit.
- The radio interfaces 308 can include transceivers, modems, interfaces, and/or other components that perform or assist in exchanging radio frequency (RF) communications with a
base station 104 via transmitter andreceiver antennas 114. By way of a non-limiting example, a telecommunication device'sradio interfaces 308 can include an RF Front End (RFFE) that receives RF signals via four receivingantennas 114 in a 4×4 MIMO configuration, an RFIC (RF Integrated Chip) that decodes the RF signals into fourdata streams 106, and a modem that performs other processing operations on the data streams 106. In other examples aprocessor 306, other modules anddata 304, and/or other components of thetelecommunication device 102 can perform or assist in transmitting and/or receiving data via theantennas 114, and/or pre-processing or post-processing of such data. - In various examples, the
display 310 is a liquid crystal display or any other type of display commonly used intelecommunication devices 102. For example,display 310 may be a touch-sensitive display screen, and can then also act as an input device or keypad, such as for providing a soft-key keyboard, navigation buttons, or any other type of input. - In some examples, the
output devices 312 can include any sort of output devices known in the art, such as adisplay 310, speakers, a vibrating mechanism, and/or a tactile feedback mechanism.Output devices 312 can also include ports for one or more peripheral devices, such as headphones, peripheral speakers, and/or a peripheral display. - In various embodiments,
input devices 314 can include any sort of input devices known in the art. For example,input devices 314 can include a microphone, a keyboard/keypad, and/or a touch-sensitive display, such as the touch-sensitive display screen described above. A keyboard/keypad can be a push button numeric dialing pad, a multi-key keyboard, or one or more other types of keys or buttons, and can also include a joystick-like controller, designated navigation buttons, or any other type of input mechanism. - The machine
readable medium 318 can store one or more sets of instructions, such as software or firmware, that embodies any one or more of the methodologies or functions described herein. The instructions can also reside, completely or at least partially, within thememory 302, processor(s) 306, and/or radio interface(s) 308 during execution thereof by thetelecommunication device 102. Thememory 302 and the processor(s) 306 also can constitute machine readable media 322. -
FIG. 4 depicts a flow chart of a method for increasing throughput to a telecommunication device by inducing abase station 104 to transmitadditional data streams 106 using MIMO techniques. - At block 400, the
telecommunication device 102 can receive RF signals from thebase station 104 usingmultiple receiver antennas 114. - At
block 402, thetelecommunication device 102 can decode the received RF signals into one or more data streams 106. For example, thetelecommunication device 102 can de-multiplex the received RF signals to distinguishdifferent data streams 106 sent over the same radio channel. In some cases thetelecommunication device 102 may not be able to successfully decode all of the data streams 106 sent by thebase station 104, such as when there is noise or interference due to multipath propagation of the MIMO signals, or other issues that affect the signals received by the telecommunication device. During or following decoding, thetelecommunication device 102 can also determine anerror rate 200 of the decoded data. For example, theerror rate 200 can be measured as a downlink Block Error Rate (DL BLER), the percentage of the total number of data blocks that CRC codes indicate have an error. - At
block 404, thetelecommunication device 102 can count the number of data streams 106 that were decoded duringblock 402. Thetelecommunication device 102 can then determine whether the number ofdifferent data streams 106 decoded from the received RF signals is equal to a maximum RI for the MIMO arrangement of thetelecommunication device 102 andbase station 104. As discussed above, the maximum RI can be the maximum number of data streams 106 that could be transmitted from thebase station 104 to thetelecommunication device 102, as limited by the number oftransmitter antennas 114 in thebase station 104 and/or the number ofreceiver antennas 114 in thetelecommunication device 102. - For example, if the
