CN107645322B - Random access method and equipment based on beamforming - Google Patents
Random access method and equipment based on beamforming Download PDFInfo
- Publication number
- CN107645322B CN107645322B CN201610578444.2A CN201610578444A CN107645322B CN 107645322 B CN107645322 B CN 107645322B CN 201610578444 A CN201610578444 A CN 201610578444A CN 107645322 B CN107645322 B CN 107645322B
- Authority
- CN
- China
- Prior art keywords
- random access
- terminal device
- beams
- downlink
- sub
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
Images
Abstract
The embodiment of the disclosure discloses a random access method and equipment based on beam forming. The method comprises the following steps: transmitting, at a base station, a broadcast signal using a plurality of downlink transmit beams; receiving a random access signal from a terminal device using a plurality of uplink receive beams, the plurality of uplink receive beams being associated with a plurality of downlink transmit beams; determining a transmit beam for the terminal device in response to receiving the random access signal; and sending a random access response to the terminal device using the determined transmission beam. The embodiment of the disclosure also provides a corresponding method for random access based on beamforming, which is executed on an opposite terminal, and a corresponding device.
Description
Technical Field
Embodiments of the present disclosure relate generally to the field of communications, and in particular, to a method and apparatus for random access based on beamforming.
Background
Due to the abundance of available frequency resources in the millimeter wave band, millimeter wave technology is considered a key contributor to meeting the increasing performance requirements for 5G new wireless (NR) access systems. However, in the millimeter wave band of operation, the wireless channel has some unfavorable propagation characteristics, such as strong path loss, atmospheric and rain absorption, low diffraction around obstacles, and the ability to penetrate objects, among others. To overcome these adverse propagation characteristics, large-scale antenna arrays and narrow beams are key technologies for data transmission.
For data transmission in the millimeter wave band, signal attenuation can be effectively mitigated by using massive Multiple Input Multiple Output (MIMO) techniques, employing highly directional transmit and receive beamforming and directionally adaptively calibrating the corresponding beams. However, for the uplink random access procedure, it cannot sufficiently benefit from the beamforming gain of the millimeter wave band due to the lack of information of the optimal transmit/receive beam pair. Therefore, the design of the uplink random access process of the millimeter wave frequency band faces a great challenge.
Disclosure of Invention
In general, embodiments of the present disclosure provide a solution to optimize a communication process by introducing hierarchical beamforming in a random access process.
According to a first aspect of the present disclosure, a method for random access based on beamforming is provided. The method comprises the following steps: transmitting, at a base station, a broadcast signal using a plurality of downlink transmit beams; receiving a random access signal from a terminal device using a plurality of uplink receive beams, the plurality of uplink receive beams being associated with a plurality of downlink transmit beams; determining a transmit beam for the terminal device in response to receiving the random access signal; and sending a random access response to the terminal device using the determined transmission beam.
In some embodiments, transmitting the broadcast signal using the plurality of downlink transmit beams at the base station comprises: the broadcast signals are transmitted using a plurality of downlink transmit beams with different time domain resources.
In some embodiments, receiving a random access signal from a terminal device using a plurality of uplink receive beams comprises: the random access signal from the terminal device is received using the same beam as the plurality of downlink transmission beams.
In some embodiments, receiving a random access signal from a terminal device using a plurality of uplink receive beams comprises: random access signals from the terminal device are received using a plurality of sub-beam groups corresponding to the plurality of downlink transmit beams.
In some embodiments, receiving the random access signal from the terminal device using a plurality of sub-beam groups corresponding to a plurality of downlink transmit beams comprises: random access signals from the terminal device are received at different times with one of the plurality of sub-beam groups, the different times being associated with a plurality of downlink transmit beams.
In some embodiments, determining a transmit beam for the terminal device comprises: detecting a random access signal; determining one of the sub-beams of the one sub-beam group as a reception beam to be used for the terminal device based on the detection; and determining a same beam as the reception beam as a transmission beam for the terminal device.
In certain embodiments, the method further comprises: determining a reception beam to be used for the terminal device in response to receiving the random access signal; and performing random access and data transmission for the terminal device using the transmit beam and the receive beam.
In some embodiments, the random access signal comprises at least a random access preamble and an indication indicating a preference of the terminal device for the plurality of downlink transmission beams.
In some embodiments, the indication indicative of the terminal device's preference for the plurality of downlink transmit beams is uniquely associated with a time domain resource of the random access signal.
In some embodiments, determining a transmit beam for the terminal device comprises: detecting a random access signal to obtain an indication of a preference of a terminal device for a plurality of downlink transmission beams; and determining a downlink transmission beam preferred by the terminal device as a transmission beam for the terminal device based on the indication.
In some embodiments, the broadcast signal at least includes configuration information related to downlink transmission beams and transmission of random access signals carried in system information.
According to a second aspect of the present disclosure, a method for random access based on beamforming is provided. The method comprises the following steps: receiving a broadcast signal at a terminal device, the broadcast signal being transmitted by a base station using a plurality of downlink transmit beams; and in response to receiving the broadcast signal, transmitting a random access signal using the uplink transmit beam, the random access signal including at least a random access preamble and an indication indicating a preference of the terminal device for the plurality of downlink transmit beams.
In some embodiments, the broadcast signal is for a base station to use a plurality of downlink transmit beams with different time domain resources, and wherein receiving the broadcast signal at the terminal device comprises: broadcast signals are received at a terminal device at different time instances associated with a plurality of downlink transmit beams.
In some embodiments, transmitting the random access signal using the uplink transmission beam includes: detecting a received broadcast signal; determining a downlink transmitting beam preferred by the terminal equipment and a receiving beam to be used based on the detection; determining a beam which is the same as the receiving beam as an uplink transmitting beam; and transmitting the random access signal using the uplink transmission beam.
In some embodiments, transmitting the random access signal using the uplink transmission beam includes: and sending the random access signal by using the time domain resource which is uniquely associated with the downlink transmission beam preferred by the terminal equipment.
In certain embodiments, the method further comprises: and carrying out random access and data transmission by using the uplink transmitting beam and the uplink receiving beam.
In some embodiments, the broadcast signal includes configuration information related to downlink transmission beams and to transmission of random access signals carried in system information.
According to a third aspect of the present disclosure, a network device is provided. The network device includes: a transceiver configured to: transmitting a broadcast signal using a plurality of downlink transmit beams; and receiving a random access signal from the terminal device using a plurality of uplink receive beams, the plurality of uplink receive beams being associated with a plurality of downlink transmit beams; and a controller configured to: in response to receiving the random access signal, a transmit beam for the terminal device is determined to cause the transceiver to transmit a random access response to the terminal device using the transmit beam.
