CN112087805A

CN112087805A - Random access leader sequence distribution, determination and data transmission method and equipment

Info

Publication number: CN112087805A
Application number: CN201910510150.XA
Authority: CN
Inventors: 林鹏; 苏笛; 张闯; 钱辰; 喻斌
Original assignee: Beijing Samsung Telecommunications Technology Research Co Ltd; Samsung Electronics Co Ltd
Current assignee: Beijing Samsung Telecom R&D Center; Beijing Samsung Telecommunications Technology Research Co Ltd; Samsung Electronics Co Ltd
Priority date: 2019-06-13
Filing date: 2019-06-13
Publication date: 2020-12-15

Abstract

Provided are a random access preamble sequence allocation, determination, data transmission method and device. The random access leader sequence distribution method comprises the following steps: judging whether the interference strength between adjacent cells is greater than a strength threshold value; and when the cell strength is greater than the strength threshold value, allocating the same ZC sequence length, cyclic shift interval, logical root sequence number and different and continuous random access preamble sequence set index numbers to each cell in the adjacent cells, wherein the ZC sequence length, the cyclic shift interval, the logical root sequence number and the random access preamble sequence set index numbers are used for determining an available random access preamble sequence set of each cell, and random access preamble sequences generated from the same logical root sequence number exist in available random access preamble sequence sets corresponding to at least two continuous random access preamble sequence set index numbers. According to the present disclosure, a random access success rate may be improved.

Description

Random access leader sequence distribution, determination and data transmission method and equipment

Technical Field

The present disclosure relates to the field of wireless communication technologies, and in particular, to a method and device for allocating and determining a random access preamble sequence and transmitting data.

Background

According to the International Telecommunications Union (ITU), the worldwide mobile data traffic will reach 62 octets (EB, where 1EB is 2 EB) in 2020³⁰GB), and from 2020to 2030, global mobile data services will grow at a growth rate of about 55% per year; in addition, the proportion of video traffic and machine-to-machine communication traffic in mobile data traffic will gradually increase; by 2030, video traffic will be 6 times that of non-video traffic and machine-to-machine communication traffic will account for around 12% of mobile data traffic (see the documents IMT traffic estimates for the years 2020to 2030, Report ITU-R M.2370-0).

The rapid growth of mobile data services, especially the exponential growth of high definition video services and ultra-high definition video services, puts higher demands on the transmission rate of wireless communication, and in order to meet the growing mobile data service demands, people need to put forward a new technology on the basis of a fourth generation mobile communication technology (abbreviated as 4G) or a fifth generation mobile communication technology (abbreviated as 5G) to further improve the transmission rate and throughput of a wireless communication system. The full-Duplex technology can further improve the Frequency spectrum utilization rate on the existing wireless communication system, and different from the traditional half-Duplex system which adopts Time Division Duplex (TDD) or Frequency Division Duplex (FDD) for uplink and downlink, the full-Duplex system allows the uplink and the downlink to transmit simultaneously in Time domain and Frequency domain, so the throughput of the full-Duplex system can reach twice of the throughput of the half-Duplex system theoretically. For a small cell and a macro cell, the radius of the macro cell is large, and in order to ensure coverage, the transmit power of a base station needs to be increased. The current full duplex technique is temporarily not applicable to macro cells, but only to small cells with a smaller radius than macro cells, since the increased power will affect the data transmission and random access procedure.

Research on full duplex systems includes reducing access delay in order to allow terminals to access a cell with shorter time delay. For a small cell with a small radius, when full duplex communication is adopted, the types and strengths of intra-cell interference and inter-cell interference may increase, for example, a random access preamble sequence transmitted by a terminal may be interfered by a downlink signal of the cell and a downlink signal of an adjacent cell. Due to the increase of the types and intensity of interference, the random access success rate of the terminal in the cell supporting full duplex communication is likely to be affected, if the initial random access fails, the terminal is likely to initiate random access again after a period of time, so that the time delay of access becomes large, and the power of the random access preamble sequence is transmitted, which causes interference to the random access preamble sequence transmission of other terminals, so that the problem of improving the random access success rate of the full duplex system for the full duplex system is to be solved.

One method for improving the random access success rate of a full-duplex system is to design resources for random access as unidirectional resources, that is, to prohibit downlink signal transmission of any local cell and neighboring cells on resources for sending random access preamble sequences, but this method will result in low resource utilization rate.

Therefore, a method for improving the success rate of random access is needed.

Disclosure of Invention

Exemplary embodiments of the present disclosure are directed to overcome the problem of large access delay in the existing wireless communication technology, and provide a scheme that may be capable of increasing the success rate of random access.

According to an exemplary embodiment of the present disclosure, there is provided a random access preamble sequence allocation method, including: judging whether the interference strength between adjacent cells is greater than a strength threshold value; and when the cell strength is greater than the strength threshold value, allocating the same ZC sequence length, cyclic shift interval, logical root sequence number and different and continuous random access preamble sequence set index numbers to each cell in the adjacent cells, wherein the ZC sequence length, the cyclic shift interval, the logical root sequence number and the random access preamble sequence set index numbers are used for determining an available random access preamble sequence set of each cell, and random access preamble sequences generated from the same logical root sequence number exist in available random access preamble sequence sets corresponding to at least two continuous random access preamble sequence set index numbers.

Optionally, the subcarrier spacing corresponding to the random access preamble sequence is lower than 1.25 KHz.

Optionally, the subcarrier interval is equal to 1KHz, and the pre-guard interval of the random access preamble sequence and the cyclic prefix of the random access preamble sequence are located in a previous transmission period of a transmission period in which the random access preamble sequence is located.

Optionally, the subcarrier spacing is higher than 1KHz and lower than 1.25KHz, and the sum of the lengths of the following items is 1 ms: the front guard interval of the random access leader sequence, the cyclic prefix of the random access leader sequence, the random access leader sequence and the rear guard interval of the random access leader sequence.

Optionally, the back guard interval is zero, and the cyclic prefix of the first OFDM symbol of the next transmission period of the transmission period in which the random access preamble sequence is located plays a role of a back guard interval of the random access preamble sequence, or the length of the front guard interval is equal to the length of the cyclic prefix of the random access preamble sequence, and a difference between a sum of the lengths of the back guard interval and the cyclic prefix of the first OFDM symbol and the length of the cyclic prefix of the random access preamble sequence is less than or equal to 2Ts, or the length of the front guard interval is zero, and a difference between the length of the back guard interval and the cyclic length prefix of the random access preamble sequence is less than or equal to 2 Ts.

According to another exemplary embodiment of the present disclosure, there is provided a random access preamble sequence determination method including: acquiring information of a target cell, wherein the information comprises ZC sequence length, logic root sequence number, random access leader sequence set index number and cyclic shift interval; calculating an initial logic root sequence number and an initial cyclic shift index according to the acquired information; and determining an available random access preamble sequence set of the target cell according to the cyclic shift interval, the calculated initial logical root sequence number and the initial cyclic shift index, wherein random access preamble sequences generated from the same logical root sequence number exist in the available random access preamble sequence set corresponding to the indexes of at least two continuous random access preamble sequence sets.

Optionally, the step of calculating the starting logical root sequence number and the starting cyclic shift index according to the obtained information includes: calculating the number of random access leader sequences which can be generated by a logic root sequence number according to the length of the ZC sequence and the cyclic shift interval; calculating the initial logical root sequence number according to the logical root sequence number, the random access leader sequence set index number and the calculated random access leader sequence number; and calculating the initial cyclic shift index according to the random access leader sequence set index number and the calculated number of the random access leader sequences.

Optionally, the step of determining the set of available random access preamble sequences of the target cell includes: determining an initial physical root sequence number corresponding to the initial logical root sequence number according to the corresponding relation between the logical root sequence number and the physical root sequence number; generating and selecting random access preamble sequences with cyclic shift quantity larger than or equal to the product of the initial cyclic shift index and the cyclic shift interval and the number of the random access preamble sequences being a predetermined number according to the initial physical root sequence number, wherein when the number of the random access preamble sequences with the cyclic shift quantity larger than or equal to the product of the initial cyclic shift index and the cyclic shift interval generated according to the initial physical root sequence number is smaller than the predetermined number, the logical root sequence number is increased by 1, in the random access preamble sequences corresponding to the logical root sequence number after the 1 is increased, the random access preamble sequences are sequentially selected from the random access preamble sequence with the smallest cyclic shift index according to the sequence of the cyclic shift indexes from small to large and are expanded into the selected random access preamble sequence, and the operation of increasing the logical root sequence number by 1 and selecting the random access preamble sequences is repeatedly executed, until the number of the selected random access preamble sequences reaches the predetermined number.

