TECHNICAL FIELD

The present application relates generally to random access operation in wireless communication systems. More specifically, this disclosure relates to random access channel structure of multi-beam operation in wireless communication systems.

BACKGROUND

5th generation (5G) mobile communications, initial commercialization of which is expected around 2020, is recently gathering increased momentum with all the worldwide technical activities on the various candidate technologies from industry and academia. The candidate enablers for the 5G mobile communications include massive antenna technologies, from legacy cellular frequency bands up to high frequencies, to provide beamforming gain and support increased capacity, new waveform (e.g., a new radio access technology (RAT)) to flexibly accommodate various services/applications with different requirements, new multiple access schemes to support massive connections, and so on. The International Telecommunication Union (ITU) has categorized the usage scenarios for international mobile telecommunications (IMT) for 2020 and beyond into 3 main groups such as enhanced mobile broadband, massive machine type communications (MTC), and ultra-reliable and low latency communications. In addition, the ITC has specified target requirements such as peak data rates of 20 gigabit per second (Gb/s), user experienced data rates of 100 megabit per second (Mb/s), a spectrum efficiency improvement of 3×, support for up to 500 kilometer per hour (km/h) mobility, 1 millisecond (ms) latency, a connection density of 106 devices/km2, a network energy efficiency improvement of 100× and an area traffic capacity of 10 Mb/s/m2. While all the requirements need not be met simultaneously, the design of 5G networks may provide flexibility to support various applications meeting part of the above requirements on a use case basis.

SUMMARY

The present disclosure relates to a pre-5th-Generation (5G) or 5G communication system to be provided for supporting higher data rates beyond 4th-Generation (4G) communication system such as long term evolution (LTE). Embodiments of the present disclosure provide multiple services in advanced communication systems.

In one embodiment, a base station (BS) for a random access operation in a wireless communication system is provided. The BS includes a transceiver configured to transmit, to a user equipment (UE), RACH configuration information including an RACH structure corresponding to a first beam identification (ID) and receive, from the UE over a first beam associated with the first beam ID, an RACH preamble configured based on the RACH structure. The BS further includes at least one processor is configured to configure an RACH response corresponding to the RACH preamble. The BS includes the transceiver further configured to transmit, to the UE, the RACH response over a second beam, wherein the first beam is different than the second beam.

In another embodiment, a user equipment (UE) for random access operation in a wireless communication system. The UE includes at least one transceiver configured to receive, from a base station (BS), RACH configuration information including an RACH structure corresponding to a first beam identification (ID). The UE further includes at least one processor configured to determine an RACH preamble and RACH resource based on the RACH structure received from the BS. The UE includes the transceiver further configured to transmit, to the BS, the RACH preamble sent over a first beam associated with the first beam ID and receive, from the BS, an RACH response corresponding to the RACH preamble over a second beam, wherein the first beam is different than the second beam.

In yet another embodiment, a method of a base station (BS) for random access operation in a wireless communication system is provided. The method comprises transmitting, to a user equipment (UE), RACH configuration information including an RACH structure corresponding to a first beam identification (ID), receiving, from the UE, an RACH preamble configured based on the RACH structure over a first beam associated with the first beam ID, configuring an RACH response corresponding to the RACH preamble, and transmitting, to the UE, the RACH response over a second beam, wherein the first beam is different than the second beam.

Other technical features may be readily apparent to one skilled in the art from the following figures, descriptions, and claims.

Before undertaking the DETAILED DESCRIPTION below, it may be advantageous to set forth definitions of certain words and phrases used throughout this patent document. The term “couple” and its derivatives refer to any direct or indirect communication between two or more elements, whether or not those elements are in physical contact with one another. The terms “transmit,” “receive,” and “communicate,” as well as derivatives thereof, encompass both direct and indirect communication. The terms “include” and “comprise,” as well as derivatives thereof, mean inclusion without limitation. The term “or” is inclusive, meaning and/or. The phrase “associated with,” as well as derivatives thereof, means to include, be included within, interconnect with, contain, be contained within, connect to or with, couple to or with, be communicable with, cooperate with, interleave, juxtapose, be proximate to, be bound to or with, have, have a property of, have a relationship to or with, or the like. The term “controller” means any device, system or part thereof that controls at least one operation. Such a controller may be implemented in hardware or a combination of hardware and software and/or firmware. The functionality associated with any particular controller may be centralized or distributed, whether locally or remotely. The phrase “at least one of,” when used with a list of items, means that different combinations of one or more of the listed items may be used, and only one item in the list may be needed. For example, “at least one of: A, B, and C” includes any of the following combinations: A, B, C, A and B, A and C, B and C, and A and B and C.

Moreover, various functions described below can be implemented or supported by one or more computer programs, each of which is formed from computer readable program code and embodied in a computer readable medium. The terms “application” and “program” refer to one or more computer programs, software components, sets of instructions, procedures, functions, objects, classes, instances, related data, or a portion thereof adapted for implementation in a suitable computer readable program code. The phrase “computer readable program code” includes any type of computer code, including source code, object code, and executable code. The phrase “computer readable medium” includes any type of medium capable of being accessed by a computer, such as read only memory (ROM), random access memory (RAM), a hard disk drive, a compact disc (CD), a digital video disc (DVD), or any other type of memory. A “non-transitory” computer readable medium excludes wired, wireless, optical, or other communication links that transport transitory electrical or other signals. A non-transitory computer readable medium includes media where data can be permanently stored and media where data can be stored and later overwritten, such as a rewritable optical disc or an erasable memory device.

Definitions for other certain words and phrases are provided throughout this patent document. Those of ordinary skill in the art should understand that in many if not most instances, such definitions apply to prior as well as future uses of such defined words and phrases.