According to a fourth aspect of the present disclosure, a terminal device is provided. The terminal device includes a transceiver configured to: receiving a broadcast signal, the broadcast signal being transmitted by a base station using a plurality of downlink transmit beams; and in response to receiving the broadcast signal, transmitting a random access signal using the uplink transmit beam, the random access signal including at least a random access preamble and an indication indicating a preference of the terminal device for the plurality of downlink transmit beams.
According to a fifth aspect of the present disclosure, an apparatus for random access based on beamforming is provided. The device includes: a first transmission unit configured to transmit a broadcast signal using a plurality of downlink transmission beams; a receiving unit configured to receive a random access signal from a terminal device using a plurality of uplink receive beams, the plurality of uplink receive beams being associated with a plurality of downlink transmit beams; a beam determination unit configured to determine a transmission beam for the terminal device in response to receiving the random access signal; and a second transmitting unit configured to transmit a random access response to the terminal device using the determined transmission beam.
According to a sixth aspect of the present disclosure, an apparatus for random access based on beamforming is provided. The device includes: a receiving unit configured to receive a broadcast signal, the broadcast signal being transmitted by a base station using a plurality of downlink transmission beams; and a transmitting unit configured to transmit a random access signal using the uplink transmission beam in response to receiving the broadcast signal, the random access signal including at least a random access preamble and an indication indicating a preference of the terminal device for the plurality of downlink transmission beams.
According to the method or the equipment disclosed by the embodiment of the invention, the directional random access channel transmission is used under the assistance of the directional broadcast channel transmission, so that the random access request receiving capacity can be effectively improved, the random access collision probability is reduced, and the system random access performance is greatly improved.
Drawings
The above and other features, advantages and aspects of various embodiments of the present disclosure will become more apparent by referring to the following detailed description when taken in conjunction with the accompanying drawings. In the drawings, like or similar reference characters designate like or similar elements, and wherein:
fig. 1 illustrates a schematic diagram of a wireless communication system in which embodiments of the present disclosure can be implemented;
fig. 2 shows an uplink random access procedure example;
fig. 3 illustrates a two-stage hierarchical beamforming mapping scheme in accordance with one embodiment of the present disclosure;
fig. 4 shows a flow diagram of a method of random access according to an embodiment of the present disclosure;
fig. 5 shows a flow diagram of a method of random access according to another embodiment of the present disclosure;
fig. 6 illustrates a schematic of a PRACH format with directional reception in accordance with an embodiment of the present disclosure;
FIG. 7 shows a schematic of a communication scenario according to one embodiment of the present disclosure;
FIG. 8 illustrates a directional random access procedure communication schematic in accordance with an embodiment of the present disclosure;
FIG. 9 shows a block diagram of an apparatus according to an embodiment of the present disclosure;
FIG. 10 shows a block diagram of an apparatus according to another embodiment of the present disclosure; and
fig. 11 shows a block diagram of a device according to an embodiment of the present disclosure.
Detailed Description
Embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings. It should be noted that the same reference numerals may be used in the drawings for similar components or functional elements. The accompanying drawings are only intended to illustrate embodiments of the present disclosure. Alternative embodiments will become apparent to those skilled in the art from the following description without departing from the spirit and scope of the disclosure.
As used herein, the term "include" and its various variants are to be understood as open-ended terms, which mean "including, but not limited to. The term "based on" may be understood as "based at least in part on". The term "one embodiment" may be understood as "at least one embodiment". The term "another embodiment" may be understood as "at least one other embodiment".
For ease of explanation, embodiments of the present disclosure will be described herein primarily with reference to 3GPP LTE/LTE-advanced (LTE-a) and with specific terminology in LTE/LTE-a, however, as will be appreciated by those skilled in the art, embodiments of the present disclosure are by no means limited to the application environment of 3GPP LTE/LTE-a, but rather may be applied in any wireless communication system with similar problems, such as WLAN, or other communication systems developed in the future, etc.
Also, the term "terminal device" as used herein refers to any terminal device capable of communicating with a base station. The terminal device may be a User Equipment (UE) or any terminal with wireless communication capability, including but not limited to, a cell phone, a computer, a personal digital assistant, a game console, a wearable device, a sensor, and the like. The term UE can be used interchangeably with mobile station, subscriber station, mobile terminal, user terminal, wireless device, or the like. The term "base station" or "network equipment" may refer to a Node B (Node B, or NB), a low power Node such as a pico base station, a femto base station, etc., a Base Transceiver Station (BTS), a Base Station (BS), or a base station subsystem (BSs), a relay, a remote radio head (RRF), etc.
A schematic block diagram of a communication system 100 in which embodiments of the present disclosure may be implemented is shown in fig. 1. The wireless communication system 100 may include a Base Station (BS)110, such as an evolved node B (eNodeB, or eNB). Network node 110 may be a plurality of terminal devices (e.g., UEs) 120 within its coverage area1、1202…120K(K is a natural number) provides a radio connection. For convenience of description, the terminal devices may be collectively referred to as UE 120 hereinafter. It should be understood that the number of base stations and terminal devices shown in fig. 1 is for illustration purposes only and is not intended to be limiting. In communication network 100, any suitable number of base stations and terminal devices may be present.
In millimeter wave communication, base station 110 and UE 1201、1202…120KCan be equipped with a plurality of antennas to utilize the beamforming gain of massive MIMO to improve the transmission performance of the system. For the uplink random access process, as mentioned above, in view of that the beamforming gain is not fully utilized yet, the present disclosure aims to provide a solution for effectively utilizing the beamforming gain brought by the massive MIMO technology in the random access process, so as to better adapt to the millimeter wave communication environment.
A brief description of a conventional uplink random access procedure, for example, in the wireless communication system 100, is provided below. The uplink random access process is mainly used for initial access and switching scenes, including uplink synchronization and random access. As an example, fig. 2 illustrates a conventional uplink random access procedure 200, which is, for example, a contention-based UE 120 initial access procedure. First, prior to making initial access, UE 120 performs a cell search at 202. During this period, the UE 120 performs downlink synchronization by acquiring synchronization information. Thereafter, the UE may perform an uplink random access procedure. At 204, the UE randomly selects a preamble and sends the preamble to BS 110 over a Physical Random Access Channel (PRACH) in available subframes.