telecommunication device 102 has fourreceiver antennas 114 and abase station 104 is capable of sending fourdata streams 106 to those fourreceiver antennas 114 in a 4×4 MIMO configuration, the maximum RI can be set to four and thetelecommunication device 102 can determine atblock 404 whether or not it decoded fourdata streams 106 from the received RF signals. In other examples the maximum RI can be set to any other value limited by the number ofantennas 114 at thetelecommunication device 102 and/orbase station 104, and thetelecommunication device 102 can check atblock 404 if it decoded a number ofdata streams 106 equal to that maximum RI. - If the
telecommunication device 102 determines atblock 404 that it decoded a number ofdata streams 106 equal to the maximum RI, it can set the value of anRI 110 to the maximum RI atblock 406. For example, if the maximum RI is four and thetelecommunication device 102 decoded fourdata streams 106, it can set the RI to “4.” TheRI 110 can be reported to thebase station 104 atblock 414, as will be discussed below. - However, if the
telecommunication device 102 determines that it decoded a number of data streams 106 that is less than the maximum RI, atblock 408 it can set the value of theRI 110 to the number of decodeddata streams 106 and then move to block 410. For example, if the maximum RI is four, but thetelecommunication device 102 decoded only three data streams, it can set theRI 110 to “3.” - If the
telecommunication device 102 did not set theRI 110 to the maximum RI, atblock 410 thetelecommunication device 102 can determine if theerror rate 200 of the decoded data is below an RI increase threshold 204. As shown inFIG. 2 , the RI increase threshold 204 can be less than or equal to theacceptable error rate 202. For example, when theacceptable error rate 202 is set to a DL BLER of 10%, the RI increase threshold 204 can be set to a DL BLER of 10%, or to any lower percentage, such as 8%. - If the
error rate 200 of the decoded data is found duringblock 410 to be above the RI increase threshold 204, thetelecommunication device 102 can maintain the value of theRI 110 set duringblock 408 and move to block 414 to report theRI 110 to thebase station 104. For example, if theacceptable error rate 202 is a BLER of 10% and the RI increase threshold 204 is set to a BLER of 6%, when theerror rate 200 is found to be a BLER of 9% theoriginal RI 110 value can be maintained even though theerror rate 200 is below theacceptable error rate 202. - However, if the
error rate 200 of the decoded data is found duringblock 410 to be at or below the RI increase threshold 204, thetelecommunication device 102 can increase the value of theRI 110 from the value set duringblock 408. TheRI 110 can be increased by any desired amount, up to the maximum RI. For example, if the maximum RI is four but theRI 110 was set to “3” duringblock 408 because only three data streams were decoded, when theerror rate 200 is below the RI increase threshold 204 theRI 110 can be increased to “4” atblock 412. Thetelecommunication device 102 can then report this increasedRI 110 to thebase station 104 atblock 414. - At
block 414, thetelecommunication device 102 can send areport 108 to thebase station 104 that includes theRI 110 set using the process ofFIG. 4 . In some examples thetelecommunication device 102 can also include aCQI 112 in thereport 108. As described above, thetelecommunication device 102 can use the measurederror rate 200 to also determine theCQI 112. For example, thetelecommunication device 102 can determine the DL BLER in received data and then report aCQI 112 value associated with an MCS that is expected to lead to a DL BLER under a predefinedacceptable error rate 202, such as a BLER of 10%. In some examples thereport 108 can include the measurederror rate 200 in place of, or in addition to, theCQI 112. - After the
base station 104 receives thereport 108, thebase station 104 can use the reportedRI 110 to determine the number ofdata streams 106 to transmit to thetelecommunication device 102 using MIMO techniques during future transmissions. Thebase station 104 can also use the reportedCQI 112 and/orerror rate 200 to determine an MCS to use when sending data during future transmissions. - In situations in which the telecommunication device inflated the reported
RI 110 beyond what it otherwise would have reported, because theerror rate 200 was found duringblock 410 to be lower than an RI increase threshold 204, thebase station 104 can follow the reportedRI 110 and next attempt to send a corresponding number of data streams using MIMO techniques. Thetelecommunication device 102 can thus adaptively induce thebase station 104 to send a higher number ofdata streams 106 than would otherwise be sent, thereby increasing the data throughput to thetelecommunication device 102. - For example, when the
