This application claims the benefit under 35 U.S.C. § 119(a) of a Korean patent application filed on Nov. 3, 2016 in the Korean Intellectual Property Office and assigned Serial number 10-2016-0146076, the entire disclosure of which is hereby incorporated by reference.
Efforts to develop an improved fifth generation (5G) communication sys tem after the commercialization of the fourth generation (4G) communication system have been conducted. The main features of the 5G communication system compared to the 4G communication system are a high data transmission rate, a low communication latency, and a massive connection support. The present disclosure relates to a signal, a channel structure, and an operating method and apparatus for supporting a random access for a system capable of drastically increasing communication capacity using beamforming on a wide frequency band in a next generation communication supporting a millimeter wave (mmWave) band.
To meet a demand for radio data traffic that is on an increasing trend since commercialization of a fourth generation (4G) communication system, efforts to develop an improved fifth generation (5G) communication system or a pre-5G communication system have been conducted. For this reason, the 5G communication system or the pre-5G communication system is called a beyond 4G network communication system or a post long term evolution (LTE) system. To achieve a high data transmission rate, the 5G communication system is considered to be implemented in a very high frequency millimeter wave (mmWave) band (e.g., like 60 GHz band). To relieve a path loss of a radio wave and increase a transfer distance of the radio wave in the very high frequency band, in the 5G communication system, beamforming, massive multiple input multiple output (MIMO), full dimensional MIMO (FD-MIMO), array antenna, analog beam-forming, and large scale antenna technologies have been discussed. Further, to improve a network of the system, in the 5G communication system, technologies such as an evolved small cell, an advanced small cell, a cloud radio access network (cloud RAN), an ultra-dense network, a device to device communication (D2D), a wireless backhaul, a moving network, cooperative communication, coordinated multi-points (CoMP), and reception interference cancellation have been developed. In addition to this, in the 5G system, hybrid frequency shift keying (FSK) and quadrature amplitude modulation (QAM) modulation (FQAM) and sliding window superposition coding (SWSC) that are an advanced coding modulation (ACM) scheme and a filter bank multi carrier (FBMC), a non orthogonal multiple access (NOMA), and a sparse code multiple access (SCMA) that are an advanced access technology, and so on have been developed.
Meanwhile, the Internet is evolved from a human-centered connection network through which a human being generates and consumes information to the Internet of things (IoT) network that transmits/receives information between distributed components such as things and processes the information. The Internet of everything (IoE) technology in which the big data processing technology, etc. is combined with the IoT technology by connection with a cloud server, etc. has also emerged. To implement the IoT, technology elements, such as a sensing technology, wired and wireless communication and network infrastructure, a service interface technology, and a security technology, have been required. Recently, technologies such as a sensor network, machine to machine (M2M), and machine type communication (MTC) for connecting between things have been researched. In the IoT environment, an intelligent Internet technology (IT) service that creates a new value in human life by collecting and analyzing data generated in the connected things may be provided. The IoT may apply for fields, such as a smart home, a smart building, a smart city, a smart car or a connected car, a smart grid, health care, smart appliances, and an advanced healthcare service, by fusing and combining the existing information technology (IT) with various industries.
Therefore, various tries to apply the 5G communication system to the IoT network have been conducted. For example, the 5G communication technologies, such as the sensor network, the machine to machine (M2M), and the machine type communication (MTC), have been implemented by techniques such as the beamforming, the MIMO, and the array antenna. The application of the cloud radio access network (cloud RAN) as the big data processing technology described above may also be considered as an example of the fusing of the 5G communication technology with the IoT technology.
In accordance with recent development of LTE and LTE-advanced (LTE-A), there is a demand for a method and apparatus for supporting random access for a system capable of expecting remarkable increase in communication capacity using beamforming on a wide frequency band in next generation communication supporting a mmWave band.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, and no assertion is made, as to whether any of the above might be applicable as prior art with regard to the present disclosure.
According to the related art, beamforming in a base station/terminal is a beamforming method in a digital domain and dose not consider application of beamforming in an analog domain. For analog beamforming, application in a communication system of a high frequency band with less physical limitations of an antenna is easy, and a fifth generation (5G) communication system considers use of ultra-high frequency millimeter wave (mmWave) band (for example, 30 GHz and 60 GHz) capable of having a wide bandwidth to implement a high data rate. In the ultra-high frequency band, since path-loss of radio wave is mitigated, and a transmission distance of radio wave becomes short, use of the analog beamforming technology is under discussion.