Accordingly, at the base station side, in response to receiving the random access request from the UE, the BS may detect the access preamble based on the signal correlation and further may measure the timing of the UE transmission at 206. If the BS successfully detects the random access preamble, the BS then feeds back a random access response in a Physical Downlink Shared Channel (PDSCH). Accordingly, the BS transmits information such as a Timing Advance (TA), information on scheduling resources, and assignment of a temporary identity to the UE in a Random Access Response (RAR). However, in this step, if multiple UEs in the cell served by the base station use the same preamble to transmit the random access request, a collision occurs, and the base station cannot simultaneously access multiple UEs transmitting the same random preamble.
At 208, the UE adjusts uplink timing based on the received RAR information, and obtains uplink synchronization. Its own identity is then transmitted to the BS at 210 in a random access message over the Physical Uplink Shared Channel (PUSCH) resources allocated for it. Accordingly, at 212, the BS includes the UE identity in the contention resolution message to distinguish different UEs according to the UE identity transmitted on the PDSCH by the UE, thereby successfully completing the random access procedure.
The above random access procedure faces many challenges such as too long access time, increased probability of access failure, etc. due to unfavorable propagation characteristics when communicating in the millimeter wave band. In view of this, in the present disclosure, on the base station side, a two-phase hierarchical beamforming mapping scheme for directional PRACH reception in millimeter-wave bands with the aid of directional Physical Broadcast Channel (PBCH) transmission is proposed. In particular, in beamforming in the first stage, beamforming pattern design and selection for cell system information acquisition during downlink PBCH transmission. In the second stage of beamforming, a beamforming pattern is designed and selected during a subsequent uplink random access procedure. According to the embodiment of the present disclosure, the beamforming pattern of the first stage is associated with the beamforming pattern of the second stage and has a unique mapping relationship.
Those skilled in the art will appreciate that when the beamformed signals are transmitted or received using the same power, the beamformed signals are transmitted over a relatively short distance for a wide beam, but with a wider beam coverage; while for narrow beams the transmission distance of the beamformed signals is longer, but the beam coverage is correspondingly narrower. In practical applications, the beamforming pattern to be used may be determined according to cell load, planning, and the like. In addition, the beam forming pattern used in the base station radio frequency channel represents the long-time broadband channel characteristics and the direction information between the terminal equipment and the base station, so that the beam reciprocity characteristic is applicable to both TDD network deployment and FDD network deployment in the radio frequency channel.
Fig. 3 illustrates a two-stage hierarchical beamforming map 300 according to one embodiment of the present disclosure. As shown, the first stage 310 consists of N beamforming patterns 302 with coarse granularity and low beamforming gain, denoted as beam B1，……，BN. In the first stage 310, each beamforming pattern may be further divided into beamforming sub-arrays in the second stage. In a subsequent second stage 320, each beamformed sub-array contains M beamforming patterns 304 with finer granularity and higher beamforming gain than in the first stage, denoted as beam B11，……，B1M。
Thus, in the second stage 320, there are a total of N × M narrower and sharper beams. Each sub-array of beamforming in the second stage 320 (corresponding to a group of sub-beams) may cover a similar beam direction and geographical area as the corresponding beamforming pattern in the first stage 310, but with better transmit and receive capabilities due to the narrower and sharper beamforming pattern. While the beamformed sub-array indices in the second stage 320 are directly related (mapped) to the beamformed pattern indices in the first stage.
In this embodiment, since the UE 120 has less transmit power in the uplink than the base station in the downlink PBCH transmission in the millimeter-wave band, PRACH reception can be performed with a narrower and sharper beamforming pattern on the base station side to compensate for the approximate path attenuation in the uplink and downlink.
Based on the above concept, the present disclosure proposes a method of random access based on beamforming, and fig. 4 illustrates a method 400 of random access according to an embodiment of the present disclosure. The method 400 shown in fig. 4 may be performed, for example, by the base station 110 shown in fig. 1.
At step 402, a broadcast signal is transmitted at BS 110 using a plurality of downlink transmit beams. BS 110 broadcasts system information to UEs 120 in the cell via PBCH, for example, configuration information related to downlink transmission beams and transmission of random access signals is broadcasted within the cell in a System Information Block (SIB), so that UEs 120 can accurately know the random preamble transmission resources, thereby effectively initiating uplink random access. In this step, a plurality of downlink transmission beams for transmitting the broadcast signal may use a plurality of beams designed according to the beamforming pattern of the first stage as described above, for example.
It is noted that in base stations implementing massive MIMO techniques, a trade-off between performance advantages and implementation costs is typically required for the application of the various techniques. It is based on hardware costs and computational complexity and energy consumption of signal processing that base stations are usually equipped with a number of radio frequency channels that is less than the number of antennas.
In one embodiment of the present disclosure, assuming that R radio frequency channels are applied in BS 110, at a certain point in time, a broadcast channel transport block may be simultaneously transmitted in R different beamforming patterns on the R radio frequency channels. But in this case, each transport block can only utilize 1/R of the base station transmission power on the base station side, and at the same time, the pilot signal overhead consumed by R radio frequency channels increases by a factor of R.
In another embodiment of the present disclosure, a single broadcast channel transport block is transmitted over one of the R radio frequency channels using the full transmit power of BS 110. PBCH transmission may select one of the N beamforming patterns of the first stage 310 at each transmission time point, which is more efficient. Accordingly, the UE 120 then receives and detects the broadcast channel transport block at N consecutive points in time and determines and records the best beamforming pattern index from the BS 110 with the largest received power.
At step 404, a random access signal from UE 120 is received at the base station using a plurality of uplink receive beams, the uplink receive beams being associated with downlink transmit beams. In this step, all radio channels of the base station receive the random access signal from the UE 120 at the same time. The used receive beams may be, for example, beams designed according to the beamforming pattern of the second stage 320, and these uplink receive beams have a unique mapping relationship with the downlink transmit beams in step 402. A specific random access signal reception procedure will be described in detail below in conjunction with the PRACH format.
As an example, the beam pattern used in the first stage may be the same as the beam pattern used in the second stage. For example, a wider and coarse beam, or a narrow and fine beam, etc. are used, and the beams used in the first stage and the beams used in the second stage may have a one-to-one correspondence (mapping) relationship.
As another example, the beam pattern used in the first stage may be different from the beam pattern used in the second stage. For example, the first stage employs a wide beam and the second stage employs a narrow beam, with a mapping relationship between the two, such as the two-stage hierarchical beamforming mapping described above in connection with fig. 3.