base station 104 had been sending threedata streams 106 but thetelecommunication device 102 sends anRI 110 of “4” because theerror rate 200 was found to be lower than the RI increase threshold 204 duringblock 410, the reportedRI 110 can trigger thebase station 104 to begin sending in 4×4 MIMO mode, thereby increasing throughput to thetelecommunication device 102. - Because the
error rate 200 would also be lower than theacceptable error rate 202 in this example, thetelecommunication device 110 can also report ahigh CQI 112 associated with a good MCS that can also increase throughput to thetelecommunication device 102. For example, when the reportedRI 110 is “4” and the reportedCQI 112 is high and associated with an MCS that uses 256-QAM, thereport 108 can induce thebase station 104 to begin sending in 4×4 MIMO mode using 256-QAM, both of which can increase throughput to thetelecommunication device 102. - Inducing the
base station 104 to sendadditional data streams 106 may result in an increase in the measurederror rate 200. However, in many situations theadditional data stream 106 can be received and decoded by thetelecommunication device 102 without theerror rate 200 going over theacceptable error rate 202. For example, when the measurederror rate 200 is a DL BLER of 2% and theacceptable error rate 202 is a DL BLER of 10%, increasing theRI 110 to induce thebase station 104 to send anadditional data stream 106 might result in theerror rate 200 increasing to a DL BLER of 8% or other percentage that is still below theacceptable error rate 202. - Following sending a
report 108 with an increasedRI 110, thetelecommunication device 102 can monitor theerror rate 200, and then drop theRI 110 back to non-increased levels if theerror rate 200 goes over theacceptable error rate 202. For example, following sending areport 108 with an increasedRI 110 atblock 414, thetelecommunication device 102 can return to block 400. If thetelecommunication device 102 cannot decode a number ofdata streams 106 equal to the increasedRI 110 atblock 404, theRI 110 can be set to the number of decodable data streams 106 atblock 408. Because theerror rate 200 exceeded the RI increase threshold 204 in this example, thetelecommunication device 102 would not move to block 412 to increase theRI 110 again, and thelower RI 110 would be reported atblock 414. - Although the subject matter has been described in language specific to structural features and/or methodological acts, it is to be understood that the subject matter is not necessarily limited to the specific features or acts described above. Rather, the specific features and acts described above are disclosed as example embodiments.
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-
2017
- 2017-08-24 US US15/686,012 patent/US10153888B1/en active Active
-
2018
- 2018-05-09 WO PCT/US2018/031852 patent/WO2018213079A1/en unknown
- 2018-05-09 EP EP18802266.9A patent/EP3602836A4/en not_active Withdrawn
- 2018-05-09 CN CN201880032428.0A patent/CN110637420A/en active Pending
Cited By (8)
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US10715275B2 (en) * | 2018-05-11 | 2020-07-14 | At&T Intellectual Property I, L.P. | Configuring channel quality indicator for communication service categories in wireless communication systems |
US11218245B2 (en) * | 2018-05-11 | 2022-01-04 | At&T Intellectual Property I, L.P. | Configuring channel quality indicator for communication service categories in wireless communication systems |
US10492212B1 (en) | 2018-06-22 | 2019-11-26 | At&T Intellectual Property I, L.P. | Scheduling ultra-reliable low latency communications in wireless communication systems |
US11191089B2 (en) | 2018-06-22 | 2021-11-30 | At&T Intellectual Property I, L.P. | Scheduling ultra-reliable low latency communications in wireless communication systems |
US20210194545A1 (en) * | 2019-12-20 | 2021-06-24 | Qualcomm Incorporated | System and method for determination of metrics for multiple-input multiple-output communication |
US11973546B2 (en) * | 2019-12-20 | 2024-04-30 | Qualcomm Incorporated | System and method for determination of metrics for multiple-input multiple-output communication |
US20220368387A1 (en) * | 2021-05-13 | 2022-11-17 | Qualcomm Incorporated | Rank adapation for mimo transmissions and retransmissions |
US11909474B2 (en) * | 2021-05-13 | 2024-02-20 | Qualcomm Incorporated | Rank adapation for MIMO transmissions and retransmissions |
Also Published As
Publication number | Publication date |
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US10153888B1 (en) | 2018-12-11 |
EP3602836A4 (en) | 2020-12-16 |
WO2018213079A1 (en) | 2018-11-22 |
EP3602836A1 (en) | 2020-02-05 |
CN110637420A (en) | 2019-12-31 |
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