Aspects of the present disclosure are to address at least the above-mentioned problems and/or disadvantages and to provide at least the advantages described below. Accordingly, an aspect of the present disclosure is to provide an apparatus and method for accessing the base station after initial access through beamforming, random access based on beamforming in an analog domain in the base station/terminal needs to be performed, which has not been described yet in detail. Further, if a plurality of Tx Rx points (TRPs) exist in one cell, an operation for a random access process with the plurality of TRPs needs to be designed.
In accordance with an aspect of the present disclosure, a method for processing a control signal in a wireless communication system is provided. The method includes receiving a first control signal transmitted from a base station, processing the received first control signal, and transmitting a second control signal generated based on the processing to the base station.
According to the embodiment of the present disclosure, in order to implement a high data rate, one of requirements of the 5G communication system, stable random access is enabled in an mmWave band through the design of the analog beam-based synchronization signal and system information transmission signal, and the base station and terminal operation methods.
Other aspects, advantages, and salient features of the disclosure will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses various embodiments of the present disclosure.
The above and other aspects, features, and advantages of certain embodiments of the present disclosure will be more apparent from the following description taken in conjunction with the accompanying drawings, in which:
Throughout the drawings, it should be noted that like reference numbers are used to depict the same or similar elements, features, and structures.
The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of various embodiments of the present disclosure as defined by the claims and their equivalents. It includes various specific details to assist in that understanding but these are to be regarded as merely exemplary. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the various embodiments described herein can be made without departing from the scope and spirit of the present disclosure. In addition, the definitions descriptions of well-known functions and constructions may be omitted for clarity and conciseness.
The terms and words used in the following description and claims are not limited to the bibliographical meanings, but, are merely used by the inventor to enable a clear and consistent understanding of the present disclosure. Accordingly, it should be apparent to those skilled in the art that the following description of various embodiments of the present disclosure is provided for illustration purpose only and not for the purpose of limiting the present disclosure as defined by the appended claims and their equivalents.
It is to be understood that the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to “a component surface” includes reference to one or more of such surfaces.
Various advantages and features of the present disclosure and methods accomplishing the same will become apparent from the following detailed description of embodiments with reference to the accompanying drawings. However, the present disclosure is not limited to the embodiments disclosed herein but will be implemented in various forms. The embodiments have made disclosure of the present disclosure complete and are provided so that those skilled in the art can easily understand the scope of the present disclosure. Therefore, the present disclosure will be defined by the scope of the appended claims. Like reference numerals throughout the description denote like elements.
In describing a configuration and an operation according to the present disclosure, the following system is assumed. The present disclosure is a technology that may be applied to the current system universally in a non-restrictive way.
An initial access-related synchronization and system information signal and channel are transmitted by analog beams operated by the base station in a beam sweeping manner. An initial synchronization process in which the base station repeatedly transmits corresponding signal through each analog beam, the terminal receives a primary synchronization signal (PSS) and secondary synchronization signal (SSS) while sweeping the reception beam for synchronization, and a physical broadcast channel (PBCH) is received to acquire system information is assumed. In the initial access process, the terminal acquires information on the terminal transmission beam and the base station reception beam that may be used for random access and performs the random access based on the information on a random access resource region associated there with.
The present disclosure includes a signal transmission method, process, base station/terminal operation method and apparatus related to random access.
In the LTE, as illustrated in
The following is contents related to a millimeter wave (mmWave) system based random access process, which may be applied to the initial access and all cases of performing random access later. It may be contention-based random access, or non-contention-based random access in which the preamble is dedicatedly allocated.
At the time of performing beamforming-based random access in the mm Wave system, the terminal may acquire beam information for a preamble signal transmitted in a first step as in
In the case in which the beam correspondence in the terminal is established, the reception beam of the terminal may be used as the transmission beam of the terminal. That is, the terminal uses the corresponding reception beam at the time of transmission, and transmits an uplink preamble signal to some regions of a random access resource. The selection of the corresponding resource region is for a resource associated with the base station transmission beam. As an example, the base station transmission beam may be a beam transmitting a synchronization signal (SS block), and the corresponding transmission beam index may be signaled as an index of the synchronization signal block. In the case in which the beam correspondence in the base station is also established, the terminal may find information on the preferred base station transmission beam and the base station transmission beam may be used as the base station reception beam, the preamble is thus transmitted once to the random access resource region associated with the corresponding transmission beam. The terminal that did not receive the RAR in an RAR window section from the base station may retransmit the preamble signal.