At step 406, a transmit beam for the UE 120 is determined in response to receiving the random access signal. BS 110 performs measurement and detection on the received random access signal of UE 120 and determines the most ideal receive beam for UE 120. From the beam reciprocity characteristics, the base station may determine a transmit beam for the UE 120.
In one embodiment of the present disclosure, the random access signal includes a random access preamble and an indication indicating a downlink transmission beam preferred by the UE 120, which will be described in detail below. In this embodiment, BS 110 receives the random access signal and is able to learn the downlink transmission beam (or direction) desired by UE 120, and BS 110 may determine the transmission beam for UE 120 based on the detection of the random access signal and this indication of the learning.
In step 408, a random access response is transmitted to the UE 120 using the determined transmission beam. In this step, BS 110 transmits a random access response using the determined most suitable transmit beam for UE 120 so that UE 120 can better receive information from the base station with the directionality of the beam.
Referring now to fig. 5, a method 500 of random access is shown in accordance with an embodiment of the present disclosure. The method 500 shown in fig. 5 may be performed, for example, by the UE 120 shown in fig. 1. That is, the UE 120 may perform the method 500 to operate with the BS 110 performing the method 400 to implement random access.
At step 502, a broadcast signal is received at UE 120, the broadcast signal being transmitted by BS 110 using a plurality of downlink transmit beams. For example, the broadcast signal is sent by BS 110 according to step 402 in fig. 4, where the broadcast signal carries configuration information related to downlink transmission beams and transmission of the random access signal, and UE 120 can accurately know the random preamble transmission resource through the broadcast information.
In step 504, in response to receiving the broadcast signal, a random access signal is transmitted using the uplink transmission beam, where the random access signal includes at least a random access preamble and an indication indicating a downlink transmission beam preferred by the UE 120. In this step, the UE 120 may know its best reception beam by measuring and decoding broadcast signals transmitted through a plurality of beams, and may determine an uplink transmission beam for the PRACH according to the beam reciprocity characteristic. A specific procedure for transmitting the random access signal will be described in detail below with reference to the PRACH format.
In one embodiment of the present disclosure, the indication indicating the downlink transmission beam preferred by UE 120 may be implicitly communicated to BS 110, e.g., to associate with the time domain resource transmitting the random access signal. The indication indicating the downlink transmission beam preferred by UE 120 may also be explicitly communicated to BS 110, i.e. the index of the downlink transmission beam preferred by it is included in the random access signal.
Fig. 6 shows an illustration of a PRACH format 600 with directional reception according to an embodiment of the disclosure. Fig. 6 only illustrates the PRACH format in the time domain, where PRACH transmission is concentrated in a central frequency band with a minimum uplink bandwidth defined for a millimeter band, and thus the same PRACH structure may be used in the frequency domain regardless of the uplink cell bandwidth.
Each random access preamble transport block 602 may be composed of one or more OFDM symbols according to the length of the random access preamble sequence, the cyclic prefix, and the guard time. As shown in fig. 6, a plurality of preamble transport blocks carrying random access preambles are transmitted at consecutive points in time. The consecutive preamble transmission blocks 602 form PRACH transmission attempts 604, the PRACH transmission attempts 604 may have a duration of one or more subframes. Meanwhile, the PRACH transmission attempt 604 has a configurable PRACH transmission period 606.
In the PRACH format 600, the number of preamble transmission blocks 602 in each PRACH transmission attempt 604 may be configured. In one embodiment of the present disclosure, according to the two-phase hierarchical beamforming mapping scheme, N preamble transport blocks may be included in each PRACH transmission attempt, N being the number of beamforming patterns in the first phase 310.
It can be understood that the PRACH format information configured in the system will be broadcast to the UE 110 through the PBCH channel, so that the UE 110 in the cell can know how to transmit the random access signal on the PRACH. According to one embodiment of the present disclosure, the UE 120 may repeatedly transmit its preamble signal in consecutive preamble transmission blocks 602 within a PRACH transmission attempt 604, which the BS 110 will receive in consecutive points in time in a beamforming pattern in the second stage 320 defined by a two-stage hierarchical beamforming mapping scheme. This embodiment, although utilizing beamforming gain, is not the most efficient PRACH transmission method since not all beamforming patterns in the second stage 320 are suitable for the UE 120, and random access collisions may occur at every point in time.
According to another embodiment of the present disclosure, the UE 120 selects a specific time point or preamble transport block to deliver its random access request according to its preferred or preferred downlink beamforming pattern index of the BS 110. That is, the UE 120 may learn the best downlink beamforming pattern index for its own transmission based on decoding and measurement of received broadcast signals transmitted by the BS 110 in multiple transmit beams, and then the UE 120 may select to transmit a random access signal using a preamble transport block at a time in the PRACH transmission attempt 604 corresponding to the index according to the preferred or preferred downlink beamforming pattern index. As shown in fig. 6, the UE 120 may select a specific time domain resource in the PRACH transmission attempt 604 to transmit a random access signal, the specific time domain resource being associated with a downlink beamforming pattern index preferred by the UE 120, and the association being also reflected in a correspondence between a transmission beam of a broadcast signal and a PRACH transceiving beam, as described above for the two-phase hierarchical beamforming mapping.
In this way, the UE 120 will no longer send random access requests in the other preamble transmission blocks of the PRACH transmission attempt. From different UEs (e.g., UE 120)1、UE 1202…UE120K) May be scattered over multiple time points of PRACH transmission attempts, thereby significantly reducing the probability of random access collisions due to different UEs selecting a common preamble sequence at the same time point. Whereas on the BS 110 side, the BS 110 will use the best receive beam for PRACH decoding.
In one embodiment, the BS 110 uses a two-phase hierarchical beamforming mapping as shown in fig. 3, and in receiving PRACH transport blocks, receives each PRACH transport block using a different beamforming sub-array(s) in the second phase to cover all UEs located in different directions of the cell. As shown in fig. 6, during the reception period of BS 110 corresponding to PRACH transmission attempt 604, BS 110 receives in directional beamforming subarrays in N consecutive preamble transport blocks, respectively. The beamforming sub-array may be selected from a set of predefined beamforming vectors or codebooks with finer granularity and sharper beamforming patterns to achieve greater beamforming gain. In this embodiment, the beamforming subarray index is directly related to the index of the preamble transport block within the uplink PRACH transmission attempt and is mapped from the beamforming pattern index of the downlink PBCH transmission according to the two-phase hierarchical beamforming mapping in fig. 3.
