Patent Publication Number: US-10764882-B2

Title: Terminal based grouping virtual transmission and reception in wireless networks

Description:
This patent application is a continuation of U.S. patent application Ser. No. 15/590,738 filed on May 9, 2017 entitled “Terminal Based Grouping Virtual Transmission and Reception in Wireless Networks,” which is a continuation of U.S. patent application Ser. No. 14/536,435 filed on Nov. 7, 2014, now U.S. Pat. No. 9,655,094, issued on May 16, 2017 entitled “Terminal Based Grouping Virtual Transmission and Reception in Wireless Networks,” which is a continuation of U.S. patent application Ser. No. 13/646,549 filed on Oct. 5, 2012, now U.S. Pat. No. 8,902,907, issued on Dec. 2, 2014 entitled “Terminal Based Grouping Virtual Transmission and Reception in Wireless Networks,” all of which applications are hereby incorporated by reference herein as if reproduced in their entireties. 
    
    
     TECHNICAL FIELD 
     The present invention relates to the field of wireless communications and wireless networks infrastructure design and optimization, and, in particular embodiments, to a system and method for terminal based grouping virtual transmission and reception in wireless networks. 
     BACKGROUND 
     Traditionally, in wireless communication networks, terminal devices, such as user equipment (UE) are addressed by the network through individual identifiers (IDs), which are used to create individual communication channels between the network and UEs. The UE is any device used directly by an end-user to communicate. For example, the UE can be a hand-held telephone, a laptop computer equipped with a mobile broadband adapter, or any other user communications device. Recently, cooperative multi-point (CoMP) transmission/reception, where multiple E-UTRAN Node-Bs (eNBs) cooperate to transmit data to UEs, has received attention and is currently being integrated in the 3GPP standard. UE cooperation based on device-to-device (D2D) communications is another technology that has received less attention in comparison. However, with the advances in (D2D) communications in recent years, UE cooperation is expected to play a more prominent role in the future of wireless communications. 
     SUMMARY 
     In one embodiment, a method for virtualized group-wise communications between a wireless network and a plurality of UEs is disclosed. The method includes receiving, at a cooperating UE (CUE), downlink information from the wireless network, wherein the downlink information is destined for a target UE (TUE) and associated with a group ID, the group ID for targeting a virtual multi-point (ViMP) node that includes the TUE and the CUE. The method further includes sending the downlink information to the TUE. 
     In another embodiment, a UE or UE component supporting virtualized group-wise communications between a wireless network and a plurality of user equipments is disclosed. The UE includes a processor configured to forward information on the signal targeting to TUE, wherein the information is associated with a group ID indicating a ViMP node that groups the TUE and the UE. 
     In another embodiment, a method for virtualized group-wise communications between a wireless network and a plurality of user equipments is disclosed. The method includes receiving, at a TUE, downlink information that is forwarded by a CUE from the wireless network, wherein the downlink information is associated with a group ID, the group ID indicating a ViMP node that includes the TUE and the CUE. The method further includes obtaining control or data information destined for the TUE from the downlink information. 
     In another embodiment, a UE supporting virtualized group-wise communications between a wireless network and a plurality of user equipments is disclosed. The UE includes a processor configured to exchange at least some information with the wireless network via a CUE, wherein the information is associated with a group ID indicating a ViMP node that groups the UE and the CUE. 
     In yet another embodiment, a network component for supporting virtualized group-wise communications between a wireless network and a plurality of user equipments, the network component comprising a processor configured to group a plurality of UEs in a ViMP node based on proximity between the UEs, assign a group ID to the ViMP node, indicate the assigned group ID to each of the UEs in the ViMP node, and transmit information with the group ID to a plurality of UEs in a ViMP node, wherein the information is destined to a target UE (TUE) from the UEs, and wherein the group ID enables the CUE to detect the information and forward at least some of the information to the TUE. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       For a more complete understanding of the present invention, and the advantages thereof, reference is now made to the following descriptions taken in conjunction with the accompanying drawing, in which: 
         FIG. 1  illustrates an embodiment virtual multi-point (ViMP) transmission/reception system. 