According to another exemplary embodiment of the present disclosure, there is provided a data transmission method including: receiving scheduling information of a base station; judging whether the resources indicated by the scheduling information of the base station comprise resources at least overlapped with the cyclic prefix of the random access leader sequence or the random access leader sequence; acquiring indication information indicating whether data transmission on the overlapping resources is allowed; and when the judgment result is that the overlapped resources exist and the indication information indicates that the data transmission on the overlapped resources is allowed, the data is transmitted on the overlapped resources, and when the judgment result is that the overlapped resources exist and the indication information indicates that the data transmission on the overlapped resources is not allowed, the overlapped resources are avoided when the data is transmitted, wherein the subcarrier interval corresponding to the random access preamble sequence is equal to or less than 1KHz, and at least the cyclic prefix of the random access preamble sequence or the random access preamble sequence is positioned in the previous transmission period of the transmission period in which the random access preamble sequence is positioned.

According to another exemplary embodiment of the present disclosure, a system is provided comprising at least one computing device and at least one storage device storing instructions, wherein the instructions, when executed by the at least one computing device, cause the at least one computing device to perform the method as described above.

According to another exemplary embodiment of the present disclosure, a computer-readable storage medium storing instructions is provided, wherein the instructions, when executed by at least one computing device, cause the at least one computing device to perform the method as described above.

According to another exemplary embodiment of the present disclosure, there is provided a random access preamble sequence allocating apparatus including: an interference strength judging unit, configured to judge whether an interference strength between adjacent cells is greater than a strength threshold; and an index number allocation unit, configured to allocate, when greater than an intensity threshold, the same ZC sequence length, cyclic shift interval, and logical root sequence number and different and consecutive random access preamble sequence set index numbers to each of the adjacent cells, where the ZC sequence length, cyclic shift interval, logical root sequence number, and random access preamble sequence set index numbers are used to determine an available random access preamble sequence set for each cell, and there are random access preamble sequences generated from the same logical root sequence number in available random access preamble sequence sets corresponding to at least two consecutive random access preamble sequence set index numbers.

Optionally, the subcarrier spacing is higher than 1KHz and lower than 1.25KHz, and the sum of the lengths of the following items is 1 ms: the preamble sequence comprises a front guard interval of the random access preamble sequence, a cyclic prefix of the random access preamble sequence, a rear guard interval of the random access preamble sequence, and a cyclic prefix of a first OFDM symbol of a transmission period subsequent to a transmission period in which the random access preamble sequence is located.

Optionally, the length of the back guard interval is zero, and the cyclic prefix of the first OFDM symbol of the next transmission period of the transmission period in which the random access preamble sequence is located plays a role of the back guard interval of the random access preamble sequence, or the length of the front guard interval is equal to the length of the cyclic prefix of the random access preamble sequence, and a difference between a sum of the lengths of the back guard interval and the cyclic prefix of the first OFDM symbol and the length of the cyclic prefix of the random access preamble sequence is less than or equal to 2Ts, or the length of the front guard interval is zero, and a difference between the length of the back guard interval and the cyclic prefix of the random access preamble sequence is less than or equal to 2 Ts.

According to another exemplary embodiment of the present disclosure, there is provided a random access preamble sequence determination device including: an information acquisition unit, configured to acquire information of a target cell, where the information includes a ZC sequence length, a logical root sequence number, a random access preamble sequence set index number, and a cyclic shift interval; the calculation unit is used for calculating the initial logic root sequence number and the initial cyclic shift index according to the acquired information; and a random access preamble sequence set determining unit, configured to determine an available random access preamble sequence set of the target cell according to the cyclic shift interval, the calculated initial logical root sequence number, and the initial cyclic shift index, where random access preamble sequences generated from the same logical root sequence number exist in available random access preamble sequence sets corresponding to at least two consecutive random access preamble sequence set index numbers.

Optionally, the calculating unit calculates the number of random access preamble sequences that can be generated by one logical root sequence number according to the ZC sequence length and the cyclic shift interval; calculating the initial logical root sequence number according to the logical root sequence number, the random access leader sequence set index number and the calculated random access leader sequence number; and calculating the initial cyclic shift index according to the random access leader sequence set index number and the calculated number of the random access leader sequences.

Optionally, the random access preamble sequence set determining unit determines an initial physical root sequence number corresponding to the initial logical root sequence number according to a correspondence between the logical root sequence number and the physical root sequence number; generating and selecting random access preamble sequences with cyclic shift quantity larger than or equal to the product of the initial cyclic shift index and the cyclic shift interval and the number of the random access preamble sequences being a predetermined number according to the initial physical root sequence number, wherein when the number of the random access preamble sequences with the cyclic shift quantity larger than or equal to the product of the initial cyclic shift index and the cyclic shift interval generated according to the initial physical root sequence number is smaller than the predetermined number, the logical root sequence number is increased by 1, in the random access preamble sequences corresponding to the logical root sequence number after the 1 is increased, the random access preamble sequences are sequentially selected from the random access preamble sequence with the smallest cyclic shift index according to the sequence of the cyclic shift indexes from small to large and are expanded into the selected random access preamble sequence, and the operation of increasing the logical root sequence number by 1 and selecting the random access preamble sequences is repeatedly executed, until the number of the selected random access preamble sequences reaches the preset number.

According to another exemplary embodiment of the present disclosure, there is provided a data transmission apparatus including: a scheduling information receiving unit for receiving scheduling information of a base station; a judging unit, configured to judge whether a resource indicated by the scheduling information of the base station includes a resource that overlaps with at least a cyclic prefix of a random access preamble sequence or the random access preamble sequence; an indication information acquisition unit configured to acquire indication information indicating whether transmission of data on the overlapping resource is permitted; and a data transmission unit, configured to transmit data on the overlapping resource when the result of the determination indicates that the overlapping resource exists and the indication information indicates that the data is allowed to be transmitted on the overlapping resource, and avoid the overlapping resource when the result of the determination indicates that the overlapping resource exists and the indication information indicates that the data is not allowed to be transmitted on the overlapping resource, wherein a subcarrier interval corresponding to the random access preamble sequence is equal to or less than 1KHz, and at least a cyclic prefix of the random access preamble sequence or the random access preamble sequence is located in a transmission period before a transmission period in which the random access preamble sequence is located.

According to another exemplary embodiment of the present disclosure, there is provided a physical random access channel including: random access leader sequence and cyclic prefix of the random access leader sequence, wherein the subcarrier interval corresponding to the random access leader sequence is lower than 1.25 KHz.

Optionally, the subcarrier spacing is equal to 1KHz, the physical random access channel further includes a pre-guard interval, and the pre-guard interval and a cyclic prefix of the random access preamble sequence are located in a previous transmission period of a transmission period in which the random access preamble sequence is located.

Optionally, the subcarrier spacing is higher than 1KHz and lower than 1.25KHz, the physical random access channel further includes a front guard interval and a rear guard interval, and a sum of lengths of the following items is 1 ms: a front guard interval, a cyclic prefix of a random access leader sequence, a random access leader sequence and a rear guard interval.

According to the exemplary embodiments of the present disclosure, when the subcarrier spacing corresponding to the random access preamble sequence is lower than 1.25KHz, the length of the random access preamble sequence may be increased, and the number of orthogonal random access preamble sequences may also be increased, thereby improving the detection success rate of the random access preamble sequence. According to another exemplary embodiment of the present disclosure, random access preamble sequences generated from the same logical root sequence number exist in available random access preamble sequence sets corresponding to consecutive at least two random access preamble sequence set indices, so that the number of orthogonal random access preamble sequences can also be increased. According to the method and the device, when downlink signal transmission is carried out on the random access resources, the interference of the random access preamble sequence from the random access preamble sequence of the cell, the random access preamble sequence of the adjacent cell and the downlink signal of the adjacent cell on the random access preamble sequence can be reduced, the interference of the random access preamble sequence on the uplink and downlink data transmission of the cell can be reduced, and the success rate of the random access of the terminal can be improved.

Additional aspects and/or advantages of the present general inventive concept will be set forth in part in the description which follows and, in part, will be obvious from the description, or may be learned by practice of the general inventive concept.