In this embodiment, the BS 110 may detect one or more preambles and record the best beamforming pattern index for each preamble defined in the second phase in fig. 3 in each preamble transmission block within a PRACH transmission attempt, although it may also detect no preamble. Naturally, the BS 110 transmits the random access response related to the detected preamble signal using an appropriate beamforming pattern according to the beam reciprocity characteristic.
When the UE 120 selects a specific time point or a preamble transmission block to transmit its random access request according to its preference or the preferred downlink beamforming pattern index of the BS 110, this embodiment can obtain a very high beamforming gain, greatly improve the PRACH reception capability, and reduce the probability of random access collision.
This will be further explained with reference to fig. 7. Fig. 7 shows an illustration of a communication scenario 700 according to an embodiment of the present disclosure. As shown, BS 110 is configured with M-4 transceiving rf channels 7101、7102、7103、7104In communication scenario 700, there are K UEs, namely UE 1201，UE 1202，……，UE 120K. Each radio frequency channel of BS 110 may be connected to all antenna elements of BS 110 or a subset of the BS 110 antenna elements, and each radio frequency channel uses a different beamforming pattern from a beamforming subarray to cover a range of UE locations and receive signals from the UE preamble request.
In this embodiment, BS 110 may first transmit the broadcast signal in N wider downlink transmit beams. In the random access procedure, the UE 1201Selecting preamble #1, UE 1202Selecting preamble #2, UE 120KHappen to select with the UE 1201The same preamble # 1. As described previously, if a UE finds the best beamforming pattern with index n from BS 110 during downlink PBCH transmission, the UE will transmit its preamble signal at time point n during the uplink random access procedure. Thus, if the UE 1201And UE 120KDifferent beamforming patterns from BS 110 are preferred during the downlink PBCH transmission period, and they will transmit their preambles at different points in time during the PRACH transmission attempt, when no collision of uplink random access requests occurs.
The BS 110 receives a plurality of preamble sequences #1, #2 using different beamforming sub-arrays with finer granularity at N consecutive time points of the PRACH. That is, in the embodiment shown in fig. 7, the radio frequency channel # m of the BS 110 may use the beam pattern # n.m (m ═ 1, …,4) of the beamforming sub-array N (N ═ 1, …, N) to detect the UE 120 according to the two-stage hierarchical beamforming mapping relationship1，UE 1202，……，UE 120KThe leader sequence of (1). From the time domain, the nth beamforming pattern in the first stage is used for PBCH transmission in the downlink time point n, and then the nth beamforming subarray in the second stage is used for PRACH reception in the uplink time point n according to the beam reciprocity characteristic.
The four radio frequency channels of the BS 110 simultaneously receive and detect the preamble signals from different UEs and receive and detect the preamble signals from different UEs at a plurality of consecutive points in time of the PRACH transmission attempt. Each preamble will be received simultaneously by a different radio frequency channel, but the received signal quality or strength will be different in each radio frequency channel due to the different beamforming directivities. Finally, the best beamforming pattern is selected from the beamforming subarrays and associated with the preamble signal according to the maximum received power, so as to feed back a random access response to the UE 120 with the best beamforming pattern. In this way, the BS 110 may further determine the best beamforming pattern index with finer granularity and higher beamforming gain for each UE, which will be used for the following random access procedure and the following data transmission.
As can be seen from the above procedure, at the BS 110 side, the PRACH applies a receive beamforming subarray with higher pattern resolution and beamforming gain than the PBCH to improve PRACH reception capability. According to the two-stage hierarchical beamforming mapping, the beamforming subarray index during the PRACH reception period is directly related to the beamforming pattern during the downlink PBCH transmission period. This random access mechanism can obtain superior beamforming gain and link connection performance for each UE without causing preamble collision of the uplink random access procedure.
Fig. 8 illustrates a directional random access procedure communication schematic 800 in accordance with an embodiment of the disclosure. At 802, BS 110 transmits a broadcast signal over PBCH using multiple downlink transmit beams, e.g., a broadcast signal in a beam-scanning manner using a wide plurality of beams at different points in time, the broadcast signal including at least a number of preamble transport blocks, a number of beamforming patterns, a mapping table between beamforming patterns and preamble transport blocks, a duration of the preamble transport blocks, a period and location of PRACH transmission attempts, and so on.
At 804, during downlink initial cell access, the UE 120 determines its best receive beam and the most suitable or preferred downlink transmit beam through PBCH decoding based on the received directional broadcast signal, and learns preamble transmission resource related information from the broadcast signal.
Then, at 806, the UE 120 transmits a random access request (random access signal) through the PRACH using the same beam as its best reception beam at a time point in the random access attempt corresponding to its preferred downlink transmission beam index. In addition, the reception beam determined by UE 120 and the preferred downlink transmission beam in this step may be used for the subsequent communication procedure.
At 808, BS 110 receives the random access signal of UE 120 using different beamforming sub-arrays, i.e., multiple sub-beams, with finer granularity at a point in time of the PRACH, which corresponds to the downlink transmit beam index preferred by UE 120. By detecting and measuring the random access signal of the UE, the BS 110 determines the best one of the plurality of sub-beams as a transmission beam and a reception beam for the UE 120 at a later time. BS 110 then transmits a random access response using the sub-beam at 810.
Thereafter, on the UE 120 side, at 812, a random access message containing the identity of UE 120 is transmitted to BS 110 using the beamforming pattern as predetermined in 804 for UE 120, and BS 110 receives the message using the appropriate beamforming pattern determined in 808. At 814, BS 110 sends the identity of UE 120 to UE 120 using the beamforming pattern of the appropriate BS 110 determined in 808, confirming that the random access procedure for the UE was successfully completed. UE 120 and BS 110 may then use the transceive beams determined at 804 and 808, respectively, for data transmission at 818.
Fig. 9 illustrates an example block diagram of an apparatus 900 for communicating a random access procedure in a wireless communication system in accordance with an embodiment of this disclosure. In one embodiment, apparatus 900 may be implemented as, or part of, a network-side device (e.g., base station 110) in random access procedure communication. Apparatus 900 is operable to perform the methods and/or communication procedures described with reference to fig. 4, 7, and 8, as well as any other processes and methods.
