Source: https://patents.google.com/patent/TWI554071B/en
Timestamp: 2020-02-21 20:18:35
Document Index: 397275239

Matched Legal Cases: ['art\n600', 'art\n700', 'art\n800', 'art\n802', 'art\n852', 'art\n1000', 'art\n1']

TWI554071B - Notifying a ul/dl configuration in lte tdd systems - Google Patents
TWI554071B
TWI554071B TW101125431A TW101125431A TWI554071B TW I554071 B TWI554071 B TW I554071B TW 101125431 A TW101125431 A TW 101125431A TW 101125431 A TW101125431 A TW 101125431A TW I554071 B TWI554071 B TW I554071B
TW101125431A
TW201318391A (en
2012-07-13 Application filed by 黑莓有限公司 filed Critical 黑莓有限公司
2013-05-01 Publication of TW201318391A publication Critical patent/TW201318391A/en
2016-10-11 Publication of TWI554071B publication Critical patent/TWI554071B/en
Notifying an uplink/downlink configuration in a long-term evolution time-division duplex system
The present invention relates to time-division duplex configuration in a Long Term Evolution (LTE) environment.
The present application claims priority to U.S. Patent Application Serial No. 13/210,033, filed on Aug.
In the LTE system, the downlink and uplink transmissions can be organized into two duplex modes: a frequency division duplex (FDD) mode and a time division duplex (TDD) mode. The FDD mode uses a paired spectrum, where the frequency domain is used to separate uplink (UL) and downlink (DL) transmissions. 1A is a graphical illustration of uplink and downlink subframes separated in the frequency domain for FDD mode. In a TDD system, an unpaired spectrum can be used in which both UL and DL are transmitted via the same carrier frequency. UL and DL are separated in the time domain. FIG. 1B is a graphical illustration of uplink and downlink subframes sharing a carrier frequency in TDD mode.
The LTE TDD system can be made to notify the UE of the TDD UL/DL configuration (or configuration change) more frequently. The system may be capable of reallocating radio resources between the UL and the DL to meet requirements associated with, for example, traffic conditions. In an LTE TDD system, a subframe of a radio frame may be a downlink (DL), an uplink (UL), or a special subframe. The special subframe contains the downlink and uplink time zones separated by the guard period for downlink to Uplink handover, and includes three parts: i) Downlink Pilot Time Slot (DwPTS), ii) Uplink Pilot Time Slot (UpPTS), and iii) Protection Period (GP). Table 7 lists seven different UL/DL configuration scenarios for LTE TDD operation. In Table 1, D represents a downlink subframe, U represents an uplink subframe, and S is a special frame.
As shown in Table 1, two switching point periods are specified in the LTE standard: 5 ms and 10 ms. The 5 ms switching point period supports coexistence between LTE and low chip rate universal terrestrial radio access (UTRA) TDD systems, and the 10 ms switching point period supports the coexistence of LTE and high chip rate UTRA TDD systems. The supported configurations cover a wide UL/DL allocation range from a biased DL configuration (DL:UL ratio 9:1) to a biased UL configuration (DL:UL ratio 2:3). The TDD system has flexibility in terms of the proportion of resources that can be assigned to uplink and downlink communications within a given spectrum assignment. In particular, by selecting a UL/DL configuration based on different traffic characteristics, for example, DL and UL, it is possible to unevenly distribute radio resources between the uplink and the downlink to provide more efficient use. The way of radio resources.
In some embodiments, a primary information block (MIB) can be used to indicate a TDD configuration. In some cases, there may be ten spare bits in the MIB. spare Some of the bits are available for the TDD configuration indicator. In some implementations, the MIB uses a fixed schedule (eg, every 40 milliseconds), and in some embodiments, using the MIB spare bit to communicate the TDD configuration can speed up the TDD configuration recognition frequency every 40 milliseconds.
In another example embodiment, system information block type 1 (SIB1) may be updated when there is a need for a configuration change. When the system recognizes the need for a configuration change, it can update the TDD-Config Information Element (IE) in SIB1 for the next 80 millisecond transmission period. The UE can read SIB1 every 80 ms.
In some embodiments, the TDD configuration indicator can be scrambled onto a Control Format Indicator (CFI) on the Entity Control Format Indicator Channel (PCFICH). The current CFI codeword can be scrambled by the TDD configuration change indicator. Since PCFICH is transmitted based on subframes, it will allow dynamic changes to the TDD configuration.
In some embodiments, a Physical Downlink Control Channel (PDCCH) may be used to inform the TDD configuration. A DCI format that will be transmitted over a common search space can be introduced. A Radio Network Temporary Identifier (RNTI) (referred to as TDD-RNTI) may be used for scrambling cyclic redundancy check (CRC) for search purposes. A dynamic change in the TDD configuration is provided because the PDCCH is transmitted in each subframe.
In some embodiments, dedicated signaling to connected mode UEs may be used. A dedicated signaling message containing TDD-Config IE (eg, Radio Resource Control (RRC) Connection Reconfiguration) can be used to communicate the updated TDD configuration to the connected mode UE. The network can send this dedicated message to all UEs in RRC connected mode. In addition, the TDD configuration within SIB1 is also updated to provide this information to the idle mode UE.
The user equipment can operate in a cellular network (such as the network shown in Figure 2), which is based on the Third Generation Partnership Project (3GPP) Long Term Evolution (LTE), also known as Evolution Universal. Terrestrial Radio Access (E-UTRA). More specifically, FIG. 2 is a schematic representation of an example wireless cellular communication system 200 based on 3GPP LTE. The cellular network system 200 shown in FIG. 2 includes a plurality of base stations 212. In the LTE example of FIG. 2, the base station is shown as an enhanced Node B (eNB) 212. It should be understood that the base station can operate in any mobile environment, including sub-micro cells or micro cells, or the base station can operate as a node that can relay signals for other mobile stations and/or base stations. The example LTE telecommunications environment 200 of FIG. 2 may include one or more radio access networks 210, a core network (CN) 220 (shown as Evolved Packet Core (EPC) 220), and an external network 230. In some implementations, the radio access network can be an Evolved Universal Mobile Telecommunications System (UMTS) Terrestrial Radio Access Network (EUTRAN). Additionally, in some cases, core network 220 may be an evolved packet core (EPC). Additionally, one or more user devices 202 can operate within LTE system 200. In some implementations, the 2G/3G system 240 can also be integrated into the LTE telecommunications system 200, such as the Global System for Mobile Communications (GSM), the Provisional Standard 95 (IS-95), and the Universal Mobile Telecommunications System (UMTS). ) and CDMA2000 (code division multiple access).