         FIG. 2  illustrates a plurality of embodiment ViMP designs. 
         FIG. 3  illustrates a plurality of embodiment ViMP cooperation scenarios. 
         FIG. 4  illustrates an embodiment ViMP cooperation transmission/reception method. 
         FIG. 5  is a block diagram of an embodiment communications device. 
     
    
    
     DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS 
     The making and using of the presently preferred embodiments are discussed in detail below. It should be appreciated, however, that the present invention provides many applicable inventive concepts that can be embodied in a wide variety of specific contexts. The specific embodiments discussed are merely illustrative of specific ways to make and use the invention, and do not limit the scope of the invention. 
     The number of end user terminals or UEs in current cellular networks (e.g., smartphones or other mobile communications devices) keeps on increasing. The next fifth generation (5G) cellular networks are expected to feature higher number of UEs. Generally, the ratio of active UEs to inactive (or idle) UEs is relatively low. Using UE cooperation may improve diversity in space, time, and frequency and thus increase the robustness against signal fading and interference in the network. 
     Embodiments are disclosed herein for providing virtualized group-wise communications between the network and UEs using UE cooperation. A plurality of UEs are configured to form via UE cooperation one or more logical or virtual nodes that act as single distributed virtual transceivers. The embodiments include a system and method for configuring and operating a group of UEs as a virtual multi-point (ViMP) node which acts as a virtual transmitter for an uplink channel and a virtual receiver for a downlink channel. As such, the UEs of the ViMP node jointly transmit data on the uplink channel or jointly receive data on the downlink channel. The UEs of each ViMP node are assigned a unique group ID (a ViMP ID), which is used for control and data channel decoding purposes on the uplink and downlink. 
     The UEs in the ViMP node cooperate with each other using device-to-device (D2D) communications, for example according to an adjustable cooperation strategy that adapts to network conditions. This enables joint transmission/reception to/from the UEs, which can complement the cooperative multipoint (CoMP) transmission/reception concept in the LTE/LTE-A standard that deals with joint transmission/reception at the eNB side. For a ViMP node, the UEs comprise at least one target UE (TUE) and may also include one or more cooperating UEs (CUEs). The TUEs are the UEs for which data is meant to be communicated with the network and the one or more CUEs jointly cooperate with the TUEs to help transmit/receive the data to/from the network. 
       FIG. 1  illustrates an embodiment ViMP transmission/reception system  100  that can be implemented in a wireless network. The ViMP transmission/reception system  100  comprises one or more base stations (BSs)  101  and a plurality of UEs that are configured to communicate with the BSs  101  using infrastructure-to-device (I2D) links, e.g., cellular or radio links, wireless or wired backhaul links outside the wireless network&#39;s infrastructure, or combinations thereof. The BSs  101  may be base transceiver stations (BTSs) or eNBs that provide the UEs access to a wireless network and possibly other networks. The UEs may be located in cells  120  that correspond to coverage areas for the BSs  101 . The UEs include TUEs  102  and CUEs  103 , which are grouped in a plurality of ViMP nodes no. Each ViMP node no is associated with a unique ViMP ID, where each TUE and CUE in the group are assigned that same ID. The ViMP ID for each ViMP node is used for forwarding, processing, and/or decoding control and data channel communications on the uplink from the corresponding UEs and on the downlink to the same UEs. 
     The ViMP nodes no are UE-centric, i.e., tailored to the corresponding TUEs  102 . The data communicated from the network is targeted to at least one TUE  102  in each ViMP node no. The formation of the ViMP nodes no is determined by the network, for instance based on UE-to-UE proximity. The network may group the TUEs  102  and CUEs  103  together in their respective ViMP nodes no based on the proximity between the UEs, e.g., to realize sufficient proximity between the UEs in each ViMP node no to enable D2D communications. The network may use I2D links with the UEs to set up the ViMP nodes no. The UEs in the ViMP nodes no are also determined based on the availability, type, and/or range of D2D communications at the UEs. In other embodiments, the formation of ViMP nodes no, including the selection of UEs in each ViMP node no, is determined by the UEs, e.g., via UE cooperation and D2D communications, or by both the UEs and the network. 
     When the ViMP nodes no are determined, the network assigns unique IDs, also referred to herein as ViMP IDs or ViMP group IDs, to the ViMP nodes no, where each UE is configured with its ViMP node&#39;s ID. The network uses the ViMP group IDs for the transmission and decoding of control and/or data information to the TUEs  102  in the ViMP nodes no. The CUEs  103  cooperate with the TUEs  102  in their respective ViMP nodes no to receive and/or transmit control/data information from/to the network also using the assigned ViMP group IDs. Using the assigned ViMP group ID, the UEs in the ViMP node  210  are perceived by the network as a single distributed antenna receiver (RX) on the downlink and transmitter (TX) on the uplink. 
     Grouping multiple UEs that cooperate to transmit and receive on the uplink and downlink, respectively, may provide increased robustness against signal fading and/or interference. UE cooperation is achieved using D2D communications between the TUEs  102  and the CUEs  103  to establish ViMP links between them. The CUEs  103  use the ViMP links between the TUEs and I2D links with the BSs  101  to serve as relays for signals or channels on the uplink and/or downlink for the TUEs  102 . For example, the CUEs  103  may use Bluetooth connections, Wi-Fi links, and/or other D2D technologies to communicate with the CUEs  103  in the same ViMP nodes no and forward at least some of the signals or channels between the TUEs  102  and the corresponding BSs  101 . 
     Further, the network is aware (for example at a network control layer) of the UE cooperation in their respective ViMP nodes no, and hence can condition transmissions to the UEs accordingly to benefit from UE cooperation and improve communications and resource management. For instance, the network conditions and optimizes different transmission schemes, such as for scheduling, feedback, Hybrid automatic repeat request (HARQ), and/or precoding, according to the UE cooperation scenario or strategy in the ViMP nodes no. Based on network conditions, the network and the TUEs  102  may also use single or direct links (direct links between the TUEs  102  and BSs  101 ) without the help of the CUEs  103 . In this case, the TUEs  102  are treated as single entities without group virtualization similar to typical UE communications behavior in current wireless systems. 
     To improve energy efficiency, the network may turn off some of the BSs  101  and use instead UE cooperation between the CUEs  103  and the TUEs  102  to communicate with the TUEs  102 . For example, the CUEs  103  use D2D communications with the TUEs  102  to relay at least some of the channels or signals of the TUEs  102  with a reduced number of BSs  101 . Replacing the operation of some BSs  101  with the CUEs  103  also reduces network deployment cost since fewer BSs  101  may be needed. Increasing robustness against signal fading and interference, conditioning transmissions according to UE cooperation, and/or improving energy efficiency of the network components may increase network throughput or coverage. For example, the coverage gain using the ViMP transmission/reception system  100  can be about 50%, similar to gains observed in cloud radio access networks (CRANs). 
     Unlike relays in current wireless networks that are typically static and based on stationary infrastructures to support multiple UEs, the CUEs  103  in the ViMP transmission/reception system  100  are dynamically selected and configured, i.e., different CUEs  103  may be configured (by the network or through UE direct negotiation) and selected at different times and/or network conditions. Thus, the list of CUEs  103  in the network may be dynamically updated (by the network or through UE direct negotiation) over time. For example, the CUEs  103  are selected from idle UEs to support the TUEs  102  that are active (i.e., in communication with the network). The idle UEs may outnumber the active UEs. However, some or a limited number of CUEs  103  of the idle UEs may be selected and designated for the TUEs  102  at a period of time. The CUEs  102  may also be selected from active UEs that may be in proximity of the TUEs  102  to serve the TUEs  102 . Thus, one or more active and/or idle CUEs  103  may be assigned to one or more TUEs  102  in their corresponding ViMP nodes no. The selection may depend on the availability and range of D2D communications between the idle UEs and the TUEs  102  (the active UEs). Over time, the idle and active UEs may change, and hence the TUEs  102  and the CUEs  103  may also change. For example, some of the previous CUEs  103  may become TUEs  102  that are meant to receive information. Some of the previous TUEs  102  may also become CUEs  103 . Compared to relays and other static devices that may be used in traditional networks to improve capacity or range, the TUEs  102  and CUEs  103  have more limited capacity, power budget, and radio frequency (RF) isolation between access and backhaul links, and accordingly may have lower cost. 
       FIG. 2  illustrates a plurality of embodiment ViMP designs or formations  200  that can be configured in a wireless network or communications system, such as in the ViMP transmission/reception system  100 . The ViMP formations  200  include one-to-one and many-to-one mappings between multiple TUEs  202  and respective ViMP nodes  210 . Each of the TUEs  202  is associated with at least one ViMP node  210 . One TUE  202  may be assigned to more than one ViMP node  210 , which is referred to herein as a one-to-many mapping. Multiple TUEs  202  may also be assigned to the same ViMP node  210 . This is referred to herein as a many-to-one mapping. The one-to-many and many-to-one mappings may also include one or more CUEs  203  that are assigned to one or more ViMP nodes  210 . Thus, the ViMP nodes  210  may include one or more TUEs  202  and/or one or more CUEs  203 . The ViMP formations  200  may also include a singleton ViMP node (not shown), where only one TUE is assigned to the ViMP node without any other TUEs or CUEs. In this case, the ViMP node may act similar to a typical UE and communicate with the network accordingly. The singleton ViMP node is also assigned a unique ViMP group ID by the network, which is used to communicate with the single TUE of the ViMP node. 
     In embodiments, the UE cooperation between the UEs in respective ViMP nodes (if more than one UE belongs to the ViMP node) corresponds to one or more cooperation strategies. The UE cooperation strategies include strategies for handling degraded channel signals. For instance, one or more CUEs perform a decode and forward (DF) strategy to support communications for one or more TUEs in the ViMP node. The one or more CUEs can also perform an amplify and forward (AF) strategy to support the communications of the one or more TUEs. The strategies for degraded channel signals also include hierarchical modulation and/or coding. For example, a CUE receives and decodes a first modulated signal on a downlink and then forwards the first signal to a TUE, which also directly receives and decodes a second modulated signal (via a direct link from a BS). The TUE then combines the first and second signals to process the downlink data. This is referred to as soft combining. Similarly, two modulated signals (or more) on the uplink can be separately received by the network from a CUE and a TUE and then combined for processing. 
     The UE cooperation strategies also include strategies for handling non-degraded channel signals. Such strategies include joint reception on the downlink between one or more CUEs and one or more TUEs in the ViMP node, for example using log-likelihood ratio (LLR) combining or multiple-input and multiple-output MIMO (MIMO) schemes. The strategies for non-degraded channel signals also include joint transmission on the uplink between one or more TUEs and one or more CUEs, such as using Eavesdrop or HARQ schemes. The CUEs with the TUEs may switch between any of the UE cooperation strategies above based on the network channel conditions, e.g., according to whether degraded or non-degraded channel signals are detected. In an embodiment, a CUE estimates a channel between the CUE and the network and forwards the estimated channel to a corresponding TUE. The TUE also estimates a channel between the TUE and the network, and then combines the channels to obtain a combined channel for joint reception/transmission. 
       FIG. 3  illustrates a plurality of embodiment ViMP cooperation scenarios  300  that can be configured in a wireless network or communications system, such as in the ViMP transmission/reception system  100 . The ViMP cooperation scenarios  300  include a scenario for capacity enhancement (Scenario 1), where a CUE  303  forwards an additional signal of a channel between a TUE  302  in the ViMP node  310  of the CUE  303  and a BS  301  within a coverage area or cell  320 . The TUE  302  also transmits/receives directly a signal of the same or another channel to/from the BS  301 . The additional signal supported by the CUE  303  for the TUE  302  increases the communications capacity (e.g., in terms of channel bandwidth or number of channels) between the network and the TUE  302 . 
     The ViMP cooperation scenarios  300  include a scenario for coverage extension (Scenario 2), where a CUE  303  forwards control or data information between a TUE  302  (in the same ViMP node  310 ) and a BS  301  to extend the coverage area or cell  320 . In this case, the CUE  303  but not the TUE  302  is in sufficient range to establish a direct link with the BS  301 . The CUE  303  uses the direct link with the BS  301  and a D2D link with the TUE  302  to extend the coverage range and allow the TUE  302  to communicate with the BS  301 . The ViMP cooperation scenarios  300  also include scenarios for partial local offloading (Scenario 3) and full local offloading (Scenario 4). In partial local offloading, the TUE  302  receives/transmits control information directly from/to the BS  301  (via an I2D link) and receives data information via the CUE  303  (via a D2D link). The CUE  303  communicates the data information with the BS  301  via a backhaul connection to offload some of the wireless network traffic. Examples of the backhaul connection include a wired connection or infrastructure (e.g., a cable link or network) or a Wi-Fi link or other home networking connection, for example a link to the Internet. In full local offloading, both control and data information is forwarded between the TUE  302  and the BS  301  via the CUE  303  and a backhaul connection between the CUE  303  and the BS  301 . 
       FIG. 4  illustrates an embodiment ViMP cooperation transmission/reception method  400  that can be implemented in a wireless network or communications system, such as in the ViMP transmission/reception system  100 . The method  400  is performed by a CUE associated with a TUE in a ViMP node. The method begins at block or step  402 , where the CUE joins a ViMP node with the TUE, for instance via a neighbor&#39;s discovery procedure, negotiation with the TUE and the network, assistance by the network, or combinations thereof. The ViMP node joining procedure may also include one or more other TUEs and CUEs. At optional step  404 , the CUE (with the TUE) informs the network of the CUE (and the TUE) capability of joint reception. The step  404  is performed when the formation of the ViMP node is achieved on the UEs&#39; side, e.g., without the network assistance. At step  406 , the CUE (with the TUE) receives from the network a group ID assigned to the UEs in the ViMP node. 
     At step  410 , the UE receives (on the downlink) control and/or data information designated for the TUE and associated with the ViMP group ID, which is indicated in the control/data information. The control/data information is received from a transmit point (TP) or a BS that connects to the CUE via an I2D link or a backhaul connection. At step  412 , the CUE detects the control/data information using the group ID that is assigned to the ViMP node and included in the control/data information. The TUE may also receive some control/data information directly from the network or from other CUEs, and detect the information using the group ID. At an optional step  414 , the CUE decodes at least some of the received control/data information. At step  420 , the CUE sends at least some of the control/data information, for example at least some of the data in the data channel, to the TUE. 
     Additionally, the CUE may receive control/data information on the uplink from the TUE, e.g., via a D2D link that connects the TUE and the CUE. The information is also associated with the ViMP group ID. The control/data information is then sent from the CUE to the TP or BS, e.g., via an I2D link. 
       FIG. 5  illustrates a block diagram of an embodiment of a communications device  500 , which may be equivalent to one or more devices (e.g., UEs, BSs, eNBs, etc.) discussed above. The communications device  500  may include a processor  504 , a memory  506 , a cellular interface  510 , a supplemental wireless interface  512 , and a supplemental interface  514 , which may (or may not) be arranged as shown in  FIG. 5 . The processor  504  may be any component capable of performing computations and/or other processing related tasks, and the memory  506  may be any component capable of storing programming and/or instructions for the processor  504 . The processor  504  may be configured to implement or support the ViMP cooperation schemes, scenarios, and strategies described above. For example, the processor  504  may be configured to support or implement the method  400 . The cellular interface  510  may be any component or collection of components that allows the communications device  500  to communicate using a cellular signal, and may be used to receive and/or transmit information over a cellular connection of a cellular network. The supplemental wireless interface  512  may be any component or collection of components that allows the communications device  500  to communicate via a non-cellular wireless protocol, such as a Wi-Fi or Bluetooth protocol, or a control protocol. The supplemental interface  514  may be component or collection of components that allows the communications device  500  to communicate via a supplemental protocol, including wire-line protocols. In embodiments, the supplemental interface  514  may allow the device  500  to communicate with a backhaul network. 
     Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims. Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure of the present invention, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed, that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present invention. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.