To this end, the apparatus 900 comprises: a first transmission unit 910 configured to transmit a broadcast signal using a plurality of downlink transmission beams; a receiving unit 920 configured to receive a random access signal from a terminal device using a plurality of uplink receive beams, the plurality of uplink receive beams being associated with a plurality of downlink transmit beams; a beam determination unit 930 configured to determine a transmission beam for the terminal device in response to receiving the random access signal; and a second transmitting unit 940 configured to transmit a random access response to the terminal device using the determined transmission beam.
Fig. 10 illustrates an example block diagram of an apparatus 1000 for communicating a random access procedure in a wireless communication system in accordance with an embodiment of this disclosure. In one embodiment, apparatus 1000 may be implemented as, or part of, a user-side device (e.g., terminal device 120) in a random access procedure communication. Apparatus 1000 is operable to perform the methods and/or communication processes described with reference to fig. 5, 7, and 8, as well as any other processes and methods.
To this end, the device 1000 comprises: a receiving unit 1010 configured to receive a broadcast signal, the broadcast signal being transmitted by a base station using a plurality of downlink transmission beams; a transmitting unit 1020 configured to transmit, in response to receiving the broadcast signal, a random access signal using the uplink transmission beam, the random access signal including at least a random access preamble and an indication indicating a preference of the terminal device for the plurality of downlink transmission beams.
It should be understood that each unit recited in the devices 900 and 1000 corresponds to each step in the methods and/or communication processes 400, 500, 700, and 800 described with reference to fig. 4, 5, 7, and 8. Therefore, the operations and features described above in conjunction with fig. 4, 5, 7 and 8 are also applicable to the apparatuses 900 and 1000 and the units included therein, and have the same effects, and detailed details are not repeated.
The elements included in apparatus 900 and 1000 may be implemented in a variety of ways including software, hardware, firmware, or any combination thereof. In one embodiment, one or more of the units may be implemented using software and/or firmware, such as machine executable instructions stored on a storage medium. In addition to, or in the alternative to, machine-executable instructions, some or all of the elements in apparatus 900 and 1000 may be implemented at least in part by one or more hardware logic components. By way of example, and not limitation, exemplary types of hardware logic components that may be used include Field Programmable Gate Arrays (FPGAs), Application Specific Integrated Circuits (ASICs), Application Specific Standards (ASSPs), systems on a chip (SOCs), Complex Programmable Logic Devices (CPLDs), and so forth.
Fig. 11 shows a schematic block diagram of a device 1100 that may be used to implement embodiments of the present disclosure, the device 1100 may be used to implement a device for random access procedure communication, including, for example, the network device 110 or the terminal device 120 described above.
As shown, the device 1100 includes at least one controller 1110 and at least one memory 1120 coupled to the controller 1110. The controller 1110 may be implemented by any suitable device, such as a digital processor, for example, and may be controlled by instructions stored in the memory 1120. The device 1100 also includes a transceiver (Rx/Tx)1140 coupled to the controller 1110 and the memory 1120. The apparatus 1100 may also be coupled to one or more external networks or systems via a data path 1150.
When device 1100 is used to implement network device 110, controller 1110 and transceiver 1140 may cooperate to implement methods/ processes 400, 700, and/or 800 described in detail above with reference to fig. 4, 7, and 8. Similarly, when the device 1100 is used to implement the terminal device 120, the controller 1110 and the transceiver 1140 may operate in conjunction to implement the methods/ processes 500, 700, and/or 800 described in detail above with reference to fig. 5, 7, and 8.
According to the various aspects and embodiments mentioned above, by applying the hierarchical beamforming scheme in the random access process, the beamforming gain brought by the massive MIMO technology is better utilized, the performance of the system random access is improved, and the millimeter wave communication environment can be better adapted.
Those skilled in the art will readily recognize that blocks or steps of the various methods described above may be performed by a programmed computer. In the present disclosure, some embodiments are also intended to encompass program storage devices, e.g., digital data storage media, that are machine or computer readable and encode machine-executable or computer-executable programs of instructions, wherein the instructions perform some or all of the steps of the above-described methods. The program storage device may be, for example, a digital memory, a magnetic storage medium such as a magnetic disk and magnetic tape, a hard disk drive, or an optically readable digital data storage medium. This embodiment is also intended to cover a computer programmed to perform the steps of the above-described method.
The functions of the various elements of the apparatus shown in the figures may be provided through the use of software, dedicated hardware as well as hardware capable of executing software in association with appropriate software, or firmware, or a combination thereof. When provided by a processor, the functions may be provided by a single dedicated processor, by a single shared processor, or by a plurality of individual processors. Furthermore, the term "processor" may include, but is not limited to, Digital Signal Processor (DSP) hardware, network processors, Application Specific Integrated Circuits (ASICs), Field Programmable Gate Arrays (FPGAs), Read Only Memories (ROMs) for storing software, Random Access Memories (RAMs) and non-volatile storage. Other hardware, conventional and/or custom, may also be included.
Many modifications and other embodiments of the disclosure set forth herein will come to mind to one skilled in the art to which this disclosure pertains having the benefit of the teachings presented in the foregoing descriptions and the associated drawings. Therefore, it is to be understood that the embodiments of the disclosure are not to be limited to the specific embodiments disclosed and that modifications and other embodiments are intended to be included within the scope of the disclosure. Moreover, while the above description and the related figures describe example embodiments in the context of certain example combinations of components and/or functions, it should be appreciated that different combinations of components and/or functions may be provided by alternative embodiments without departing from the scope of the present disclosure. In this regard, for example, other combinations of components and/or functions than those explicitly described above are also contemplated as within the scope of the present disclosure. Although specific terms are employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation.
Claims (30)
1. A method for random access based on beamforming, comprising:
transmitting, at a base station, a broadcast signal using a plurality of downlink transmit beams;
receiving a random access signal from a terminal device using a plurality of uplink receive beams, including receiving the random access signal from the terminal device using a plurality of sub-beam groups corresponding to the plurality of downlink transmit beams, wherein the plurality of uplink receive beams are divided into the plurality of sub-beam groups each including one or more uplink receive beams, the plurality of sub-beam groups have a mapping relationship with the plurality of downlink transmit beams, and each sub-beam group in the plurality of sub-beam groups can cover the corresponding downlink transmit beam direction and geographic area;
determining one of a group of sub-beams as a transmit beam for said terminal device in response to receiving said random access signal; and
and sending a random access response to the terminal equipment by using the determined transmission beam.
2. The method of claim 1, wherein transmitting, at a base station, a broadcast signal using a plurality of downlink transmit beams comprises:
transmitting the broadcast signal using the plurality of downlink transmit beams with different time domain resources.