In the example LTE system shown in FIG. 2, EUTRAN 210 includes an eNB 212. UE 202 may operate in a cell that is served by one of eNBs 212. EUTRAN 210 may include one or more eNBs 212 and one or more UEs 202 may operate in a cell. The eNB 212 directly communicates with the UE 202. letter. In some implementations, eNB 212 and UE 202 can be in a one-to-many relationship, for example, eNB 212 in example LTE system 200 can serve multiple UEs 202 within its coverage area, but each UE 202 can only be connected to one at a time An eNB 212. In some implementations, eNB 212 and UE 202 can be in a many-to-many relationship. The eNBs 212 can be connected to each other, and if the UE 202 travels from one eNB 212 to another, UE handover can be performed. UE 202 may be any wireless electronic device used by a terminal user to communicate, for example, within LTE system 200. The UE 202 may be referred to as a mobile electronic device, a user device, a mobile station, a subscriber station, or a wireless terminal. The UE 202 can be a cellular telephone, a personal data assistant (PDA), a smart phone, a laptop, a tablet personal computer (PC), a pager, a portable computer, or other wireless communication device.
In the uplink, an uplink profile signal is transmitted via, for example, a Physical Uplink Shared Channel (PUSCH), and an uplink control signal is transmitted via, for example, a Physical Uplink Control Channel (PUCCH). In the downlink, the synchronization signal is transmitted via, for example, a synchronization channel (SCH), the downlink profile signal is transmitted via, for example, a physical downlink shared channel (PDSCH), and the channel is controlled via, for example, a physical downlink. (PDCCH) transmits a downlink control signal. A primary information block (MIB) can be configured to be transmitted as broadcast information in each cell via, for example, a physical broadcast channel (PBCH), and system information blocks (SIBs) 1 through 11 are configured to pass ( For example) PDSCH transmission.
The MIB can be configured to include entity parameters such as cell bandwidth and transmit antenna identification information, and number of system frames (SFN), and is configured to transmit over a 40 ms period. SIB1 can be configured to transmit over a period of 80 ms.
Turning briefly to FIG. 3, each radio station can be any electronic device that is operable to transmit and receive wireless signals in the LTE telecommunications system 200. In the present invention, the radio station can be a mobile electronic device (e.g., a UE) or a base station (e.g., an eNB). FIG. 3 is a schematic illustration of an example radio station 300. The radio station 300 can include a processor 302, a memory 304, a wireless transceiver 306, and an antenna 308. Processor 302 can include a microprocessor, a central processing unit, a graphics control unit, a network processor, or other processor for executing instructions stored in memory 304. The functions of processor 302 may include computation, queue management, control processing, graphics acceleration, video decoding, and execution of stored sequences of instructions from programs maintained in memory module 304. In some implementations, processor 302 can also be responsible for signal processing, including signal sampling, quantization, encoding/decoding, and/or modulation/demodulation. The memory module 304 can include a temporary state device (eg, random access memory (RAM)) and a data store. The memory module 304 can be used to temporarily or permanently store data or programs (i.e., sequences of instructions) for use in the UE.
Wireless transceiver 306 can include both transmitter circuitry and receiver circuitry. The wireless transceiver 306 can be responsible for converting the baseband signal to a passband signal or vice versa. The components of the wireless transceiver 306 can include digital to analog converters/analog to digital converters, amplifiers, frequency filters, and oscillators. Additionally, the wireless transceiver 306 can also include or be communicatively coupled to a digital signal processing (DSP) circuit 310 and a digital filter circuit 312. The DSP circuit 310 can perform several functions, including generating orthogonal frequency division multiplexing (OFDM) and/or single carrier frequency division multiple access (SC-FDMA) signals. OFDM is used as multiple pairs The frequency division multiplexing technique of the carrier modulation method. The OFDM signal can be generated by modulating an information bearing signal (e.g., a sequence of bit map symbols) on a plurality of orthogonal subcarriers. Different bit map symbols that are modulated on different subcarriers can each be considered to experience a flat fading channel, ie, the frequency response for the fading channel of each subcarrier can be considered flat, making it easier to receive Decode the information at the device. In some practical implementations, OFDM uses Fast Fourier Transform (FFT) and Inverse Fast Fourier Transform (IFFT) to alternate between the time domain representation of the signal and the frequency domain representation. The FFT operation converts the signal from the time domain representation to the frequency domain representation. IFFT operations can be converted in the opposite direction. OFDM can be used in the radio downlink, while SC-FDMA technology can be used in the radio uplink. SC-FDMA uses a modulation scheme substantially similar to OFDM to modulate an uplink signal to multiple subcarriers. In other differences from OFDM, a multi-point discrete Fourier transform (DFT) operation is performed prior to subcarrier mapping and IFFT in SC-FDMA on the transmission side in order to reduce the peak-to-average power ratio of the modulated signal. Since the uplink signal is transmitted from the UE, the lower peak-to-average power ratio of the modulated signal can result in a lower cost signal amplification at the UE.
Digital filter circuit 312 can include an equalization filter for signal equalization. Equalization can be a procedure for adjusting the balance between the frequency components within a radio signal. More specifically, the equalizer can be used to make the response from the transmitter to the equalized output and the frequency within the entire channel bandwidth of interest flat. When the channel has been equalized, the frequency domain property of the signal at the equalized output can be substantially similar to the frequency domain property of the transmitted signal at the transmitter. The equalizer may include one or more filter taps, each tap corresponding to a filter Factor. These filter coefficients can be adjusted based on changes in channel/system conditions.
Antenna 308 is a transducer that can transmit and/or receive electromagnetic waves. Antenna 308 can convert electromagnetic radiation into electrical current, or vice versa. Antenna 308 is typically responsible for the transmission and reception of radio waves and can serve as an interface between transceiver 306 and the wireless channel. In some implementations, radio station 300 can be equipped with more than one antenna to utilize multiple input multiple output (MIMO) technology. MIMO technology can provide a procedure that utilizes multiple signal paths to reduce the effects of multipath fading and/or improve the throughput. By using multiple antennas at the radio station, MIMO technology can enable multiple parallel streams of data to be transmitted over the same wireless channel, thereby increasing the throughput of the channel.