Drawings

The above and other objects and features of the exemplary embodiments of the present disclosure will become more apparent from the following description taken in conjunction with the accompanying drawings which illustrate exemplary embodiments, wherein:

fig. 1 shows a schematic diagram of at least a portion of a frame comprising a random access preamble sequence according to an example embodiment of the present disclosure;

fig. 2 shows a schematic diagram of a physical random access channel according to an example embodiment of the present disclosure;

fig. 3 to 5 show diagrams of interference caused by resource overlap according to exemplary embodiments of the present disclosure;

fig. 6 shows a flow chart of a data transmission method according to an example embodiment of the present disclosure;

fig. 7 illustrates a flowchart of a random access preamble sequence allocation method according to an exemplary embodiment of the present disclosure;

fig. 8 illustrates a diagram of assigning random access preamble sequence set index numbers according to an exemplary embodiment of the present disclosure;

fig. 9 shows a schematic diagram of a random access preamble sequence interference situation between cells according to an example embodiment of the present disclosure;

fig. 10 illustrates a schematic diagram of an exemplary suppression of inter-cell interference according to the present disclosure;

fig. 11 illustrates a flowchart of a random access preamble sequence determination method according to an exemplary embodiment of the present disclosure;

fig. 12 shows a schematic diagram of grouping random access preamble sequences according to an example embodiment of the present disclosure;

fig. 13 shows a block diagram of a data transmission device according to an example embodiment of the present disclosure;

fig. 14 illustrates a block diagram of a random access preamble sequence allocating apparatus according to an exemplary embodiment of the present disclosure;

fig. 15 illustrates a block diagram of an apparatus for determining a random access preamble sequence according to an exemplary embodiment of the present disclosure.

Detailed Description

Reference will now be made in detail to the embodiments of the present disclosure, examples of which are illustrated in the accompanying drawings, wherein like reference numerals refer to the like elements throughout. The embodiments are described below in order to explain the present disclosure by referring to the figures.

According to an example embodiment of the present disclosure, there is provided a physical random access channel that may include a random access preamble sequence and a cyclic prefix of the random access preamble sequence, wherein a subcarrier spacing corresponding to the random access preamble sequence is below 1.25KHz (kilohertz).

For a typical physical random access channel, the subcarrier spacing is equal to 1.25 KHz. According to the physical random access channel of the exemplary embodiment of the present disclosure, the subcarrier spacing is lower than 1.25KHz, that is: the subcarrier spacing is reduced. Since the reciprocal of the subcarrier spacing is the length of the random access preamble sequence, the length of the random access preamble sequence is increased. Increasing the length of the random access leader sequence increases the probability of identifying the random access leader sequence, thereby increasing the success rate of random access by using the random access leader sequence.

The Physical Random Access Channel according to the exemplary embodiment of the present disclosure is suitable for a full-duplex system, and supports an adjacent cell to transmit a longer Random Access preamble sequence on the same Physical Random Access Channel (PRACH) resource, thereby improving the resource utilization rate and the Random Access success rate.

As an example, the subcarrier spacing may be equal to 1 KHz. In this case, as described below with reference to fig. 1, the physical random access channel further includes a pre-guard interval, and the pre-guard interval and a cyclic prefix of the random access preamble sequence are located in a previous transmission period of a transmission period in which the random access preamble sequence is located.

As an example, the subcarrier spacing may be higher than 1KHz and lower than 1.25 KHz. In this case, as described below with reference to fig. 2, the physical random access channel further includes a pre-guard interval and a post-guard interval, and the sum of the lengths of the following items is 1ms or 30720 Ts: pre guard interval, pre random accessA cyclic prefix of the preamble sequence, a random access preamble sequence, and a postguard interval. Here, 1Ts represents 1/(30.72X 10)⁶) And second.

According to another exemplary embodiment of the present disclosure, there may be provided a random access preamble sequence allocation method, including: and setting a random access preamble sequence, wherein the subcarrier interval corresponding to the set random access preamble sequence is lower than 1.25 KHz. The features of the random access preamble sequence may be implemented with reference to the above exemplary embodiments. The random access preamble sequence allocation method may be performed by a network layer for parameter allocation.

More specifically, the embodiment shown in FIG. 2 may include one of the following: the length of the front guard interval is equal to the length of the cyclic prefix of the random access preamble sequence, and the length of the rear guard interval is zero; the length of the front guard interval is equal to the length of the cyclic prefix of the random access preamble sequence, and the difference between the sum of the length of the cyclic prefix of the first OFDM symbol of the next transmission period of the transmission period in which the rear guard interval and the random access preamble sequence are located and the length of the cyclic prefix of the random access preamble sequence is less than or equal to 2Ts (e.g., 0 Ts); the length of the post-guard interval is equal to the length of the cyclic prefix of the random access preamble sequence. When the length of the back guard interval is zero, the cyclic prefix of the first OFDM symbol of the next transmission period of the transmission period in which the random access preamble sequence is positioned plays a role of the back guard interval of the random access preamble sequence.

A specific structure of a physical random access channel according to an exemplary embodiment of the present disclosure is described in detail below.

Fig. 1 shows a schematic diagram of at least a portion of a frame including a random access preamble sequence according to an example embodiment of the present disclosure. In fig. 1, the abscissa represents time (time domain) and the ordinate represents frequency (frequency domain). A physical random access channel according to an exemplary embodiment of the present disclosure is included in fig. 1, and the physical random access channel included in fig. 1 is at least suitable for random access of a small cell, for example, suitable for a cell having a smaller radius than the small cell.

As shown in fig. 1, the transmission period may be 1 millisecond (abbreviated ms), the CP is a cyclic prefix of a random access preamble sequence, a guard band may be set in a frequency domain, and a guard interval may be set in a time domain. The structural parameters of the physical random access channel according to the exemplary embodiment of the present disclosure are shown in table 1 below.

TABLE 1

The structural parameters of PRACH of the exemplary embodiments of the present disclosure are explained below with reference to table 1:

(1) resource bandwidth of PRACH

In order to ensure that sufficient resources allocated to the user for random access still exist under the condition of the minimum system bandwidth, similar to a Long Term Evolution (LTE)/New Radio (NR) system, the bandwidth of the PRACH resource (i.e., the resource bandwidth of the PRACH) carrying the random access preamble sequence is still designed to be 1.08MHz (megahertz).

(2) Subcarrier spacing and random access preamble sequence length

The cyclic prefix on an Orthogonal Frequency Division Multiplexing (OFDM) symbol of conventional data (e.g., the data in fig. 1) is typically 5 μ s (microseconds). The length of the postguard interval may be made zero and the cyclic prefix of the first OFDM symbol in the next transmission period of the transmission period in which the random access preamble sequence is transmitted is made to function as the postguard interval of the random access preamble sequence. As an example, the latter half of the last OFDM symbol in the former transmission period of the transmission period for transmitting the random access preamble sequence may also be used for transmitting the cyclic prefix of the random access preamble sequence and the former half of the last OFDM symbol may also be used as the front guard interval. By using the frame structure shown in fig. 1 for random access, the coverage radius can be at least 700m (meters) and even 750m, so that the coverage requirement of a small cell with a radius of 500m or a cell with a smaller radius than the small cell can be satisfied.

Therefore, according to the random access preamble sequence of the exemplary embodiment of the present disclosure, the random access preamble sequence guard interval in the LTE system or the NR system may not be reserved in a transmission period in which the random access preamble sequence is transmitted, so that a longer time domain range may be reserved for the random access preamble sequence. Since the longer the random access preamble sequence, the more easily it is detected, the random access preamble sequence according to the exemplary embodiment of the present disclosure may be more easily detected.

In addition, there is orthogonality between the subcarrier spacing of the normal data and the subcarrier spacing of the random access preamble sequence, that is, the subcarrier spacing Δ f of the normal data_dataSubcarrier spacing from random access preamble sequence Δ f_preambleSatisfies the following conditions: Δ f_data＝K×Δf_preambleWhere K is a positive integer and the subcarrier spacing is Δ f_preambleFor random access of preamble sequence length T_SEQInverse of (e.g. when random access preamble sequence length T_SEQAt 1ms, the subcarrier spacing Δ f_preambleIs 1 kHz.

(3) Length and position of cyclic prefix

Setting the cyclic prefix is an effective means to combat the effects of multipath, and the cyclic prefix should be preserved regardless of the cell radius and at least as long as the maximum delay spread of the spatial propagation channel.

In order to maximize the detection capability of the random access preamble sequence, the length of the random access preamble sequence may be designed to be 1 ms. As shown in fig. 1, the length of the cyclic prefix of the random access preamble sequence may be designed to be 0.5 normal OFDM symbols and disposed at the latter half of the last symbol of the transmission period preceding the transmission period in which the random access preamble sequence is transmitted, the former half of the last symbol being used as a guard interval.

(4) Guard band and ZC (Zadoff-Chu, abbreviated as ZC) sequence length in frequency domain

In order to distinguish the random access preamble sequence from the normal data or other data and protect the random access preamble sequence, a guard band designed in the LTE system or the NR system, a ZC sequence length N, may be used_ZCIt may be designed to be greater than 839,e.g. N_ZC1049, the ZC sequence length of this embodiment can be increased by at least 25% as compared with the ZC sequence of length 839 in the LTE system or the NR system, and accordingly, the detection performance can be improved by at least 10% in theory.

