WO2017067436A1

WO2017067436A1 - Downlink synchronization method, user equipment and base station

Info

Publication number: WO2017067436A1
Application number: PCT/CN2016/102381
Authority: WO
Inventors: 黄磊; 王艺
Original assignee: 华为技术有限公司
Priority date: 2015-10-23
Filing date: 2016-10-18
Publication date: 2017-04-27
Also published as: CN106612540A; CN106612540B

Abstract

Provided are a downlink synchronization method, a user equipment and a high-frequency base station located in a high- and low-frequency hybrid networking system. The downlink synchronization method comprises: a user equipment receiving synchronization information transmitted by a high-frequency base station, wherein a synchronization wireless frame used by the synchronization information comprises at least one special subframe, the special subframe comprises a DLBP, the DLBP comprises Nu sub-intervals and each sub-interval transmits Nd synchronization signals, where Nu and Nd are positive integers greater than 1; and the user equipment conducting synchronization according to the synchronization information. In the embodiments of the invention, a high-frequency base station transmits synchronization information in a special subframe and a UE finishes synchronization with the high-frequency base station by receiving synchronization signals in the special subframe, thus facilitating the UE rapidly accessing a high-frequency system and saving power consumption in access.

Description

Downlink synchronization method, user equipment, and base station

Technical field

The embodiments of the present invention relate to the field of communications, and in particular, to a method, a user equipment, and a base station for downlink synchronization in a high and low frequency hybrid networking system.

Background technique

With the ever-increasing demands for data transmission rates, communication qualities, and the like for mobile communications today, existing frequency bands for mobile communications have become very crowded. However, in the millimeter-wave band of 6-300 GHz, a large amount of spectrum resources are still not allocated. Introducing the millimeter wave band into cellular access communication and making full use of the large bandwidth resources of the millimeter wave band is one of the important research directions of the next generation 5G mobile communication system.

In the existing research, the high frequency band represented by the millimeter wave band is mainly used in indoor short-range communication scenarios. In outdoor scenes, due to the complex terrain, the high-frequency path loss is large, the ability to penetrate obstacles is weak, and there is a severe rain attenuation effect at some frequencies, which seriously restricts the application of high-frequency bands in outdoor scenes. However, due to its short wavelength, the high frequency band is easy to implement a large-scale array antenna, and can achieve a large directional antenna gain by beam-forming technology, thereby effectively compensating for its high path loss, which is also high in the outdoor frequency band. The application of medium to long distance transmission of the scene offers the possibility.

From the current research status, the higher the frequency band, the smaller the range that can be covered, and the larger the array antenna available to the base station. For example, for an E-band system, it is generally possible to cover a cell radius of 25 meters to 100 meters, and the base station array antenna can have a size of 1024 antenna array units. For systems below 30 GHz, the radius of the cell can be covered from 50 meters to 200 meters, and the size of the base station array antenna can reach 256 antenna array units. High-frequency array antennas are used in high-frequency systems to form directional beams with high gain, which can overcome the high path loss caused by high frequency bands and improve link coverage. However, directional beams present challenges to the design and transmission of broadcast channels, control channels, synchronization channels, and random access channels.

In the existing mobile communication systems, such as the Universal Mobile Telecommunications System (UMTS) and the Long Term Evolution (LTE) system, the transmission of the above-mentioned channels is realized by transmission and reception of an omnidirectional antenna. For the downlink broadcast channel, the downlink control channel, and the synchronization channel, the base station transmits the above channel information through the omnidirectional antenna, and all the user equipments covered by the base station can be successfully received. For uplink control channel, random access In the case of the incoming channel, the user equipment sends the above channel information once, and the associated base station can successfully receive the omnidirectional antenna. However, in the high-frequency communication system, due to the limitation of the beamwidth of the directional beam, the signal transmitted through one directional beam can only cover a small part of a certain direction, and the corresponding information cannot be successfully received outside the area. . Therefore, in order to obtain the effect of omnidirectional coverage in existing mobile communication systems, it is necessary to traverse all directional beam combinations of the transmitting end and the receiving end. If the transceivers are all directional beams, the number of beam combinations described above is very large, which will lead to a sharp increase in high-frequency system overhead.

In a high-frequency communication system, both the base station and the user equipment can perform beamforming using a large-scale antenna array by adjusting the phase, amplitude, and/or digital weighting vectors on multiple radio frequency (RF) channels of each antenna unit. Directional beams of different widths (wide beam, narrow beam) can be formed. Usually the beamwidth of a wide beam is more than twice the beamwidth of a narrow beam.

In addition, in high frequency communication systems, the high path loss caused by the high frequency band needs to be compensated by the high beam gain of the antenna array. The acquisition of high beam gain is based on beam alignment at both ends of the transceiver. Once the beam is mis-aligned at both ends, the received signal quality will drop dramatically and normal data communication will be interrupted. Therefore, in the high-frequency communication system, in order to ensure normal data communication, beam training and beam tracking are required to be performed periodically or irregularly, so that the transmitting and receiving ends can adopt the optimal transmitting and receiving beam pairs. The transmission of data.

In the prior art, each wireless subframe reserves part of resources for transmission of a downlink synchronization signal, which is a distributed transmission mode. The user equipment needs to perform downlink comparison of the synchronization signals of multiple wireless subframes to achieve downlink synchronization of the system. This method of synchronization takes a long time, causing a large overhead and further affecting the performance of the system.

Summary of the invention

The invention provides a method for downlink synchronization in a high-low frequency hybrid networking, which can save overhead and improve system performance.

In a first aspect, a method for downlink synchronization is provided, including:

The user equipment receives the synchronization information sent by the high-frequency base station, and the synchronization information is carried by the synchronous radio frame, where the synchronization radio frame includes at least one special subframe, where the special subframe is used to transmit a synchronization signal, where the special sub-frame The frame includes a downlink synchronization and a beam training interval DLBP, the DLBP includes Nu subintervals, and each of the subintervals transmits Nd synchronization signals, where Nu and Nd are a positive integer greater than one;

The user equipment synchronizes according to the synchronization information.

Optionally, the synchronous radio frame further includes at least one general subframe, where the general subframe is used for transmitting data.

In this way, in the synchronous radio frame, the data is transmitted by the general sub-frame, and the synchronization signal is transmitted by the special sub-frame. Further, the user equipment can perform downlink synchronization according to the tight frame structure, and the synchronization overhead is small, thereby improving the high-low frequency networking system. Synchronize efficiency and improve system performance.

In conjunction with the first aspect, in a first possible implementation manner of the first aspect, each of the sub-intervals includes Nd time slices, and the length of each time slice includes at least two OFDM symbols.

With reference to the first possible implementation of the first aspect, in a second possible implementation manner of the first aspect, the first OFDM symbol of the at least two OFDM symbols is used to send a primary synchronization signal, where the at least The second of the two OFDM symbols is used to transmit a secondary synchronization signal.

In conjunction with the second possible implementation of the first aspect, in a third possible implementation of the first aspect, the second OFDM symbol is used to send a specific sequence of the secondary synchronization signal. The specific sequence includes an identifier ID of a time slice in which the specific sequence is located, and an ID of a sub-interval in which the specific sequence is located.

Alternatively, the ID of the time slice in which the specific sequence is located may be replaced with the ID of the transmission beam. Optionally, the specific sequence may also include the ID of the high frequency base station. In this way, a specific sequence is transmitted on a specific time slice of a specific subinterval, and the user equipment can perform coherent detection on the secondary synchronization signal, acquire the ID of the time slice in which the specific sequence is located, and the ID of the subinterval in which the specific sequence is located, and thus can learn the secondary synchronization. The position of the OFDM symbol in the special subframe in which the signal is located, thereby enabling acquisition of radio frame synchronization.

With reference to the first aspect, or any possible implementation manner of the foregoing first aspect, in a fourth possible implementation manner of the first aspect, the each subinterval further includes Nd subsequent to the Nd time slices Switch the guard interval SGP.

With reference to the first aspect, or any possible implementation manner of the foregoing first aspect, in the fifth possible implementation manner of the first aspect, the Nd synchronization signals are that the high frequency base station uses Nd different transmit beams Send in order.

With reference to the first aspect, or any one of the foregoing possible implementation manners, the user equipment, in the sixth possible implementation manner of the first aspect, that the user equipment receives the synchronization information that is sent by the high frequency base station, including: the user equipment Receiving the Nu subintervals separately using Nu different receiving beams Synchronization signal. That is, the user equipment uses one receive beam to receive Nd sync signals on one subinterval.

With reference to the first aspect, or any possible implementation manner of the foregoing first aspect, in a seventh possible implementation manner of the first aspect, in the first special subframe in the synchronization information, the high frequency base station Transmitting, by using a first sequence of transmit beams, the synchronization signal; in a second special subframe of the synchronization information, the high frequency base station transmits the synchronization signal by using a second sequence of transmit beams, where The second sequence is generated by cyclic shifting of the first sequence.

With reference to the first aspect, or any possible implementation manner of the foregoing first aspect, in the eighth possible implementation manner of the first aspect, each of the synchronous radio frames includes a special subframe, where the first special subframe is a special subframe in the first synchronization radio frame, where the second special subframe is a special subframe in the second synchronization radio frame; wherein the second synchronization radio frame is adjacent to the first synchronization radio frame The next sync radio frame.

With reference to the first aspect, or any possible implementation manner of the foregoing first aspect, in a ninth possible implementation manner of the first aspect, each of the synchronous radio frames includes 2N special subframes; the first special subframe For the 2ith special subframe of the 2N special subframes, the second special subframe is the 2i+1th special subframe of the 2N special subframes; where N is a positive integer, i is a positive integer less than or equal to N.

With reference to the first aspect, or any one of the foregoing possible implementation manners, the user equipment, in the tenth possible implementation manner of the first aspect, that the user equipment receives the synchronization information sent by the high frequency base station, including: the user equipment Determining a starting position of the synchronization detecting window according to the low frequency signal sent by the low frequency base station in the system; the user equipment separately receives the Nu group synchronization signal from the starting position by using Nu different receiving beams, wherein each group The sync signal includes Nd sync signals.

Optionally, the user equipment further receives the low frequency signal sent by the low frequency base station. Specifically, the user equipment determines the starting position of the synchronization detection window according to the frame structure used by the low frequency base station to transmit the low frequency signal. In this way, the user equipment determines the starting point of the synchronization by the low frequency assistance, making the high frequency synchronization more efficient.

In conjunction with the first aspect, or any one of the foregoing possible implementations of the first aspect, in the eleventh possible implementation of the first aspect, the second sequence is generated by cyclic shifting by the first sequence .

In conjunction with the first aspect, or any one of the foregoing possible implementations of the first aspect, in the twelfth possible implementation of the first aspect, the length of the cyclically shifted time slice is greater than the high and low frequency of the system Delay.

Due to the high and low frequency delays in the system, the user equipment has a synchronization dead zone when synchronizing. Here, by the cyclic shift greater than the high and low frequency delays, it is ensured that the user equipment receives the synchronization signal that is originally in the synchronization dead zone, so that the user equipment can quickly obtain the high frequency downlink synchronization.

With reference to the first aspect, or any possible implementation manner of the foregoing first aspect, in a thirteenth possible implementation manner of the foregoing aspect, the special subframe further includes a cyclic suffix CS located after the DLBP, where The CS transmits K synchronization signals, where K is a positive integer less than Nd.

With reference to the first aspect, or any possible implementation manner of the foregoing first aspect, in the fourteenth possible implementation manner of the foregoing aspect, the Nd synchronization signals are sequentially used by the high frequency base station by using Nd transmit beams And transmitting, wherein the K synchronization signals are sequentially transmitted by the high frequency base station using the first K transmission beams of the Nd transmission beams.

With reference to the first aspect, or any one of the foregoing possible implementation manners, in the fifteenth possible implementation manner of the first aspect, the user equipment receives the synchronization information sent by the high frequency base station, including: the user The device determines a first start position of the first synchronization detection window according to the low frequency signal sent by the low frequency base station in the system; the user equipment separately receives the Nu group synchronization signal from the first start position by using different receiving beams of Nu The set of synchronization signals includes Nd synchronization signals; the user equipment determines a second start position of the second synchronization detection window according to the low frequency signal sent by the low frequency base station in the system and the additional reception delay; the user The device receives the Nu group synchronization signals from the second starting position using Nu different receiving beams, wherein each group of synchronization signals includes Nd synchronization signals.

With reference to the first aspect, or any one of the foregoing possible implementation manners of the first aspect, in the sixteenth possible implementation manner of the first aspect, the second special subframe is located after the first special subframe The first special subframe.

In conjunction with the first aspect, or any one of the foregoing possible implementation manners, in the seventeenth possible implementation manner of the first aspect, the additional receiving delay is preset in the user equipment. Optionally, the additional receiving delay may be pre-configured in the user equipment according to the high and low frequency delay of the system.

In conjunction with the first aspect, or any one of the foregoing possible implementations of the first aspect, in the eighteenth possible implementation of the first aspect, the additional receiving delay is that the user equipment is from the low frequency Obtained by the base station. Optionally, the low frequency base station may determine the additional receiving delay according to the high and low frequency delay of the system, and send the determined additional receiving delay to the user equipment.

In conjunction with the first aspect, or any one of the foregoing possible implementations of the first aspect, in the nineteenth possible implementation manner of the first aspect, the additional receiving delay is sent by the user equipment by using the low frequency base station Obtained by RRC signaling. That is to say, the RRC signaling sent by the low frequency base station to the user equipment includes an additional reception delay.

With reference to the first aspect, or any possible implementation manner of the foregoing first aspect, in the twentieth possible implementation manner of the first aspect, the length of the additional receiving delay is greater than the high and low frequency delay of the system, The length of the time slice occupied by the CP is greater than or equal to the sum of the high and low frequency delay and the additional receiving delay.

Due to the high and low frequency delays in the system, the user equipment has a synchronization dead zone when synchronizing. Here, by setting an additional reception delay greater than the high and low frequency delay and setting a CP greater than the sum of the high and low frequency delay and the additional reception delay, it is possible to ensure that the user equipment receives the synchronization signal that is originally in the synchronization dead zone, thereby enabling the user to The device quickly obtains high frequency downlink synchronization.

In conjunction with the first aspect, or any one of the foregoing possible implementation manners of the foregoing first aspect, in the twenty-first possible implementation manner of the first aspect, before the user equipment receives the synchronization information sent by the high frequency base station, Receiving RRC signaling sent by the low frequency base station, where the RRC signaling includes: a frequency point used by the high frequency base station, and/or a value of Nd.

Since the value of Nd is related to the frequency used by the high frequency base station. Then, if the RRC signaling includes the value of Nd, the user equipment can directly know the value of Nd. If the RRC signaling includes a frequency point adopted by the high frequency base station, the user equipment can determine the value of Nd according to the frequency point.

With reference to the first aspect, or any one of the foregoing possible implementation manners, in the second possible implementation manner of the foregoing aspect, the special subframe further includes a reserved data interval RDP and uplink and downlink switching protection. Interval GP.

Optionally, the RDP can be used for uplink data transmission or uplink random access.

With reference to the first aspect, or any one of the foregoing possible implementation manners of the first aspect, in the second thirteenth possible implementation manner of the first aspect, the synchronous radio frame further includes a general subframe, where the general subframe includes Eight time slots of length 0.125 milliseconds, the time slots comprising Ns OFDM symbols, wherein Ns is a positive integer.

With reference to the first aspect, or any possible implementation manner of the foregoing first aspect, in the twenty-fourth possible implementation manner of the first aspect, the week of the synchronous radio frame used by the high frequency base station The period is the length of M radio frames, where M is a positive integer.

In a second aspect, a method for downlink synchronization is provided, including:

The high frequency base station generates synchronization information, the synchronization information is carried by a synchronous radio frame, the synchronous radio frame includes at least one special subframe, and the special subframe is used to transmit a synchronization signal, where the special subframe includes downlink synchronization. And a beam training interval DLBP, the DLBP includes Nu subintervals, each of the subintervals transmitting Nd synchronization signals, where Nu and Nd are positive integers greater than one;

The high frequency base station transmits the synchronization information to a user equipment.

In this way, in the synchronous radio frame, the data is transmitted by the general subframe, the synchronization signal is transmitted by the special subframe, and the synchronization information transmitted by the high-frequency base station has a compact frame structure. Further, the user equipment can perform downlink synchronization according to the tight frame structure, and the synchronization overhead is small, thereby improving the synchronization efficiency of the high and low frequency networking system and improving system performance.

With reference to the second aspect, in a first possible implementation manner of the second aspect, the each subinterval includes Nd time slices, and the length of each time slice includes at least two orthogonal frequency division multiplexing OFDM symbols. .

With reference to the first possible implementation of the second aspect, in a second possible implementation manner of the second aspect, the first OFDM symbol of the at least two OFDM symbols is used to send a primary synchronization signal, where the at least The second of the two OFDM symbols is used to transmit a secondary synchronization signal.

With reference to the second aspect, or any possible implementation of the foregoing second aspect, in a third possible implementation of the second aspect, the second OFDM symbol is used to send a specific sequence of the secondary synchronization signal. The specific sequence includes an ID of a time slice in which the specific sequence is located, and an ID of a subinterval in which the specific sequence is located.

With reference to the second aspect, or any possible implementation manner of the foregoing second aspect, in the fourth possible implementation manner of the second aspect, each of the sub-intervals further includes the Nd time Nd switching protection intervals SGP after the slice.

With reference to the second aspect, or any one of the foregoing possible implementation manners, in the fifth possible implementation manner of the second aspect, the high frequency base station sends the synchronization information to the user equipment, including: The high frequency base station transmits the Nd synchronization signals using Nd different transmit beams.

With reference to the second aspect, or any one of the foregoing possible implementation manners, in the sixth possible implementation manner of the foregoing aspect, the high frequency base station sends the synchronization information to the user equipment, including:

And transmitting, by the high frequency base station, the synchronization signal by using a first sequence of transmit beams on a first special subframe in the synchronization information;

The second high frequency base station transmits the synchronization signal using a second sequence of transmit beams on a second special subframe in the synchronization information.

With reference to the second aspect, or any possible implementation manner of the foregoing second aspect, in a seventh possible implementation manner of the second aspect, each of the synchronous radio frames includes a special subframe;

The first special subframe is a special subframe in the first synchronization radio frame, and the second special subframe is a special subframe in the second synchronization radio frame;

The second synchronization radio frame is a next synchronization radio frame adjacent to the first synchronization radio frame.

With reference to the second aspect, or any possible implementation manner of the foregoing second aspect, in the eighth possible implementation manner of the second aspect, each of the synchronous radio frames includes 2N special subframes;

The first special subframe is the 2ith special subframe of the 2N special subframes, and the second special subframe is the 2i+1th special subframe of the 2N special subframes;

Where N is a positive integer and i is a positive integer less than or equal to N.

In conjunction with the second aspect, or any one of the foregoing possible implementations of the second aspect, in a ninth possible implementation of the second aspect, the second sequence is generated by cyclic shifting of the first sequence.

With reference to the second aspect, or any possible implementation manner of the foregoing second aspect, in a tenth possible implementation manner of the second aspect, the length of the cyclically shifted time slice is greater than the high and low frequency delay of the system .

Due to the high and low frequency delays in the system, the user equipment has a synchronization dead zone when synchronizing. Here, by the cyclic shift greater than the high and low frequency delays, it can be ensured that the user equipment receives the same The synchronization signal of the blind zone enables the user equipment to quickly obtain high frequency downlink synchronization.

With reference to the second aspect, or any one of the foregoing possible implementation manners of the second aspect, in the eleventh possible implementation manner of the second aspect, the special subframe further includes a cyclic suffix CS located after the DLBP, where The CS transmits K synchronization signals, where K is a positive integer less than Nd.

With reference to the second aspect, or any one of the foregoing possible implementation manners, in the twelfth possible implementation manner of the second aspect, the high frequency base station sends the synchronization information to the user equipment, including :

The high frequency base station sequentially transmits the Nd synchronization signals by using Nd transmission beams;

The high frequency base station sequentially transmits the K synchronization signals using the first K transmit beams of the Nd transmit beams.

With reference to the second aspect, or any possible implementation manner of the foregoing second aspect, in the thirteenth possible implementation manner of the foregoing aspect, the special subframe further includes a reserved data interval (RDP) and an uplink and downlink handover protection interval. GP.

With reference to the second aspect, or any possible implementation manner of the foregoing second aspect, in the fourteenth possible implementation manner of the second aspect, the period of the synchronous radio frame used by the high frequency base station is M The length of the wireless frame, where M is a positive integer.

In a third aspect, a user equipment is provided, including:

a receiving unit, configured to receive synchronization information sent by a high frequency base station, where the synchronization information is carried by a synchronous radio frame, where the synchronization radio frame includes at least one special subframe, where the special subframe is used to transmit a synchronization signal, where The special subframe includes a DLBP, the DLBP includes Nu subintervals, and each of the subintervals transmits Nd synchronization signals, where Nu and Nd are positive integers greater than one;

And a processing unit, configured to perform synchronization according to the synchronization information.

With reference to the third aspect, in a first possible implementation manner of the third aspect, the each subinterval includes Nd time slices, and the length of each time slice includes at least two orthogonal frequency division multiplexing OFDM symbols. .

With reference to the first possible implementation manner of the third aspect, in a second possible implementation manner of the third aspect, the first OFDM symbol of the at least two OFDM symbols is used to send a primary synchronization signal, where the at least The second of the two OFDM symbols is used to transmit a secondary synchronization signal.

With reference to the third aspect, or any one of the foregoing possible implementation manners of the foregoing third aspect, in a third possible implementation manner of the third aspect, the second OFDM symbol is used to send the secondary synchronization A specific sequence of numbers, wherein the specific sequence includes an ID of a time slice in which the specific sequence is located, and an ID of a subinterval in which the specific sequence is located.

With reference to the third aspect, or any one of the foregoing possible implementation manners of the third aspect, in the fourth possible implementation manner of the third aspect, the each subinterval further includes Nd respectively located after the Nd time slices Switch protection interval SGP.

With reference to the third aspect, or any one of the foregoing possible implementation manners of the foregoing third aspect, in the fifth possible implementation manner of the third aspect, the Nd synchronization signals are that the high frequency base station uses Nd different transmissions The beam is sent.

With reference to the third aspect, or any one of the foregoing possible implementation manners of the foregoing third aspect, the receiving unit is specifically configured to: receive, respectively, by using different receiving beams of Nu The synchronization signal of the Nu subintervals.

With reference to the third aspect, or any one of the foregoing possible implementation manners of the third aspect, in the seventh possible implementation manner of the third aspect, in the first special subframe in the synchronization information, the high frequency The base station transmits the synchronization signal using a first sequence of transmit beams; and in the second special subframe of the synchronization information, the high frequency base station transmits the synchronization signal using a second sequence of transmit beams.

With reference to the third aspect, or any one of the foregoing possible implementation manners of the foregoing third aspect, in the eighth possible implementation manner of the third aspect, each of the synchronous radio frames includes a special subframe;

With reference to the third aspect, or any one of the possible implementation manners of the foregoing third aspect, in a ninth possible implementation manner of the third aspect, each of the synchronous radio frames includes 2N special subframes;

With reference to the third aspect, or any one of the foregoing possible implementation manners of the foregoing third aspect, in the tenth possible implementation manner of the third aspect, the receiving unit is specifically configured to:

Determining a starting position of the synchronization detection window according to the low frequency signal sent by the low frequency base station in the system;

Receiving a Nu group synchronization signal from the starting position respectively using Nu different receiving beams No., wherein each set of synchronization signals includes Nd synchronization signals.

With reference to the third aspect, or any one of the foregoing possible implementation manners of the third aspect, in the eleventh possible implementation manner of the third aspect, the second sequence is generated by cyclic shifting by the first sequence of.

With reference to the third aspect, or any one of the foregoing possible implementation manners, in the twelfth possible implementation manner of the third aspect, the length of the cyclically shifted time slice is greater than the high and low frequency of the system Delay.

With reference to the third aspect, or any one of the foregoing possible implementation manners of the third aspect, in the thirteenth possible implementation manner of the third aspect, the special subframe further includes a cyclic suffix CS located after the DLBP, The CS transmits K synchronization signals, where K is a positive integer less than Nd.

With reference to the third aspect, or any one of the foregoing possible implementation manners of the third aspect, in the fourteenth possible implementation manner of the third aspect, the Nd synchronization signals are that the high frequency base station uses Nd transmit beams Sending in sequence;

The K synchronization signals are that the high frequency base station sequentially transmits using the first K transmission beams of the Nd transmission beams.

With reference to the third aspect, or any one of the foregoing possible implementation manners of the foregoing third aspect, in the fifteenth possible implementation manner of the third aspect, the receiving unit is specifically configured to:

Determining, according to the low frequency signal sent by the low frequency base station in the system, a first starting position of the first synchronization detection window;

Receiving a Nu group synchronization signal respectively from the first starting position using Nu different receiving beams, wherein each group of synchronization signals includes Nd synchronization signals;

Determining a second starting position of the second synchronization detecting window according to the low frequency signal sent by the low frequency base station in the system and the additional receiving delay;

The Nu group synchronization signals are respectively received from the second start position using Nu different receive beams, wherein each set of synchronization signals includes Nd synchronization signals.

In conjunction with the third aspect, or any one of the foregoing possible implementation manners of the foregoing third aspect, the second special subframe is located after the first special subframe The first special subframe.

In conjunction with the third aspect, or any one of the foregoing possible implementation manners, in the seventeenth possible implementation manner of the third aspect, the additional receiving delay is preset in the user equipment.

In conjunction with the third aspect, or any one of the foregoing possible implementation manners of the third aspect, in the eighteenth possible implementation manner of the third aspect, the receiving unit is further configured to acquire the Receive delay.

With reference to the third aspect, or any one of the foregoing possible implementation manners of the foregoing third aspect, the receiving unit is configured to use the radio resource that is sent by the low frequency base station, in a nineteenth possible implementation manner of the third aspect, Controlling RRC signaling to obtain the additional reception delay.

With reference to the third aspect, or any one of the foregoing possible implementation manners, in the twentieth possible implementation manner of the third aspect, the length of the additional receiving delay is greater than the high and low frequency delay of the system. The length of the time slice occupied by the CP is greater than or equal to the sum of the high and low frequency delay and the additional receiving delay.

In conjunction with the third aspect, or any one of the foregoing possible implementation manners of the foregoing third aspect, the receiving unit is further configured to:

Receiving radio resource control RRC signaling sent by the low frequency base station, where the RRC signaling includes:

The frequency point used by the high frequency base station, and/or the value of Nd.

With reference to the third aspect, or any one of the foregoing possible implementation manners of the foregoing third aspect, the special subframe further includes a reserved data interval RDP and an uplink and downlink switch. Protection interval GP.

With reference to the third aspect, or any one of the foregoing possible implementation manners of the foregoing third aspect, in the twenty-third possible implementation manner of the third aspect, the synchronous radio frame further includes a general subframe, where the general subframe There are eight time slots of length 0.125 milliseconds, the time slots comprising Ns OFDM symbols, wherein Ns is a positive integer.

With reference to the third aspect, or any one of the foregoing possible implementation manners of the third aspect, in the twenty-fourth possible implementation manner of the third aspect, the period of the synchronous radio frame used by the high frequency base station is The length of M radio frames, where M is a positive integer.

In a fourth aspect, a high frequency base station is provided, including:

a generating unit, configured to generate synchronization information, where the synchronization information is carried by a synchronous radio frame, where the synchronization radio frame includes at least one special subframe, where the special subframe is used to transmit a synchronization signal, where the special subframe includes DLBP, the DLBP includes Nu subintervals, each of the subintervals transmitting Nd synchronization signals, where Nu and Nd are positive integers greater than one;

And a sending unit, configured to send the synchronization information to the user equipment.

In conjunction with the fourth aspect, in a first possible implementation of the fourth aspect, each of the sub-areas The Nd time slices are included, and the length of each time slice includes at least two orthogonal frequency division multiplexing OFDM symbols.

With reference to the first possible implementation manner of the fourth aspect, in a second possible implementation manner of the fourth aspect, the first OFDM symbol of the at least two OFDM symbols is used to send a primary synchronization signal, where the at least The second of the two OFDM symbols is used to transmit a secondary synchronization signal.

With reference to the second possible implementation of the fourth aspect, in a third possible implementation manner of the fourth aspect, the second OFDM symbol is used to send a specific sequence of the secondary synchronization signal, where the specific The sequence includes the ID of the time slice in which the particular sequence is located, and the ID of the subinterval in which the particular sequence is located.

With reference to the fourth aspect, or any one of the foregoing possible implementation manners, the fourth possible implementation manner of the fourth aspect, the each subinterval further includes Nd respectively after the Nd time slices Switch protection interval SGP.

With reference to the fourth aspect, or any one of the foregoing possible implementation manners, in the fifth possible implementation manner of the foregoing aspect, the sending unit is specifically configured to: use Nd different transmit beam sending stations Nd synchronization signals are described.

With reference to the fourth aspect, or any one of the possible implementation manners of the foregoing fourth aspect, in the sixth possible implementation manner of the fourth aspect, the sending unit is specifically configured to:

Transmitting, by using a first sequence of transmit beams, the synchronization signal on a first special subframe in the synchronization information;

And transmitting, on the second special subframe in the synchronization information, the synchronization signal by using a second sequence of transmission beams.

With reference to the fourth aspect, or any one of the possible implementation manners of the foregoing fourth aspect, in a seventh possible implementation manner of the fourth aspect, each of the synchronous radio frames includes a special subframe;

With reference to the fourth aspect, or any one of the foregoing possible implementation manners, in the eighth possible implementation manner of the fourth aspect, each of the synchronous radio frames includes 2N special subframes;

With reference to the fourth aspect, or any one of the foregoing possible implementation manners of the fourth aspect, in the ninth possible implementation manner of the fourth aspect, the second sequence is generated by cyclic shifting by the first sequence .

With reference to the fourth aspect, or any one of the foregoing possible implementation manners, in the tenth possible implementation manner of the fourth aspect, the length of the cyclically shifted time slice is greater than the high and low frequency of the system Delay.

With reference to the fourth aspect, or any one of the foregoing possible implementation manners of the fourth aspect, in the eleventh possible implementation manner of the fourth aspect, the special subframe further includes a cyclic suffix CS located after the DLBP, The CS transmits K synchronization signals, where K is a positive integer less than Nd.

With reference to the fourth aspect, or any one of the foregoing possible implementation manners of the foregoing fourth aspect, in the twelfth possible implementation manner of the fourth aspect, the sending unit is configured to: sequentially send the device by using Nd transmit beams. Decoding Nd synchronization signals; sequentially transmitting the K synchronization signals using the first K transmission beams of the Nd transmission beams.

With reference to the fourth aspect, or any one of the foregoing possible implementation manners, in the thirteenth possible implementation manner of the fourth aspect, the special subframe further includes a reserved data interval RDP and uplink and downlink switching protection Interval GP.

With reference to the fourth aspect, or any one of the foregoing possible implementation manners, the fourth possible implementation manner of the fourth aspect, the period of the synchronous radio frame used by the high frequency base station is M The length of the radio frames, where M is a positive integer.

In a fifth aspect, a user equipment is provided, including a processor, a transceiver, and a memory. The transceiver is configured to receive synchronization information sent by the high-frequency base station, where the synchronization radio frame that carries the synchronization information includes at least one special subframe, where the special subframe is used to transmit a synchronization signal, where the special subframe includes a DLBP The DLBP includes Nu subintervals, each of which transmits Nd synchronization signals, where Nu and Nd are positive integers greater than one. The processor is configured to synchronize according to the synchronization information.

Alternatively, the transceiver in the fifth aspect may be implemented by a receiver.

In a sixth aspect, a high frequency base station is provided, including a processor, a transceiver, and a memory. The processor is configured to generate synchronization information, where the synchronization radio frame carrying the synchronization information includes at least one special subframe, the special subframe includes a DLBP, the DLBP includes Nu subintervals, and each subinterval transmits Nd synchronization signals, Wherein Nu and Nd are positive integers greater than one. Transceiver for The synchronization information is sent to the user equipment.

Alternatively, the transceiver in the sixth aspect may be implemented by a transmitter.

In a seventh aspect, a computer program product is provided, the computer program product comprising: computer program code, when the computer program code is run by a receiving unit, a processing unit or a transceiver of a user equipment, a processor, The user equipment performs the above-described first aspect, and a method of downlink synchronization of any of its various implementations.

According to an eighth aspect, a computer program product is provided, the computer program product comprising: computer program code, when the computer program code is run by a generating unit, a transmitting unit or a transceiver of a high frequency base station, and a processor, The high frequency base station performs the above second aspect, and a method of downlink synchronization of any of the various implementations.

In a ninth aspect, a computer readable storage medium is provided, the computer readable storage medium storing a program causing a user equipment to perform the first aspect described above, and any one of the various implementations of the downlink synchronization Methods.

According to a tenth aspect, there is provided a computer readable storage medium storing a program causing a high frequency base station to perform the second aspect described above, and any of the various implementations thereof The method of synchronization.

In the present invention, the high frequency base station transmits synchronization information in a special subframe, and the UE completes synchronization with the high frequency base station by receiving the synchronization signal in the special subframe, which is advantageous for the UE to quickly access the high frequency system and save access. Power consumption.

DRAWINGS

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments or the prior art description will be briefly described below. Obviously, the drawings in the following description are only some of the present invention. For the embodiments, other drawings may be obtained from those skilled in the art without any inventive labor.

FIG. 1 is a schematic diagram of a scenario of a high and low frequency hybrid networking system according to an embodiment of the present invention.

2 is a schematic structural diagram of a synchronous radio frame according to an embodiment of the present invention.

3 is a schematic diagram of a frame structure used by a high frequency base station according to an embodiment of the present invention.

FIG. 4 is a schematic structural diagram of a special subframe according to an embodiment of the present invention.

FIG. 5 is another schematic structural diagram of a special subframe according to an embodiment of the present invention.

FIG. 6 is another schematic structural diagram of a special subframe according to an embodiment of the present invention.

FIG. 7 is another schematic structural diagram of a special subframe according to an embodiment of the present invention.

FIG. 8 is a schematic structural diagram of a DLBP according to an embodiment of the present invention.

FIG. 9 is a schematic structural diagram of a subinterval of a DLBP according to an embodiment of the present invention.

FIG. 10 is another schematic structural diagram of a special subframe according to an embodiment of the present invention.

11 is a schematic diagram of a receive beam used by a UE according to an embodiment of the present invention.

Figure 12 is a schematic illustration of a synchronization detection window in accordance with an embodiment of the present invention.

Figure 13 is another schematic diagram of a synchronization detection window in accordance with an embodiment of the present invention.

FIG. 14 is another schematic diagram of a receive beam used by a UE according to an embodiment of the present invention.

Figure 15 is a diagram showing a transmission beam used by a high frequency base station according to an embodiment of the present invention.

16 is another schematic diagram of a transmission beam used by a high frequency base station according to an embodiment of the present invention.

17 is another schematic diagram of a transmission beam used by a high frequency base station according to an embodiment of the present invention.

FIG. 18 is a schematic diagram of a UE receiving a synchronization signal on a special subframe according to an embodiment of the present invention.

FIG. 19 is another schematic diagram of a UE receiving a synchronization signal on another special subframe according to an embodiment of the present invention.

20 is another schematic diagram of a transmission beam used by a high frequency base station according to an embodiment of the present invention.

21 is another schematic diagram of a transmission beam used by a high frequency base station according to an embodiment of the present invention.

Figure 22 is another schematic diagram of a synchronization detection window in accordance with an embodiment of the present invention.

FIG. 23 is a schematic diagram of a UE receiving a synchronization signal on a special subframe according to an embodiment of the present invention.

FIG. 24 is another schematic diagram of a UE receiving a synchronization signal on another special subframe according to an embodiment of the present invention.

Figure 25 is a flow diagram of a method of downlink synchronization in accordance with one embodiment of the present invention.

26 is a flow chart of a method of downlink synchronization in accordance with another embodiment of the present invention.

Figure 27 is a block diagram showing the structure of a user equipment according to an embodiment of the present invention.

FIG. 28 is a structural block diagram of a user equipment according to another embodiment of the present invention.

Figure 29 is a block diagram showing the structure of a high frequency base station according to an embodiment of the present invention.

Figure 30 is a block diagram showing the structure of a high frequency base station according to another embodiment of the present invention.

detailed description

The technical solution in the embodiment of the present invention will be described below with reference to the accompanying drawings in the embodiments of the present invention. It is clear that the described embodiments are part of the embodiments of the invention, and not all of the embodiments. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without creative efforts are within the scope of the present invention.

In the embodiment of the present invention, the base station may be a Global System for Mobile communication (GSM) system or a Base Transceiver Station (BTS) in a Code Division Multiple Access (CDMA) system, or may be A base station (NodeB) in a Wideband Code Division Multiple Access (WCDMA) system, which may also be an evolved Node B (eNB or eNodeB) in an LTE system, or a base station in a future 5G network. The device, the small base station device, and the like are not limited by the present invention.

In the embodiment of the present invention, a user equipment (User Equipment, UE) may communicate with one or more core networks (Core Network) via a radio access network (RAN), and the UE may be referred to as an access terminal or a terminal. Device, subscriber unit, subscriber station, mobile station, mobile station, remote station, remote terminal, mobile device, user terminal, terminal, wireless communication device, user agent or user device. The UE may be a cellular phone, a cordless phone, a Session Initiation Protocol (SIP) phone, a Wireless Local Loop (WLL) station, a Personal Digital Assistant (PDA), or a wireless communication function. Handheld devices, computing devices or other processing devices connected to wireless modems, in-vehicle devices, wearable devices, and terminal devices in future 5G networks.

FIG. 1 is a schematic diagram of an application scenario of an embodiment of the present invention. A high and low frequency hybrid networking system is shown in FIG. 1, including a low frequency base station 11, a high frequency base station 12, and a UE 13.

In the embodiment of the present invention, the frequency band of the low frequency base station 11 is lower than the frequency band of the high frequency base station 12. The frequency band used by the low frequency base station 11 may be a low frequency band below 6 GHz, for example, 2 GHz and 5 GHz. The frequency band used by the high frequency base station 12 may be a high frequency band represented by a millimeter wave frequency band (ie, 6 GHz or higher). For example, the frequency used by the high frequency base station 12 may be 72 GHz, 28 GHz or 14 GHz.

The low-frequency base station 11 covers a large area, and the high-frequency base station 12 performs hotspot coverage within the coverage of the low-frequency base station to improve the capacity of the hot spot. The UE 13 is typically equipped with both a low frequency transceiver and a high frequency transceiver, a low frequency transceiver for data communication with the low frequency base station 11, and a high frequency transceiver for data communication with the high frequency base station 12.

The UE 13 needs to establish a normal communication link with the high frequency base station 12, and first needs to pass the downlink synchronization. The channel acquires the downlink synchronization of the high frequency system, and then accesses the high frequency system through the random access process.

2 shows a synchronous radio frame in a frame structure used by a high frequency base station to transmit a synchronization signal in an embodiment of the present invention. It can be understood that the frame structure shown in FIG. 2 is a general frame structure of a high frequency communication system.

The frame length of the synchronous radio frame shown in FIG. 2 is 10 milliseconds (ms), which is compatible with the frame structure of the existing LTE system. A radio frame consists of 10 radio subframes with a frame length of 1 ms. In the embodiment of the present invention, two types of wireless subframes are defined: a general subframe and a special subframe. Among them, the general subframe is mainly used for normal data transmission, and the special subframe is used for transmitting high frequency synchronization signals.

In the embodiment of the present invention, the frame structure used by the high frequency base station 12 may include two types: a synchronous radio frame and a general radio frame. The synchronous radio frame includes at least one special subframe and a plurality of general subframes, and the general radio frame includes 10 general subframes. Moreover, the frame length of one synchronous radio frame is 10 ms, and the frame length of a general radio frame is also 10 ms.

In the embodiment of the present invention, the period of the synchronous radio frame used by the high-frequency base station 12 may be the length of M radio frames, where M is a positive integer. That is to say, in the frame structure used by the high-frequency base station 12, M-1 normal radio frames are spaced after one synchronous radio frame, and the next synchronous radio frame is used, as shown in FIG. In the frame structure used by the high frequency base station 12, one synchronous radio frame and M-1 general radio frames are included in every M consecutive radio frames.

It can be understood that if M=1, it means that in the frame structure used by the high-frequency base station 12, each radio frame is a synchronous radio frame.

It can be understood that the frame length of a general subframe is 1 ms, and the frame length of a special subframe is also 1 ms. A synchronous radio frame includes at least one special subframe, as shown in FIG. 2, a synchronous radio frame including two special subframes 201 and 202.

A general subframe is divided into eight time slots having a length of 0.125 ms, and each time slot is composed of Ns Orthogonal Frequency Division Multiplexing (OFDM) symbols. The size of Ns depends on the frequency used by the high-frequency communication system. Specifically, when the frequency is 72 GHz, Ns=80; when the frequency is 28 GHz, Ns=40; when the frequency is 14 GHz, Ns=20 .

Alternatively, a general subframe may be divided into a plurality of equally long time slots, wherein each time slot may have a length of 0.1 ms to 0.2 ms. For example, a general subframe may include 10 time slots of length 0.1 ms.

The special subframe may include a downlink synchronization and a beam training interval (Downlink) Synchronization & Beam-training Period, DLBP). In addition, the special subframe may further include a Reserved Data Period (RDP) and an uplink and downlink handover guard interval (GP). It can be understood that the special subframe in the embodiment of the present invention is used for downlink synchronization and beam training.

It should be noted that, in the embodiment of the present invention, the DLBP may also be referred to as a downlink synchronization interval or a beam training interval, etc., and the name of the interval is not limited herein.

The embodiment of the present invention does not limit the order or position of the DLBP and the RDP included in the special subframe, as shown in FIG. 4 to FIG. 7. As shown in FIG. 4, the case where the DLBP starts from the first OFDM symbol and the uplink RDP terminates in the last (assumed to be the Nmth) OFDM symbol. As shown in FIG. 5, the case where the uplink RDP starts from the first OFDM symbol and the DLBP terminates in the last (assumed to be the Nmth) OFDM symbol. As shown in FIG. 6, the downlink RDP starts from the first OFDM symbol, ends in the k1-1th (k1>1) OFDM symbol, the DLBP starts from the k1st OFDM symbol, and the uplink RDP terminates in the last one ( The case of the Nmth OFDM symbol is assumed. As shown in Figure 7, the uplink RDP starts with the first OFDM symbol, and the DLBP terminates at the k2 (k2 < Nm) OFDM symbols, and the downlink RDP starts with k2 + 1 OFDM symbols, ending with the last one (hypothesis) The case of the Nmth) OFDM symbol.

In the embodiment of the present invention, the DLBP may include Nu subintervals. As shown in FIG. 8, the Nu subintervals are: DLBP ₀ , DLBP ₁ , . . . , DLBP _Nu-2 , DLBP _Nu-1 . Each subinterval can be composed of Nd time slices. As shown in FIG. 8, the first subinterval DLBP ₀ includes Nd time slices, which are: S ₀ , S ₁ , . . . , S _Nd-1 . The magnitudes of Nu and Nd respectively correspond to the number of wide beams transmitted by the high frequency base station 12 and the number of wide beams received by the user equipment 13, and the value depends on the frequency used by the high frequency communication system. As an example, when the frequency point is 72 GHz, Nd = 16 or 12, and Nu = 12. When the frequency is 28 GHz, Nd = 12 and Nu = 8. When the frequency is 14 GHz, Nd=8 and Nu=6.

It can be understood that, in the embodiment of the present invention, Ns, Nd, and Nu are both positive integers greater than 1, and the values of Ns, Nd, and Nu are related to the frequency points used by the high frequency base station in the system.

Among them, the value of Nu is not only related to the frequency, but also related to the performance of the UE itself. For example, when the frequency point is 28 GHz, Nu=8 of one UE and Nu=12 of another UE.

In addition, each sub-interval may further include Nd Switching Guard Periods (SGPs) respectively located after Nd time slices.

In the embodiment of the present invention, the length of one time slice may be Nr OFDM symbols, where Nr is a positive integer.

For example, Nr can be 1.

For example, Nr can be 2. That is, the length of each time slice includes two OFDM symbols. The first OFDM symbol of the two OFDM symbols is used to send a Primary Synchronization Signal (PSS), and the second OFDM symbol of the two OFDM symbols is used to send a Secondary Synchronization Signal (SSS). As shown in FIG. 9, the time slice S ₀ includes two OFDM symbols for transmitting the SSS and the PSS, respectively.

For example, Nr can be greater than two. That is, the length of each time slice includes at least two OFDM symbols. Wherein the first OFDM symbol of the at least two OFDM symbols is used for transmitting the PSS, and the second OFDM symbol of the at least two OFDM symbols is used for transmitting the SSS. That is, at least one of the Nr OFDM symbols is used to transmit the PSS; at least one of the Nr OFDM symbols is used to transmit the SSS.

In the frequency domain, PSS and SSS are transmitted through the intermediate W megahertz of the system bandwidth, typically W=500. Similar to the LTE system, a specific sequence of PSS is transmitted in a specific cell of a given high frequency base station, and is used to indicate to the UE 13 its cell ID in a high frequency base station, assuming that one high frequency base station controls up to six high frequency cells. The value of the high frequency cell ID is 0 to 5.

In particular, the second OFDM symbol can transmit a specific sequence of SSS. The specific sequence includes an identifier (Identity, ID) of a time slice in which the specific sequence is located, and an ID of a subinterval in which the specific sequence is located.

Alternatively, the specific sequence may include at least one of: an ID of the high frequency base station, a time slice of the specific sequence, and an ID of a subinterval in which the specific sequence is located. Alternatively, the specific sequence may include at least one of: an ID of the high frequency base station, an ID of a transmission beam used on a time slice in which the specific sequence is located, and an ID of a subinterval in which the specific sequence is located. The invention is not limited thereto.

For example, a specific sequence of SSS may be transmitted on a specific time slice in a subinterval of a specific DLBP of the high frequency base station, for indicating to the UE 13, the high frequency base station ID in which it is located, and the subinterval of the specific DLBP. The ID (value is 0 to Nu-1) and the transmit beam ID or time slice ID of the high frequency base station used on the specific time slice (values 0 to Nd-1).

Specifically, the UE 13 performs non-coherent detection on the PSS, acquires symbol synchronization, and obtains a high frequency cell ID. Assuming that the channel coherence duration is much longer than one OFDM symbol period, the correlation between the PSS and the SSS is used to perform coherent detection on the SSS to obtain the high frequency base station ID, the subinterval ID of the DLBP, and the base station transmit beam ID (time slice ID). Since the sub-interval ID of the DLBP and the base station transmit beam ID (time slice ID) are in one-to-one correspondence with the OFDM symbol position in the special subframe in which the SSS is located in a special subframe, the above information can be obtained to obtain the SSS. The OFDM symbol position in the special subframe can obtain the radio frame synchronization. 10, UE 13 is assumed successfully detected signal PSS sent DLBP ₁ subintervals, coherent detection of the signal SSS DLBP ₁ subinterval signals transmitted by the PSS. When the DLBP subinterval ID number is 1, and the base station transmit beam ID (time slice ID) is 1, the start position of the special sub-frame can be obtained by pushing a DLBP period and adding a time slice period from the symbol position of the SSS. According to the position of the special subframe in the radio frame, the position of the starting point of the radio frame can be directly pushed out, and the radio frame synchronization is successfully obtained. For the case where there are two or more special subframes in one radio frame, it is necessary to distinguish each special subframe by a sequence indicating the high frequency base station ID.

For a description of the transmit beam, refer to the following specific embodiments.

In the embodiment of the present invention, the high frequency base station 12 can transmit the synchronization signal by using the synchronous radio frame as shown in the foregoing. Specifically, on a special subframe (such as subframe #1 in FIG. 2), in each subinterval of the DLBP, the high frequency base station 12 can transmit the synchronization signal using different transmission beams on the Nd time slices. In other words, in each subinterval, the high frequency base station 12 can transmit Nd synchronization signals through the Nd first sequential transmission beams. It can also be understood that, on the DLBP of a special subframe, the high frequency base station 12 transmits Nd synchronization signals through Nd first sequential transmission beams, and the transmission period is Nu.

For example, the first order may be #0 to #Nd-1. For example, transmits a synchronization signal transmission beam # 0 in the time sheet S _0, the time the sheet S ₁ by the transmission beams # 1 transmits a synchronization signal, ..., a time slice S _Nd-1 transmission Nd-1 by transmitting beams # on Synchronization signal. Among them, SGP is used for switching between different transmit beams. Referring to FIG. 8, it can be understood that the ID of the time slice can also be the ID of the transmission beam.

With reference to FIG. 8, it can be understood that on the DLBP, the transmit beam is determined with a period of Nu, wherein the periodically used transmit beams are the first order of Nd transmit beams.

In this embodiment of the present invention, a special subframe may be considered as a reserved number of OFDM symbols. Then, the process of transmitting the synchronization signal by the high-frequency base station 12 can be understood as: the high-frequency base station 12 has a fixed transmission beam switching period (Nu cycles) on a plurality of reserved transmission symbols (special subframes) reserved. And a fixed transmit beam logic sequence (#0, #1, ..., #Nd-1), which in turn switches the transmit beam to transmit the synchronization signal.

It should be noted that the logical order (ie, the first order) of the transmit beams herein is not limited to #0 to #Nd-1. For example, it may be #1, #2, ..., #Nd-1, #0; or it may be #Nd-1, #Nd-2,..., #1, #0, and the like.

Thus, after receiving the synchronization signal transmitted by the high frequency base station 12, the UE 13 can complete synchronization with the high frequency base station 12 and establish a normal communication link.

Specifically, the UE may receive the synchronization signal through a fixed receive beam in one subinterval. In different subintervals, the UE 13 switches between different receive beams to receive the synchronization signal. That is to say, the UE respectively receives the beams on the Nu subintervals through the Nu receiving beams. As shown in Figure 11. The UE receives the synchronization signal on the sub-interval DLBP ₀ through the reception beam #0, receives the synchronization signal on the sub-interval DLBP ₁ through the reception beam #1, ..., and receives the synchronization on the sub-interval DLBP _Nu-1 through the reception beam #Nu-1 signal.

For the high and low frequency hybrid networking system shown in FIG. 1, the UE 13 can quickly obtain the downlink synchronization of the high frequency system through the low frequency assistance. A radio frame of the low frequency base station 11 having a serial number #k and a synchronous radio frame of the high frequency base station 12 having a serial number #k are shown in FIG. Wherein, 0 to 9 indicate the sequence number of the subframe.

It should be noted that although a synchronous radio frame of the high frequency base station 12 shown in FIG. 12 having the sequence number #k includes two special subframes, which are subframes of sequence number 1 and sequence number 6, respectively. However, the present invention does not limit the number of special subframes included in a synchronous radio frame. For example, one synchronous radio frame may include only one special subframe, or one synchronous radio frame may include more special subframes. (3, 4, etc.).

It should be noted that although the special subframes shown in FIG. 12 include DLBP, GP, and RDP, the structure of the special subframe of the present invention is not limited thereto. For details, refer to the related descriptions of FIG. 2 to FIG. 7 described above.

Assuming that the high and low frequencies can be strictly synchronized, the UE 13 can obtain the frame synchronization of the high frequency base station 12 through the low frequency base station 11, that is, the UE 13 can determine the start time of the subframe 0 of the high frequency base station 12, and then the UE 13 can The start time of the special subframe (such as the subframe numbered 1) in the high-frequency base station 12 starts, and the high-frequency downlink synchronization signal detection is performed.

Specifically, the length of the synchronization detection window is the length of the DLBP defined in the special subframe. In a synchronization detection window, the UE 13 can traverse the combination of the transmission beam of all the high frequency base stations 12 and the reception beam of the UE 13. In this way, the UE 13 can obtain the downlink synchronization of the high frequency system through a synchronization detection window, and simultaneously acquire the transmission beam of the corresponding high frequency base station 12 and the reception wave of the UE 13. The ID number of the bundle, the cell ID number, the sub-interval ID number included in the DLBP, and the like.

However, for the system of the high and low frequency hybrid networking shown in FIG. 1, the high and low frequency signals received by the UE 13 are difficult to be strictly synchronized. For example, if the low frequency base station 11 and the high frequency base station 12 are not co-located, the low frequency base station 11 and the high frequency base station 12 cannot guarantee that strict time synchronization can be obtained. For another example, the distance from the UE 13 to the low frequency base station 11 is different from the distance to the high frequency base station 12, and the signals respectively transmitted from the low frequency base station 11 and the high frequency base station 12 experience different propagation paths, resulting in a difference in signal transmission delay. . It can be seen that the low frequency signal of the low frequency base station 11 received by the UE 13 and the high frequency signal of the high frequency base station 12 are difficult to be strictly synchronized, and there is generally a high and low frequency delay between the two, and the high and low frequency delay is followed. The position of the UE 13 changes.

As shown in FIG. 1, the UE 13 is closer to the high frequency base station 12 and is farther from the low frequency base station 11. Then, the low frequency base station 11 and the high frequency base station 12 send signals at the same time, the high frequency signal received by the UE 13 arrives first, and the received low frequency signal arrives later, as shown in FIG. 13, between the low frequency signal and the high frequency signal. There are high and low frequency delays. The description of the low-frequency radio frame and the high-frequency synchronous radio frame is the same as the corresponding content in FIG. 12, and details are not described herein again.

At this time, the UE 13 can determine the starting position of the high frequency base station synchronization detection window according to the low frequency signal transmitted by the low frequency base station. The length of the synchronization detection window is equal to the length of time of the DLBP. Further, the UE 13 receives the synchronization signal using Nu different receive beams starting from the start position of the synchronization detection window. Wherein each receiving beam receives Nd synchronization signals. That is, the Nu different receive beams respectively receive the Nu group sync signals, wherein each set of sync signals includes Nd sync signals.

It can be understood that the UE 13 also receives the low frequency signal transmitted by the low frequency base station before the high frequency synchronization is performed.

It should be noted that in Fig. 13 and subsequent embodiments of the present invention, the start position of the sync detection window is located within the special subframe. However, the present invention is not limited thereto. For example, in other cases, the start position of the sync detection window may also be within a normal subframe.

If the UE 13 uses the low frequency signal as the synchronization reference point, the high frequency synchronization signal can be detected on the synchronization detection window of the special subframe (subframes of sequence numbers 1 and 6). Due to the presence of high and low frequency delays, the synchronization detection window (the synchronization detection window in FIG. 13) in which the UE 13 actually performs the synchronization detection, and the synchronization detection window (the synchronization detection window in FIG. 12, corresponding to the DLBP) corresponding to the synchronous detection should be performed. An offset occurs, which will cause the UE 13 to traverse the combination of the transmit beam of all the high frequency base stations 12 and the receive beams of the UE 13 in the sync detection window. Thus, the detection missing problem of the combination of the transmission beam of the high frequency base station 12 and the reception beam of the UE 13 occurs. And because the special subframe is sent the same The step signals are all periodic, so the combination of the transmit beam of the high frequency base station 12 and the receive beam of the UE 13 can never be detected (ie, the detection missing problem exists in any special subframe), which will result in some The synchronization of some users failed.

Due to the randomness of the high and low frequency delays, the synchronization start time point of the UE 13 cannot be guaranteed to be aligned with the start time point of the synchronization symbol (DLBP), which will result in the sampling point of a synchronization symbol not being completely received. The sync signal on this symbol cannot be detected correctly. 14, the synchronization start time point falls within the UE 13 if the blind spot detection S _0, then the sheet S at time ₀ by synchronizing the base station transmits a high frequency signal # 0 transmitted beam 12 not be correctly detected.

In this embodiment, in the embodiment of the present invention, the transmission beam used by the synchronization signal sent by the high-frequency base station 12 may be in the form of: in the first special subframe, the high-frequency base station 12 transmits the synchronization signal by using the first-order transmission beam; On the second special subframe, the high frequency base station 12 transmits the synchronization signal using the second order transmission beam. Wherein, the second order may be generated by cyclic shifting in the first order. Moreover, the length of the cyclically shifted time slice is greater than the high and low frequency delay of the system.

In the embodiment of the present invention, the frame structure used by the high-frequency base station 12 to transmit the synchronization signal includes a plurality of synchronous radio frames.

If the number of special subframes in each synchronization radio frame is 1, that is, one synchronization radio frame includes one special subframe. Then, the foregoing first special subframe may be a special subframe in the first synchronous radio frame, and the second special subframe may be a special subframe in the second synchronous radio frame. The second synchronization radio frame is a next synchronization radio frame adjacent to the first synchronization radio frame. That is to say, for two consecutive synchronous radio frames, the transmission beam order used by the respective special subframes is different. Specifically, the special subframes in the first synchronization radio frame use the first sequential transmission beam, and the second synchronization wireless The special subframe in the frame transmits the beam using the second order.

It should be noted that the second synchronous radio frame referred to herein refers to the first synchronous radio frame located after the first synchronous radio frame. For example, the first synchronous radio frame may be the synchronous radio frame 301 in FIG. 3, and the second synchronous radio frame may be the synchronous radio frame 302 in FIG.

If the number of special subframes in each synchronization radio frame is even, that is, one synchronization radio frame includes 2N special subframes. Then, the foregoing first special subframe may be the 2ith special subframe in one synchronous radio frame, and the second special subframe may be the 2i+1th special subframe in one synchronous radio frame.

If the number of special subframes in each synchronous radio frame is an odd number, that is, one synchronous radio frame includes 2N+1 special subframes. Then, the foregoing first special subframe may be in the first synchronous radio frame. The 2ith special subframe or the 2i+1th special subframe in the second synchronization radio frame, and the second special subframe may be the 2i+1th special subframe in the first synchronization radio frame or The 2ith special subframe in the second synchronization radio frame.

In other words, all radio frames used by the high frequency base station 12 can be considered as a whole. The special subframes in all the radio frames are consecutively numbered consecutively, wherein the sequence number can start from 0, or start from 1, or start from any value, which is not limited herein. Further, a special subframe numbered oddly may be defined as a first special subframe, and a special subframe numbered as an even number is defined as a second special subframe. Alternatively, a special subframe numbered with an even number may be defined as a first special subframe, and a special subframe numbered as an odd number may be defined as a second special subframe.

Since the number of special subframes included in one synchronous radio frame is at least 1, the number of special subframes in all radio frames (at least two simultaneous radio frames) is at least two. And, at least two special subframes may be sequentially numbered. For example, the number of at least two special subframes may be special subframe #0, special subframe #1, special subframe #2, and the like. For another example, the numbers of the at least two special subframes may be special subframe #1, special subframe #2, special subframe #3, and the like.

The following embodiments of the present invention are described by taking one synchronous radio frame as two special subframes as an example. Suppose a synchronous radio frame includes two special subframes. For example, assume that 10 subframes of the synchronous radio frame are subframe #0, subframe #1, ..., subframe #8, and subframe #9. Among them, the subframe #1 and the subframe #6 are special subframes. Then, the two special subframes may be numbered as special subframe #0 and special subframe #1, or numbered as special subframe #1 and special subframe #2.

Optionally, as an embodiment, subframe #1 may be defined as a first special subframe, and subframe #6 may be defined as a second special subframe. Thus, the first order transmission beam can be used on the first special subframe, and the second sequential transmission beam can be used on the second special subframe.

Alternatively, in the special subframe in which the number is odd in the two special subframes, the Nd synchronization signals are transmitted by the high frequency base station 12 using Nd first order transmission beams. In the special subframes with even numbers in the two special subframes, the Nd synchronization signals are transmitted by the high frequency base station 12 using Nd second order transmission beams. Here, the second order may be generated by cyclic shifting of the first order. In other words, in the subinterval of the DLBP of the first special subframe, the high frequency base station 12 sequentially switches the transmit beam transmission synchronization signal in the first specific order, in the subinterval of the DLBP of the second special subframe, the high frequency The base station 12 sequentially switches the transmit beam transmission synchronization signals in a second specific order. The second specific order is a cyclic shift of the first specific order Bit.

For example, subframe #1 is special subframe #0, and subframe 6 is special subframe #1. That is to say, the subframe #1 is a special subframe whose sequence number is an even number, and the subframe #6 is a special subframe whose sequence number is an odd number. Then, subframe #6 can use the first sequence of transmit beams, and subframe #1 can use the second sequence of transmit beams, as shown in FIG. 15, the time slice S _i in the figure indicates the use of the transmit beam #i transmission synchronization. signal. The first order is #0 to #Nd-1, and the second order is #K to #Nd-1, #0 to #K-1. That is, the second order is generated after the first order is cyclically shifted by K bits.

For example, subframe #1 is special subframe #1, and subframe 6 is special subframe #2. That is to say, the subframe #1 is a special subframe whose sequence number is an odd number, and the subframe #6 is a special subframe whose sequence number is an even number. Then, subframe #1 can use the first order of the transmit beam, and subframe #6 can use the second order of the transmit beam, as shown in FIG. 16, the time slice S _i in the figure indicates the use of the transmit beam #i transmission synchronization. signal. The first order is #0 to #Nd-1, and the second order is #K to #Nd-1, #0 to #K-1. That is, the second order is generated after the first order is cyclically shifted by K bits.

Specifically, in this embodiment, the high frequency base station 12 switches the transmission beam according to the normal transmission beam logic order in the first special subframe (subframe #6 in FIG. 15 or subframe #1 in FIG. 16). That is, the transmission beam transmission synchronization signal is sequentially switched in the sub-sections #0 to #Nu-1 of the respective DLBPs in accordance with the logical numbers #0 to #Nd-1 of the transmission beam. In the second special subframe (subframe #1 in FIG. 15 or subframe #6 in FIG. 16), the high frequency base station 12 switches and transmits in the logical sequence of the cyclically shifted transmission beam in the subinterval of each DLBP. The beam, that is, the transmission beam transmission synchronization signal is sequentially switched in the respective DLBP subintervals #0 to #Nu-1 in accordance with the logical sequence numbers #K to #Nd-1 to #0 to #K-1 of the transmission beam.

As another understanding, in the DLBP of the special subframes with odd numbers in the two special subframes, the Nd synchronization signals are transmitted by the high frequency base station 12 using Nd first sequential transmission beams. In the DLBP of the special subframe with the even number in the two special subframes, the Nd synchronization signals are transmitted by the high frequency base station 12 using Nd second order transmission beams. In other words, in the DLBP of the first special subframe, the high frequency base station 12 sequentially switches the transmit beam transmission synchronization signal in the first specific order, and in the DLBP of the second special subframe, the high frequency base station 12 is in the second specific The sequence sequentially switches the transmit beam to transmit the synchronization signal. The second particular order is a cyclic shift of the first particular order.

In this interpretation, the DLBP as a whole is cyclically shifted. Another explanation for the situation shown in FIG. 16 is shown in FIG. 17, subframe #1 may use the first order of the transmit beam, the sub-frame Frame #6 can use the second order of transmit beams. The first order is #0 to #Nd-1, #0 to #Nd-1, ..., #0 to #Nd-1, and the second order is #K to #Nd-1, #0 to #Nd- 1, ..., #0 to #Nd-1, #0 to #K-1. That is, the second order is generated after the first order is cyclically shifted by K bits. Here, the first order is Nu#0 to #Nd-1, that is, the first order includes Nu×Nd transmit beams.

That is, the high frequency base station 12 switches the transmission beam of the base station in the first special subframe (subframe #1 shown in FIG. 17) in the logical sequence of the normal transmission beam, that is, in the subinterval #0 of the DLBP. In #Nu-1, the transmission beam transmission synchronization signal is switched in accordance with the logical sequence numbers #0 to #Nd-1 of the transmission beam. In the second special subframe (such as subframe #6 shown in FIG. 17), the high-frequency base station 12 switches the transmission beam of the base station in the DLBP according to the logical sequence of the cyclically shifted transmission beam, that is, the first K of the DLBP ₀ . The transmit beam (#0 to #K-1) is transmitted after being shifted to DLBP _Nu-1 . In the second special subframe, the high frequency base station 12 firstly switches the transmission beam of the logical sequence number #K to #Nd-1 in the DLBP ₀ subinterval to transmit the synchronization signal, and then sequentially in the DLBP ₁ to DLBP _Nu-1 subintervals. The transmission beam transmission synchronization signal is switched according to the logical sequence numbers #0 to #Nd-1 of the transmission beam, and finally, the transmission beam transmission synchronization signals of the logical numbers #0 to #K-1 in the DLBP ₀ sub-interval are sequentially switched.

It should be understood that in the embodiment of the present invention, although the transmission beam used by the high frequency base station 12 to transmit the synchronization signal is explained by the above two different explanations, the actual transmission beams of Figs. 16 and 17 are the same.

It should be noted that the length of the cyclically shifted time slice in FIGS. 15 to 17 (the length of the time slice corresponding to S ₀ to S _K ) should be greater than the high and low frequency delay of the system (ie, the high and low frequency times shown in FIG. 13). Length of extension).

Specifically, the high frequency base station 12 may determine the K value before transmitting the synchronization signal. For example, the high-frequency base station 12 may preset one or more values of K. Before transmitting the synchronization signal, the high-frequency base station 12 may first determine the K value according to the coverage and other indicators, and then determine the first value using the determined K value. A sequence and a second sequence, and a synchronization signal is transmitted.

It should be noted, in the embodiment shown in FIG. 15 to FIG. 17, S _i represents transmission using transmission beam #i synchronization signal.

As another understanding, it is assumed that the IDs of the transmission beams #0, #1, ..., #Nd used by the high-frequency base station 12 are 0, 1, ..., Nd, respectively. Then, the manner of transmitting the transmission beam used by the synchronization signal can be understood as follows:

On the time slice Si of the DLBP of the first special subframe, the ID of the transmitted beam used is: b _i = i mod N _d i = 0, 1, 2, ..., N _d × N _u -1.

On the time slice Si of the DLBP of the second special subframe, the ID of the transmitted beam used is: b _i = (i + K) mod N _d i = 0, 1, 2, ..., N _d × N _u -1.

The number of time slices included in one special subframe is N _d ×N _u .

Assuming that the low frequency synchronization signal received by the UE 13 lags behind the high frequency synchronization signal, taking Nd=12 and Nu=12 as an example, FIG. 18 and FIG. 19 respectively show the first special subframe and the second special subframe UE 13 synchronization signal. Receiving situation.

In the first special subframe, as shown in FIG. 18, due to the introduction of the high and low frequency delay Δt, the UE 13 synchronizes with the receive beam #0 from the second time slice (the first S1 in FIG. 18). Signal detection. Since the start time of the start of the synchronization signal detection by the UE 13 is located in the middle of the time slice S1, the synchronization signal transmitted by the high frequency base station 12 transmitting the beam #1 on the time slice S1 cannot be completely received by the UE 13. Since the switching period of the receiving beam of the UE 13 is equal to the period in which the high-frequency base station 12 completes the transmission of the Nd=12 time-on-chip synchronization signals, the UE 13 cannot correctly receive the high-frequency base station 12 through the transmitting beam on all the receiving beams. #1 Synchronization signal sent. In addition, since the high and low frequency delay Δt is greater than the length of one time slice, the last reception beam of the UE 13 is leaked to receive a synchronization signal transmitted on a time slice. As shown in FIG. 18, the UE 13 cannot receive the synchronization signal transmitted by the high frequency base station 12 through the transmission beam #0 during the reception period of its reception beam #11.

In the second special subframe, as shown in FIG. 19, the transmission beam sequence in the first special subframe is cyclically shifted, and the total length of the time slice occupied by the K beams to be cyclically shifted is greater than the high and low frequency delay. Δt, as shown in FIG. 19, K=2, starts transmitting the synchronization signal from the transmission beam #2. Similar to the first special subframe, due to the introduction of the high and low frequency delay Δt, the UE 13 starts the detection of the synchronization signal with the reception beam #0 from the second time slice (the first S3 in Fig. 19). Since the start time of the start of the synchronization signal detection by the UE 13 is located in the middle of the time slice S3, the synchronization signal transmitted by the high frequency base station 12 transmitting the beam #3 on the time slice S3 cannot be completely received by the UE 13. Since the switching period of the receiving beam of the UE 13 is equal to the period in which the high-frequency base station 12 completes the transmission of the Nd=12 time-on-chip synchronization signals, the UE 13 cannot correctly receive the high-frequency base station 12 through the transmitting beam on all the receiving beams. #3 The sync signal sent. In addition, since the high and low frequency delay Δt is greater than the length of one time slice, the last reception beam of the UE 13 is leaked to receive a synchronization signal transmitted on a time slice. As shown in FIG. 19, the UE 13 cannot receive the synchronization signal transmitted by the high frequency base station 12 through the transmission beam #2 during the reception period of its reception beam #11. In the second special subframe, the UE 13 is capable of receiving a synchronization signal that cannot be successfully received in the first special subframe. As shown in Figure 19, The high frequency base station 12 transmits the synchronization signal transmitted by the beam #1 on the time slice S1, and the high frequency base station 12 transmits through the transmission beam #0, and the UE 13 passes the synchronization signal received by the beam #11.

The UE 13 searches through the synchronization signals of the first special subframe and the second special subframe, and can traverse all the combinations of the high frequency base station 12 transmit beam and the UE 13 receive beam to obtain synchronization of the high frequency system.

Alternatively, in the embodiment of the present invention, the form of the used transmit beam used by the high frequency base station 12 may also be as follows:

Each special subframe in the synchronous radio frame further includes a Cyclic Suffix (CS) located after the DLBP, and CS is used to transmit K synchronization signals, where K is a positive integer smaller than Nd. That is, the CS includes K time slices.

At this time, the high frequency base station 12 transmits Nd synchronization signals using Nd first order transmission beams in the subinterval of each DLBP. On the CS, K synchronization signals are transmitted using the first K transmit beams in the Nd first-order transmit beams.

For example, a synchronous radio frame includes two special subframes, as shown in FIG. 20, where subframe #1 and subframe #6 are special subframes. Taking subframe #1 as an example, it includes a DLBP and a CS located after the DLBP. Each sub-interval of the DLBP transmits Nd synchronization signals, and the Nd synchronization signals are transmitted by the high-frequency base station 12 using Nd first-order transmission beams, and the first sequence shown in FIG. 20 is #0, #1, ..., #Nd-1. The CS transmits K synchronization signals, and the K synchronization signals are transmitted by the high frequency base station 12 using the first K transmission beams of the Nd first order transmission beams. The transmission beam used by the CS in FIG. 20 is: #0, #1,...,#K-1.

As another understanding, this embodiment may also be interpreted as: the special subframe further includes a Cyclic Prefix (CP) located before the DLBP, and the CP transmits K synchronization signals. That is, the CP includes K time slices. At this time, the high frequency base station 12 transmits Nd synchronization signals using Nd first order transmission beams in the subinterval of each DLBP. On the CP, K synchronization signals are transmitted using the last K transmission beams of the Nd first-order transmission beams.

As shown in Figure 21, where the CP is located before the DLBP. Each sub-interval of the DLBP transmits Nd synchronization signals, and the Nd synchronization signals are transmitted by the high-frequency base station 12 using Nd first-order transmission beams, and the first sequence shown in FIG. 21 is #0, #1, ..., #Nd-1. The CP uses to transmit K synchronization signals, which are transmitted by the high frequency base station 12 using the last K transmission beams of the Nd first order transmission beams. The transmission beam used by the CP in FIG. 21 is: #Nd -K, #Nd-K+1,...,#Nd-1.

It can be understood that if the first order is #Nd-K, #Nd-K+1,...,#Nd-1,#0,#1,..., #Nd-K-1, then, Figure 21 can also be understood as the CS is located after the DLBP. Therefore, the transmit beams used in Figures 20 and 21 are identical.

It should be noted that the length of the time slice of the CS in FIG. 20 and the CP in FIG. 21 (the length of the K time slices) should be greater than the high and low frequency delay of the system (ie, the length of the high and low frequency delay shown in FIG. 13). .

Specifically, the high frequency base station 12 may determine the K value before transmitting the synchronization signal. For example, the high-frequency base station 12 may preset one or more values of K. Before transmitting the synchronization signal, the high-frequency base station 12 may first determine the K value according to the coverage and other indicators, and then determine the CS by using the determined K value. Or CP, and send a sync signal.

It should be noted, in the embodiment shown in FIG. 21 to FIG. 20, S _i represents transmission using transmission beam #i synchronization signal.

On the time slice Si of the special subframe (including DLBP and CS or CP), the ID of the transmitted beam used is: b _i = i mod N _d i = 0, 1, 2, ..., N _d × N _u +K-1.

The number of time slices included in one special subframe is N _d ×N _u +K.

At this time, the UE 13 may determine the first start position of the first synchronization detection window according to the low frequency signal transmitted by the low frequency base station. Subsequently, the UE 13 receives the synchronization signal using Nu different receive beams starting from the first start position of the first sync detection window. Wherein each receiving beam receives Nd synchronization signals. That is, the Nu different receive beams respectively receive the Nu group sync signals, wherein each set of sync signals includes Nd sync signals. The UE 13 may further determine a second start position of the second synchronization detection window according to the low frequency signal transmitted by the low frequency base station and the additional reception delay. Subsequently, the UE 13 receives the synchronization signal using Nu different receive beams starting from the second start position of the second sync detection window. Wherein each receiving beam receives Nd synchronization signals. That is, the Nu different receive beams respectively receive the Nu group sync signals, wherein each set of sync signals includes Nd sync signals.

The length of time of the first synchronization detection window is equal to the length of time of the DLBP, and the length of time of the second synchronization detection window is equal to the length of time of the DLBP.

The second special subframe may be the first special subframe located after the first special subframe. For example, for the synchronous radio frame shown in FIG. 2, the first special subframe may be subframe #1, and the second special subframe is subframe #6.

The length of the additional receiving delay is greater than the high and low frequency delay of the system, and the length of the time slice occupied by the CS and the CP is greater than or equal to the sum of the high and low frequency delay and the additional receiving delay.

The additional receiving delay may be preset in the UE 13, or the additional receiving delay may be obtained by the UE 13 from the low frequency base station 11. For example, the additional receiving may be obtained by receiving the low frequency signaling sent by the low frequency base station 11. Receive delay.

The additional receiving delay may be pre-configured in the UE 13 according to the high and low frequency delay of the system. Alternatively, the low frequency base station 11 determines an additional reception delay based on the high and low frequency delay of the system, and transmits the additional reception delay to the UE 13.

For example, before the UE 13 accesses the high frequency system, the low frequency base station 11 can notify the UE 13 of the addition by transmitting low frequency signaling (for example, the low frequency signaling can be for Radio Resource Control (RRC) signaling). Receive delay (for example, Δt _a ).

It is assumed that the low frequency synchronization signal received by the UE 13 lags behind the high frequency synchronization signal. As shown in FIG. 22, the starting time of the special subframe obtained by the UE 13 at the low frequency synchronization is used as the starting point of the first synchronization detection window, and the first high frequency is started. Synchronization signal detection, the length of the first synchronization detection window is the length of the DLBP. The start time of the next adjacent special subframe obtained by the UE 13 at the low frequency synchronization is delayed by an additional reception delay as the starting point of the second synchronization detection window, and the second high frequency synchronization signal detection is started.

Specifically, the length of the cyclic prefix or the cyclic suffix interval, that is, the total time slice length occupied by the K beams needs to be greater than the sum of the high and low frequency delays and the additional receiving delay.

Assuming that the low frequency synchronization signal received by the UE 13 lags behind the high frequency synchronization signal, taking Nd=12, Nu=12 as an example, FIG. 23 and FIG. 24 respectively show the first special subframe and the second special subframe UE 13 synchronization signal. Receiving situation. Among them, K=4. 23 corresponds to the first synchronization detection window, and FIG. 24 corresponds to the second synchronization detection window.

In the first special subframe, as shown in FIG. 23, due to the introduction of the high and low frequency delay Δt, the UE 13 synchronizes with the receive beam #0 from the second time slice (the first S1 in FIG. 23). Signal detection. Since the start time of the start of the synchronization signal detection by the UE 13 is located in the middle of the time slice S1, the synchronization signal transmitted by the high frequency base station 12 transmitting the beam #1 on the time slice S1 cannot be completely received by the UE 13. Since the switching period of the receiving beam of the UE 13 is equal to the period in which the high-frequency base station 12 completes the transmission of the Nd=12 time-on-chip synchronization signals, the UE 13 cannot correctly receive the high-frequency base station 12 through the transmitting beam on all the receiving beams. #1 Synchronization signal sent. However, due to the presence of the CP, the length of the time slice occupied by the CP is greater than the high and low frequency delay. As shown in Figure 23, the UE 13 During the reception period of its reception beam #11, the synchronization signal transmitted by the high-frequency base station 12 through the transmission beam #0 can be received.

In a second special subframe, as shown in FIG. 24, the second synchronous detection window additionally introduces additional time delay Δt _a receiver, receiving the additional time delay Δt _a high frequency must be greater than equal to the time delay [Delta] t, that is Δt _a >Δt. Similar to the first synchronization detection window, due to the introduction of the high and low frequency delay Δt and the additional reception delay Δt _a , the start timing of the second synchronization signal detection by the UE 13 is located in the middle of the time slice S3, so the time slice S3 passes high. The synchronization signal transmitted by the transmission beam #3 of the frequency base station 12 cannot be completely received by the UE 13. Since the switching period of the receiving beam of the UE 13 is equal to the period in which the high-frequency base station 12 completes the transmission of the Nd=12 time-on-chip synchronization signals, the UE 13 cannot correctly receive the high-frequency base station 12 through the transmitting beam on all the receiving beams. #3 The sync signal sent. In the second synchronization detection window, the UE 13 is capable of receiving a synchronization signal that cannot be successfully received in the first special subframe. As shown in FIG. 24, the synchronization signal transmitted by the base station on the time slice S1 by the transmission beam #1 can be successfully detected in the second synchronization detection window.

The UE 13 can traverse all the combination of the transmitting beam of the high frequency base station 12 and the receiving beam of the UE 13 through the synchronization signal search of the first synchronization detecting window and the second synchronization detecting window to obtain synchronization of the high frequency system.

It should be noted that, before the UE 13 accesses the high frequency system, the low frequency base station 11 may send low frequency signaling (for example, RRC signaling) to the UE 13 before the UE 13 accesses the high frequency system. The low frequency signaling may include at least one of an additional reception delay, a frequency of the high frequency system, and a number of subintervals included in the DLBP (ie, a value of Nd).

Specifically, if the UE 14 is to obtain the frame synchronization successfully, the length of the DLBP subinterval, that is, the number of time slices in the DLBP subinterval in the high frequency system, that is, the number of transmit beams Nd of the high frequency base station 12, needs to be known in advance. The number of time slices in the DLBP subinterval, that is, the number of transmission beams Nd of the high frequency base station 12 can be preset as a fixed value related to the frequency point by a standard, for example, a typical Nd for 72 GHz, 28 GHz, and 14 GHz systems. Can be set to 16, 12 and 8, respectively. The UE 13 can obtain the frequency of the high frequency system to be accessed by low frequency signaling, that is, the Nd value can be obtained. Alternatively, the UE 13 can obtain the Nd value directly by low frequency signaling, that is, the low frequency base station 11 informs the UE 13 of the required high frequency system through its low frequency signaling (eg, RRC signaling) before accessing the high frequency system. The frequency point and/or the number of time slices in the DLBP subinterval in the high frequency system, that is, the number of transmission beams Nd of the high frequency base station 12.

Figure 25 is a flow diagram of a method of downlink synchronization in accordance with one embodiment of the present invention. The square shown in Figure 25. The method is executed by the user equipment and is applied to the high and low frequency hybrid networking system. The method includes:

S110, the user equipment receives synchronization information sent by a high-frequency base station, where the synchronization information is carried by a synchronous radio frame, where the synchronization radio frame includes at least one special subframe, where the special subframe is used to transmit a synchronization signal, where The special subframe includes a DLBP including Nu subintervals, each of which transmits Nd synchronization signals, where Nu and Nd are positive integers greater than one.

S120. The user equipment synchronizes according to the synchronization information.

In the embodiment of the present invention, the high-frequency base station transmits the synchronization information in the special subframe, and the UE completes the synchronization with the high-frequency base station by receiving the synchronization signal in the special subframe, which facilitates the UE to quickly access the high-frequency system and saves the connection. Power consumption at the time of entry.

Among them, the values of Nu and Nd are related to the frequency used by the system. For example, when the frequency used by the high frequency base station is 72 GHz, Nd=16, Nu=12; when the frequency used by the high frequency base station is 28 GHz, Nd=12, Nu=8; When the frequency used by the high-frequency base station is 14 GHz, Nd=8 and Nu=6.

Optionally, as an embodiment, before S110, the method further includes: receiving, by the UE, low-frequency signaling sent by the low-frequency base station in the system, where the low-frequency signaling includes a value of a frequency point and/or a Nd used by the high-frequency base station. The low frequency signaling may be RRC signaling.

Each subinterval of the DLBP may include Nd time slices, and the length of each time slice includes at least two OFDM symbols. A first one of the at least two OFDM symbols is used to transmit a primary synchronization signal, and a second one of the at least two OFDM symbols is used to transmit a secondary synchronization signal.

Specifically, the second OFDM symbol is used to transmit a specific sequence of the secondary synchronization signal. The specific sequence includes an identifier ID of the high frequency base station, an ID of a time slice in which the specific sequence is located, and an ID of a subinterval in which the specific sequence is located.

It should be noted that, regarding the primary synchronization signal and the secondary synchronization signal, reference may be made to the foregoing detailed description of FIG. 9 and FIG. 10, and to avoid repetition, details are not described herein again.

The special subframe may further include an RDP and an uplink and downlink handover protection interval GP, as shown in FIG. 4 to FIG. 7 above. Each subinterval may further include Nd switching guard intervals SGP respectively located after the Nd time slices, as shown in FIG. 8 above.

In addition, in the embodiment of the present invention, the synchronous radio frame further includes a general subframe, where the general subframe includes eight time slots having a length of 0.125 milliseconds, and the time slot includes Ns OFDM symbols, where Ns is positive. Integer. As an example, it can be as shown in FIG. 2.

Among them, the value of Ns is related to the frequency used by the system. For example, when the frequency used by the high frequency base station is 72 GHz, Ns=80; when the frequency used by the high frequency base station is 28 GHz, Ns=40; when the frequency used by the high frequency base station is When the point is 14 GHz, Ns=20.

In the embodiment of the present invention, the period of the synchronous radio frame used by the high-frequency base station may be the length of the M radio frames, where M is a positive integer. That is, one synchronous radio frame and M-1 general radio frames are included in every M radio frames. Here, M can be equal to 1.

Optionally, as an embodiment, the Nd synchronization signals transmitted in each subinterval of the DLBP may be that the high frequency base station sequentially transmits using Nd different transmit beams. That is to say, the high frequency base station uses Nu as a period, and each period is Nd different transmission beams, and transmits a synchronization signal.

Correspondingly, in S110, the UE may separately receive the synchronization signals on the Nu subintervals using Nu different receive beams. That is, the UE uses Nu different receive beams, each receive beam receives the transmit beams of the Nd high frequency base stations.

In order to solve the problem caused by the high and low frequency delays, as an example, in the first special subframe of the synchronization information, the high frequency base station sends the synchronization by using the first sequence of transmit beams. signal. The second high frequency base station transmits the synchronization signal using a second sequence of transmit beams on a second special subframe in the synchronization information. The second sequence is generated by cyclic shifting of the first sequence, and the length of the cyclically shifted time slice is greater than the high and low frequency delay of the system.

Specifically, the understanding may be: transmitting, by using a first sequence of transmit beams, on the DLBP of the first special subframe, and transmitting, by using a second sequence of transmit beam, on the DLBP of the second special subframe. Said synchronization signal. Alternatively, the understanding may also be: transmitting the synchronization signal using a first sequence of transmit beams on each subinterval of the DLBP of the first special subframe; using each subinterval of the DLBP of the second special subframe, The second sequence of transmit beams transmits the synchronization signal.

Wherein, each synchronous radio frame includes a special subframe. Then, the first special subframe is a special subframe in the first synchronization radio frame, and the second special subframe is a special subframe in the second synchronization radio frame. The second synchronization radio frame is a next synchronization radio frame adjacent to the first synchronization radio frame.

Wherein, each synchronous radio frame includes 2N special subframes. The first special subframe is the 2ith special subframe of the 2N special subframes, and the second special subframe is the 2i+1th special subframe of the 2N special subframes. frame. Where N is a positive integer and i is less than or equal to N Positive integer.

Wherein, each synchronous radio frame includes 2N+1 special subframes. Then, the first special subframe is the 2ith special subframe of the 2N+1 special subframes in the first synchronization radio frame or the 2N+1 special subframes in the second synchronization radio frame. a 2i+1 special subframe; the second special subframe is a 2i+1th special subframe of the 2N+1 special subframes in the first synchronous radio frame or the second synchronization The 2ith special subframe of 2N+1 special subframes in the radio frame. The second synchronous radio frame is a next synchronous radio frame adjacent to the first synchronous radio frame, where N is a positive integer, and i is a positive integer less than or equal to N.

For example, the first synchronous radio frame may be the synchronous radio frame 301 in FIG. 3, and the second synchronous radio frame may be the synchronous radio frame 302 in FIG.

Correspondingly, for this embodiment, S110 may include: the user equipment determines a starting position of a synchronization detection window according to a low frequency signal sent by a low frequency base station in the system; the user equipment uses a Nu different receiving beam from the The start position begins to receive a Nu group sync signal, wherein each set of sync signals includes Nd sync signals.

For details, refer to the corresponding descriptions of the foregoing FIG. 13 to FIG. 19 for the embodiment. To avoid repetition, details are not described herein again.

In the embodiment of the present invention, the UE quickly obtains downlink synchronization of the high frequency system through low frequency assistance. In the radio frame structure used by the high-frequency base station, the order of different transmit beams (cyclic shift) is used on two adjacent special subframes, so that all the transmit beams of the UE and the transmit beam of the high-frequency base station can be guaranteed to be traversed. Combine to ensure the efficiency and quality of synchronization.

In order to solve the problem caused by the high and low frequency delays, as another example, in the embodiment of the present invention, the special subframe may further include a CS located after the DLBP, where the CS transmits K synchronization signals, where K is A positive integer less than Nd. The Nd synchronization signals of each sub-interval are sequentially transmitted by the high-frequency base station using the Nd transmission beam. The K synchronization signals of the CS are transmitted by the high frequency base station sequentially using the first K transmission beams in the Nd transmission beam. That is, the CS sequentially switches the transmission beams in the order of the first K transmission beams of the first subinterval of the DLBP to transmit the synchronization signal.

Alternatively, it can also be understood that the special subframe may further include a CP located before the DLBP, and the CP transmits K synchronization signals, where K is a positive integer smaller than Nd. The Nd synchronization signals of each sub-interval are sequentially transmitted by the high-frequency base station using Nd transmission beams. The K synchronization signals of the CP are used by the high frequency base station to use the last K transmission beams in the Nd transmission beams. Transmitted. That is, the CP sequentially switches the transmit beams in the order of the last K transmit beams of the last subinterval of the DLBP to transmit the synchronization signal.

Correspondingly, for this embodiment, S110 may include: the user equipment determines a first start position of the first synchronization detection window according to the low frequency signal sent by the low frequency base station in the system; the user equipment uses Nu different receptions The beams respectively receive the Nu group synchronization signals from the first starting position, wherein each group of synchronization signals includes Nd synchronization signals; the user equipment determines according to the low frequency signals and the additional reception delays sent by the low frequency base stations in the system. a second start position of the second synchronization detection window; the user equipment respectively receives a Nu group synchronization signal from the second start position using Nu different receive beams, wherein each set of synchronization signals includes Nd synchronization signals .

The second special subframe is a first special subframe located after the first special subframe.

The additional receiving delay is preset in the user equipment; or the additional receiving delay is obtained by the user equipment from the low frequency base station. For example, the additional receiving delay is obtained by the user equipment by using the RRC signaling sent by the low frequency base station.

The length of the additional receiving delay is greater than the high and low frequency delay of the system, and the length of the time slice occupied by the CS or the CP is greater than or equal to the sum of the high and low frequency delay and the additional receiving delay. .

In the embodiment of the present invention, the UE quickly obtains downlink synchronization of the high frequency system through low frequency assistance. In the radio frame structure used by the HF base station, a cyclic suffix (or cyclic prefix) is additionally added to the special subframe to additionally use the K transmit beams to transmit the synchronization signal. Moreover, the UE can ensure that all combinations of the receiving beam of the UE and the transmitting beam of the high-frequency base station are traversed by using the additional receiving delay, thereby ensuring the efficiency and quality of synchronization.

Figure 26 is a diagram of a method of downlink synchronization in accordance with another embodiment of the present invention. The method shown in Fig. 26 is performed by a high frequency base station and is applied to a high and low frequency hybrid networking system. The method includes:

S210: The high frequency base station generates synchronization information, where the synchronization information is carried by a synchronous radio frame, where the synchronization radio frame includes at least one special subframe, where the special subframe is used to transmit a synchronization signal, where the special sub The frame includes a DLBP including Nu subintervals, each of which transmits Nd synchronization signals, where Nu and Nd are positive integers.

S220. The high frequency base station sends the synchronization information to a user equipment.

In the embodiment of the present invention, the high frequency base station sends synchronization information in a special subframe, and the UE receives the synchronization information. The synchronization signal in the special subframe completes synchronization with the high-frequency base station, which facilitates the UE to quickly access the high-frequency system and saves power consumption during access.

Wherein each of the subintervals of the DLBP includes Nd time slices, and the length of each time slice includes at least two OFDM symbols. A first one of the at least two OFDM symbols is used to transmit a primary synchronization signal, and a second one of the at least two OFDM symbols is used to transmit a secondary synchronization signal.

Specifically, the second OFDM symbol can be used to send a specific sequence of the secondary synchronization signal. The specific sequence includes an ID of the high frequency base station, an ID of a time slice in which the specific sequence is located, and an ID of a subinterval in which the specific sequence is located.

Optionally, as an embodiment, S220 may include: the high frequency base station sends the Nd synchronization signals by using Nd different transmit beams.

In order to solve the problem caused by the high and low frequency delays, as an example, in the embodiment of the present invention, the S220 may include: in the first special subframe in the synchronization information, the high frequency base station uses the first sequence The transmit beam transmits the synchronization signal; on the second special subframe in the synchronization information, the high frequency base station transmits the synchronization signal using a second sequence of transmit beams. The second sequence is generated by cyclic shifting of the first sequence, and the length of the cyclically shifted time slice is greater than the high and low frequency delay of the system.

Wherein, each synchronous radio frame includes 2N special subframes. The first special subframe is the 2ith special subframe of the 2N special subframes, and the second special subframe is the 2i+1th special subframe of the 2N special subframes. frame. Where N is a positive integer and i is a positive integer less than or equal to N.

In the embodiment of the present invention, in the radio frame structure used by the high-frequency base station, the sequence of different transmit beams (cyclic shift) is used on two adjacent special subframes, so that the UE is performing downlink In the step, all combinations of the receiving beam of the UE and the transmitting beam of the high-frequency base station can be ensured, thereby ensuring the efficiency and quality of synchronization.

In another embodiment, in the embodiment of the present invention, the special subframe further includes a CS that is located after the DLBP, and the CS transmits K synchronization signals, where K is smaller than A positive integer of Nd. S220. The S220 may include: the high frequency base station sequentially transmitting the Nd synchronization signals by using Nd transmit beams; and the high frequency base station sequentially transmitting the K synchronization signals by using the first K transmit beams of the Nd transmit beams. .

Or, it can be understood that the high frequency base station sends the Nd synchronization signals by using Nd first sequential transmission beams, and sends the K by using the first K transmission beams of the Nd first sequential transmission beams. Synchronization signals.

Alternatively, it can also be understood that the special subframe may further include a CP located before the DLBP, and the CP transmits K synchronization signals, where K is a positive integer smaller than Nd. The Nd synchronization signals of each sub-interval are transmitted by the high-frequency base station using Nd first-order transmission beams. The K synchronization signals of the CP are transmitted by the high frequency base station using the last K transmission beams of the Nd first order transmission beams. That is, the CP sequentially switches the transmit beams in the order of the last K transmit beams of the last subinterval of the DLBP to transmit the synchronization signal.

In the embodiment of the present invention, in the radio frame structure used by the high-frequency base station, a CS (or CP) is additionally added to the special subframe to additionally use the K transmit beams to transmit the synchronization signal. In this way, when the UE performs downlink synchronization, the additional reception delay can ensure that all combinations of the reception beam of the UE and the transmission beam of the high-frequency base station are ensured, thereby ensuring synchronization efficiency and quality.

Figure 27 is a block diagram showing the structure of a user equipment according to an embodiment of the present invention. The user equipment 300 shown in FIG. 27 is in a high and low frequency hybrid networking system, and the user equipment 300 includes a receiving unit 310 and a processing unit 320.

The receiving unit 310 is configured to receive synchronization information that is sent by the high-frequency base station, where the synchronization information is carried by a synchronous radio frame, where the synchronization radio frame includes at least one special subframe, where the special subframe is used to transmit a synchronization signal, where The special subframe includes a DLBP, the DLBP includes Nu subintervals, and each of the subintervals transmits Nd synchronization signals, where Nu and Nd are positive integers greater than one.

The processing unit 320 is configured to perform synchronization according to the synchronization information.

In the embodiment of the present invention, the high frequency base station sends the synchronization information in the special subframe, and the UE completes the synchronization with the high frequency base station by receiving the synchronization signal in the special subframe, which is beneficial to the UE to quickly access. High-frequency system saves power consumption during access.

Optionally, as an embodiment, the receiving unit 310 is further configured to receive low frequency signaling sent by the low frequency base station in the system, where the low frequency signaling includes a frequency point and/or a value of Nd used by the high frequency base station. The low frequency signaling may be RRC signaling.

In addition, in the embodiment of the present invention, the synchronous radio frame may further include a general subframe, where the general subframe includes eight time slots having a length of 0.125 milliseconds, and the time slot includes Ns OFDM symbols, where Ns is A positive integer. As an example, it can be as shown in FIG. 2.

Optionally, as an embodiment, the Nd synchronization signals may be sent by the high frequency base station by using Nd different transmit beams.

Optionally, as another embodiment, the receiving unit 310 is configured to: separately receive synchronization signals on the Nu subintervals by using different receiving beams. That is, the receiving unit 310 receives Nd synchronization signals on one subinterval using one receive beam.

Optionally, as another embodiment, on the first special subframe in the synchronization information, the high frequency base station sends the synchronization signal by using a first sequence of transmit beams. The second high frequency base station transmits the synchronization signal using a second sequence of transmit beams on a second special subframe in the synchronization information. The second sequence is generated by cyclic shifting of the first sequence, and the length of the cyclically shifted time slice is greater than the high and low frequency delay of the system.

Correspondingly, the receiving unit 310 is specifically configured to: determine a starting position of the synchronization detecting window according to the low frequency signal sent by the low frequency base station in the system; and receive the Nu group from the starting position respectively by using different receiving beams of Nu A synchronization signal, wherein each set of synchronization signals includes Nd synchronization signals.

Optionally, as another embodiment, the special subframe may further include a cyclic suffix CS located after the DLBP, where the CS transmits K synchronization signals, where K is a positive integer smaller than Nd. The Nd synchronization signals of each sub-interval are transmitted by the high-frequency base station using Nd first-order transmission beams. The K synchronization signals of the CS are transmitted by the high frequency base station using the first K transmission beams of the Nd first order transmission beams. That is, the CS sequentially switches the transmission beams in the order of the first K transmission beams of the first subinterval of the DLBP to transmit the synchronization signal.

Correspondingly, the receiving unit 310 is configured to: determine, according to the low frequency signal sent by the low frequency base station in the system, a first start position of the first synchronization detection window; use the Nu different receive beams to start from the first start position Receiving a Nu group synchronization signal, wherein each group of synchronization signals includes Nd synchronization signals; determining a second start position of the second synchronization detection window according to the low frequency signal sent by the low frequency base station and the additional reception delay in the system; Nu different receive beams respectively receive a Nu group sync signal from the second start position, wherein each set of sync signals includes Nd sync signals.

The length of the additional receiving delay is greater than the high and low frequency delay of the system, and the length of the time slice occupied by the CS or the CP is greater than or equal to the high and low frequency delay and the additional receiving time. Delayed sum.

It should be noted that, in the embodiment of the present invention, the receiving unit 310 may be implemented by a transceiver, and the processing unit 320 may be implemented by a processor. As shown in FIG. 28, user equipment 400 can include a processor 410, a transceiver 420, and a memory 430. The memory 430 can be used to store a receive beam or the like, and can also be used to store code and the like executed by the processor 410. Wherein, the transceiver 420 can be implemented by a receiver.

The various components in user device 400 are coupled together by a bus system 440, which in addition to the data bus includes a power bus, a control bus, and a status signal bus.

The user equipment 300 shown in FIG. 27 or the user equipment 400 shown in FIG. 28 can implement various processes implemented by the user equipment in the foregoing method embodiments. To avoid repetition, details are not described herein again.

It should be noted that the above described method embodiments of the present invention may be applied to a processor or implemented by a processor. The processor may be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the foregoing method embodiment may be completed by an integrated logic circuit of hardware in a processor or an instruction in a form of software. The processor may be a general-purpose processor, a digital signal processor (DSP), an application specific integrated circuit (ASIC), a Field Programmable Gate Array (FPGA), or the like. Programming logic devices, discrete gates or transistor logic devices, discrete hardware components. The methods, steps, and logical block diagrams disclosed in the embodiments of the present invention may be implemented or carried out. The general purpose processor may be a microprocessor or the processor or any conventional processor or the like. The steps of the method disclosed in the embodiments of the present invention may be directly implemented by the hardware decoding processor, or may be performed by a combination of hardware and software modules in the decoding processor. The software module can be located in a conventional storage medium such as random access memory, flash memory, read only memory, programmable read only memory or electrically erasable programmable memory, registers, and the like. The storage medium is located in the memory, and the processor reads the information in the memory and combines the hardware to complete the steps of the above method.

It is to be understood that the memory in the embodiments of the present invention may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memory. Among them, non-volatile memory can Read-Only Memory (ROM), Programmable Read ROM (PROM), Erasable PROM (EPROM), EEPROM (Electrically Erasable Programmable Read Only Memory) Electrically EPROM, EEPROM) or flash memory. The volatile memory can be a Random Access Memory (RAM) that acts as an external cache. By way of example and not limitation, many forms of RAM are available, such as static random access memory (SRAM), dynamic random access memory (DRAM), synchronous dynamic random access memory (Synchronous DRAM). SDRAM), Double Data Rate SDRAM (DDR SDRAM), Enhanced Synchronous Dynamic Random Access Memory (ESDRAM), Synchronous Connection Dynamic Random Access Memory (Synchlink DRAM, SLDRAM) ) and direct memory bus random access memory (DR RAM). It should be noted that the memories of the systems and methods described herein are intended to comprise, without being limited to, these and any other suitable types of memory.

Figure 29 is a block diagram showing the structure of a high frequency base station according to an embodiment of the present invention. The high frequency base station 500 shown in FIG. 29 is a high frequency base station in a high and low frequency hybrid networking system, and the high frequency base station 500 includes a generating unit 510 and a transmitting unit 520.

The generating unit 510 is configured to generate synchronization information, where the synchronization information is carried by a synchronous radio frame, where the synchronization radio frame includes at least one special subframe, where the special subframe is used to transmit a synchronization signal, where the special subframe A DLBP is included, the DLBP including Nu subintervals, each of which transmits Nd synchronization signals, where Nu and Nd are positive integers greater than one.

The sending unit 520 is configured to send the synchronization information to the user equipment.

The user equipment is in the high and low frequency hybrid networking system.

Wherein each of the subintervals of the DLBP includes Nd time slices, and the length of each time slice includes at least two OFDM symbols. First OFDM of the at least two OFDM symbols The symbol is used to transmit a primary synchronization signal, and the second one of the at least two OFDM symbols is used to transmit a secondary synchronization signal.

Optionally, as an embodiment, the sending unit 520 is specifically configured to: send the Nd synchronization signals by using Nd different transmit beams.

Optionally, as another embodiment, the sending unit 520 is specifically configured to: send, by using a first sequence of transmit beams, the synchronization signal, on the first special subframe in the synchronization information; The second sequence of subframes transmits the synchronization signal using a second sequence of transmit beams. The second sequence is generated by cyclic shifting of the first sequence, and the length of the cyclically shifted time slice is greater than the high and low frequency delay of the system.

Specifically, the understanding may be: transmitting, by using a first sequence of transmit beams, on the DLBP of the first special subframe, and transmitting, by using a second sequence of transmit beam, on the DLBP of the second special subframe. Said synchronization signal. Alternatively, the understanding may also be: transmitting the synchronization signal using a first sequence of transmit beams on each subinterval of the DLBP of the first special subframe; using each subinterval of the DLBP of the second special subframe, The second sequence of transmit beams transmits the same Step signal.

In the embodiment of the present invention, in the radio frame structure used by the high-frequency base station, the sequence of different transmit beams (cyclic shift) is used on two adjacent special subframes, so that the UE can ensure downlink synchronization. All combinations of the receive beam of the UE and the transmit beam of the high frequency base station are traversed to ensure synchronization efficiency and quality.

Optionally, as another embodiment, the special subframe further includes a CS located after the DLBP, where the CS transmits K synchronization signals, where K is a positive integer smaller than Nd. The sending unit 520 is specifically configured to: send the Nd synchronization signals by using Nd first-order transmit beams; and send the K synchronization signals by using the first K transmit beams in the Nd first-order transmit beams. .

Alternatively, it can also be understood that the special subframe may further include a CP located before the DLBP, and the CP transmits K synchronization signals, where K is a positive integer smaller than Nd. Among them, each child The Nd synchronization signals of the interval are transmitted by the high frequency base station using Nd first order transmission beams. The K synchronization signals of the CP are transmitted by the high frequency base station using the last K transmission beams of the Nd first order transmission beams. That is, the CP sequentially switches the transmit beams in the order of the last K transmit beams of the last subinterval of the DLBP to transmit the synchronization signal.

It should be noted that, in the embodiment of the present invention, the sending unit 520 may be implemented by a transceiver, and the generating unit 510 may be implemented by a processor. As shown in FIG. 30, the high frequency base station 600 can include a processor 610, a transceiver 620, and a memory 630. The memory 630 can be used to store a transmit beam or the like, and can also be used to store code and the like executed by the processor 610. The transceiver 620 can be implemented by a transmitter.

The various components in the high frequency base station 600 are coupled together by a bus system 640, which in addition to the data bus includes a power bus, a control bus, and a status signal bus.

The high-frequency base station 500 shown in FIG. 29 or the high-frequency base station 600 shown in FIG. 30 can implement the various processes implemented by the high-frequency base station in the foregoing method embodiments. To avoid repetition, details are not described herein again.

It should be noted that the above described method embodiments of the present invention may be applied to a processor or implemented by a processor. The processor may be an integrated circuit chip with signal processing capabilities. In the implementation process, each step of the foregoing method embodiment may be completed by an integrated logic circuit of hardware in a processor or an instruction in a form of software. The above described processor may be a general purpose processor, DSP, ASIC, FPGA or other programmable logic device, discrete gate or transistor logic device, discrete hardware component. The methods, steps, and logical block diagrams disclosed in the embodiments of the present invention may be implemented or carried out. The general purpose processor may be a microprocessor or the processor or any conventional processor or the like. The steps of the method disclosed in the embodiments of the present invention may be directly implemented by the hardware decoding processor, or may be performed by a combination of hardware and software modules in the decoding processor. The software module can be located in a conventional storage medium such as random access memory, flash memory, read only memory, programmable read only memory or electrically erasable programmable memory, registers, and the like. The storage medium is located in the memory, and the processor reads the information in the memory and combines the hardware to complete the steps of the above method.

It is to be understood that the memory in the embodiments of the present invention may be a volatile memory or a non-volatile memory, or may include both volatile and non-volatile memory. Among them, non-volatile memory can It is ROM, PROM, EPROM, EEPROM or flash memory. The volatile memory can be RAM, which acts as an external cache. By way of illustration and not limitation, many forms of RAM are available, such as SRAM, DRAM, SDRAM, DDR SDRAM, ESDRAM, SLDRAM, and DR RAM. It should be noted that the memories of the systems and methods described herein are intended to comprise, without being limited to, these and any other suitable types of memory.

Those of ordinary skill in the art will appreciate that the elements and algorithm steps of the various examples described in connection with the embodiments disclosed herein can be implemented in electronic hardware or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the solution. A person skilled in the art can use different methods for implementing the described functions for each particular application, but such implementation should not be considered to be beyond the scope of the present invention.

A person skilled in the art can clearly understand that for the convenience and brevity of the description, the specific working process of the system, the device and the unit described above can refer to the corresponding process in the foregoing method embodiment, and details are not described herein again.

In the several embodiments provided by the present application, it should be understood that the disclosed systems, devices, and methods may be implemented in other manners. For example, the device embodiments described above are merely illustrative. For example, the division of the unit is only a logical function division. In actual implementation, there may be another division manner, for example, multiple units or components may be combined or Can be integrated into another system, or some features can be ignored or not executed. In addition, the mutual coupling or direct coupling or communication connection shown or discussed may be an indirect coupling or communication connection through some interface, device or unit, and may be in an electrical, mechanical or other form.

The units described as separate components may or may not be physically separated, and the components displayed as units may or may not be physical units, that is, may be located in one place, or may be distributed to multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of the embodiment.

In addition, each functional unit in each embodiment of the present invention may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

The functions may be stored in a computer readable storage medium if implemented in the form of a software functional unit and sold or used as a standalone product. Based on such understanding, the technical solution of the present invention, which is essential or contributes to the prior art, or a part of the technical solution, may be embodied in the form of a software product stored in a storage medium. A number of instructions are included to cause a computer device (which may be a personal computer, server, or network device, etc.) to perform all or part of the steps of the methods described in various embodiments of the present invention. The foregoing storage medium includes various media that can store program codes, such as a USB flash drive, a mobile hard disk, a ROM, a RAM, a magnetic disk, or an optical disk.

The above is only a specific embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily think of changes or substitutions within the technical scope of the present invention. It should be covered by the scope of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.

Claims

A method for downlink synchronization, characterized in that it comprises:

The user equipment receives the synchronization information sent by the high-frequency base station, and the synchronization information is carried by the synchronous radio frame, where the synchronization radio frame includes at least one special subframe, where the special subframe is used to transmit a synchronization signal, where the special sub-frame The frame includes a downlink synchronization and a beam training interval DLBP, the DLBP includes Nu subintervals, and each of the subintervals transmits Nd synchronization signals, where Nu and Nd are positive integers greater than one;

The user equipment synchronizes according to the synchronization information.
The method according to claim 1, wherein each of the subintervals comprises Nd time slices, and the length of each time slice comprises at least two orthogonal frequency division multiplexing OFDM symbols, the at least two The first OFDM symbol in the OFDM symbol is used to transmit a primary synchronization signal, and the second one of the at least two OFDM symbols is used to transmit a secondary synchronization signal.
The method according to claim 2, wherein said second OFDM symbol is used to transmit a specific sequence of said secondary synchronization signal,

The specific sequence includes an identification ID of a time slice in which the specific sequence is located, and an ID of a subinterval in which the specific sequence is located.
A method according to any one of claims 1 to 3, characterized in that

And transmitting, by the high frequency base station, the synchronization signal by using a first sequence of transmit beams on a first special subframe in the synchronization information;

In the second special subframe in the synchronization information, the high frequency base station transmits the synchronization signal by using a second sequence of transmission beams,

Wherein the second sequence is generated by cyclic shifting of the first sequence.
The method of claim 4 wherein each of the synchronized radio frames comprises a special subframe;

The first special subframe is a special subframe in the first synchronization radio frame, and the second special subframe is a special subframe in the second synchronization radio frame;

The second synchronization radio frame is a next synchronization radio frame adjacent to the first synchronization radio frame.
The method according to claim 4, wherein each of the synchronous radio frames comprises 2N special subframes;

The first special subframe is a 2ith special subframe of the 2N special subframes, where the The second special subframe is the 2i+1th special subframe of the 2N special subframes;

Where N is a positive integer and i is a positive integer less than or equal to N.
The method according to any one of claims 4 to 6, wherein the user equipment receives the synchronization information sent by the high frequency base station, including:

Determining, by the user equipment, a starting position of the synchronization detection window according to the low frequency signal sent by the low frequency base station in the system;

The user equipment separately receives a Nu group synchronization signal from the starting position using Nu different receiving beams, wherein each group of synchronization signals includes Nd synchronization signals.
The method according to any one of claims 4 to 7, wherein the length of the cyclically shifted time slice is greater than the high and low frequency delay of the system.
The method according to any one of claims 1 to 8, wherein before the user equipment receives the synchronization information sent by the high frequency base station, the method further includes:

Receiving radio resource control RRC signaling sent by the low frequency base station, where the RRC signaling includes:

The frequency point used by the high frequency base station, and/or the value of Nd.
The method according to any one of claims 1 to 9, wherein the special subframe further comprises a reserved data interval RDP and an uplink and downlink handover protection interval GP.
The method according to any one of claims 1 to 10, wherein the period of the synchronous radio frame used by the high frequency base station is the length of M radio frames, where M is a positive integer.
A method for downlink synchronization, characterized in that it comprises:

The high frequency base station generates synchronization information, the synchronization information is carried by a synchronous radio frame, the synchronous radio frame includes at least one special subframe, and the special subframe is used to transmit a synchronization signal, where the special subframe includes downlink synchronization. And a beam training interval DLBP, the DLBP includes Nu subintervals, each of the subintervals transmitting Nd synchronization signals, where Nu and Nd are positive integers greater than one;

The high frequency base station transmits the synchronization information to a user equipment.
The method according to claim 12, wherein each of the subintervals comprises Nd time slices, and the length of each time slice comprises at least two orthogonal frequency division multiplexing OFDM symbols, the at least two The first OFDM symbol in the OFDM symbol is used to transmit a primary synchronization signal, and the second one of the at least two OFDM symbols is used to transmit a secondary synchronization signal.
The method according to any one of claims 12 to 13, wherein the high frequency base station sends the synchronization information to the user equipment, including:

And transmitting, by the high frequency base station, the synchronization signal by using a first sequence of transmit beams on a first special subframe in the synchronization information;

In the second special subframe in the synchronization information, the high frequency base station transmits the synchronization signal by using a second sequence of transmission beams,

Wherein the second sequence is generated by cyclic shifting of the first sequence.
The method of claim 14 wherein each of the synchronized radio frames comprises a special subframe;

The first special subframe is a special subframe in the first synchronization radio frame, and the second special subframe is a special subframe in the second synchronization radio frame;

The second synchronization radio frame is a next synchronization radio frame adjacent to the first synchronization radio frame.
The method according to claim 14, wherein each of the synchronous radio frames comprises 2N special subframes;

The first special subframe is the 2ith special subframe of the 2N special subframes, and the second special subframe is the 2i+1th special subframe of the 2N special subframes;

Where N is a positive integer and i is a positive integer less than or equal to N.
The method according to any one of claims 14 to 16, wherein the length of the cyclically shifted time slice is greater than the high and low frequency delay of the system.
A user equipment, comprising:

a receiving unit, configured to receive synchronization information sent by a high frequency base station, where the synchronization information is carried by a synchronous radio frame, where the synchronization radio frame includes at least one special subframe, where the special subframe is used to transmit a synchronization signal, where The special subframe includes a downlink synchronization and a beam training interval DLBP, the DLBP includes Nu subintervals, and each of the subintervals transmits Nd synchronization signals, where Nu and Nd are positive integers greater than one;

And a processing unit, configured to perform synchronization according to the synchronization information.
The user equipment according to claim 18, wherein each of the subintervals comprises Nd time slices, and the length of each time slice comprises at least two orthogonal frequency division multiplexing OFDM symbols, the at least two The first OFDM symbol in the OFDM symbols is used to transmit a primary synchronization signal, and the second OFDM symbol in the at least two OFDM symbols is used to transmit a secondary synchronization signal.
User equipment according to claim 18 or 19, characterized in that

And transmitting, by the high frequency base station, the synchronization signal by using a first sequence of transmit beams on a first special subframe in the synchronization information;

In the second special subframe in the synchronization information, the high frequency base station transmits the synchronization signal by using a second sequence of transmission beams,

Wherein the second sequence is generated by cyclic shifting of the first sequence.
The user equipment according to claim 20, wherein each of the synchronous radio frames comprises a special subframe;

The first special subframe is a special subframe in the first synchronization radio frame, and the second special subframe is a special subframe in the second synchronization radio frame;

The second synchronization radio frame is a next synchronization radio frame adjacent to the first synchronization radio frame.
The user equipment according to claim 20, wherein each of the synchronous radio frames comprises 2N special subframes;

The first special subframe is the 2ith special subframe of the 2N special subframes, and the second special subframe is the 2i+1th special subframe of the 2N special subframes;

Where N is a positive integer and i is a positive integer less than or equal to N.
The user equipment according to any one of claims 20 to 22, wherein the receiving unit is specifically configured to:

Determining a starting position of the synchronization detection window according to the low frequency signal sent by the low frequency base station in the system;

The Nu group synchronization signals are respectively received from the start position using Nu different receive beams, wherein each set of synchronization signals includes Nd synchronization signals.
The user equipment according to any one of claims 20 to 23, wherein the length of the cyclically shifted time slice is greater than the high and low frequency delay of the system.
A high frequency base station, comprising:

a generating unit, configured to generate synchronization information, where the synchronization information is carried by a synchronous radio frame, where the synchronization radio frame includes at least one special subframe, where the special subframe is used to transmit a synchronization signal, where the special subframe includes a downlink synchronization and beam training interval DLBP, the DLBP includes Nu subintervals, each of the subintervals transmitting Nd synchronization signals, where Nu and Nd are positive integers greater than one;

And a sending unit, configured to send the synchronization information to the user equipment.
The high frequency base station according to claim 25, wherein each of the subintervals includes Nd time slices, and the length of each time slice includes at least two orthogonal frequency division multiplexing OFDM symbols, the at least A first one of the two OFDM symbols is used to transmit a primary synchronization signal, and a second one of the at least two OFDM symbols is used to transmit a secondary synchronization signal.
The high-frequency base station according to claim 25 or 26, wherein the transmitting unit is specifically configured to:

Transmitting, by using a first sequence of transmit beams, the synchronization signal on a first special subframe in the synchronization information;

Transmitting the synchronization signal using a second sequence of transmit beams on a second special subframe in the synchronization information,

Wherein the second sequence is generated by cyclic shifting of the first sequence.
The high frequency base station according to claim 27, wherein each of the synchronous radio frames includes a special subframe;

The first special subframe is a special subframe in the first synchronization radio frame, and the second special subframe is a special subframe in the second synchronization radio frame;

The second synchronization radio frame is a next synchronization radio frame adjacent to the first synchronization radio frame.
The high frequency base station according to claim 27, wherein each of the synchronous radio frames comprises 2N special subframes;

The first special subframe is the 2ith special subframe of the 2N special subframes, and the second special subframe is the 2i+1th special subframe of the 2N special subframes;

Where N is a positive integer and i is a positive integer less than or equal to N.
The high frequency base station according to any one of claims 27 to 29, characterized in that the length of the cyclically shifted time slice is greater than the high and low frequency delay of the system.