The base station beam receiving the preamble may be implemented in a form of wide beam or a composite beam in which narrow beams for each antenna panel are combined in order to decrease overhead of resources. In this case, the base station detects a random access channel (RACH) preamble for each antenna panel, thereby measuring signal strength based on the narrow beam for each panel and acquiring base station narrow beam information for a specific terminal transmitting the preamble.
In the case of acquiring the corresponding information, the base station may use the corresponding narrow beam at the time of transmitting a second signal in
If the terminal acquires information of one or more available base station beams, the terminal may transmits a preamble through the corresponding beams in one or more random access resource regions. According to an embodiment, if there is a terminal transmitting a preamble to two random access resource regions, the following base station/terminal operations may be possible. Here, the resource region basically means a RACH preamble transmission section configured through time-division multiplexing (TDM), and the base station indicates that transmission may be performed through one or more beams when providing information on configuration for a specific RACH resource.
In a case in which a beam of the terminal is the same at the time of preamble transmission, when receiving two RARs, the terminal performs communication using a terminal beam corresponding to a base station beam indicated by the base station in the RAR. If the base station indicates that one or more beams are used, the communication is performed using one terminal beam for two beams.
The additional beam information means beam information other than information the terminal knows about the base station beam. In a case in which a random access request based on the base station beam information known by the terminal, that is, information on the fact that a composite beam transmitting the initial access signal (i.e., a beam consisting of narrow beams 2, 4, 6, and 8) is preferred, is transmitted to a random access resource region associated with the base station beam, the base station may additionally give an indication that beam 2 or beam 4 is preferred to the terminal through the preamble reception.
Referring to
Each RAR corresponding to each request may include both of two beam information selected by the base station, or may include only one beam information corresponding to each request.
The beam information included in the RAR by the base station may be an indication for one or more base station beams. This enables efficient beam management of the base station and the terminal and allows the base station to perform communication with the terminal using a plurality of beams. The embodiment in which the beam information indication by the base station is included in an RAR has been described above, however, the present disclosure is not limited thereto. The beam information indication by the base station may be included in a downlink signal transmitted by the base station to the terminal in the random access process, other than the RAR.
In a case in which multiple TRPs exist in one cell, after performing RRC connection through a random access process after acquiring base station/terminal beam information in the initial access process, the terminal may not acquire information on with which TRP the connection is still maintained. The present disclosure proposes a method and process in which the terminal may acquire information on with which specific TRP among multiple TRPs the connection is made in the random access process.
If multiple TRPs exist in one cell, each TRP may be distinguished by the following method.
Among the two method described above, in the case in which TRPs are distinguished based on a beam ID, TRPs may be simultaneously distinguished by including a beam ID in an RAR or a downlink signal other than the RAR in a previous random access process.
In the case in which TRPs are distinguished using a virtual TRP ID, it is possible to know from which TRP a corresponding beam is transmitted, by including a virtual TRP ID other than the beam ID information in an RAR or a downlink signal of her than the RAR in the random access process.
Referring to
Referring to
Referring to
Referring to
If two or more random access requests are transmitted, and corresponding request messages are received by two or more TRPs, the terminal may maintain connection with one or more TRPs and data communication through the random access process. For convenience of explanation, if the terminal is connected with two TRPs through the random access process, the following communication modes may be selected
In the case of TRP selection mode, configuration may be made by the method as in
According to an embodiment, when 2 bit indication is made for indication for TRP selection/diversity/multiplexing/control signal & data transmission TRP separation, an example of a corresponding indication Table is as in
Referring to
Referring to
Referring to
The memory 150 stores information signaled by the base station or information buffered at the time of decoding. In the embodiment of the specification described above, all information stored in the terminal in advance are stored in the memory. The transceiver 130 receives a downlink signal according to the embodiments described above, receives a base station signal by applying terminal beamforming according to an indication of the controller 110, transmits a signal to the base station, and stores corresponding results in the memory 150. The controller 110 controls overall operations for the terminal in the embodiments described above. Further, the comparator 170 performs comparison and confirmation operations performed by the device 100 in the embodiments described above according to an indication of the controller 110. Description of detailed operations of each configuration will be omitted.
Referring to
While the present disclosure has been shown and described with reference to various embodiments thereof, it will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the present disclosure as defined by the appended claims and their equivalents.
Number | Date | Country | Kind |
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10-2016-0146076 | Nov 2016 | KR | national |