As described above, the cyclic prefix of the random access preamble sequence may be located in the last OFDM symbol of the transmission period before the transmission period in which the random access preamble sequence is located, a part of the last OFDM symbol before the time is used as the pre-guard interval of the random access preamble sequence, and the rest of the last OFDM symbol is the cyclic prefix.

It should be understood that the above description has been made only for convenience of illustrating the present disclosure, and is not intended to limit the scope of the present disclosure, and the physical random access channel may be set in various ways in the case where the subcarrier spacing corresponding to the random access preamble sequence is made lower than 1.25 KHz.

Fig. 2 illustrates a schematic diagram of a physical random access channel according to an exemplary embodiment of the present disclosure. As shown in fig. 2, a physical random access channel according to an exemplary embodiment of the present disclosure may include a front guard interval G1, a rear guard interval G2, a cyclic prefix CP, and a random access preamble sequence, wherein a subcarrier spacing corresponding to the random access preamble sequence is higher than 1KHz and lower than 1.25 KHz.

Table 2 shows six configurations of a physical random access channel in the case where the subcarrier spacing corresponding to the random access preamble sequence is higher than 1KHz and lower than 1.25 KHz.

TABLE 2

In six configurations, configuration 0to configuration 5, the sum of the length of the random access preamble sequence, the length of the cyclic prefix of the random access preamble sequence, the length of the front guard interval, and the length of the rear guard interval is a specific value (e.g., 30720 Ts). When the length of the random access preamble sequence is determined, the length of each of the cyclic prefix, the pre-guard interval, and the post-guard interval may be flexibly allocated according to actual needs. The lengths of at least two of the cyclic prefix, the pre-guard interval, and the post-guard interval may be broadcast in the cell by way of a broadcast.

Referring to table 2, in configurations 0 and 3, a difference between a length of a cyclic prefix of the random access preamble sequence and a length of a pre-guard interval is less than or equal to 2Ts (e.g., 0Ts), and a length of a post-guard interval is zero, in which case the cyclic prefix of a first OFDM symbol of a transmission period next to the transmission period in which the random access preamble sequence is located may be made to function as the post-guard interval of the random access preamble sequence. Thus, the set PRACH may not include the post-guard interval but include the pre-guard interval and the cyclic prefix of the random access preamble sequence, and the time domain length of the pre-guard interval is equal to the time domain length of the cyclic prefix of the random access preamble sequence. Configuration 0 and configuration 3 are applicable to scenarios where the cell radius is small (e.g., less than 500 m).

In configurations 1 and 4, the PRACH may include a pre-guard interval, a cyclic prefix of the random access preamble sequence, and a post-guard interval, a difference between a length of the pre-guard interval and a length of the cyclic prefix of the random access preamble sequence being less than or equal to 2Ts (e.g., 0Ts), and a difference between a sum of the post-guard interval and a length of the cyclic prefix of the first OFDM symbol and a length of the cyclic prefix of the random access preamble sequence being less than or equal to 2Ts (e.g., 0 Ts). Configuration 1 and configuration 4 are applicable in scenarios where the cell radius is slightly larger (e.g., larger than the radius of the cell for which configuration 0 or configuration 3 is applicable).

In configurations 2 and 5, the PRACH may not include a pre-guard interval (i.e., the length of the pre-guard interval is zero), and the difference between the length of the post-guard interval and the length of the cyclic prefix of the random access preamble sequence is less than or equal to 2Ts (e.g., 0Ts), which is applicable to a scenario in which the cell radius is larger (e.g., larger than the radius of the cell to which configurations 1 and 4 are applicable).

In an exemplary embodiment of the present disclosure, various PRACH are provided. When random access is carried out, the access can be carried out by utilizing the method and the flow in the existing LTE system or NR system.

In addition, when using the PRACH according to the exemplary embodiments of the present disclosure, interference issues also need to be considered.

Specifically, for example, in the exemplary embodiment shown in fig. 1, the cyclic prefix of the random access preamble sequence is located in a previous transmission period of the transmission period for transmitting the random access preamble sequence, and when the base station schedules other terminals for uplink and downlink data transmission in the previous transmission period, there may be resource overlap between data of a last OFDM symbol in the previous transmission period and the cyclic prefix of the random access preamble sequence. When there is resource overlap, uplink and downlink data transmission will be interfered by the cyclic prefix of the random access preamble sequence. The interference situation when there is resource overlap is described below with reference to fig. 3 to 5.

In fig. 3, a terminal 1 is a terminal to be accessed, a terminal 2 is a terminal that receives downlink data from a base station, and a terminal 3 is a terminal that transmits uplink data to the base station.

Referring to fig. 3 and 4, if resources scheduled to terminals (e.g., terminal 2 and terminal 3) that have accessed are on the previous transmission cycle of PRACH resources (resources transmitting a random access preamble sequence) for random access and overlap with the PRACH resources in the frequency domain when accepting base station scheduling, corresponding processing needs to be performed.

As shown in fig. 4, in the uplink data transmission, uplink data 1 and uplink data 2 are transmitted through a subframe n, and the uplink data 2 occupies one OFDM symbol. In the random access preamble sequence transmission process, a part of the cyclic prefix CP of the random access preamble sequence is also transmitted through the subframe n, and even a pre-guard interval G and a part of the cyclic prefix CP of the random access preamble sequence are transmitted through the subframe n, wherein the pre-guard interval G and the cyclic prefix occupy one OFDM symbol. In this case, there is an overlap in time between a part of the rear of the uplink data 2 and the cyclic prefix of the random access preamble sequence, so that the uplink data is subject to cyclic prefix interference.

Specifically, when the base station starts to transmit the last OFDM symbol of the subframe n at time t, where t is a one-way delay, the base station starts to transmit the last OFDM symbol of the subframe n at time tt from the perspective of the terminal due to the two-way delay. In this case, the terminal does not know how much time is ahead of time for which the signal transmission should be performed because the uplink synchronization is not performed. In this case, the random access preamble sequence is selected to start to be transmitted at time tt, and since the transmitted random access preamble sequence still needs to pass through a single-pass delay with length t to reach the base station, from the perspective of the base station, the terminal starts to transmit the random access preamble sequence at time t2t, in which case, as shown in fig. 4, the two-pass delay is 2 t. When the length of the two-way delay cannot make the transmission of the uplink data 2 avoid being interfered, a corresponding process, for example, the process shown in fig. 6, needs to be performed.

As shown in fig. 5, there may be interference during data transmission or random access preamble sequence transmission through subframe n. For example, the base station may perform downlink data transmission, and during the downlink data transmission, the last OFDM symbol, the second to last OFDM symbol, and other symbols before the second to last OFDM symbol may be used. In the process of receiving downlink data by the accessed terminal, the last OFDM symbol, the second to last OFDM symbol and other symbols before the second to last OFDM symbol can be used. The accessed terminal not only receives downlink data from the base station but also may passively receive the random access preamble sequence from other terminals, which causes the same accessed terminal to have a process of receiving downlink data and a process of receiving the random access preamble sequence. During the process of receiving the random access preamble sequence by the accessed terminal, according to the relative delay and the one-way delay, the transmission of the random access preamble sequence may cause interference to the accessed terminal for transmitting downlink data using the last OFDM symbol or for transmitting downlink data using the last OFDM symbol and the second to last OFDM symbol.

Referring to fig. 3 and 5, the base station transmits the maximum of subframe n at time tDownlink data on the latter OFDM symbol, the last OFDM symbol passing through t₁After time terminal 2, i.e. terminal 2 from tt₁Starting to receive the downlink data at the moment; the terminal 1 transmits a random access preamble sequence at time tt, which may be after t₂Time later, terminal 2 arrives, and therefore terminal 2 is at tt₂The random access preamble sequence of the passive reception terminal 1 starts at the moment.

Relative time delay of t₂-t₁If t is₂＜t₁I.e. the distance between terminal 1 and terminal 2 is shorter than the distance between the base station and terminal 2, the cyclic prefix of the random access preamble sequence reaches terminal 2 earlier than the downlink data carried by the last OFDM symbol, in which case the transmission of the downlink data on the second last OFDM symbol may be interfered.

That is, since the distance between the terminal to be accessed and the terminal that has been accessed is unknown, for the accessed terminal that receives downlink data in the transmission period preceding the period of transmitting the random access preamble sequence, although the base station may configure the accessed terminal not to receive data on the last symbol, the downlink data of the penultimate OFDM symbol of the accessed terminal may be interfered by the passively received cyclic prefix of the random access preamble sequence. For example, if the distance between terminal 2 receiving downlink data and the base station in fig. 3 is greater than the distance between the terminal and terminal 1 to be accessed, and terminal 2 is in the coverage of terminal 1, then not only will the downlink data on the last OFDM symbol for terminal 2 be interfered by the cyclic prefix of the random access preamble sequence sent by terminal 1, but also the downlink data on the second last OFDM symbol will be interfered by the cyclic prefix of the random access preamble sequence, i.e. the situation shown in fig. 5.

In an exemplary embodiment of the present disclosure, when a pre-guard interval is set before a cyclic prefix, interference of the cyclic prefix of the random access preamble sequence with downlink data on the second to last OFDM symbol may be prevented.

In order to solve the interference problem caused by resource overlapping, for example, interference of the cyclic prefix of the random access preamble sequence to downlink data on the last OFDM symbol, the accessed terminal may also indicate whether to transmit or receive data on the resource overlapping with the cyclic prefix of the random access preamble sequence according to the overlapping resource transceiving data indication information given by the base station. If the base station indicates that data cannot be transmitted or received on the overlapping resources, the terminal avoids the overlapping resources when transmitting or receiving data, and conversely, if the base station indicates that data can be transmitted or received on the overlapping resources, the terminal does not need to avoid the overlapping resources when transmitting or receiving data. Here, the overlapping resources may mean resources in which there is an overlap in both time and frequency domains.

Referring to a flowchart of a data transmission method according to an exemplary embodiment of the present disclosure shown in fig. 6, a terminal may perform the following operations: in step S110, receiving scheduling information of a base station; in step S120, it is determined whether the resources indicated by the scheduling information of the base station include resources that at least overlap with the cyclic prefix of the random access preamble sequence or the random access preamble sequence (e.g., resources that overlap with the cyclic prefix and the random access preamble sequence, etc.); at step S130, acquiring indication information indicating whether data transmission on the overlapping resource is allowed; in step S140, when the result of the judgment indicates that there is an overlapping resource and the indication information indicates that data transmission on the overlapping resource is allowed, transmitting data on the overlapping resource, and when the result of the judgment indicates that there is an overlapping resource and the indication information indicates that data transmission on the overlapping resource is not allowed, avoiding the overlapping resource when transmitting data, wherein a subcarrier spacing corresponding to a random access preamble sequence is equal to or less than 1KHz, at least a cyclic prefix of the random access preamble sequence or the random access preamble sequence is located in a transmission period before a transmission period in which the random access preamble sequence is located. In addition, the resource that the base station received by the terminal schedules for the terminal may not be in the previous transmission period of the random access preamble sequence, or even in the previous transmission period, the frequency domain resource may be different from the frequency domain resource occupied by the cyclic prefix of the random access preamble sequence, and there is no overlapping resource in these two cases. If the overlapped resources do not exist, the indication information is invalid indication information, and at this time, data transmission can be carried out without the indication information.

The indication information may be sent or notified in various manners, for example, the indication information may be transmitted by using 1 bit in the downlink Control information corresponding to the current scheduling, may be notified to the terminal in the cell in a system information broadcast manner, and may also be notified to the terminal when the terminal performs Radio Resource Control (RRC) connection.

According to an exemplary embodiment of the present disclosure, if the radius of a cell is relatively small, such as the radius is less than or equal to 500m (the radius of a small cell), a scheme that neighbor cells share a logical root sequence number may be adopted to at least partially eliminate interference between neighbor cells due to a random access preamble sequence.

Fig. 7 illustrates a flowchart of a random access preamble sequence allocation method for reducing inter-cell interference, which may be performed by a network layer for parameter allocation, according to an exemplary embodiment of the present disclosure. As shown in fig. 7, the random access preamble sequence allocation method according to an exemplary embodiment of the present disclosure includes: s210, judging whether the interference strength between adjacent cells is greater than a strength threshold value; and S220, when the strength threshold is greater than the strength threshold, allocating the same ZC sequence length, cyclic shift interval, and logical root sequence number and different and consecutive random access preamble sequence set indices (that is, the random access preamble sequence set indices of the adjacent cells are different and consecutive) to each of the adjacent cells, where the ZC sequence length, cyclic shift interval, logical root sequence number, and random access preamble sequence set indices are used to determine an available random access preamble sequence set for each cell, and there are random access preamble sequences generated from the same logical root sequence number in random access preamble sequences corresponding to at least two consecutive random access preamble sequence set indices. Here, any two random access preamble sequences among the respective random access preamble sequences generated from the same logical root sequence number are orthogonal.

In addition, when the interference strength is lower than the strength threshold, any two cells are allocated according to one of the following modes: the logical root sequence numbers are different from each other and the random access preamble sequence set index numbers are different from each other, and the logical root sequence numbers are different from each other and the random access preamble sequence set index numbers are different from each other. For the length of the ZC sequence and the cyclic shift interval, if the logical root sequences are the same in number (i.e. the random access preamble sequence set indexes are different from each other), the length of the ZC sequence is the same and the cyclic shift interval is also the same; if the logical root sequence numbers are different from each other (i.e., the random access preamble sequence set indices may be the same or different from each other), the ZC sequences of the two cells may be the same in length and the cyclic shift intervals may be the same.

As an example, the cyclic shift index sequence may be generated according to the following steps, wherein the cyclic shift index sequence does not need to be actually generated, i.e. only one virtual sequence: calculating the number of random access leader sequences which can be generated by a logic root sequence number according to the length of the ZC sequence and the cyclic shift interval, wherein the calculated number of the random access leader sequences is more than the number of available random access leader sequences of a cell; according to the logic root sequence number, generating cyclic shift indexes with the number of the calculated random access leader sequences; adding 1 to the logical root sequence number, and generating cyclic shift indexes, the number of which is the calculated number of the random access preamble sequences, according to the logical root sequence number after the 1 is added, wherein the step (the step of adding 1 to the logical root sequence number and generating the cyclic shift indexes according to the logical root sequence number after the 1 is added) is executed at least once; the generated cyclic shift indexes are arranged in a predetermined order to generate a cyclic shift index sequence, for example, the cyclic shift indexes generated each time the above steps are performed are arranged in a descending order, and the cyclic shift index generated by the previous execution of the above steps is arranged before the cyclic shift index generated by the next execution of the above steps.

As an example, the step of assigning the random access preamble sequence set index number includes: dividing the cyclic shift index sequence into a plurality of sets according to the number of the available random access leader sequences, wherein each set corresponds to a unique random access leader sequence set index number; allocating a different random access preamble sequence set index number to each of the at least two neighboring cells.

For small cells with radius of 500m or similar cells, the cyclic shift interval N of the random access preamble sequence_CSIt is only necessary to be 9 or more. In this case, there may be 116 random access preamble sequences that can be generated by one physical root sequence number. In the present exemplary embodiment, the number of available random access preamble sequences per cell may be set to 64.

Unlike the LTE system and the NR system, neighboring cells may share the same cyclic shift interval N_CSAnd the same logical root sequence number (since the logical root sequence number corresponds to the physical root sequence number, the same physical root sequence number is shared by adjacent cells), and a unique random access preamble sequence set index number is allocated to each cell.

Specifically, the cyclic shift interval of the random access preamble sequence may be set to N_CSA random access preamble sequence allocation method according to an exemplary embodiment of the present disclosure is described in conjunction with fig. 8 as 9.

Referring to fig. 8, at least two neighboring cells share a cyclic shift interval N_CSThe same logical root sequence number is also shared 9. Can pass through

To calculate the number N of random access preamble sequences that can be generated by a logical root sequence number, wherein N is_ZCThe length of the ZC sequence is indicated,

meaning rounding down, for example, the number of random access preamble sequences N that can be generated by obtaining one logical root sequence number by calculation under a given ZC sequence length is 116.

In case of ZC sequence length, logical root sequence number and cyclic shift interval determination, a cyclic shift index vector may be defined

The vector is illustrated only for convenience of description, and may not be actually generated, wherein,

a cyclic shift index indicating the logical root sequence number L and having a value of 0, and a corresponding cyclic shift amount

A cyclic shift index having a value of 1 indicating the logical root sequence number L, and a corresponding cyclic shift amount

And so on. If the random access preamble sequence transmitted by the terminal is generated according to the logical root sequence number L and the cyclic shift amount is

The terminal selects the cyclic shift index

0n＜N。

The logical root sequence number shared by the cells can be represented as L_sharedAccording to the logical root sequence number L_sharedEach element in the generated cyclic shift index vector (i.e.:

to

) The values of the logical root sequence numbers are arranged in the order from small to large. Subsequently, the logical root sequence number is increased by 1, the corresponding cyclic shift index is generated and arranged (for example, the arrangement described in the exemplary embodiment of the present disclosure), and such an operation is performed at least once. Subsequently, a cyclic shift index sequence shown in fig. 8 is formed.

Due to the available random access preamble sequences of each cellThe number is set to 64, so the first 64 of the cyclic shift index sequences can be defined as set 0, and allocated to the cell with the index number of the random access preamble sequence set 0, i.e. the user in the cell with the index number of the random access preamble sequence set 0

Selecting a random access preamble sequence of the 64 cyclic shift indexes; defining 64 cyclic shift indexes behind the set 0 as a set 1, and allocating the cyclic shift indexes to a cell with the index number of a random access preamble sequence set 1, namely, users in the cell with the index number of the random access preamble sequence set 1 are in

Selecting a random access preamble sequence of the 64 cyclic shift indexes; defining 64 cyclic shift indexes behind the set 1 as a set 2, and allocating the cyclic shift indexes to a cell with the random access preamble sequence set index number of 2, namely, users in the cell with the random access preamble sequence set index number of 2 are in the cell

Selecting a random access preamble sequence of the 64 cyclic shift indexes; and so on.

As can be seen from this, according to the random access preamble sequence allocation method of the exemplary embodiment of the present disclosure, of the random access preamble sequence of each cell and the random access preamble sequence of at least one cell adjacent to the each cell, at least a part of the random access preamble sequences exists that are generated from the same logical root sequence number, so that the part of the random access preamble sequences that are smaller than each other and the part of the random access preamble sequences of the at least one cell are orthogonal to each other. The degree of interference between orthogonal random access preamble sequences is lower than that between non-orthogonal random access preamble sequences, thereby reducing the mutual interference between random access preamble sequences between adjacent cells.

In the exemplary embodiment of the present disclosure, the number of the random access preamble sequences is set to 64, which is not intended to limit the scope of the present disclosure, and any predetermined number of random access preamble sequences is possible.

Fig. 9 shows a schematic diagram of a random access preamble sequence interference situation between cells according to an example embodiment of the present disclosure.

As shown in fig. 9, cell C1 of base station B1 and cell C2 of base station B2 are adjacent, terminal a is in cell C1, and terminal B and terminal C are in cell C2. According to the logical root sequence number allocation scheme of the existing LTE system or NR system, the cell C1 and the cell C2 are allocated with different logical root sequence numbers. Terminals in both cells may transmit random access preamble sequences on the same PRACH resource for the sake of reducing system overhead. In this case, depending on the nature of the ZC sequence, no matter what cyclic shift index is selected as the random access preamble sequence in the two cells, there is no possibility that the random access preamble sequence of cell C1 is orthogonal to the random access preamble sequence of cell C2, resulting in interference generation, for example, when the base station B1 of cell 1 performs random access preamble sequence detection, there is energy of the random access preamble sequence from cell C2 (e.g., the random access preamble sequence from terminal B or terminal C) superimposed on background interference or noise of cell C1. Due to the small radius of these two cells, the energy superimposed on the background interference or noise of cell C1 may be of such a degree as to affect the detection of the random access preamble sequence of terminal a. In addition, a terminal failing in random access in cell C2 may raise the transmission power of the terminal in order to attempt re-access, which may also have an impact on random access preamble sequence detection in cell C1.

According to an exemplary embodiment of the present disclosure, it is assumed that cell C1 is allocated with random access preamble sequence set 0 in fig. 8, cell C2 is allocated with random access preamble sequence set 1, and terminal b selects

As a random access preamble sequence, terminal c selects

As a random access preamble sequence. In this case, since the random access preamble sequence of the terminal b and the random access preamble sequence of the terminal a are orthogonal, the influence on the random access preamble sequence detection of the terminal a is reduced.

In the exemplary embodiment of the present disclosure, features involved in the random access preamble sequence allocation and random access preamble sequence determination method may be similar to those described above for the PRACH, for example, a subcarrier interval corresponding to the random access preamble sequence may be lower than 1.25KHz, which is not described herein again.

In this case, referring to fig. 9, since the length of the random access preamble sequence increases, the influence on the random access preamble sequence detection of the terminal b is also reduced.

Fig. 10 illustrates an exemplary diagram of suppressing inter-cell interference according to the present disclosure. As shown in FIG. 10, when the base station B1 utilizes a logical root sequence number of L_sharedWhen detecting the root ZC sequence, the random access leader sequence correlation peak of the terminal b is the root sequence number L of the cell C1_sharedOutside the receiving window, the random access preamble sequence detection for the terminal a is not affected. Thus, inter-cell interference is at least partially eliminated.

In the present exemplary embodiment, when allocating the random access preamble sequence in the above manner, the random access preamble sequence may also be implemented according to the definition of the physical random access channel in the above embodiments, for example, the subcarrier spacing corresponding to the random access preamble sequence may be made lower than 1.25 KHz.

Corresponding to the random access preamble sequence allocation method, according to an exemplary embodiment of the present disclosure, when a terminal performs an access operation, a usable random access preamble sequence may be determined according to a random access preamble sequence allocation scheme of a cell (target cell) to be accessed by the terminal.

Fig. 11 illustrates a flowchart of a random access preamble sequence determination method according to an exemplary embodiment of the present disclosure. The random access preamble sequence determination method according to an exemplary embodiment of the present disclosure includes: s310, obtaining information of a target cell, including ZC sequence length, logic root sequence number, random access leader sequence set index number and cyclic shift interval; s320, calculating an initial logic root sequence number and an initial cyclic shift index according to the acquired information; s330, determining the available random access leader sequence of the target cell according to the cyclic shift interval, the calculated initial logical root sequence number and the initial cyclic shift index, wherein the random access leader sequences generated from the same logical root sequence number exist in the available random access leader sequence sets corresponding to the index numbers of at least two continuous random access leader sequence sets.

As an example, the step of calculating the starting logical root sequence number and the starting cyclic shift index from the acquired information includes: calculating the number of random access leader sequences which can be generated by a logic root sequence number according to the length of the ZC sequence and the cyclic shift interval; calculating the initial logical root sequence number according to the logical root sequence number, the random access leader sequence set index number and the calculated random access leader sequence number; and calculating the initial cyclic shift index according to the random access leader sequence set index number and the calculated number of the random access leader sequences.

As an example, the step of determining the available random access preamble sequence of the target cell comprises: determining an initial physical root sequence number corresponding to the initial logical root sequence number according to the corresponding relation between the logical root sequence number and the physical root sequence number; generating a cyclic shift index having a cyclic shift amount greater than or equal to a product of the starting cyclic shift index and the cyclic shift interval from the starting physical root sequence number to generate a cyclic shift index sequence; and selecting a random access preamble sequence from the cyclic shift index sequence as an available random access preamble sequence of the target cell, wherein when the number of cyclic shift indexes in the generated cyclic shift index sequence is less than 64, the logical root sequence number is increased by 1, in the random access preamble sequence corresponding to the logical root sequence number increased by 1, the random access preamble sequence is sequentially selected from the random access preamble sequence with the minimum cyclic shift index and expanded into the selected random access preamble sequence according to the sequence from the small cyclic shift index to the large cyclic shift index, and the operation of increasing the logical root sequence number by 1 and selecting the random access preamble sequence is repeatedly executed until the number of the selected random access preamble sequence reaches 64.

For example, when a terminal in a target cell monitors a broadcast signal of the target cell, it can be known through the broadcast signal that the logical root sequence number of the target cell is L_sharedThe random access leader sequence set index number is

And a cyclic shift interval of N_CS. The terminal can first calculate the number of random access preamble sequences that can be generated by a logical root sequence number as

Indicating a rounding down. Then, the terminal may determine that the starting logical root sequence number of the target cell is:

the starting cyclic shift index is:

wherein,

meaning rounding down, mod is a modulo operation.

In an exemplary embodiment of the present disclosure, PRACH resources may be designed, configured, and selected according to a method of designing, configuring, and selecting PRACH resources of an LTE system, an NR system, or other communication systems. In case that the terminal obtains PRACH resources for transmitting the random access preamble sequence, the random access preamble sequence available to the terminal may be determined according to the method described above, and then, the random access preamble sequence may be selected from the available random access preamble sequences and transmitted.

All random access preamble sequences may be zero-phasedThe ZC sequences of interest are generated and may be derived from one or more root ZC sequences. Each cell broadcasts the length N of the ZC sequence used in the cell_ZCLogical root sequence number L_sharedRandom access preamble sequence set index number

Cyclic shift interval N_CS。

In this case, the terminal may calculate the starting logical root sequence number L of the cell according to the method in the above embodiment_startAnd a starting cyclic shift index v_start. The terminal may map and initiate a logical root sequence number, L, according to tables 5.7.2-4 in the LTE 36.211 protocol_startOne-to-one initial physical root sequence number u_start. According to cyclic shift interval N_CSAnd a starting cyclic shift index v_startCan generate the initial physical root sequence number u_startAll corresponding cyclic shift amounts are greater than or equal to N_CS×v_startThe cyclic shift sequence of (1).

When starting the physical root sequence number u_startWhen the number of all available cyclic shift sequences is less than 64, the logical root sequence number is increased by 1, and the logical root sequence number L is increased_startIn all random access leader sequences corresponding to +1, the random access leader sequence with the minimum cyclic shift index is selected in sequence as the expansion of the random access leader sequence selectable in the cell, if the sequence number L is up to the logical root sequence number_startThe number of the available random access leader sequences in the cell can not reach 64 by the last cyclic shift of +1, and the number of the logic root sequences is increased by 1 to continue to expand the available random access leader sequences in the cell. And the like, until the terminal can obtain all 64 available random access preamble sequences of the cell. In addition, the ZC sequence logic root sequence number is cyclic, namely: in the mapping table of the logical root sequence number and the physical root sequence number, the logical root sequence number after the last logical root sequence number is increased by 1 is the first logical root sequence number in the mapping table.

The 64 random access preamble sequences are arranged in the order of increasing the cyclic shift index first and then increasing the number of logical root sequences. Fig. 12 shows a schematic diagram of grouping random access preamble sequences according to an example embodiment of the present disclosure. The 64 random access preamble sequences are divided into 3 groups as shown in fig. 12. The first P of the 64 random access preamble sequences are used for contention-based random access, and the remaining 64-P random access preamble sequences are used for non-contention-based random access, wherein the first Q of the random access preamble sequences used for contention-based random access are called group a, and the last P-Q are called group B, and the grouping is performed to increase the prior information of the terminal to subsequently transmit message 3(msg 3) in the random access process. And the terminal acquires the values of P and Q from the system information broadcasted by the cell.

The same as the existing access method, if the terminal performs random access based on non-competition, the terminal directly obtains the specific random access leader sequence from the high-level signaling sent by the base station to the terminal. If the terminal performs random access based on contention, the terminal first determines whether to select a random access preamble sequence in group a or select a random access preamble sequence in group B, and the manner of determining the random access preamble sequence group is the same as that of the conventional method, which is not described in detail in this patent. After determining the random access preamble sequence group, the terminal randomly selects one random access preamble sequence with equal probability among the determined group.

No matter base station allocation or terminal random selection, the terminal obtains the physical root sequence number and the cyclic shift index of the random access preamble sequence to be sent, which are respectively marked as u and v. The u-th root ZC sequence is defined as:

by root ZC sequence x_u(n), the terminal can obtain the actually transmitted digital baseband random access preamble sequence x_u,v(n)＝x_u((n+v·N_CS)modN_ZC). After IDFT and resource mapping according to the frame structure given in the first embodiment, a baseband random access preamble sequence signal can be obtained. In phase with LTE/NR systemsMeanwhile, in the up-conversion process, in order to ensure that the random access preamble sequence and the front and back data subcarriers have the same guard band, the frequency offset of a plurality of subcarriers needs to be carried out in the high-frequency direction, and for the random access preamble sequence structure provided by the patent, the frequency offset is

Wherein

Fig. 13 shows a block diagram of a data transmission device 400 according to an exemplary embodiment of the present disclosure.

As shown in fig. 13, the data transmission apparatus 400 may include: a scheduling information receiving unit 410, configured to receive scheduling information of a base station; a determining unit 420, configured to determine whether a resource indicated by the scheduling information of the base station includes a resource overlapping with a cyclic prefix of the random access preamble sequence; an indication information acquisition unit 430 for acquiring indication information indicating whether transmission of data on the overlapping resources is permitted; a data transmission unit 440, configured to transmit data on the overlapping resource when the result of the determination indicates that the overlapping resource exists and the indication information indicates that the data is allowed to be transmitted on the overlapping resource, and avoid the overlapping resource when the result of the determination indicates that the overlapping resource exists and the indication information indicates that the data is not allowed to be transmitted on the overlapping resource, wherein a subcarrier interval corresponding to a random access preamble sequence is equal to 1KHz, and a cyclic prefix of the random access preamble sequence is located in a transmission period before a transmission period in which the random access preamble sequence is located.

Fig. 14 illustrates a block diagram of a random access preamble sequence allocating apparatus 500 according to an exemplary embodiment of the present disclosure.

As shown in fig. 14, the random access preamble sequence allocating apparatus 500 may include: an interference strength determining unit 510, configured to determine whether an interference strength between adjacent cells is greater than a strength threshold; an index number allocating unit 520, configured to allocate, when greater than the strength threshold, the same ZC sequence length, cyclic shift interval, and logical root sequence number and different and consecutive random access preamble sequence set index numbers to each of the neighboring cells, where the ZC sequence length, cyclic shift interval, logical root sequence number, and random access preamble sequence set index numbers are used to determine an available random access preamble sequence set for each cell, and among available random access preamble sequence sets corresponding to at least two consecutive random access preamble sequence set index numbers, there are random access preamble sequences generated from the same logical root sequence number.

As an example, the subcarrier spacing corresponding to the random access preamble sequence is below 1.25 KHz.

As an example, the subcarrier spacing is equal to 1KHz, and the pre-guard interval of the random access preamble sequence and the cyclic prefix of the random access preamble sequence are located in a previous transmission period of the transmission period in which the random access preamble sequence is located.

As an example, the subcarrier spacing is above 1KHz and below 1.25KHz, the sum of the lengths of the following is 1 ms: a front guard interval of the random access leader sequence, a cyclic prefix of the random access leader sequence, a random access leader sequence, and a rear guard interval of the random access leader sequence.

As an example, the length of the back guard interval is zero, and the cyclic prefix of the first OFDM symbol of the next transmission period of the transmission period in which the random access preamble sequence is located functions as the back guard interval of the random access preamble sequence, or the length of the front guard interval is equal to the length of the cyclic prefix of the random access preamble sequence, and the difference between the sum of the length of the back guard interval and the cyclic prefix of the first OFDM symbol and the length of the cyclic prefix of the random access preamble sequence is less than or equal to 2Ts, or the length of the front guard interval is zero, and the difference between the length of the back guard interval and the cyclic length prefix of the random access preamble sequence is less than or equal to 2 Ts.

Fig. 15 shows a block diagram of a random access preamble sequence determination apparatus 600 according to an exemplary embodiment of the present disclosure.

As shown in fig. 15, the random access preamble sequence determining apparatus 600 may include: an information obtaining unit 610, configured to obtain information of a target cell, where the information includes a ZC sequence length, a logical root sequence number, a random access preamble sequence set index number, and a cyclic shift interval; a calculating unit 620, configured to calculate an initial logical root sequence number and an initial cyclic shift index according to the acquired information; a random access preamble sequence set determining unit 630, configured to determine an available random access preamble sequence set of the target cell according to the cyclic shift interval, the calculated initial logical root sequence number, and the initial cyclic shift index.

As an example, the calculating unit 620 calculates the number of random access preamble sequences that one logical root sequence number can generate, based on the ZC sequence length and the cyclic shift interval; calculating the initial logical root sequence number according to the logical root sequence number, the random access leader sequence set index number and the calculated random access leader sequence number; and calculating the initial cyclic shift index according to the random access leader sequence set index number and the calculated number of the random access leader sequences.

As an example, the random access preamble sequence set determining unit 630 determines a starting physical root sequence number corresponding to the starting logical root sequence number according to a correspondence between the logical root sequence number and the physical root sequence number; generating and selecting 64 random access preamble sequences with a cyclic shift amount greater than or equal to the product of the initial cyclic shift index and the cyclic shift interval according to the initial physical root sequence number, wherein when the number of random access preamble sequences for which the amount of cyclic shift generated from the starting physical root sequence number is greater than or equal to the product of the starting cyclic shift index and the cyclic shift interval is less than 64, the logical root sequence number is increased by 1, and in the random access leader sequences corresponding to the logical root sequence numbers increased by 1, sequentially selecting the random access leader sequences from the random access leader sequence with the smallest cyclic shift index according to the sequence of the cyclic shift indexes from small to large, expanding the random access leader sequences into the selected random access leader sequences, and repeatedly executing the operation of increasing the logical root sequence numbers by 1 and selecting the random access leader sequences until the number of the selected random access leader sequences reaches 64.

Exemplary embodiments of the present disclosure design a time domain structure of PRACH resources for a full-duplex cell. The detection capability of the random access leader sequence is improved by increasing the length of the random access leader sequence, and the number of the orthogonal random access leader sequences is improved by distributing the random access leader sequence by sharing the logic root sequence number. On one hand, the mutual interference between random access preamble sequences of different terminals in the cell can be reduced, and on the other hand, the capability of resisting the interference of downlink signals of the cell and adjacent cells to the random access preamble sequences is also improved, so that the mutual interference of the random access preamble sequences between the adjacent cells can be reduced or even completely eliminated.

According to another exemplary embodiment of the present disclosure, a computer-readable storage medium is provided, in which a computer program is stored, which, when being executed by a processor, carries out the method as set forth above.

According to another exemplary embodiment of the present disclosure, there is provided an electronic apparatus, wherein the electronic apparatus includes: a processor; a memory storing a computer program which, when executed by the processor, implements the method as described above.

The computer readable storage medium is any data storage device that can store data which can be read by a computer system. Examples of the computer-readable recording medium include: read-only memory, random access memory, read-only optical disks, magnetic tapes, floppy disks, optical data storage devices, and carrier waves (such as data transmission through the internet via wired or wireless transmission paths).

Further, it should be understood that various units of a device (e.g., a terminal, a base station, etc.) according to exemplary embodiments of the present disclosure may be implemented as hardware components and/or software components. The individual units may be implemented, for example, using Field Programmable Gate Arrays (FPGAs) or Application Specific Integrated Circuits (ASICs), depending on the processing performed by the individual units as defined by the skilled person.

Furthermore, the method according to the exemplary embodiments of the present disclosure may be implemented as computer code in a computer-readable storage medium. The computer code can be implemented by those skilled in the art from the description of the method above. The computer code when executed in a computer implements the above-described methods of the present disclosure.

Although a few exemplary embodiments of the present disclosure have been shown and described, it would be appreciated by those skilled in the art that changes may be made in these embodiments without departing from the principles and spirit of the disclosure, the scope of which is defined in the claims and their equivalents.

Claims

1. A random access preamble sequence allocation method, comprising:

judging whether the interference strength between adjacent cells is greater than a strength threshold value;

when the strength is larger than the strength threshold value, each cell in the adjacent cells is allocated with the same ZC sequence length, cyclic shift interval and logic root sequence number and different and continuous random access preamble sequence set index numbers,

wherein the ZC sequence length, the cyclic shift interval, the logical root sequence number and the random access preamble sequence set index number are used for determining an available random access preamble sequence set of each cell,

wherein, the random access leader sequence generated from the same logic root sequence number exists in the available random access leader sequence set corresponding to the index numbers of at least two continuous random access leader sequence sets.

2. The random access preamble sequence allocation method of claim 1, wherein a subcarrier spacing corresponding to the random access preamble sequence is lower than 1.25 KHz.

3. The random access preamble sequence allocation method of claim 2, wherein the subcarrier spacing is equal to 1KHz, and the pre-guard interval of the random access preamble sequence and the cyclic prefix of the random access preamble sequence are located within a previous transmission period of a transmission period in which the random access preamble sequence is located.

4. The random access preamble sequence allocation method of claim 2, wherein the subcarrier spacing is higher than 1KHz and lower than 1.25KHz, and the sum of the lengths of the following items is 1 ms: the front guard interval of the random access leader sequence, the cyclic prefix of the random access leader sequence, the random access leader sequence and the rear guard interval of the random access leader sequence.

5. The random access preamble sequence allocation method of claim 4, wherein,

the back guard interval is zero, and the cyclic prefix of the first OFDM symbol of the next transmission period of the transmission period in which the random access preamble sequence is located functions as the back guard interval of the random access preamble sequence, or

The length of the pre-guard interval is equal to the length of the cyclic prefix of the random access preamble sequence, and the difference between the sum of the length of the pre-guard interval and the cyclic prefix of the first OFDM symbol and the length of the cyclic prefix of the random access preamble sequence is less than or equal to 2Ts, or

The length of the pre-guard interval is zero and the difference between the length of the post-guard interval and the length of the cyclic prefix of the random access preamble sequence is less than or equal to 2 Ts.

6. A method for random access preamble sequence determination, comprising:

acquiring information of a target cell, wherein the information comprises ZC sequence length, logic root sequence number, random access leader sequence set index number and cyclic shift interval;

calculating an initial logic root sequence number and an initial cyclic shift index according to the acquired information;

determining an available random access preamble sequence set of the target cell according to the cyclic shift interval, the calculated initial logical root sequence number and the initial cyclic shift index,

7. The random access preamble sequence determination method of claim 6, wherein the step of calculating the starting logical root sequence number and the starting cyclic shift index from the acquired information comprises:

calculating the number of random access leader sequences which can be generated by a logic root sequence number according to the length of the ZC sequence and the cyclic shift interval;

calculating the initial logical root sequence number according to the logical root sequence number, the random access leader sequence set index number and the calculated random access leader sequence number;

and calculating the initial cyclic shift index according to the random access leader sequence set index number and the calculated number of the random access leader sequences.

8. The random access preamble sequence determination method of claim 6, wherein the step of determining the set of available random access preamble sequences of the target cell comprises:

determining an initial physical root sequence number corresponding to the initial logical root sequence number according to the corresponding relation between the logical root sequence number and the physical root sequence number;

generating and selecting random access preamble sequences with a cyclic shift amount greater than or equal to the product of the initial cyclic shift index and the cyclic shift interval and the number of the random access preamble sequences is a predetermined number according to the initial physical root sequence number,

when the number of random access preamble sequences with the cyclic shift amount which is generated according to the initial physical root sequence number and is larger than or equal to the product of the initial cyclic shift index and the cyclic shift interval is smaller than the preset number, the logical root sequence number is increased by 1, the random access preamble sequences are sequentially selected from the random access preamble sequence with the minimum cyclic shift index and expanded into the selected random access preamble sequence according to the sequence from the small cyclic shift index to the large cyclic shift index in the random access preamble sequence corresponding to the logical root sequence number which is increased by 1, and the operation of increasing the logical root sequence number by 1 and selecting the random access preamble sequence is repeatedly executed until the number of the selected random access preamble sequences reaches the preset number.

9. A method of data transmission, comprising:

receiving scheduling information of a base station;

judging whether the resources indicated by the scheduling information of the base station comprise resources at least overlapped with the cyclic prefix of the random access leader sequence or the random access leader sequence;

acquiring indication information indicating whether data transmission on the overlapping resources is allowed;

transmitting data on the overlapping resources when the determination result is that the overlapping resources exist and the indication information indicates that transmission of data on the overlapping resources is allowed, avoiding the overlapping resources when transmitting data when the determination result is that the overlapping resources exist and the indication information indicates that transmission of data on the overlapping resources is not allowed,

the interval of the sub-carrier corresponding to the random access leader sequence is equal to or less than 1KHz, and at least the cyclic prefix of the random access leader sequence or the random access leader sequence is positioned in the previous transmission period of the transmission period in which the random access leader sequence is positioned.

10. A system comprising at least one computing device and at least one storage device storing instructions that, when executed by the at least one computing device, cause the at least one computing device to perform the method of any of claims 1 to 9.

11. A computer-readable storage medium storing instructions that, when executed by at least one computing device, cause the at least one computing device to perform the method of any of claims 1 to 9.

12. A random access preamble sequence allocation apparatus, comprising:

an interference strength judging unit, configured to judge whether an interference strength between adjacent cells is greater than a strength threshold;

an index number allocation unit for allocating the same ZC sequence length, cyclic shift interval, and logical root sequence number and different and consecutive random access preamble sequence set index numbers to each of the adjacent cells when greater than the strength threshold,

13. A random access preamble sequence determination device, comprising:

an information acquisition unit, configured to acquire information of a target cell, where the information includes a ZC sequence length, a logical root sequence number, a random access preamble sequence set index number, and a cyclic shift interval;

the calculation unit is used for calculating the initial logic root sequence number and the initial cyclic shift index according to the acquired information;

a random access leader sequence set determining unit, for determining the available random access leader sequence set of the target cell according to the cyclic shift interval, the calculated initial logical root sequence number and the initial cyclic shift index,

14. A data transmission device comprising:

a scheduling information receiving unit for receiving scheduling information of a base station;

a judging unit, configured to judge whether a resource indicated by the scheduling information of the base station includes a resource that overlaps with at least a cyclic prefix of a random access preamble sequence or the random access preamble sequence;

an indication information acquisition unit configured to acquire indication information indicating whether transmission of data on the overlapping resource is permitted;

a data transmission unit for transmitting data on the overlapping resources when the result of the judgment indicates that the overlapping resources exist and the indication information indicates that the data is allowed to be transmitted on the overlapping resources, avoiding the overlapping resources when transmitting the data when the result of the judgment indicates that the overlapping resources exist and the indication information indicates that the data is not allowed to be transmitted on the overlapping resources,