KR20140106505A - Half-duplex/full-duplex operation for tdd carrier aggregation - Google Patents

Abstract

Aspects of the disclosure relate to methods of communicating using TDD and carrier aggregation.

Description

[0001] HALF-DUPLEX / FULL-DUPLEX OPERATION FOR TDD CARRIER AGGREGATION FOR TDD CARRIER AGGREGATION [0002]

35 Priority claim under U.S.C. §119

This patent application is a continuation-in-part of U.S. Provisional Patent Application entitled "HALF-DUPLEX OPERATION FOR TDD CARRIER AGGREGATION ", filed October 11, 2011, 61 / 542,765. ≪ / RTI >

Aspects of the present disclosure generally relate to wireless communication systems, and more particularly, to such systems that utilize carrier aggregation and time division duplex (TDD) techniques.

BACKGROUND OF THE INVENTION Wireless communication networks have been extensively deployed to provide various communication services such as voice, video, packet data, messaging, broadcast, and the like. These wireless networks may be multiple access networks capable of supporting multiple users by sharing available network resources. Embodiments of such multiple access networks include Code Division Multiple Access (CDMA) networks, Time Division Multiple Access (TDMA) networks, Frequency Division Multiple Access (FDMA) networks, Orthogonal FDMA (Single-Carrier FDMA) networks.

A wireless communication network may include multiple base stations capable of supporting communication for multiple user equipments (UEs). The UE may also communicate with the base station on the downlink and uplink. The downlink (or forward link) refers to the communication link from the base station to the UE, and the uplink (or reverse link) refers to the communication link from the UE to the base station.

Techniques for wireless communication using carrier aggregation are described herein.

In an aspect, a method is provided for wireless communication by a base station. The method generally includes the steps of determining whether a user equipment (UE) is to communicate in half-duplex (HD) or full-duplex (FD), and, based at least in part on its determination, (S) (CCs) or communications with the UE.

In another aspect, a method is provided for wireless communication by a user equipment. The method generally includes the steps of determining, for at least one subframe, whether the uplink subframe and the downlink subframe on different component carriers (CCs) used to communicate with the UE by the base station overlap, And following at least one prioritization rule to determine whether to transmit or receive during one subframe.

According to one aspect, an apparatus for communicating by a base station is provided. The apparatus generally includes means for determining whether user equipment (UE) is to communicate in half-duplex (HD) or full-duplex (FD) and, based at least in part on its determination, (CCs) or means for scheduling communications with the UE.

According to an aspect, an apparatus is provided for half-duplex (HD) operations by a user equipment (UE). The apparatus generally comprises means for determining, for at least one subframe, whether uplink subframes and downlink subframes on different component carriers (CCs) used to communicate with the UE by the base station overlap and at least one And means for following at least one prioritization rule to determine whether to transmit or receive during a subframe of the frame.

According to one aspect, an apparatus for communicating by a base station is provided. The apparatus generally determines whether user equipment (UE) is to communicate in half-duplex (HD) or full-duplex (FD) and, based at least in part on its determination, Lt; RTI ID = 0.0 > (e. G., CCs) or < / RTI >

According to an aspect, an apparatus is provided for half-duplex (HD) operations by a user equipment (UE). The apparatus generally determines, for at least one subframe, whether the uplink subframe and the downlink subframe on different component carriers (CCs) used to communicate with the UE by the base station overlap and at least one At least one processor configured to comply with at least one prioritization rule to determine whether to transmit or receive during a subframe; And a memory coupled with the at least one processor.

According to an aspect, a computer program product is provided for communicating by a base station, the computer program product including a computer readable medium having stored code. The code is typically used by one or more processors to determine whether the user equipment (UE) is to communicate in half-duplex (HD) or full-duplex (FD) , Resources on different component carriers (CCs), or communications with the UE.

According to one aspect, a computer program product is provided for half-duplex (HD) operations by a user equipment (UE), including a computer readable medium having stored code. The code is typically used by one or more processors to determine, for at least one subframe, whether the uplink subframe on the different component carriers (CCs) used to communicate with the UE by the base station and the downlink subframe overlap And to follow at least one prioritization rule to determine whether to transmit or receive for at least one subframe.

Various aspects and features of the disclosure are described in further detail below.

1 is a block diagram conceptually showing an example of a communication system;
2 is a block diagram conceptually illustrating an example of a downlink frame structure in a communication system;
3 is a block diagram conceptually illustrating a design of a base station / eNodeB and UE configured in accordance with an aspect of the present disclosure;
Figure 4A discloses a continuous carrier aggregation type;
4b discloses a discontinuous carrier aggregation type;
5 discloses MAC layer data aggregation;
6 is a block diagram illustrating a method for controlling wireless links in a plurality of carrier configurations;
Figure 7 illustrates an exemplary wireless network configuration including a macrocell and a limited subscriber group;
Figures 8 and 8A illustrate exemplary TDD mode subframe configurations;
9 is a flow diagram representation of an exemplary process of wireless communication;
10 is a flow diagram representation of exemplary operations for wireless communication that may be performed at a base station;
11 is a flow diagram representation of exemplary operations for wireless communication that may be performed at a user equipment (UE).

The detailed description set forth below in conjunction with the appended drawings is intended as a description of various configurations and is not intended to represent only those configurations in which the concepts described herein may be practiced. The detailed description includes specific details for the purpose of providing a thorough understanding of the various concepts. However, it will be apparent to those skilled in the art that these concepts may be practiced without these specific details. In some instances, well-known structures and components are shown in block diagram form in order to avoid obscuring these concepts.