Returning to the illustration of FIG. 2, the UE 202 can transmit voice, video, multimedia, text, website content, and/or any other user/client specific content. On the one hand, the transmission of some of these content (eg, video and website content) may require high channel throughput to meet end user needs. On the other hand, the channel between UE 202 and eNB 212 may be contaminated by multipath fading due to multiple signal paths resulting from many reflections in the wireless environment. Therefore, the UE's transmission can adapt to the wireless environment. In short, the UE 202 generates a request, sends a response, or otherwise communicates with the Evolved Packet Core (EPC) 220 and/or the Internet Protocol (IP) network 230 via one or more eNBs 212 using different means.
The Radio Access Network (RAN) is part of a mobile telecommunications system that implements radio access technologies such as UMTS, CDMA2000 and 3GPP LTE. In many applications, the RAN included in the LTE telecommunications system 200 is called EUTRAN 210. EUTRAN 210 can be located between UE 202 and EPC 220. EUTRAN 210 includes at least one eNB 212. The eNB may be a radio base station that can control all or at least some of the radio related functions in the fixed portion of the system. At least one eNB 212 may provide a radio interface for the UE 202 to communicate within its coverage area or cell. The eNBs 212 can be distributed throughout the cellular network to provide a wide coverage area. The eNB 212 is in direct communication with one or more UEs 202, other eNBs, and EPC 220.
The eNB 212 may be an endpoint of a radio protocol towards the UE 202 and may relay signals between the radio connection and connectivity towards the EPC 220. In some implementations, EPC 220 is a major component of the core network (CN). The CN can be a backbone network, and the backbone network can be a central part of the telecommunications system. The EPC 220 may include an Active Management Entity (MME), a Servo Gateway (SGW), and a Packet Data Network Gateway (PGW). The MME may be the primary control element in the EPC 220, which is responsible for the functionality of the control plane functions involved in user and job phase management. The SGW can act as a regional mobility anchor, such that packets are delivered via this point to achieve EUTRAN 210 internal mobility and the mobility of other legacy 2G/3G systems 240. The SGW function can include user plane tunnel management and handover. The PGW can provide connectivity to a service domain that includes an external network 230, such as an IP network. UE 202, EUTRAN 210, and EPC 220 are sometimes referred to as Evolutionary Evolution Packet System (EPS). It should be understood that the evolution of the architecture of the LTE system 200 is concentrated on the EPS. Functional evolution evolution may include both EPS and external network 230.
Although described in accordance with FIGS. 2 through 3, the present invention is not limited to this environment. In general, a cellular telecommunications system can be described as being composed of numerous radio cells or A cellular network consisting of a free radical platform or other fixed transceiver transceiver cell. The cell is used to cover different areas in order to provide radio coverage to the area. Example cellular telecommunications systems include the Global System for Mobile Communications (GSM) protocol, Universal Mobile Telecommunications System (UMTS), 3GPP Long Term Evolution (LTE), and others. In addition to cellular telecommunications systems, wireless broadband communication systems are also suitable for use in the various implementations described in this disclosure. Example wireless broadband communication systems include IEEE 802.11 wireless local area networks, IEEE 802.16 WiMAX networks, and the like.
Turning briefly to FIG. 4, each UE 202 can be any electronic device that is operable to receive and transmit wireless signals in the LTE telecommunications system 200. 4 is a schematic illustration of an example user equipment (UE) 202. The UE 202 can include a processor 402, a memory 404, a wireless transceiver 406, and an antenna 408. Processor 402 can include a microprocessor, a central processing unit, a graphics control unit, a network processor, or other processor for executing instructions stored in memory 404. The functions of processor 402 may include computation, queue management, control processing, graphics acceleration, video decoding, and execution of stored sequences of instructions from programs maintained in memory module 404. In some implementations, processor 402 may also be responsible for signal processing, including signal sampling, quantization, encoding/decoding, and/or modulation/demodulation. The memory module 404 can include a temporary state device (eg, a random access memory (RAM)) or a data store. The memory module 204 can be used to temporarily or permanently store data or programs (i.e., sequences of instructions) for use in the UE. Wireless transceiver 406 can include both transmitter circuitry and receiver circuitry. The wireless transceiver 406 can be responsible for upconverting the baseband signal to a passband signal or vice versa. Wireless transceiver The components of 406 may include digital to analog converters/analog to digital converters, amplifiers, frequency filters, and oscillators. Antenna 408 is a transducer that can transmit and/or receive electromagnetic waves. Antenna 408 can convert electromagnetic radiation into electrical current, or vice versa. Antenna 408 is typically responsible for the transmission and reception of radio waves and can serve as an interface between transceiver 406 and the wireless channel.
The LTE network environment and UE described above with respect to Figures 2 through 4 may function to dynamically identify or update TDD configuration information. In an embodiment, a method for configuring Time Division Duplex (TDD) UL/DL allocation in a UE in an LTE network may include receiving an enhancement in the LTE network at a predefined period during the connection state Each information block transmitted by a Node B (eNB), wherein each information block is transmitted according to a fixed schedule having a predefined transmission period and includes information identifying the TDD configuration. The UE may determine that an update of the TDD configuration is requested or requested based at least in part on the information identifying the TDD configuration in the information block, and the information indicating the TDD configuration indicates that the TDD configuration is updated. In response to at least identifying the updated TDD configuration, the UE can automatically update the TDD UL/DL allocation of the UE according to the updated TDD configuration.
The transmitted information block can be in System Information Block Type 1 (SIB1) or Main Information Block (MIB). The MIB uses a fixed schedule with a 40 ms period and repeats within 40 ms. The first transmission of the MIB is scheduled in subframe 0 of the radio frame of the number of system frames (SFN) modulo 4 = 0, and is repeated in subframe 0 of all other radio frames. The new TDD-Config information can be applied as soon as possible at the beginning of the next 40 ms MIB cycle. In some example implementations, there may be ten "standby" bits in the MIB. The following example MIB structure without TDD-Config bit is provided:
In some embodiments, the MIB can be updated to include a TDD configuration. Three bits from the "standby" bit can be used to represent seven TDD configurations. The following shows an example MIB structure that includes TDD configuration bits:
In some embodiments, by limiting the selection of changes to the TDD configuration, two bits can be used to indicate this change (ie, tdd-Config BIT STRING(SIZE(2)). For example, if new TDD The configuration has the same switching cycle as the current TDD configuration, the total number of configurations can be divided into two groups, and there are up to four configurations in each group (see Table 2 for details). A bit is sufficient to indicate a change in the TDD configuration. Similarly, one bit can be used to indicate movement from one configuration to another. For example, an organization based on the TDD configuration shown in Table 2 below. If the existing configuration is configured as "1", one bit is sufficient to indicate the movement down to the configuration "2" or up to the configuration "6". In general, the term "TDD configuration changes" This can include an indication of the new TDD configuration or an indication of whether/how to change the TDD configuration.
When the MIB message is used to identify the TDD configuration, the new release UE receives and understands the TDD configuration and changes the configuration accordingly in the next frame. The new release version UE can operate in accordance with the present invention, and legacy UEs can operate in accordance with Release 10 and earlier release versions. The legacy UE may not attempt to decode the last 10 bits of the bit string, so the legacy UE can maintain the same configuration as before. When the TDD configuration changes, it is possible that the system also updates the TDD configuration information in SIB1 based on the modification period. The system can then trigger a system information modification notification procedure. Therefore, the legacy UE will eventually update the configuration in the next modification cycle. If there are multiple configuration changes during the (minimum) 640 ms modification period, the most recent changes will be applied. As a result, legacy UEs will also change the TDD configuration to the updated configuration.
If the configuration changes are extremely frequent, it is not always necessary to have the legacy UE follow the change via the SIB1 information change. The system can track the configuration change rate (CCR) for each given cycle (for example, 640 ms). If the CCR is less than a predefined threshold T CCR , the system may update the TDD configuration information in SIB1 and the system information modification notification procedure will proceed. Otherwise, the system does not update SIB1. In this example implementation, the system can save system radio resources and battery power of legacy UEs. During the duration of the sub-frame from the UL handover to the DL, interference problems between the new UE and the legacy UE ("release between releases") may occur (especially if the UEs are positioned very close to each other between releases). The UL/DL configuration can be divided into two groups according to the number of DL sub-frames in the ascending order according to the switching point period: a group with a period of 5 ms (configuration 0, 1, 2, 6 of Table 2) ), and a group with a period of 10 ms (configurations 3, 4, 5 of Table 1). Table 2 shows how the seven configurations can be grouped.
The candidate configuration is limited to the same group of the UE's current configuration. In this way, the number of subframes with link direction changes will be relatively small. In addition, the eNB may not grant any UL transmissions to the legacy UE at the link direction collision subframe in the subsequent frame. For example, if the current configuration is 0 and the system decides to change to configuration 6, the eNB should reject the sub-frame 9 at the subsequent frame. Any UL grant. For UL control signal transmission and non-adaptive retransmission, it will be transmitted without UL grant.
For TDD LTE systems, the Sounding Reference Signal (SRS) is transmitted at one or two symbols in the UpPTS, and the SRS does not change with configuration changes. The eNB knows where to detect the sounding reference signal.
Physical Uplink Control Channel (PUCCH) transmission: Entity of legacy UEs, considering the fact that there is no data transmission (UL grant denied) and retransmission (see Hybrid Automatic Repeat Request (HARQ) retransmission handling below) The Uplink Control Channel (PUCCH) transmission will be placed at the frequency edge of the bandwidth. In addition, periodic channel status parameters for legacy UEs, including channel quality indicators, precoding matrix indices, and/or level indicators, may also be scheduled in the UL subframes that are not changed within the configuration group. Only those sub-frames with link direction changes at these frequency edges will cause interference problems. The number of subframes causing trouble is extremely limited, so the eNB should be able to avoid new releases of UEs near the schedule at the edge of the frequency within the time frame of the subframe with the link direction change.
HARQ Retransmission Handling: The eNB may check if there is/will be retransmission at the time of the link direction change subframe before the configuration change indicator is sent. If so, the eNB should postpone the configuration change.
SPS scheduling: In the case of UL transmission at the direction collision subframe due to SPS scheduling, the eNB may perform one of the following steps: by transmitting a sps-Config message (existing IE radio resource configuration) Dedicated) to reconfigure the SPS; or postpone configuration changes as used in HARQ disposition.
DRX: For technologies based on MIB and SIB1, the UE needs to wake up every time. The configuration information is read from the MIB or SIB1 so that the UE knows the current configuration. The MIB is transmitted on a physical channel, specifically on a physical broadcast channel (PBCH). It is designed such that each transmission is self-decodable. Most likely, the UE will likely detect the MIB on the first subframe 0 transmission. SIB1 is always scheduled on subframe 5, and it can also be self-decoded on each transmission. If the first subframe is not subframe 0 when the UE wakes up (when using MIB for TDD configuration) or subframe 5 (when using SIB1 for TDD configuration), or if the UE cannot be in the first transmission A pre-defined configuration can be taken if the current configuration is successfully detected. For example, configuration 2 (for a 5 ms cycle group) or configuration 5 (for a 10 ms cycle group) should be taken temporarily until the current configuration is detected. The reason is that configurations 2 and 5 have the fewest UL subframes and will not cause interference to other UEs due to direction conflicts.
After transitioning from the discontinuous reception (DRX) mode or the idle mode to the connected mode, the UE may have a delay to receive the system information block identifying the TDD configuration. In response to the delay, the UE can automatically update the TDD UL/DL allocation to a predefined TDD configuration. Once the UE receives the system information block, the UE can immediately update the TDD UL/DL allocation to the predefined TDD configuration.
The paging and physical random access channel (PRACH) is not affected by the use of the MIB to transmit the TDD configuration. For paging, LTE TDD uses subframes 0, 1, 5, and 6 for paging. These sub-frames are always used for DL regardless of the configuration. For PRACH, LTE TDD introduces a short RACH called Format 4. It is always transmitted on the UpPTS, and the UpPTS is in a special subframe and does not change direction as the configuration changes.
In some embodiments, when the configuration changes, the system will page the connected The UE performs a system information change notification. The connected UE reads the new configuration. The idle UE will not attempt to receive system information during each modification cycle. Therefore, the battery efficiency of the idle UE can be unaffected. However, this scheme requires the network to distinguish between paging to the connected UE and the idle UE. It will result in a more complex paging mechanism. For this purpose, a new paging RNTI (P-RNTI) can be introduced.
In some embodiments, the connected UE can read the MIB every 40 ms. This operation comes at the expense of additional power consumption. It can be understood that the UE power consumption is mainly on the RF transceiver chain, and the fundamental frequency processing consumes only a small portion of the total power. For this procedure, the increase in power consumption should not be significant.
5A is a flow diagram of an example program for a TDD configuration of a primary information block (MIB) message for an enhanced Node B (eNB). During a given period (eg, 40 ms for MIB and 80 ms for SIB1), the traffic period (502) can be monitored. The TDD configuration can be identified and set based on the monitored traffic (504). It may be determined whether the identified TDD configuration information from the monitored traffic is different from the existing TDD configuration used by the UE in communication with the eNB (506). If the identified TDD configuration is different, the TDD configuration can be communicated to the UE using MIB or SIB1. Specifically, the TDD-Config field (508) of the MIB or SIB1 can be updated by the new TDD configuration information. If the TDD configuration information is not new or different, the traffic can be returned to (502) to continue to be monitored, and the TDD configuration information can be identified until the different TDD configurations are identified to update the MIB or SIB1 TDD-Config field. .
5B is an example program flow diagram 550 for a TDD configuration of MIB or SIB1 messages for a user device. The UE connection mode can be determined (554). For a UE that is not idle (ie, connected UE), determine whether the UE is in DRX mode (556). For UEs that are not in DRX mode, the UE may be able to pick up a new configuration from MIB or SIB1 (558). For UEs in DRX, the UE updates the new configuration (560) with the MIB or SIB1 while waking up or entering the wake-up cycle (or the time period within the wake-up cycle). For a UE in an idle state, it will update the configuration based on MIB or SIB1 whenever it becomes connected or enters connected mode (562). For a UE in DRX or for an idle UE, there is a delay (564) if a new TDD configuration is identified (eg, the first subframe does not contain MIB or SIB1 when the UE wakes up, or if the UE cannot successfully If the current configuration is detected on a transmission (for example, because of interference), you can temporarily take configuration 2 (for a 5 ms period group) or 5 (for a 10 ms period group) until the current configuration is detected. (566). This temporary period can be short because the MIB retransmits once for each frame and SIB1 retransmits every other frame. The identified TDD configuration (568) can be used if there is no delay or after the delay expires.
Note that the given period in Figures 5A-5B is typically set to 40 ms or 80 ms, but for embodiments where the UE reads the MIB less frequently (e.g., every 120 ms or 160 ms), the period may be Configuration parameters.
6 is an example program flow diagram 600 for a hybrid new release UE and legacy UE scenario. For a given time period (eg, 40 ms for MIB and 80 ms for SIB1), the traffic is monitored (602). The TDD configuration can be identified based on the traffic (604). It may be determined whether the identified TDD configuration is different from the TDD configuration used by the UE at that time (606). If the identified TDD configuration is different from the TDD configuration used by the UE at that time, the information block (608) can be updated by the new TDD configuration. The MIB can be updated at the beginning of the next 40 ms period; Update SIB1 at the beginning of the next 80 ms period. For example, the TDD-Config field of the MIB can be updated by a bit representing a change in the new TDD configuration or TDD configuration. The configuration change rate (CCR) can be updated (610). In some implementations, the system may initiate processing of legacy UE UE UL transmissions, HARQ retransmissions, and control signaling transmissions (611) on the direction collision subframe.
The system can track the CCR for each given cycle. Compare CCR with T CCR (612). If the CCR is less than a predefined threshold T CCR , the system may update the TDD configuration information in SIB 1 (614) and the system information modification notification procedure may proceed (618). If the CCR is greater than T CCR (616), the system can continue to monitor the traffic (602) without updating the TDD configuration for the legacy UE.
In some embodiments, SIB1 can be used for TDD configuration. SIB1 uses a fixed schedule with a period of 80 ms and repeated in 80 ms. The first transmission is scheduled in subframe 5 of the radio frame of SFN modulo 8 = 0, and is repeated in subframe 5 of all other radio frames scheduled in SFN modulo 2 = 0. The new TDD configuration information can be applied as soon as possible at the beginning of the next 80 ms SIB1 cycle. The SIB1 technology is similar to the MIB-based technology. Use SIB1 to provide a lower maximum configuration change rate.
In some embodiments, a method for configuring time division duplex (TDD) UL/DL allocation of user equipment (UE) in a Long Term Evolution (LTE) network includes on a physical channel from an LTE network The eNB receives an indicator identifying the TDD configuration of the UE. A physical channel is a transmission channel that conveys user data and control messages on the physical layer. The TDD configuration information is embedded or multiplexed onto the physical channel. The TDD UL/DL allocation of the UE can be automatically updated according to the TDD configuration. The entity control format indicator channel (PCFICH) is currently used to indicate that it is used in each The number of OFDM symbols for transmitting the PDCCH in a subframe. It is called the Control Format Indicator (CFI). The TDD configuration or configuration change information can be carried via the CFI to update the TDD configuration. Three different CFI codewords are used in the current version of LTE and the fourth CFI codeword is reserved for future use, as shown in Table 3. Each codeword is 32 bits long.
The CFI codeword can be scrambled by the TDD configuration or configuration change indicator. In some embodiments, seven configuration indicator values can be used. Each value may correspond to one of the UL/DL configurations listed in Table 1. As a result, there can be as many as 21 different CFI codewords in the end. This reduces the minimum distance of the codeword. On the UE side, after detecting the signal on the PCFICH, the UE will descramble the received codeword to recover the original CFI value.
In some embodiments, two configuration change indicator values can be used. Each value corresponds to an upper or lower shift in the TDD configuration group. The configuration can be divided into two groups according to the switching period, and organized in ascending order according to the number of DL subframes, as shown in Table 2 above. One group is configured [0, 6, 1 and 2] and the other group is [3, 4 and 5]. When the UE detects the upshift indicator, it changes the configuration to one of the levels above the current level, for example, from configurations 1 through 6 in group one. If it receives a downshift indicator, it will change to one of the levels below the current level, for example self-configuration 6 to 1.
An example of implementation of a two-valued configuration change indicator is as follows. The first six bits are taken from each CFI codeword (1, 2, 3), and binary "+1" and "-1" are performed for each of them. Each codeword can be extended to 32 bits using the same repetition code as in the current LTE specifications. Examples of the resulting nine code words are shown in Table 4.
A CFI value has three codewords associated with it. It means that the configuration is moved up one level, down one level, and not changed. Table 5 shows an example of a CFI codeword.
7 is an example program flow diagram 700 for scrambling one or more CFI codewords by TDD configuration information. The original codeword can be identified (702). The system can check if a configuration change indication is received (704). If no configuration change indication is received, The system can then transmit the original CFI codeword (706). If a "down" indication is received (708), a check (708) of whether the current TDD configuration has been set to (configuration 2 above) configuration 2 or 5 can be performed. If a downshift indication is received (ie, a more heavily weighted DL) and the TDD configuration is already configured 2 or 5, the eNB will not indicate any configuration changes to the UE and the system can transmit the original CFI codeword (706) . If a configuration change indicator is received and the configuration is not one of configurations 2 or 5, the CFI codeword can be identified by the downshift indicator scrambling code (710). The scrambled CFI codeword (712) may be transmitted and the TDD-Config field of the SIB1 may be updated (714) by the new TDD configuration. If the received configuration change indication is an "upward" indication (ie, more heavily UL), then the check can be performed to configure whether to configure (0) of configuration 0 or 3 (above Table 2). If a configuration change indicator is received and the TDD configuration is set to configuration 0 or 3, the eNB will not indicate any configuration changes to the UE and may transmit the original CFI codeword (706). If a configuration change indicator is received and the TDD configuration is not one of configuration 0 or 3, the CFI codeword can be identified by up-shifting the indicator scrambling code (718). The scrambled CFI codeword (712) may be transmitted and SIB1 (714) may be updated by the new TDD configuration information.
There are various embodiments of up and down indicators. An error correction coding scheme can also be used instead of the current repetition code to increase the reliability of CFI codeword transmission. In addition, if there is an error in the detection, the UE will have the opportunity to correct the error via the updated SIB1 according to the regular system information change notification procedure. Therefore, the risk of propagation errors can be reduced.
8A is a flow diagram 800 of an example program for a PCFICH-based TDD configuration for a new release version of the UE. At the UE, for the new release version UE 802, after detecting the CFI codeword (804), the UE can adjust the configuration accordingly (806). 8B is an example program flow diagram 850 of a legacy UE for PCFICH based TDD configuration. For legacy UE 852, the original CFI codeword (854) will be detected based on the minimum distance as shown in Table 5. The TDD configuration (856) can be updated via the normal system information change program.
The LTE TDD system can change the TDD configuration by the frequency of each frame. The eNB may use the same configuration change indicator scrambling CFI value for each frame duration. The UE will detect the same configuration change indicator during the frame. Doing so increases the robustness of the detection.
In some embodiments, the TDD configuration changes in each DL subframe. The eNB may use an independent configuration change indicator in each subframe to scramble the CFI value. This scenario requires careful coordination of other system procedures, such as HARQ, interference, and so on.
The PCFICH-based TDD configuration also allows legacy UEs to operate as normal because PCFICH detection is based on a minimum distance. Although the legacy UE cannot recognize the new CFI codeword in Table 5, it will be able to detect the original CFI codeword from the new CFI codeword based on the minimum distance. Therefore, it will continue to operate as normal. The problem of UL transmission, HARQ retransmission, and control signaling transmission for legacy UEs can operate in a manner similar to that described above for MIB-based TDD configuration.
In some embodiments, the PDCCH can be used for TDD configuration. The PDCCH channel carries Downlink Control Information (DCI). It supports multiple formats and the UE needs to search and blindly detect the format of the PDCCH. The search space is defined in the LTE specification. It describes a collection of CCEs that the UE needs to monitor. There are two types of search spaces: a common search space and a UE-specific search space. Common search The seek space carries the common control information and is monitored by all UEs in the cell. A new DCI format called Format TDDConfig can be transmitted on a common search space. A new radio network temporary identifier called TDD-RNTI is used for the CRC of the scrambling format TDDConfig. TDD-RNTI can be defined. For example, the TDD-RNTI values as shown in Table 6 can be defined based on availability.
For seven TDD configurations (for example, the configuration defined in Table 1 above), three bits are sufficient to represent all configurations. In some embodiments, three bits will be appended by the CRC of the sixteen bit scrambling code. To increase the robustness of error protection, three bits can be encoded by a simple forward error correction (FEC) code such as a repetition code or Bosch and Rechohry (BCH) code. The codeword after the encoder will be the payload of the DCI format TDD-Config. As an example, in order to make the size comparable to other DCI formats on the common search space (the payload size differs with respect to the number and bandwidth of the antennas), Table 7 shows the payload of the DCI format TDDConfig by using nine repetition codes. It is twenty-seven. The 27-bit codeword will then be appended by the scrambled CRC.
The scrambled code CRC is obtained by performing a bitwise exclusive or (XOR) operation between a 16-bit CRC and a 16-bit TDD-RNTI (FFFC). Therefore, the total number of bits used for the DCI format TDDConfig is forty-three. Considering altogether The fact that the PDCCH on the search space is at least at the summary level four, after the channel coding, the final code rate will be extremely low. This will provide an excellent possibility for error detection. For the PDCCH-based TDD configuration, the information received by the UE may be a configuration indicator that directly indicates the configuration. This will give you more flexibility in configuration selection. The information received by the UE may also be a configuration change indicator that only needs one bit to represent.
9 and 10 illustrate implementations of PDCCH-based techniques proposed at eNBs and UEs. 9 is an example enhanced Node B program flow diagram 900 for a PDCCH based TDD configuration. The DCI format TDD-Config (902) can be defined. The CRC bit can be scrambled using TDD-RNTI and attached to the payload (904). Next, a tail-biting wrap coding can be performed. The encoded stream is matched to a predefined rate rate via gaps or padding bits. The channel can be encoded and a rate matching procedure can be implemented (906). The payload is transmitted on the common search space of the PDCCH along with the scrambled code CRC bits (908).
10 is an example UE program flow diagram 1000 for a PDCCH based TDD configuration. The UE can receive the payload. The channel can be decoded (1002) after the rate matching procedure. The PDCCH (1004) may be searched based on the scrambling code TDD-RNTI.
For PDCCH-based and PCFICH-based technologies, the TDD configuration detection delay problem is mitigated because configuration information is embedded in each DL subframe.
In addition to the existing search rules, the new release version of the TDD UE can also search for the DCI format TDD-Config and detect the TDD configuration. If there is no legacy UE in the network, all served UEs will change to the new configuration at the same time. However, for legacy UEs, the UE follows existing search rules and does not have to detect new TDD groups. State ability. As mentioned previously, the legacy UE will update the TDD configuration via SIB1 using the standard system information change procedure. If legacy UEs are present in the network, inter-issue UE interference can be handled in a manner similar to that described above.
The TDD configuration change can be made at the frequency of each frame. For example, the eNB may use the same TDD configuration in the DCI format TDDConfig for the duration of each frame. The UE can detect the same configuration or configuration change indicator at each subframe of the frame during the frame, which can increase the robustness of the detection. In some embodiments, the eNB may use the same TDD configuration in the DCI format TDD-Config for the duration of each frame; however, it may not transmit on each DL or special subframe, it may only In a few DL or special frames (for example, only in subframe 0 or only on two special frames, etc.). Doing so can alleviate the load on the PDCCH. In some implementations, a TDD configuration indicator can be sent in each DL subframe. For example, the eNB may use different TDD configurations in the DCI format TDD-Config for the duration of each subframe. This solution requires careful coordination of other system procedures, such as HARQ, interference, and so on.
The TDD-Config Information Element (IE) is in the SIB1 and Radio Resource Configuration Common IE. As mentioned above, the UE can read SIB1 only once every 640 ms due to adaptation to the DRX of the idle UE. An increase in the SIB1 read frequency will indicate an increase in UE power consumption. This increase is significant as it relates to the RF transceiver chain. Therefore, it is possible that the message-based TDD configuration indication can use the RRC connection reconfiguration procedure. If TDD reconfiguration is required, the TDD-Config IE can be changed to indicate the desired configuration. Can start pair in RRC_Connected state The RRC connection reconfiguration procedure for the UE in progress, including mobilityControlInfo (which contains the Radio Resource Configuration Common IE, which has a new TDD-Config). The SIB1 can be updated with the new configuration. It should be understood that the RRC message is an instance. New programs can be defined (for example, TDD reconfiguration programs) and new messages are introduced. The idle UE can obtain the current configuration via SIB1 when it becomes connected.
The use of dedicated signals for TDD configuration is backward compatible between the new release UE and the legacy UE. In some embodiments, a new program (eg, a TDD reconfiguration procedure) can be introduced that sends a message only to communicate the TDD-Config IE to the connected UE.
The use of dedicated signals can be used as a complementary TDD configuration technique in addition to the other techniques described herein for handling legacy UE configuration changes. In this way, the legacy UE does not have to wait for a modification period of 640 ms. It can change the configuration within 20 ms.
While this specification contains many specific implementation details, these details are not to be construed as limiting the scope of the claimed subject matter. Certain features that are described in this specification in the context of separate embodiments can also be implemented in a single implementation. Conversely, various features that are described in the context of a single implementation can be implemented in various embodiments, either separately or in any suitable sub-combination. Moreover, while features may be described above as acting in certain combinations and even initially claimed herein, one or more features from the claimed combination may be deleted from the combination in some instances, and claimed Combinations can be made for sub-combinations or sub-combinations.
Similarly, although the operations are depicted in the drawings in a specific order, they should not This is to be understood as requiring that such operations be performed in a particular order, or in a sequential order, or all the operations described. In some cases, multitasking and parallel processing may be advantageous. In addition, the separation of various system components in the above-described implementations should not be construed as requiring such separation in all implementations, and it is understood that the described program components and systems can be generally integrated together in a single software product or Packaged into multiple software products.
Thus, specific implementations of the subject matter have been described. Other implementations are within the scope of the following patent claims. In some cases, the actions cited in the scope of the patent application can be performed in a different order and still achieve the desired result. In addition, the procedures depicted in the figures are not necessarily in a particular In some implementations, multitasking and parallel processing may be advantageous.
200‧‧‧Wireless Honeycomb Communication System / Honeycomb Network System / Long Term Evolution (LTE) Telecom Environment / Long Term Evolution (LTE) Telecommunication System
202‧‧‧User Equipment (UE)
210‧‧‧radio access network
212‧‧‧Base Station/Enhanced Node B (eNB)
220‧‧‧ Core Network (CN)/Evolution Packet Core (EPC)
230‧‧‧External network
240‧‧2G/3G system
300‧‧‧ radio station
304‧‧‧Memory/Memory Module
306‧‧‧Wireless transceiver
308‧‧‧Antenna
310‧‧‧Digital Signal Processing (DSP) Circuit
312‧‧‧Digital filter circuit
404‧‧‧Memory/Memory Module
406‧‧‧Wireless transceiver
550‧‧‧Program flow chart
600‧‧‧Program flow chart
700‧‧‧Program flow chart
800‧‧‧Program flow chart
802‧‧‧ new release user device
850‧‧‧Example program flow chart
852‧‧‧Old-style user equipment
900‧‧‧Program flow chart
1000‧‧‧Program flow chart
1A is a graphical illustration of uplink and downlink subframes separated in the frequency domain for FDD mode.
FIG. 1B is a graphical illustration of uplink and downlink subframes sharing a carrier frequency in TDD mode.
2 is a schematic representation of an example wireless cellular communication system based on 3GPP LTE.
Figure 3 is a schematic illustration of an example radio station.
4 is a schematic illustration of an example user equipment (UE).
5A is a flow diagram of an example program for a TDD configuration of a primary information block (MIB) message for an enhanced Node B (eNB).
5B is a flow chart of an example program for a TBD configuration based on MIB messages for a user device.
6 is a flow chart of an example program for a scenario of a hybrid new release UE and legacy UE.
7 is a flow diagram of an example program for scrambling one or more Control Format Indicator (CFI) codewords by TDD configuration information.
8A is a flow diagram of an example program for a TDD configuration of a Physical Control Format Indicator Channel (PCFICH) for a new release user device.
8B is a flow chart of an example program for a PCFICH-based TDD configuration of a legacy UE.
9 is an example enhanced Node B program flow diagram for TDD configuration based on a Physical Downlink Control Channel (PDCCH).
10 is a flow diagram of an example UE procedure for TDD configuration based on PDCCH.
A method for configuring time division duplex (TDD) uplink/downlink (UL/DL) allocation of one of user equipment (UE) in a Long Term Evolution (LTE) network, comprising: Receiving, on a physical downlink control channel (PDCCH), a TDD configuration identifying one of the TDD configuration changes associated with resource allocation between the UL and DL of the UE from one of the enhanced Node Bs in the LTE network Changing the indicator; and receiving the TDD configuration change indicator therein includes detecting a downlink control information (DCI) message received on the PDCCH, the DCI message including being associated with a cyclic redundancy check (CRC) One or more bits, the CRC bits of the DCI message are scrambled by a TDD Radio Network Temporary Identifier (TDD-RNTI), the TDD-RNTI is exclusively dedicated to TDD configuration information; and at least partially Des scrambling the scrambled code CRC based on the TDD-RNTI to identify the CRC bits and an associated payload; and identifying the TDD configuration change indicator in the associated payload; And automatically updating the TDD UL/DL allocation of the UE based on the TDD configuration change identified by the TDD configuration change indicator.
The method of claim 1, further comprising determining a TDD UL/DL allocation corresponding to one of the plurality of TDD UL/DL configurations based on the received TDD configuration change indicator.
The method of claim 2, further comprising determining the TDD UL/DL configuration corresponding to a value indicating one of the two TDD configuration groups One moves up or down.
The method of claim 3, wherein the two TDD configuration groups comprise a first group having a first switching period and a second group having a second switching period longer than the first switching period .
The method of claim 4, wherein the first group and the second group are configured in a step-up order according to the number of DL subframes.
The method of claim 4, wherein the first switching period is 5 milliseconds and the second switching period is 10 milliseconds.
The method of claim 1, wherein the DCI message is received from a common search space of the PDCCH.
The method of claim 1, wherein the TDD configuration change indicator identifies a particular TDD configuration.
The method of claim 1, wherein the TDD configuration change indicator identifies a change in an existing TDD configuration.
The method of claim 1, wherein the TDD configuration change associated with the resource allocation between the UL and the DL comprises a change in the number of UL subframes and DL subframes in a radio frame.
A user equipment comprising: a processor configured to receive an identification of an UL associated with the UE from an enhanced Node B in an LTE network on a Physical Downlink Control Channel (PDCCH) An indicator of a time division duplex (TDD) configuration associated with resource allocation between DLs, wherein receiving the indicator includes detecting a downlink control information (DCI) message received on the PDCCH, DCI messages are associated with a cyclic redundancy check (CRC) One or more bits, the CRC bits of the DCI message are scrambled by a TDD Radio Network Temporary Identifier (TDD-RNTI), the TDD-RNTI being exclusively dedicated to TDD configuration information; based at least in part on the The TDD-RNTI descrambles the scrambled code CRC to identify a CRC and an associated payload; and identifies the TDD configuration change indicator in the associated payload; and the processor is further configured The TDD uplink (UL) and downlink (DL) allocations of the UE are automatically updated in accordance with the TDD configuration identified by the TDD configuration change indicator.
The user equipment of claim 11, wherein the TDD configuration change associated with the resource allocation between the UL and the DL of the UE comprises one of a number of UL subframes and DL subframes in a radio frame. .
A method for configuring time division duplex (TDD) uplink/downlink (UL/DL) allocation of one of user equipment (UE) in a Long Term Evolution (LTE) network, comprising: Identifying one of the TDD configuration changes associated with resource allocation between the UL and the DL, wherein identifying the TDD configuration change comprises identifying a TDD configuration indicator indicating one of the TDD groups for one UE State; based at least in part on a TDD-Radio Temporary Identifier (TDD-RNTI) scrambling code and one or more bits associated with a Cyclic Redundancy Check (CRC) of one of the downlink control information (DCI) messages, The TDD-RNTI is exclusively dedicated to TDD configuration information; and Transmitting, from an enhanced Node B in the LTE network, an indicator identifying a TDD configuration for the UE on a Physical Downlink Control Channel (PDCCH), wherein transmitting the indicator comprises transmitting using the PDCCH The DCI message.
The method of claim 13, wherein the TDD configuration change associated with the resource allocation between the UL and the DL comprises a change in the number of UL subframes and DL subframes in a radio frame.
An apparatus for configuring a Time Division Duplex (TDD) UL/DL allocation of one of User Equipment (UE) in a Long Term Evolution (LTE) network, comprising: a processor configured to Identifying one of the TDD configuration changes associated with resource allocation between the UL and the DL, wherein identifying the TDD configuration change comprises identifying a TDD configuration indicator indicating one of the TDD groups for one UE And one or more bits associated with a cyclic redundancy check (CRC) based at least in part on a TDD Radio Network Temporary Identifier (TDD-RNTI) scrambling code and a downlink control information (DCI) message The TDD-RNTI is exclusively dedicated to TDD configuration information; and the processor is further configured to transmit identification from an enhanced Node B in the LTE network on a Physical Downlink Control Channel (PDCCH) An indicator of a TDD configuration of the UE, wherein transmitting the indicator comprises transmitting the DCI message using the PDCCH.
The apparatus of claim 15, wherein the TDD configuration change associated with the resource allocation between the UL and the DL comprises a change in the number of UL subframes and DL subframes in a radio frame.
TW101125431A 2011-08-15 2012-07-13 Notifying a ul/dl configuration in lte tdd systems TWI554071B (en)
TW201318391A TW201318391A (en) 2013-05-01
TWI554071B true TWI554071B (en) 2016-10-11
TW200709700A (en) * 2005-06-14 2007-03-01 Lg Electronics Inc Method of communicating signals in a mobile communication system
TW200742473A (en) * 2006-03-24 2007-11-01 Interdigital Tech Corp Method and apparatus for performing a handover procedure between a 3 GPP LTE network and an alternative wireless network
TW201012271A (en) * 2008-09-09 2010-03-16 Htc Corp Methods utilized in mobile device and mobile device thereof