3. The method of claim 1, wherein receiving random access signals from a terminal device using a plurality of uplink receive beams comprises:
receiving the random access signal from the terminal device using the same beam as the plurality of downlink transmit beams.
4. The method of claim 1, wherein receiving the random access signal from the terminal device using a plurality of sub-beam groups corresponding to the plurality of downlink transmit beams comprises:
receiving said random access signal from said terminal device in one of said plurality of sub-beam sets at different time instants, said different time instants being associated with said plurality of downlink transmit beams.
5. The method of claim 4, wherein determining a transmit beam for the terminal device comprises:
detecting the random access signal;
determining one of said one group of sub-beams as a receive beam to be used for said terminal device based on said detecting; and
determining a same beam as the receive beam as the transmit beam for the terminal device.
6. The method of claim 1, further comprising:
determining a reception beam to be used for the terminal device in response to receiving the random access signal; and
the random access and data transmission are performed for the terminal device using the transmit beam and the receive beam.
7. The method of claim 1, wherein the random access signal includes at least a random access preamble and an indication indicating a preference of the terminal device for the plurality of downlink transmit beams.
8. The method of claim 7, wherein the indication indicating the terminal device's preference for the plurality of downlink transmit beams is uniquely associated with a time domain resource of the random access signal.
9. The method of claim 7, wherein determining a transmit beam for the terminal device comprises:
detecting the random access signal to obtain the indication of the terminal device's preference for the plurality of downlink transmit beams; and
determining a downlink transmission beam preferred by the terminal device as a transmission beam for the terminal device based on the indication.
10. The method of claim 1, wherein the broadcast signal includes at least configuration information related to the downlink transmit beam and to transmission of the random access signal carried in system information.
11. A method for random access based on beamforming, comprising:
receiving a broadcast signal at a terminal device, the broadcast signal being transmitted by a base station using a plurality of downlink transmit beams;
detecting the received broadcast signal in response to receiving the broadcast signal;
determining a downlink transmission beam preferred by the terminal equipment and a receiving beam to be used based on the detection;
determining a beam which is the same as the receiving beam as an uplink transmitting beam;
sending a random access signal by using an uplink transmission beam, wherein the random access signal at least comprises a random access preamble and an indication indicating the preference of the terminal equipment to the plurality of downlink transmission beams; and
the terminal device will use the transmit beam for data transmission with an uplink receive beam determined by the base station for the terminal device,
the determined uplink receive beam is included in one sub-beam group of a plurality of uplink receive beams, the plurality of uplink receive beams are divided into a plurality of sub-beam groups each including one or more uplink receive beams, a mapping relationship exists between the plurality of sub-beam groups and the plurality of downlink transmit beams, and each sub-beam group of the plurality of sub-beam groups can cover the corresponding downlink transmit beam direction and geographic area.
12. The method of claim 11, wherein the broadcast signal is for the base station to use the plurality of downlink transmit beams with different time domain resources, and wherein receiving a broadcast signal at a terminal device comprises:
receiving the broadcast signal at the terminal device at different time instances associated with the plurality of downlink transmit beams.
13. The method of claim 11, wherein transmitting the random access signal using the uplink transmit beam comprises:
and sending the random access signal by using a time domain resource which is uniquely associated with the downlink transmission beam preferred by the terminal equipment.
14. The method of claim 11, further comprising:
and performing the random access and data transmission by using the uplink transmitting beam and the receiving beam.
15. The method of claim 11, wherein the broadcast signal includes configuration information related to the downlink transmit beam and to transmission of the random access signal carried in system information.
16. A network device, comprising:
a transceiver configured to:
transmitting a broadcast signal using a plurality of downlink transmit beams; and
receiving a random access signal from a terminal device using a plurality of uplink receive beams, including receiving the random access signal from the terminal device using a plurality of sub-beam groups corresponding to the plurality of downlink transmit beams, wherein the plurality of uplink receive beams are divided into the plurality of sub-beam groups each including one or more uplink receive beams, the plurality of sub-beam groups have a mapping relationship with the plurality of downlink transmit beams, and each sub-beam group in the plurality of sub-beam groups can cover the corresponding downlink transmit beam direction and geographic area; and
a controller configured to determine one of a group of sub-beams as a transmit beam for the terminal device in response to receiving the random access signal, to cause the transceiver to transmit a random access response to the terminal device using the transmit beam.
17. The network device of claim 16, the transceiver configured to:
transmitting the broadcast signal using the plurality of downlink transmit beams with different time domain resources.
18. The network device of claim 16, the transceiver configured to:
receiving the random access signal from the terminal device using the same beam as the plurality of downlink transmit beams.
19. The network device of claim 16, the transceiver further configured to:
receiving said random access signal from said terminal device in one of said plurality of sub-beam sets at different time instants, said different time instants being associated with said plurality of downlink transmit beams.
20. The network device of claim 19, the controller configured to:
detecting the random access signal;
determining one of said one group of sub-beams as a receive beam to be used for said terminal device based on said detecting; and
determining a same beam as the receive beam as the transmit beam for the terminal device.
21. The network device of claim 16, the controller further configured to:
determining a reception beam to be used for the terminal device in response to receiving the random access signal; and
determining to use the transmit beam and the receive beam for the random access and data transmission for the terminal device.
22. The network device of claim 16, wherein the random access signal includes at least a random access preamble and an indication indicating the terminal device's preference for the plurality of downlink transmit beams.
23. The network device of claim 22, wherein the indication indicating the terminal device's preference for the plurality of downlink transmit beams is uniquely associated with a time domain resource of the random access signal.
24. The network device of claim 22, the controller further configured to:
detecting the random access signal to obtain the indication of the terminal device's preference for the plurality of downlink transmit beams; and
determining a downlink transmission beam preferred by the terminal device as a transmission beam for the terminal device based on the indication.
25. The network device of claim 16, wherein the broadcast signal includes at least configuration information related to the downlink transmit beam and to transmission of the random access signal carried in system information.