The techniques described herein may be used for various wireless communication networks, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and other networks. The terms "network" and "system" are often used interchangeably. A CDMA network may implement wireless technologies such as Universal Terrestrial Radio Access (UTRA), cdma2000, and the like. UTRA includes Wideband CDMA (WCDMA) and other variants of CDMA. cdma2000 covers IS-2000, IS-95 and IS-856 standards. The TDMA network may implement a radio technology such as Global System for Mobile Communications (GSM). The OFDMA network may implement wireless technologies such as Evolved UTRA (U-UTRA), Ultra Mobile Broadband (UMB), IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802.20, Flash-OFDMA, UTRA and E-UTRA are part of the Universal Mobile Telecommunication System (UMTS). 3GPP Long Term Evolution (LTE) and LTE-Advanced (LTE-A) are new releases of UMTS that use E-UTRA. UTRA, E-UTRA, UMTS, LTE, LTE-A and GSM are described in documents from an organization named " 3rd Generation Partnership Project (3GPP) ". cdma2000 and UMB are described in documents from the organization named "3rd Generation Partnership Project 2" (3GPP2). The techniques described herein may also be used for the wireless technologies and wireless networks described above as well as for other wireless networks and wireless technologies. For clarity, certain aspects of the techniques are described below for LTE, and the term LTE is used in most of the discussions below.

Figure 1 illustrates a wireless communication network 100 that may be an LTE network. Wireless network 100 may include multiple eNodeBs (evolved Node Bs) 110 and other network entities. The eNodeB may be a station that communicates with the UEs and may also be referred to as a base station, an access point, and so on. Node B is another example of a station communicating with UEs.

Each eNodeB 110 may provide communication coverage for a particular geographic area. In 3GPP, the term "cell" may refer to the coverage area of the eNodeB and / or the eNodeB subsystem serving this coverage area, depending on the context in which the term is used.

The eNodeB may provide communication coverage for macro cells, picocells, femtocells, and / or other types of cells. The macrocell may cover a relatively large geographic area (e.g., a few kilometers in radius) and may allow unrestricted access by UEs subscribed to the service. The picocell may cover a relatively small geographic area and may allow unrestricted access by UEs subscribed to the service. The femtocell may cover a relatively small geographic area (e. G., A home) and may also be associated with UEs associated with a femtocell (e.g., UEs in a restricted subscriber group (CSG), UEs in a home , Etc.). ≪ / RTI > The eNodeB for the macro cell may also be referred to as the macro eNodeB. The eNodeB for the picocell may also be referred to as pico eNodeB. The eNodeB for a femtocell may also be referred to as a femto eNodeB or a home eNodeB. In the example shown in FIG. 1, the eNodeBs 110a, 110b, and 110c may be macro eNodeBs for the macrocells 102a, 102b, and 102c, respectively. eNodeB 110x may be a pico eNodeB for picocell 102x. The eNodeBs 110y and 110z may be femto eNodeBs for the femtocells 102y and 102z, respectively. The eNodeB may support one or more (e.g., three) cells.

The wireless network 100 may also include relay stations. A relay station is a station that receives a transmission of data and / or other information from an upstream station (e.g., eNodeB or UE) and transmits a transmission of data and / or other information to a downstream station (e.g., UE or eNodeB) . The relay station may also be a UE relaying transmissions to other UEs. In the example shown in FIG. 1, relay station 110r may communicate with eNodeB 110a and UE 120r to facilitate communication between eNodeB 110a and UE 120r. The relay station may also be referred to as a repeater eNodeB, a repeater, or the like.

The wireless network 100 may be a heterogeneous network that includes different types of eNodeBs, such as macro eNodeBs, pico eNodeBs, femto eNodeBs, repeaters, and the like. These different types of eNodeBs may have different transmission power levels, different coverage areas, and different impacts on interference in the wireless network 100. For example, macro eNodeBs may have a high transmit power level (e.g., 20 watts), while pico eNodeBs, femto eNodeBs and repeaters may have a lower transmit power level (e.g., 1 watt).

The wireless network 100 may support synchronous or asynchronous operation. For synchronous operation, eNodeBs may have similar frame timing, and transmissions from different eNodeBs may be roughly time aligned. For asynchronous operation, eNodeBs may have different frame timings, and transmissions from different eNodeBs may not be time aligned. The techniques described herein may be used for both synchronous and asynchronous operation.

The network controller 130 may couple to the set of eNodeBs and provide coordination and control for these eNodeBs. The network controller 130 may communicate with the eNodeBs 110 via a backhaul. eNodeBs 110 may also communicate directly or indirectly and also with each other, e.g., via a wireless or wired backhaul.

The UEs 120 may be distributed throughout the wireless network 100, and each UE may be stationary or mobile. The UE may also be referred to as a terminal, a mobile station, a subscriber unit, a station, and so on. The UE may be a cellular phone, a personal digital assistant (PDA), a wireless modem, a wireless communication device, a handheld device, a laptop computer, a wireless telephone, a wireless local loop (WLL) The UE may communicate with macro eNodeBs, pico eNodeBs, femto eNodeBs, repeaters, and the like. In Figure 1, a solid line with double arrows indicates the desired transmission between the UE and the serving eNodeB, where the serving eNodeB is the eNodeB designated to serve the UE on the downlink and / or uplink. A dashed line with double arrows indicates interference transmissions between the UE and the eNodeB.

LTE utilizes orthogonal frequency division multiplexing (OFDM) on the downlink and utilizes single-carrier frequency division multiplexing (SC-FDM) on the uplink. OFDM and SC-FDM divide the system bandwidth into multiple (K) orthogonal subcarriers, which are also commonly referred to as tones, bins, and so on. Each subcarrier may be modulated by data. In general, modulation symbols are transmitted in the frequency domain via OFDM and in the time domain via SC-FDM. The spacing between adjacent subcarriers may be fixed and the total number K of subcarriers may depend on the symbol bandwidth. For example, the spacing of subcarriers may be 15 kHz and the minimum resource allocation (referred to as a 'resource block') may be 12 subcarriers (or 180 kHz). As a result, the nominal FFT size may be equal to 128, 256, 512, 1024, or 2048 for a system bandwidth of 1.25, 2.5, 5, 10, or 20 megahertz (MHz), respectively. The system bandwidth may also be divided into subbands. For example, the subband may cover 1.08 MHz (i.e., 6 resource blocks) and may be 1, 2, 4, 8, or 10 for system bandwidths of 1.25, 2.5, 5, Or 16 subbands may be present.

2 shows a downlink frame structure used in LTE. The transmission timeline for the downlink may be divided into units of radio frames. Each radio frame may have a predetermined duration (e.g., 10 milliseconds (ms)) and may be divided into 10 subframes with indices of 0 to 9. Each subframe may include two slots. Thus, each radio frame may comprise 20 slots with indices of 0 to 19. Each slot may comprise L symbol periods, e.g., 7 symbol periods for a general cyclic prefix (such as shown in FIG. 2) or 14 symbol periods for an extended cyclic prefix. In the 2L symbol periods in each subframe, indexes of 0 to 2L-1 may be allocated. The available time frequency resources may be divided into resource blocks. Each resource block may cover N subcarriers (e.g., 12 subcarriers) in one slot.

In LTE, the eNodeB may send a primary synchronization signal (PSS) and a secondary synchronization signal (SSS) for each cell at the eNodeB. The primary synchronization signal and the secondary synchronization signal are transmitted in symbol periods 6 and 5, respectively, in subframe 0 and subframe 5 of each radio frame having a common cyclic prefix, as shown in FIG. 2 Lt; / RTI > The synchronization signals may be used by the UEs for cell detection and acquisition. The eNodeB may also transmit a physical broadcast channel (PBCH) in symbol periods 0 to 3 in slot 1 of subframe 0. The PBCH may carry certain system information.

The eNodeB is depicted throughout the first symbol period of FIG. 2, but may also transmit a Physical Control Format Indicator Channel (PCFICH) only in a portion of the first symbol period of each subframe. The PCFICH may carry the number M of symbol periods used for the control channels, where M may be equal to 1, 2, or 3 and may be different for each subframe. M may also be equal to 4 for a small system bandwidth having fewer than 10 resource blocks, for example. In the embodiment shown in FIG. 2, M = 3. The eNodeB may transmit a physical HARQ indicator channel (PHICH) and a physical downlink control channel (PDCCH) in a first M (M = 3 in FIG. 2) symbol periods of each subframe. The PHICH may also carry information to support hybrid automatic retransmission (HARQ). The PDCCH may carry information on uplink and downlink resource allocation for UEs and power control information on uplink channels. Although not shown in the first symbol period of FIG. 2, it is understood that PDCCH and PHICH are also included in the first symbol period. Similarly, PHICH and PDCCH are also present in both the second and third symbol periods, but the scheme is not shown in Fig. The eNodeB may send a physical downlink shared channel (PDSCH) in the remaining symbol periods of each subframe. The PDSCH may carry data for the scheduled UEs for data transmission on the downlink. The various signals and channels in LTE are described in 3GPP TS 36.211, entitled " Evolved Universal Terrestrial Radio Access (E-UTRA), Physical Channels and Modulation ", which is publicly available.

The eNodeB may also transmit PSS, SSS, and PBCH at the center 1.08 MHz of the system bandwidth used by the eNodeB. The eNodeB may transmit these channels over the entire system bandwidth in each of the symbol periods in which the PCFICH and PHICH are transmitted. The eNodeB may send the PDCCH to groups of UEs in certain parts of the system bandwidth. The eNodeB may send the PDSCH to specific UEs in certain parts of the system bandwidth. The eNodeB may transmit PSS, SSS, PBCH, PCFICH and PHICH in a broadcast manner to all UEs, transmit a PDCCH in a unicast manner to specific UEs, and transmit PDSCH in a unicast manner to specific UEs It is possible.

Multiple resource elements may be available in each symbol period. Each resource element may cover one subcarrier in one symbol period and may be used to transmit one modulation symbol, which may be a real or a complex value. Elements that are not used for the reference signal in each symbol period may be arranged in resource element groups (REGs). Each REG may include four resource elements in one symbol period. The PCFICH may occupy four REGs in symbol period 0, which may be spaced approximately equally across the frequency. The PHICH may occupy three REGs that may be spread over a frequency in one or more configurable symbol periods. For example, all three REGs for PHICH may belong to symbol period 0, or may be spread in symbol periods 0, 1 and 2. The PDCCH may occupy 9, 18, 32 or 64 REGs that may be selected from the available REGs in the first M number of symbol periods. Only certain combinations of REGs may be allowed for the PDCCH.

The UE may know the specific REGs used in the PHICH and PCFICH. The UE may search for different combinations of REGs for the PDCCH. The number of combinations for searching is generally less than the number of combinations allowed for the PDCCH. The eNodeB may send the PDCCH to the UE in any combinations the UE will search for.

The UE may be within the coverage of multiple eNodeBs. One of these eNodeBs may be selected to serve the UE. The serving eNodeB may be selected based on various criteria such as received power, path loss, signal-to-noise ratio (SNR), and the like.

FIG. 3 shows a block diagram of a design of a base station / eNodeB 110 and a UE 120, which may be one of the base stations / eNodeBs and the UEs in FIG. For a limited relevance scenario, the base station 110 may be the macro eNodeB 110c in FIG. 1, and the UE 120 may be the UE 120y. The base station 110 may also be some other type of base station. The base station 110 may comprise antennas 634a through 634t and the UE 120 may comprise antennas 652a through 652r.

At base station 110, transmit processor 620 may receive data from data source 612 and control information from controller / processor 640. The control information may be for PBCH, PCFICH, PHICH, PDCCH, and the like. The data may be for PDSCH or the like. Processor 620 may process data and control information (e.g., encoding and symbol mapping) to obtain data symbols and control symbols, respectively. Processor 620 may also generate reference symbols for, for example, PSS, SSS, and cell specific reference signals. A transmit multiple input multiple output (MIMO) processor 630 may perform spatial processing (e.g., precoding) on data symbols, control symbols, and / or reference symbols, And may provide output symbol streams to modulators (MODs) 632a through 632t. Each modulator 632 may process each output symbol stream (e.g., for OFDM, etc.) to obtain an output sample stream. Each modulator 632 may further process (e.g., analog convert, amplify, filter, and upconvert) the output sample stream to obtain a downlink signal. The downlink signals from modulators 632a through 632t may be transmitted via antennas 634a through 634t, respectively.

At UE 120, antennas 652a through 652r may receive downlink signals from base station 110 and provide received signals to demodulators (DEMODs) 654a through 654r, respectively . Each demodulator 654 may condition (e.g., filter, amplify, downconvert, and digitize) each received signal to obtain input samples. Each demodulator 654 may further process the input samples (e.g., for OFDM, etc.) to obtain the received symbols. MIMO detector 656 may obtain received symbols from all demodulators 654a through 654r, perform MIMO detection on received symbols, if applicable, and provide detected symbols. The receive processor 658 processes (e.g., demodulates, deinterleaves, and decodes) the detected symbols, provides decoded data for the UE 120 to the data sink 660, Controller / processor 680. < / RTI >

At the UE 120 on the uplink, the transmit processor 664 receives data from the data source 662 (e.g., for the PUSCH) and data from the controller / processor 680 (e.g., PUCCH) The control information may be received and processed. Transmit processor 664 may also generate reference symbols for the reference signal. The symbols from transmit processor 664 may be precoded by TX MIMO processor 666 if applicable and further processed by demodulators 654a through 654r (e.g., for SC-FDM, etc.) And may be transmitted to the base station 110. At base station 110, the uplink signals from UE 120 may be received by antennas 634, processed by modulators 632, and applied to MIMO detector 636, if applicable And may be further processed by the receive processor 638 to obtain decoded data and control information transmitted by the UE 120. [ Receive processor 638 may provide the decoded data to data sink 639 and provide decoded control information to controller / processor 640. [

The controllers / processors 640 and 680 may direct the operation at the base station 110 and the UE 120, respectively. The processor 640 and / or other processors and modules at the base station 100 may perform or direct the execution of various processes for the techniques described herein. The processor 680 and / or other processors and modules at the UE 120 may be configured to perform the functions described herein with respect to the functional blocks illustrated in Figures 4A, 4B, 5 and 6, and / or other processes for the techniques described herein May also be performed or directed. Memories 642 and 682 may store data and program codes for base station 110 and UE 120, respectively. Scheduler 644 may schedule the UEs for data transmission on the downlink and / or uplink.

In one configuration, the UE 120 for wireless communication includes means for detecting interference from an interfering base station during a connection mode of the UE, means for selecting an interfering base station's yielded resource, Means for obtaining an error rate of the link control channel, and means for declaring a radio link failure that is executable in response to an error rate exceeding a predetermined level. In one aspect, the above-mentioned means comprise a processor (s), a controller / processor 680, a memory 682, a receive processor 658, a MIMMO detector (not shown) configured to perform the functions listed by the above- 656, demodulators 654a, and antennas 652a. In another aspect, the above-mentioned means may be a module or any device configured to perform the functions listed by the above-mentioned means.

carrier Aggregation

LTE-Advanced UEs use spectrum up to 20 MHz bandwidths, allocated to carrier aggregations (5 component carriers) up to a total of 100 MHz used for transmission in each direction. In general, since less traffic is transmitted on the uplink than on the downlink, the uplink spectrum allocation may be smaller than the downlink allocation. For example, if 20 MHz is allocated to the uplink, 100 MHz may be allocated to the downlink. These asymmetric FDD allocations will preserve the spectrum and are well suited for generally asymmetric bandwidth utilization by broadband subscribers.

carrier Aggregation  Types

For LTE-Advanced mobile systems, two types of carrier aggregation (CA) methods have been proposed (consecutive CA and discontinuous CA). These are illustrated in Figures 4A and 4B. The discontinuous CA occurs when a number of available component carriers are separated along the frequency band (FIG. 4B). On the other hand, a consecutive CA occurs when a number of available component carriers are adjacent to one another (Fig. 4A). Both consecutive CAs and discontinuous CAs aggregate multiple LTE / component carriers to serve a single unit of the LTE Advanced UE.

Multiple RF receiving units and multiple FFTs are used with discontinuous CAs in the LTE-Advanced UE because the carriers are separated along the frequency band. Propagation path loss, Doppler shift, and other radio channel characteristics may change significantly in different frequency bands, since discontinuous CAs support data transmission over a large number of separate carriers.

Thus, methods to adaptively adjust the coding, modulation, and transmit power for different component carriers may be used to support broadband data transmission under the discontinuous CA approach. For example, in an LTE-Advanced system where the Enhanced Node B (eNodeB) has a fixed transmit power on each component carrier, the effective coverage or supportable modulation and coding of each component carrier may be different.

data Aggregation  Methods

5 illustrates the aggregation of transmission blocks (TBs) from different component carriers in an intermediate access control (MAC) layer (FIG. 5) for an IMT-Advanced system. By MAC layer data aggregation, each component carrier has its own Hybrid Automatic Repeat Request (HARQ) entity at its MAC layer and its own transmission configuration parameters (e.g., transmit power, modulation and coding Schemes, and multiple antenna configurations). Similarly, in the physical layer, one HARQ entity is provided for each component carrier.

Control Signaling

In general, there are different approaches to using control channel signaling for multiple component carriers. The first approach involves slight modification of the control structure in LTE systems where each component carrier is given its coded control channel.

A second approach entails jointly coding control channels of different component carriers and moving control channels in dedicated component carriers. Control information for multiple component carriers will be integrated as signaling content in a dedicated control channel. As a result, backward compatibility with the control channel structure is maintained in LTE systems, and the signaling overhead in the CA is reduced.

The multiple control channels for the different component carriers are jointly coded and then transmitted over the entire frequency band formed by the third CA method. This approach provides low signaling overhead and high decoding performance on the control channels for high power consumption on the UE side. However, this method is not compatible in LTE systems.

Handover  Control

If the CA is not used in the IMT-Advanced UE, it is desirable to support transmission continuity during handover procedures across multiple cells. However, reserving sufficient system resources (i. E., Component carriers with good transmission quality) for the ingress UE may be a challenge for the next eNodeB according to specific CA configurations and quality of service (QoS) requirements. The reason is that the channel conditions of two (or more) adjacent cells (eNodeBs) may be different for a particular UE. In one approach, the UE measures the performance of only one component carrier in each neighboring cell. This provides measurement delay, complexity, and energy consumption similar to those in LTE systems. The estimation of the performance of the other component carriers in the corresponding cell may be based on the measurement results of one component carrier. Based on this estimation, the handover determination and transmission configuration may be determined.

In accordance with various embodiments, a UE operating in a multi-carrier system (also referred to as carrier aggregation) may operate on multiple carriers, such as control and feedback functions, on the same carrier, which may be referred to as a "primary carrier" And is configured to aggregate certain functions. The remaining carriers that depend on the primary carrier for support are referred to as associated secondary carriers. For example, the UE may provide control functions such as those provided by an optional dedicated channel (DCH), unscheduled grants, a physical uplink control channel (PUCCH), and / or a physical downlink control channel (PDCCH) You can also assemble them. The signaling and payload may be transmitted on both the downlink to the UE by the eNodeB and the uplink to the eNodeB by the UE.

In some embodiments, there may be multiple primary carriers. In addition, the secondary carriers may be added or removed without affecting the basic operation of the UE, including RLF procedures and physical channel establishment, which are Layer 2 procedures, as in 3GPP Technical Specification 36.331 for the LTE RRC protocol.

6 illustrates a method 600 of controlling wireless links in a multi-carrier wireless communication system by grouping physical channels according to an example. As shown, the method includes, at block 605, aggregating control functions from at least two carriers into a single carrier to form a primary carrier and one or more associated secondary carriers. Next, at block 610, communication links are established for the primary carrier and each secondary carrier. Thereafter, communication is controlled based on the primary carrier at block 615.

TDD carrier Aggregation

Certain conventional wireless communication standards such as Long Term Evolution (LTE) Release 10 (Rel-10) allow only aggregation of time domain duplexing (TDD) or only frequency domain duplexing (FDD) component carriers do. However, as the demand for wireless bandwidth increases, additional techniques may be required. (E.g., frequency domain duplexing (FDD) or time domain duplexing (TDD) aggregation) of the CCs in time and / or frequency domains is used to address the increased demand for bandwidth among others Technology.

In some designs, the TDD carrier may only transmit an uplink (UL) portion (e.g., only subframes designated UL) or a downlink (DL portion) of another TDD carrier (also referred to as bi-directional aggregation) 0.0 > subframes < / RTI > designated < / RTI >

7, an exemplary embodiment for implementing TDD-TDD aggregation in a wireless network 700 that includes a macro cell 702 and a restricted subscriber group (CSG) 704 is illustrated. 7, two component carriers CC1 and CC2, which may be TDD carriers, are assumed, where CC1 is the anchor component carrier for the macrocell 702 and CC2 is the anchor component carrier for the anchor for the CSG 704. In this embodiment, Component carriers.

UE 710 may be part of CSG 704, as illustrated. Some UEs, such as UE 712, may be within the coverage of CSG 704, but can not connect to eNB 714 of CSG 704, for example due to limited access at CSG 704. The lines with unidirectional arrows connecting the eNBs 714 and 716 with the corresponding UEs 710 and 712 in FIG. 7 may possibly indicate unidirectional carrier aggregation (only UL or DL) The lines with bi-directional arrows may be bi-directional UL and DL carrier aggregation whenever possible.

In Fig. 7, transmissions on CC1 are indicated by solid line arrows, while transmissions on CC2 are indicated by dashed arrows. As indicated, each component carrier may be a unidirectional CC (as indicated by a single directional arrow) or a bi-directional CC (as indicated by a double arrow), where bidirectional component carriers include UL and DL carriers, The carriers include UL or DL carriers.

The LTE TDD CC is a single carrier using the same frequency bands for the uplink and downlink. The transmission directions are distinguished by carrying UL and DL data in different subframes. The uplink and downlink subframe assignments are periodic and are defined by the periodicity of the downlink-uplink switch point. The periodicity may be 10 msec or 5 msec. See FIG. On the other hand, the LTE FDD CC uses paired frequency carriers (one carrier is UL and the other carrier is DL) to distinguish UL and DL in frequency.

In some designs, the aggregation performed in the macrocell 702 may protect (e.g., not aggregate) the anchor CC2 with respect to the CSG 704. In some designs, therefore, CC1 may be aggregated in both UL and DL, while CC2 may be aggregated only in DL subframes. In addition, if the aggregation is performed in the CSG 704, the aggregated carrier should ensure that the DL carrier used by the macrocell 702 is protected. Therefore, in some designs, carrier CC2 may be aggregated in both UL and / or DL directions, while CC1 may be aggregated only in UL subframes, not DL subframes.

TDD carrier Aggregation  Lt; RTI ID = 0.0 & Duplex /pool- Duplex  action

Carrier aggregation of TDD carriers with different UL-DL subframe configurations may be considered. One of the problems to be addressed is related to full-duplex versus half-duplex operation in connection with this type of carrier aggregation. In different subframe configurations, the downlink and uplink subframes may overlap, which means that downlink and uplink transmissions in different component carriers occur in the same subframe. This is illustrated in Figure 8A which shows an example of two different configurations used for two different CCs.

In general, conventional systems utilized only half-duplex operation for TDD. However, aspects of the present disclosure contemplate full-duplex operation when the UE has carriers of different UL-DL configurations configured, which allows UEs to transmit and receive simultaneously in certain cases.

Half-duplex operation is not introduced due to configuration reasons (which may or may not actually be because "per carrier" radios must be available due to the assumption that carriers are in different bands) And FD operation are possible, certain aspects presented herein allow the eNB to make decisions regarding how to process the UE as an HD and to employ scheduling constraints, or to send and receive simultaneously in different CCs as FDs, You can also address the problem. As described below, various criteria may be considered when determining how a UE should be considered (as FD or HD).

Utilizing TDD carrier aggregation (CA) with different UL-DL sub-frame arrangements is typically done in such a way that UL and DL sub-frames in some sub-frames on different component carriers (CCs) Indicating that they will overlap together.

For UEs operating in full-duplex (FD), this may not be a problem since the UE may transmit and receive simultaneously in different CCs without any problems. However, this is not the case, because the UE can only support half-duplex (HD) communications, or can be used for various reasons such as de-sensing (to reduce interference caused by transmitting simultaneously with reception) If so, you can present a challenge. In this case, in overlapping UL-DL subframes, the UE may only transmit or receive.

In each UL-DL subframe overlap, the UE may be configured to transmit according to one or more prioritization rules. For example, if there is nothing to transmit (PUCCH / PUSCH), such as data, CQI or ACK / NACK feedback, the UE may be configured to transmit in the UL. In this case, the DL reception may be restricted or completely stopped. In some cases, DL subframes on all CCs are blocked when UL transmission is scheduled.

In some cases, even in a UL subframe, the UE may be able to receive DLs at the CC, for example, if the UE has a separate RF chain from that used for transmission on the UL on another CC. However, in such cases, the received signal may be poor (e.g., due to interference caused by transmission) and may therefore be discarded. Thus, the prioritization rules may indicate that the UE should continue downlink reception on at least one component carrier (CC) for at least one subframe and discard the corresponding downlink transmission if the signal quality is not sufficient .

Therefore, in some cases, in overlapping subframes, the UE may be configured to transmit on the DL only if no UL transmissions are scheduled.

Because of potential limitations, the eNB (or generally any type of base station) may utilize some type of intelligent scheduling algorithm to avoid lost DLs for UE HD operation. This may impose scheduling restrictions. For example, if a primary component carrier (PCC) is used heavily for UL transmissions, there may be more scheduling constraints due to PUCCH transmissions. On the other hand, if the PCC is heavily used for the DL, it may be easier to apply / schedule scheduling constraints because the scheduling constraints are only a function of the PUSCH scheduled transmissions.

The HD operation by the UE may be due to structural limitations or operational limitations. For structural limitations, HD operation may be imposed due to the structural incompetence of the UE in receiving and transmitting simultaneously. Operationally, RF limitations may exist, where the HD operation is imposed due to the de-sense issues (transmit interference to the received signal).

However, if there are no structural limitations, the eNB may assume HD operation for some UEs with FD operation and some other groups of UEs. FD UEs can transmit and receive in the same subframe, and thus there may be very little or no scheduling constraints. On the other hand, HD UEs can only receive when not transmitting. The scheduling constraints (as described above) may be implemented by the eNB to avoid wasting resources.

Various signaling options exist to convey information regarding FD or HD operation by the UE. In some cases, the UE may signal the eNB with respect to its FD / HD capability. In such a case, the eNB may determine that the UE is FD capable, and thus may schedule resources. In some cases, the eNB may (again) send signaling to the UE indicating that the eNB considers the UE to be an FD or HD UE. In some cases, the determination may vary (e.g., based on changing conditions or based on updated performance messages from the UE).

There are various criteria that may be utilized to determine whether the eNB treats the UE as FD capable or HD capable (e.g., the determination may be performed based on one or more parameters). One or more of these criteria may relate to the associated transmit and / or receive power of the UE (indicating possible interferences caused by simultaneous transmission and reception). These criteria may include the UE location (UEs closer to the base station may have lower transmit power and higher receiver power), UE transmit power, UE receive power, or the amount of transmit and receive power.

Various other criteria may also be considered, such as the target demodulated SNR, the UE antenna configuration, the Rx diversity capability and the Tx-Rx antenna coupling, the general UE performance, and the allocated resources on the UL and / or DL. Frequency separation between allocated resources (e.g., bands, channels and resources) where CCs with overlapping UL-DL subframes are located may also be considered. For example, the actual frequency separation between CCs used for transmission and reception may reduce the amount of interference.

UE performance associated with the ability to support HD or FD, such as signaled by the UE itself, may also be considered. In some cases, a UE capable of both HD and FD operations may make a decision regarding its use based on both its structural capabilities and / or aspects listed above, and may signal such determination to the eNB.

From a UE perspective, when operating in the HD mode, the UE may simply follow the prioritization rules to determine how to operate in overlapping subframes (with UL and DL subframes occurring in different component carriers) . As described above, the prioritization rules may be as simple as receiving DL transmissions only when there is no transmission on the UL.

The UE still has to dynamically switch between UL-DL transmissions of UL-DL overlapping subframes and may adhere to a 4ms increase if it is strictly HD if the same RF chain is used. Due to the scheduling constraints imposed by the eNB, some scheduling delay (packet delay) may be observed.

From an eNB perspective, an intelligent scheduling algorithm may be utilized to help efficiently schedule resources based on determined UE performance. These algorithms may be relatively complex and may rely on aggregated UL-DL configurations. If multi-user diversity can not be fully exploited, the system throughput performance loss may be predicted in addition to the user delay experience.

The eNB is mistaken about the UE's ability to perform HD / FD operations (e.g., incorrectly estimates the UE's ability to receive a good DL while transmitting), and the UE is receiving it as a de- If you transmit a part of it through the DL while it can not, some performance loss will occur.

However, the network must eventually be able to detect it based on the lack of predicted UL transmissions. Thus, the network may correct the determination of the operating mode of the UE. In addition, the eNB may correct its operation based on explicit signaling from the UE.

In some cases, the eNB may impose restrictions on carrier aggregation utilizing different subframe configurations for different CCs. For example, the eNB may limit this type of aggregation to FD capable UEs, rather than imposing scheduling restrictions on HD operation.

In some cases, a limited carrier aggregation may be used to aggregate only two UL-DL configurations, or to aggregate very different subframe configurations (e.g., with a limit on the maximum number of overlapping subframes) , But may be allowed for UEs lacking the ability to support FDs.

9 is a flow chart illustrating exemplary operations 900 for implementing prioritization rules for overlapping subframes. Operations 900 starting at 902 may be performed, for example, by a UE capable of communicating in half-duplex or full-duplex. If there are no constraints on the UE to operate in FD mode (as determined at 904), then the UE may not have to perform other operations.

However, if the UE is half-duplex and UL and DL subframes on different component carriers overlap, as determined at 906, the UE may have to decide whether to transmit or receive. At 908, if UE traffic (e.g., PUCCH or PUSCH) is present, the UE may stop receiving the DL and transmit it via UL. On the other hand, if UL traffic is not present, at 910, the UE receives via DL.

10 is a flow chart illustrating exemplary operations 1000 for wireless communication that may be performed at a base station. As shown, the base station may, at 1002, determine whether the user equipment (UE) is communicating in half-duplex (HD) or full-duplex (FD). At 1004, the base station may schedule resources or communications with the UE on different component carriers (CCs) based at least in part on its determination.

11 is a flow diagram representation of exemplary operations 1100 for wireless communication that may be performed at a user equipment (UE). As shown at 1102, the UE may determine, for at least one subframe, whether the uplink subframe and the downlink subframe on different component carriers (CCs) used to communicate with the UE by the base station overlap . At 1104, the UE may follow at least one prioritization rule to determine whether to transmit or receive for at least one subframe.

As described above, the techniques presented herein may allow the UE to operate in a full-duplex mode, where possible.

Those skilled in the art will understand that information and signals may be represented using any of a variety of different technologies and techniques. For example, data, instructions, commands, information, signals, bits, symbols, and chips that may be referenced throughout the above description may be represented by voltages, currents, electromagnetic waves, magnetic fields or magnetic particles, Optical fields or particles, or any combination thereof.

Those skilled in the art will further appreciate that the various illustrative logical blocks, modules, circuits, and algorithm steps described in connection with the disclosure herein may be implemented as electronic hardware, computer software, or combinations of both. In order to clearly illustrate this interchangeability of hardware and software, various illustrative components, blocks, modules, circuits, and steps have been described above generally in terms of their functionality. Whether such functionality is implemented as hardware or software depends upon the particular application and design constraints imposed on the overall system. Skilled artisans may implement the described functionality in varying ways for each particular application, but such implementation decisions should not be interpreted as causing a departure from the scope of the present disclosure.

The various illustrative logical blocks, modules, and circuits described in connection with the disclosure herein may be implemented or performed with a general purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a field programmable gate array Programmable logic device, discrete gate or transistor logic, discrete hardware components, or any combination thereof designed to perform the functions described herein. A general purpose processor may be a microprocessor, but, in the alternative, the processor may be any conventional processor, controller, microcontroller, or state machine. The processor may also be implemented in a combination of computing devices, e.g., a combination of a DSP and a microprocessor, a plurality of microprocessors, one or more microprocessors in conjunction with a DSP core, or any other such configuration.

The steps of a method or algorithm described in connection with the present disclosure may be embodied directly in hardware, in a software module executed by a processor, or in a combination of both. The software module may reside in a RAM memory, a flash memory, a ROM memory, an EPROM memory, an EEPROM memory, registers, a hard disk, a removable disk, a CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to the processor such that the processor can read information from, or write information to, the storage medium. In the alternative, the storage medium may be integral to the processor. The processor and the storage medium may reside within the ASIC. The ASIC may reside within the user terminal. In the alternative, the processor and the storage medium may reside as discrete components in a user terminal.

In one or more exemplary designs, the functions described above may be implemented in hardware, software, firmware, or any combination thereof. When implemented in software, the functions may be stored or transmitted on one or more instructions or code as computer readable media. Computer-readable media includes both computer storage media and communication media including any medium that enables transmission of a computer program from one place to another. The storage media may be any available media that can be accessed by a general purpose computer or a special purpose computer. By way of example, and not limitation, such computer-readable media may comprise any form of computer-readable media, such as RAM, ROM, EEPROM, CD-ROM or other optical disk storage, magnetic disk storage or other magnetic storage devices, Or storage, and may include a general purpose computer, a special purpose computer, or any other medium that can be accessed by a general purpose processor or a special purpose processor. Also, any connection is properly termed a computer readable medium. For example, if the software is transmitted from a web site, server, or other remote source using wireless technologies such as coaxial cable, fiber optic cable, twisted pair, digital subscriber line, or infrared, wireless, and microwave, , Twisted pair, digital subscriber line, or wireless technologies such as infrared, radio, and microwave are included within the definition of the medium. Disks and discs as used herein include compact discs (CDs), laser discs, optical discs, digital versatile discs (DVD), floppy discs and Blu-ray discs, Normally, data is reproduced magnetically, and discs optically reproduce data using a laser. Combinations of the above should also be included within the scope of computer readable media.

The previous description of the disclosure is provided to enable any person skilled in the art to make or use the disclosure. Various modifications of the disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to various modifications without departing from the spirit or scope of the disclosure. Accordingly, the disclosure is not intended to be limited to the examples and designs described herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims (29)

A method for communicating by a base station,
Determining whether the user equipment (UE) communicates in half-duplex (HD) or full-duplex (FD); And
And scheduling resources on the different component carriers (CCs) or communications with the UE based at least in part on the determination. The method according to claim 1,
Wherein the determination is performed based on one or more parameters obtained for the UE. 3. The method of claim 2,
Wherein the parameters comprise at least one of: UE location, UE transmit power, UE receive power, or a ratio of UE transmit power to UE receive power. The method according to claim 1,
Wherein the determination is performed based on signaling from the UE in connection with the performance of the UE to perform communications with HD or full-duplex (FD). The method according to claim 1,
Wherein the determination is performed based on a frequency classification between resources used to communicate with the UE. The method according to claim 1,
Wherein the determination is performed based on a ratio of resources allocated for uplink and downlink transmissions. The method according to claim 1,
Further comprising the step of signaling the UE in connection with the determination. The method according to claim 1,
Further comprising modifying the decision. ≪ Desc / Clms Page number 21 > 9. The method of claim 8,
Wherein the decision is changed from FD to HD based on a lack of predicted transmission from the UE. The method according to claim 1,
Wherein when communicating with the UEs restricted to HD operation, a limited number of subframe configurations are allowed on different component carriers. 11. The method of claim 10,
Wherein the limited number of subframe configurations are determined based on a maximum number of overlapping subframes in which uplink and downlink transmissions are configured in the same subframe on different component carriers. 1. A method for half-duplex (HD) operations by a user equipment (UE)
Determining, for at least one subframe, whether the uplink subframe and the downlink subframe overlap on different component carriers (CCs) used by the base station to communicate with the UE; And
(HD) operations by a user equipment (UE), comprising following at least one prioritization rule to determine whether to transmit or receive during the at least one subframe. 13. The method of claim 12,
Wherein the at least one prioritization rules are:
If the UE has at least one of uplink data or uplink control for transmission in the at least one subframe, then the UE must transmit for the at least one subframe
(HD) operations by user equipment (UE). 14. The method of claim 13,
The at least one prioritization rules are also:
The UE must cease downlink reception on at least one component carrier (CC) during the at least one subframe
(HD) operations by user equipment (UE). 14. The method of claim 13,
The at least one prioritization rules are also:
The UE continues to receive downlink on at least one component carrier (CC) during the at least one subframe; And
If the signal quality is not sufficient, the corresponding downlink transmission must be discarded
(HD) operations by user equipment (UE). 14. The method of claim 13,
The at least one prioritization rules are also:
If the UE has uplink data to transmit, the UE must stop downlink reception at all CCs
(HD) operations by user equipment (UE). 13. The method of claim 12,
Further comprising signaling the base station in connection with the capabilities of the UE to perform communications in HD or full-duplex (FD). 13. The method of claim 12,
Further comprising receiving from the base station signaling that the base station considers the UE to be communicating in HD. ≪ Desc / Clms Page number 19 > 13. The method of claim 12,
(HD) operations by the user equipment (UE), further comprising determining whether to operate in FD mode or in HD mode. 20. The method of claim 19,
Wherein the determination is performed based on one or more parameters. ≪ Desc / Clms Page number 21 > 21. The method of claim 20,
Wherein the parameters comprise at least one of: UE location, UE transmit power, UE receive power, or a ratio of UE transmit power to UE receive power. 20. The method of claim 19,
(HD) operations by a user equipment (UE), which is performed based on signaling from the UE in connection with the performance of the UE for performing communications in HD or full-duplex (FD) Way. 20. The method of claim 19,
Wherein the determination is performed based on a ratio of resources allocated for uplink and downlink transmissions. An apparatus for communication by a base station,
Means for determining whether user equipment (UE) will communicate in half-duplex (HD) or full-duplex (FD); And
And means for scheduling resources on different component carriers (CCs) or communications with the UE based at least in part on the determination. An apparatus for half-duplex (HD) operations by a user equipment (UE)
Means for determining, for at least one subframe, whether uplink subframes and downlink subframes on different component carriers (CCs) used by the base station to communicate with the UE overlap; And
(HD) operations by user equipment (UE), comprising means for following at least one prioritization rule to determine whether to transmit or receive during said at least one subframe. An apparatus for communication by a base station,
(UEs) determine whether to communicate in half-duplex (HD) or full-duplex (FD), and based at least in part on the determination, resources on different component carriers Or at least one processor configured to schedule communications with the UE; And
And a memory coupled to the at least one processor. An apparatus for half-duplex (HD) operations by a user equipment (UE)
Determine, for at least one subframe, whether an uplink subframe and a downlink subframe on different component carriers (CCs) used by the base station to communicate with the UE overlap; and determine, for the at least one subframe, At least one processor configured to comply with at least one prioritization rule to determine whether or not to receive or receive a packet; And
(HD) operations by user equipment (UE), the memory coupled to the at least one processor. 21. A computer program product comprising a computer readable medium having stored code for communicating by a base station,
The code may be executed by one or more processors,
Determine whether the user equipment (UE) is to communicate in half-duplex (HD) or full-duplex (FD); And
And computer readable media executable for scheduling resources on different component carriers (CCs) or communications with the UE based at least in part on the determination. 18. A computer program product comprising a computer readable medium having stored code, for half-duplex (HD) operations by a user equipment (UE)
The code may be executed by one or more processors,
Determine, for at least one subframe, whether the uplink subframe and the downlink subframe on different component carriers (CCs) used by the base station to communicate with the UE overlap; And
Wherein the computer program product is executable to comply with at least one prioritization rule to determine whether to transmit or receive during the at least one subframe.

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