26. A terminal device, comprising:
a transceiver configured to:
receiving a broadcast signal, the broadcast signal being transmitted by a base station using a plurality of downlink transmit beams; and
detecting the received broadcast signal in response to receiving the broadcast signal;
determining a downlink transmission beam preferred by the terminal equipment and a receiving beam to be used based on the detection;
determining a beam which is the same as the receiving beam as an uplink transmitting beam;
sending a random access signal by using an uplink transmission beam, wherein the random access signal at least comprises a random access preamble and an indication indicating the preference of the terminal equipment to the plurality of downlink transmission beams; and
using the transmission beam for data transmission with an uplink reception beam determined by the base station for the terminal device, the determined uplink reception beam being included in one sub-beam group of a plurality of uplink reception beams, the plurality of uplink reception beams being divided into a plurality of sub-beam groups each including one or more uplink reception beams, there being a mapping relationship between the plurality of sub-beam groups and the plurality of downlink transmission beams, and each of the plurality of sub-beam groups being capable of covering a corresponding downlink transmission beam direction and geographic area.
27. The terminal device of claim 26, wherein the broadcast signal is for the base station to use the plurality of downlink transmit beams with different time domain resources, and wherein the transceiver is configured to:
receiving the broadcast signal at the terminal device at different time instances associated with the plurality of downlink transmit beams.
28. The terminal device of claim 26, the transceiver configured to:
and sending the random access signal by using a time domain resource which is uniquely associated with the downlink transmission beam preferred by the terminal equipment.
29. The terminal device of claim 26, the controller of the terminal device further configured to:
determining to use the uplink transmit beam and the receive beam for the random access and data transmission.
30. The terminal device of claim 26, wherein the broadcast signal includes configuration information related to the downlink transmit beam and to transmission of the random access signal carried in system information.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610578444.2A CN107645322B (en) | 2016-07-21 | 2016-07-21 | Random access method and equipment based on beamforming |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN201610578444.2A CN107645322B (en) | 2016-07-21 | 2016-07-21 | Random access method and equipment based on beamforming |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN107645322A CN107645322A (en) | 2018-01-30 |
| CN107645322B true CN107645322B (en) | 2021-09-24 |
Family
ID=61108761
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN201610578444.2A Active CN107645322B (en) | 2016-07-21 | 2016-07-21 | Random access method and equipment based on beamforming |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN107645322B (en) |
Families Citing this family (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110139382B (en) * | 2018-02-09 | 2024-03-19 | 华为技术有限公司 | Random access preamble transmitting method, random access preamble receiving method and random access preamble receiving device |
| CN110149612B (en) * | 2018-02-11 | 2021-07-09 | 华为技术有限公司 | Beam determination method, first communication device and second communication device |
| CN110769515B (en) * | 2018-07-25 | 2024-01-16 | 珠海市魅族科技有限公司 | Initial access method, initial access device and communication equipment |
| KR20210037677A (en) * | 2018-07-27 | 2021-04-06 | 광동 오포 모바일 텔레커뮤니케이션즈 코포레이션 리미티드 | Random access method, terminal device and storage medium |
| EP3855824A4 (en) | 2018-09-20 | 2022-06-08 | Beijing Xiaomi Mobile Software Co., Ltd. | Communication method and apparatus, terminal, base station, and storage medium |
| CN115486197A (en) * | 2022-07-22 | 2022-12-16 | 北京小米移动软件有限公司 | Random access method/device/equipment and storage medium |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101772182A (en) * | 2009-01-05 | 2010-07-07 | 大唐移动通信设备有限公司 | Random access method and equipment |
| CN101848551A (en) * | 2009-03-26 | 2010-09-29 | 大唐移动通信设备有限公司 | Method, system and device for indicating downlink carrier and random access |
| CN104718712A (en) * | 2012-08-17 | 2015-06-17 | 三星电子株式会社 | Method and apparatus for system access in system using beamforming |
| CN105122662A (en) * | 2012-12-26 | 2015-12-02 | 三星电子株式会社 | Method and apparatus for random access in communication system with large number of antennas |
Family Cites Families (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| KR102118693B1 (en) * | 2013-06-24 | 2020-06-03 | 삼성전자주식회사 | Apparatus and method for determining transmit beam pattern for random access in wireless communication system |
-
2016
- 2016-07-21 CN CN201610578444.2A patent/CN107645322B/en active Active
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN101772182A (en) * | 2009-01-05 | 2010-07-07 | 大唐移动通信设备有限公司 | Random access method and equipment |
| CN101848551A (en) * | 2009-03-26 | 2010-09-29 | 大唐移动通信设备有限公司 | Method, system and device for indicating downlink carrier and random access |
| CN104718712A (en) * | 2012-08-17 | 2015-06-17 | 三星电子株式会社 | Method and apparatus for system access in system using beamforming |
| CN105122662A (en) * | 2012-12-26 | 2015-12-02 | 三星电子株式会社 | Method and apparatus for random access in communication system with large number of antennas |
Also Published As
| Publication number | Publication date |
|---|---|
| CN107645322A (en) | 2018-01-30 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US10779323B2 (en) | System and method for beam-based physical random-access | |
| CN107645322B (en) | Random access method and equipment based on beamforming | |
| US10841926B2 (en) | Default beam for uplink transmission after connection reestablishment | |
| US10355761B2 (en) | Beam administration methods for cellular/wireless networks | |
| EP3497816B1 (en) | Rach conveyance of dl synchronization beam information for various dl-ul correspondence states | |
| KR102616415B1 (en) | Apparatus and method for differential beamforming-based random access in a wireless communication system | |
| US10548101B2 (en) | Method for accessing millimeter wave cell in wireless communication system and apparatus therefor | |
| ES2949298T3 (en) | User equipment and random access method | |
| KR102199523B1 (en) | Apparatus and method for communication based on beam-forming in wireless communication system | |
| US20200015273A1 (en) | Methods and apparatus for enhanced random access procedure | |
| EP3249825A1 (en) | Method and apparatus for obtaining location of user equipment (ue) | |
| CN106804043B (en) | Uplink access method, user equipment and base station | |
| US20180279364A1 (en) | Method and apparatus for random access in mobile communication system | |
| WO2018082017A1 (en) | Methods and apparatus for random access procedure in nr system with beamforming | |
| US20220078848A1 (en) | Systems, methods, and devices for beam management for random access | |
| US10903877B2 (en) | Initial access procedure for multi-beam operation | |
| KR20190034298A (en) | RANDOM ACCESS METHOD, DEVICE AND SYSTEM, TERMINAL, AND BASE STATION | |
| KR20180109047A (en) | Method and apparatus for random access in mobile communication system | |
| US11968547B2 (en) | Method and apparatus for beamforming control in a wireless communication network | |
| US20240032109A1 (en) | Random access channel occasion with multiple beams | |
| KR20170072816A (en) | Method and apparatus for receiving uplink signal |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |