CN109729548B

CN109729548B - Method for rapidly judging whether cell supports eMTC (enhanced cellular communication technology)

Info

Publication number: CN109729548B
Application number: CN201910133332.XA
Authority: CN
Inventors: 段红光; 郑建宏; 罗一静; 肖子荐
Original assignee: Chongqing University of Post and Telecommunications
Current assignee: Chongqing University of Post and Telecommunications
Priority date: 2019-02-22
Filing date: 2019-02-22
Publication date: 2021-11-16
Anticipated expiration: 2039-02-22
Also published as: CN109729548A

Abstract

The present invention claims to protect a method for quickly judging whether the cell supports the eMTC function. The process is that after the eMTC terminal is powered on, it first performs a frequency blind scan to search for a list of frequency points with signals, and then performs primary and secondary synchronization search (referred to as: PSS/SSS) on the frequency list with signals one by one. PSS/SSS synchronization signal, extract two PBCH repeat signals in the corresponding position, and perform correlation calculation. If there is an obvious correlation peak, it indicates that the cell corresponding to the frequency point supports eMTC service, and finally the cell is normalized. PBCH interpretation process. The invention speeds up the cell search speed of the eMTC terminal, and also saves the power consumption of the terminal.

Description

Method for rapidly judging whether cell supports eMTC (enhanced cellular communication technology)

Technical Field

The invention belongs to the field of communication systems in the Internet of things, and provides a method for quickly judging whether a cell supports eMTC (enhanced cellular communication technology) by using a terminal of the Internet of things.

Background

With the development of mobile communication technology, people put forward specific practical requirements on object-to-object connection, and the requirements of three dimensions, namely low cost, low power consumption and wide coverage, are mainly met according to different practical application scenes. The internet of things has also been systematically studied in the third generation partnership project (3 GPP) organization and provided complete standard specifications to advance the development of the internet of things industry.

In the 3GPP standard, in the R8 version, transmission level 1 (abbreviated as CAT1) is adopted to support internet of things, but although the terminal of CAT1 is fully compatible with long term evolution (abbreviated as 4G LTE) version, the requirements of internet of things on power consumption and cell coverage cannot be met. In the R12 version, the 3GPP introduced a version of machine type communication (MTC for short) specifically for transmission of the internet of things, also referred to as CAT0 version. No matter the terminal of the internet of things of CAT1 or CAT0 version, compatibility modification is mainly made on a high-level protocol of 4G LTE to meet the requirement of the internet of things. Until the R13 release, the 3GPP has formally proposed a complete internet of things protocol release, and systematically considers from the perspective of higher layer protocols, physical layers, and core networks, and finally determines enhanced machine type communication (eMTC) and narrowband internet of things (NB-IOT). The eMTC mainly meets the use of low-speed moving or static scenes and supports the uplink and downlink speed of about 1Mbps, and the NB-IOT mainly meets the use of static scenes and supports the uplink and downlink speed of 50 Kbps.

eMTC is therefore an important branch of internet of things technology, which has evolved based on the LTE protocol, and the LTE protocol including the physical layer is tailored and optimized for better suitability for communication with objects and lower cost. The eMTC is deployed based on a cellular network, and user equipment can directly access the existing LTE hardware equipment by supporting radio frequency and baseband bandwidth of 1.4MHz, and the eMTC can be supported only by upgrading software.

In the eMTC system, a cell transmits a synchronization signal, wherein a Primary Synchronization Signal (PSS) and a Secondary Synchronization Signal (SSS) are shared with a 4G LTE cell, but a Physical Broadcast Channel (PBCH) is different from the PBCH of the 4G LTE cell. Frequency division multiplexing mode (FDD), defined by 3GPP 36.211 release R15 under the conventional prefix condition, and the relation of various synchronization signals and broadcast channels in eMTC cells is shown in fig. 1.

An eMTC device (also known as an eMTC terminal) is capable of searching for or detecting whether a cell supports eMTC functionality. The search or detection process is as follows: generally speaking, firstly, broadband power measurement is performed, which frequency points have wireless signals, then, searching is performed according to PSS and SSS time-frequency content and position definition in an LTE system, PSS and SSS content is read out, and a cell physical identity (Pcell Id for short) is determined, in the process, PSS and SSS are sequence signals and have no specific check code, so that eMTC cannot 100% determine whether a PSS/SSS has an LTE cell or an eMTC cell.

If the terminal in the cell is the terminal of 4G LTE, the terminal calculates the position of the cell reference signal (CRS for short) according to the Pcell Id determined by the PSS/SSS, then carries out channel estimation and finally analyzes the PBCH content in the 4G LTE cell. In the eMTC system, an eMTC terminal also detects PSS/SSS signals at first, determines the Pcell Id value of an eMTC cell, then determines the CRS signal of the cell, then reads eMTC PBCH repeating blocks 1 to 4, and finally reads the content of the eMTC PBCH by adopting a combination mode. Since the CRC check bits are already added in the channel processing procedure of the eMTC PBCH, it is indicated that the cell supports the eMTC function as long as the CRC for interpreting the data of the eMTC PBCH is correct.

The conventional processing method is that the eMTC terminal interprets the eMTC PBCH to determine whether the cell supports the eMTC function, but in some application scenarios, if there are many cells or frequency points of 4G LTE and they only support 4G LTE services and do not support the eMTC function, the eMTC terminal also needs to make an interpretation attempt of the eMTC PBCH until finding that the CRC of the eMTC PBCH is incorrect, and cannot determine that the cell does not support the eMTC. This manner of operation is relatively time consuming and also increases the power consumption of the eMTC.

Disclosure of Invention

The present invention is directed to solving the above problems of the prior art. The method for rapidly judging whether the cell supports the eMTC or not accelerates the cell search speed of the eMTC terminal and also saves the power consumption of the terminal. The technical scheme of the invention is as follows:

a method for rapidly judging whether a cell supports eMTC or not comprises the following steps:

step 1: the eMTC terminal is powered on, the capability of the terminal for supporting the eMTC is determined, and the supported frequency band is initialized;

step 2: according to the frequency band capability supported by the eMTC, performing blind scanning on signal intensity in the supported frequency band, measuring the signal intensity of each frequency point, and then sequencing from large to small according to the signal intensity;

and step 3: in the frequency point list with signals, frequency points are taken out in sequence from large to small according to the signal intensity, then PSS/SSS on the frequency points is detected, whether physical signal identification Pcell Id exists or not is detected, if effective Pcell Id is not detected, a secondary strong frequency point is selected, and PSS/SS continues to be detected;

and 4, step 4: if the effective Pcell Id is detected on a frequency point, extracting PBCH data blocks of first repetition and second repetition of eMTC PBCH according to the condition that PBCH data of each eMTC occupies 4 symbol lengths at the time-frequency position determined by the PSS/SSS signals;

and 5: respectively forming two pieces of complete PBCH data by the two pieces of extracted eMTC PBCH data, then carrying out correlation calculation, if a correlation peak value exists, indicating that the cell supports eMTC services, otherwise, not supporting the eMTC services;

step 6: if the cell supports the eMTC service in the step 5, the content of the eMTC PBCH is read by adopting a conventional method according to a PBCH merging algorithm of the eMTC, in the process of analyzing eMTC PBCH data, if the CRC check of the eMTC PBCH is judged to be correct, the cell is finally determined to support the eMTC service, otherwise, the next frequency point is continuously searched until all frequency points with signal intensity are searched.

Further, step 2, according to the frequency band capability supported by the eMTC, blind scanning the signal strength in the supported frequency band, measuring the signal strength of each frequency point, and then sorting according to the signal strength from large to small, specifically includes:

and according to the frequency bands supported by the eMTC terminal, performing broadband scanning on each frequency band, measuring the RSSI signal quality on each frequency point, if the eMTC supports a plurality of frequency bands, continuing to scan another frequency band after one frequency band is scanned, and then sequencing all the RSSI frequency points to be measured according to the intensity of the RSSI from large to small.

Further, the step 3 specifically includes:

the eMTC terminal determines whether effective PSS/SSS signals exist on the frequency point in sequence according to the sequence of the RSSI signal strength from large to small, and after the RSSI measurement module determines the frequency point, radio frequency front end setting is carried out, namely time frequency data of the frequency point is obtained after FFT; PSS/SSS synchronization signals are searched in received time-frequency data, an eMTC terminal needs to detect a network identifier 1 and a network identifier 2, then Pcell Id is formed, a cell cyclic prefix mode is synchronously checked according to the positions of the PSS and the SSS, the blind detection process is completely the same as an LTE method, and the local PSS/SSS signals and the received PSS/SSS signals are adopted for carrying out correlation calculation.

Further, extracting PBCH data blocks of the first repetition and the second repetition of the eMTC PBCH in the step 4 specifically includes: according to the PSS/SSS signals detected on the frequency point and the cyclic prefix mode obtained by detection, corresponding eMTC PBCH data can be taken out according to PBCH distribution definition about eMTC and an eMTC PBCH data block correlation calculation module in 36.211, if the frequency point belongs to an FDD frequency point, the position relation of resource particles is determined, according to the FDD or TDD property of the frequency point and the detected CP mode, an eMTC PBCH time-frequency distribution mode is selected, and a first repeated PBCH block and a second repeated PBCH block of the eMTC PBCH are taken out from the corresponding positions.

Further, in the related calculation module of the eMTC PBCH data block, the related calculation is directly carried out on the first repeated data block and the second repeated data block of the eMTC PBCH, if a related peak value exists, the cell supports the eMTC service, otherwise, the cell is directly judged not to support the eMTC service, and the searching process of the next frequency point is entered.

Further, if it is determined that the cell supports the eMTC service in the process of performing eMTC PBCH data block correlation calculation, the eMTC PBCH parsing module determines cell parameters according to the PSS/SSS detection module, extracts a relevant reference signal CRS, performs channel estimation, then performs merge parsing on repeated eMTC PBCH transmission, and finally parses eMTC PBCH data, where the process is the same as conventional eMTC PBCH parsing, and if CRC check of the eMTC PBCH is correct, it is finally determined that the cell supports the eMTC service, otherwise, other frequency points are continuously tried.

The invention has the following advantages and beneficial effects:

the method makes full use of the characteristic that the eMTC PBCH block data needs to be repeatedly sent in the frame structure, and can screen out which cells do not support the eMTC function in advance without complex calculation. The method accelerates the cell search speed of the eMTC terminal and saves the power consumption of the terminal. The concrete expression is as follows:

firstly, the method comprises the following steps: if the terminal analyzes the content of the complete PBCH data block by detecting whether one cell supports the eMTC function in a conventional mode, the processes of data combination processing, channel estimation, channel decoding and the like of the repeated data block are required to be carried out, and finally whether the CRC of the PBCH is correct is checked. If it is correct, it can be determined that the cell supports eMTC. However, in the invention, the PBCH channel decoding process is not needed, the repeated characteristic of the PBCH data block is directly utilized, and whether the cell supports the eMTC function or not can be directly judged by adopting the correlation calculation.

Secondly, the method comprises the following steps: the invention can judge whether the cell supports the eMTC function without directly analyzing the PBCH data block, and the terminal does not need to read the PBCH data blocks which do not support the eMTC cell, thereby saving the time for searching the eMTC cell when the terminal is started.

Thirdly, the method comprises the following steps: in the conventional reading of the PBCH data block, the Fast Fourier Transform (FFT) calculation is firstly carried out on the received time domain data, the received data is transformed to the frequency domain, then the PBCH channel estimation and the channel decoding can be carried out, and the processes start a hardware accelerator, so that the power consumption of searching an eMTC cell when the terminal is started up is increased.

Fourthly: in the invention, after FFT calculation of data received from radio frequency, PSS/SSS search is only needed, and PBCH data which possibly exists is extracted, and direct correlation calculation processing is not needed, and channel estimation and PBCH channel decoding process are not needed, thereby simplifying the processing process.

Drawings

Fig. 1 is a prior art of various synchronization signal and broadcast channel relationships in an eMTC cell;

fig. 2 is a flowchart of a method for quickly determining whether a cell supports an eMTC service according to a preferred embodiment of the present invention;

fig. 3 is a signal reception diagram of an eMTC terminal;

fig. 4 is a procedure for an eMTC terminal to perform cell eMTC PBCH resolution.

Detailed Description

The technical solutions in the embodiments of the present invention will be described in detail and clearly with reference to the accompanying drawings. The described embodiments are only some of the embodiments of the present invention.

The technical scheme for solving the technical problems is as follows:

the invention provides a method for rapidly judging whether a cell supports an eMTC function or not according to the repeated transmission characteristic in a Physical Broadcast Channel (PBCH) in an eMTC system. The method comprises the steps that after an eMTC terminal is started, frequency blind scanning is firstly carried out, a frequency point list with signals is searched, then main and auxiliary synchronous searching (PSS/SSS for short) is carried out on the frequency list with the signals one by one, if effective PSS/SSS synchronous signals are searched, two PBCH repeated signals are extracted from corresponding positions and relevant calculation is carried out, if obvious relevant peak values exist, a cell corresponding to the frequency point supports eMTC services, and finally a normal PBCH reading process is carried out on the cell.

The specific treatment process of the invention is as follows:

step 1: the eMTC terminal is powered on, the eMTC terminal capability is determined, the supported frequency band is initialized, and preparation is made for subsequent eMTC cell search. As in process 1 of figure 2.

Step 2: according to the frequency band capability supported by the eMTC, blind scanning of signal strength is carried out in the supported frequency band, the signal strength (RSSI value for short) of each frequency point is measured, and then sequencing is carried out from large to small according to the signal strength. As in process 2 of figure 2.

And step 3: in the frequency point list with signals, frequency points are taken out in sequence from large to small according to the signal intensity, then the PSS/SSS on the frequency points is detected, whether a physical signal identifier (Pcell Id for short) exists or not is detected, if no effective Pcell Id is detected, a secondary strong frequency point is selected, and the PSS/SS is continuously detected. As in processes 3.1, 3.2 and 4 of figure 2.

And 4, step 4: and if the effective Pcell Id is detected on a frequency point, extracting PBCH data blocks of repetition 1 and repetition 2 of eMTC PBCH according to the condition that PBCH data of each eMTC occupies 4 symbol lengths at the time-frequency position determined by the PSS/SSS signal. As in process 5 of figure 2.

And 5: and respectively combining the two extracted eMTC PBCH data into two complete PBCH data, and then carrying out correlation calculation. If the correlation peak exists, the cell supports the eMTC service, otherwise, the cell does not support the eMTC service. As in process 6 of figure 2.

Step 6: if the cell supports the eMTC service in the step 5, the eMTC PBCH content is normally read according to a PBCH merging algorithm of the eMTC, and in the process of analyzing eMTC PBCH data, if the CRC check of the eMTC PBCH is judged to be correct, the cell is finally determined to support the eMTC service. Otherwise, continuing to search the next frequency point until all frequency points with the signal intensity are searched. As in fig. 2 processes 7 and 4.

Judging whether a cell supports eMTC services, wherein the common realization mode is that after detecting that a PSS/SSS effective signal exists in a frequency point, a cell reference signal CRS is decoded, channel estimation is carried out, data of eMTC PBCH are recovered, data of all eMTC PBCH repetition times are extracted, algorithm combination is carried out, eMTC PBCH decoding is finally carried out, and if CRC of the eMTC PBCH is correct, the cell is judged to support the eMTC services.

The conventional implementation method does not try whether the cell supports the eMTC service or not before the eMTC PBCH reading is carried out, and if one cell does not support the eMTC service or a plurality of LTE frequency points exist around the cell and do not support the eMTC service, the eMTC terminal consumes a lot of time and power to carry out the eMTC PBCH reading of the eMTC service.

The method skillfully utilizes the characteristic that the data of the eMTC PBCH needs to be repeatedly sent on the frame structure, and can screen out the cells which do not support the eMTC in advance without complex calculation. Generally, the method accelerates the cell search speed of the eMTC terminal and also saves the power consumption of the terminal.

In the 3GPP TS 36.211V15.3.0(2018-09) release in the 3GPP standardization organization, a variety of eMTC cell deployment scenarios are given in physical channel and modulation specifications, specifically in the 6.6.4 resource mapping section of 36.211, in the description of table 6.6.4-1, the eMTC PBCH distribution cases of the normal prefix and the extended prefix in FDD mode are given.

TABLE 6.6.4-1 frame Structure type 1 frame offset, time slot and symbol for repeated PBCH blocks

In the 6.6.4 resource mapping section of 36.211, table 6.6.4-2 gives the eMTC PBCH distribution of normal and extended prefixes in TDD mode.

Table 6.6.4-2 slots and symbols for repeated PBCH blocks in frame structure type 2

From the above analysis, no matter in FDD mode or TDD mode, or in normal prefix and extended prefix mode, eMTC PBCH is distributed on time-frequency resources in a repeat mode, so that the method of the present invention can be used when it is necessary to determine whether a cell supports eMTC services.

In the embodiment of the present invention, the application of the present invention in an actual product will be described by using a normal prefix extension scenario in an FDD mode.

Fig. 3 is a signal reception diagram of an eMTC terminal. The diagram only shows the modules relevant to the present invention, omitting or simplifying the same components as the LTE terminal.

In the schematic diagram, the radio frequency channel module mainly completes signal processing of an LTE signal from an antenna to an ADC, including processing of a low noise amplifier, filtering and down conversion, automatic gain, and the like; the ADC module is used for digitizing analog baseband signals after the radio frequency channel, so that digital signal processing can be conveniently carried out on the baseband; a Fast Fourier Transform (FFT) module, which transforms the received time domain wireless signal into time frequency resource information through FFT; the data buffering module is configured to store received wireless data, and according to distribution of PBCH of the eMTC on a time-frequency resource grid, the PBCH of the eMTC occupies 4 symbols at most in a time domain, and each symbol occupies 6 physical resource blocks (for short, PRB) in a frequency band, so that a size of a resource to be buffered in each eMTC PBCH data block is 4x6x 12-288 resource elements (for short, RE), and each eMTC PBCH is repeated for 4 times in total, so that the total 288x 4-1152 resource elements are obtained. A certain delay exists in the data processing process, and other PSS/SSS and CRS signals are also required to be included, so that the content reading of eMTC PBCH is convenient to perform at the later stage; a PSS/SSS detection module, which has the same processing mode as the LTE mode, mainly completes searching and detection to determine whether PSS/SSS signals exist in digital signals after FFT, and if yes, needs to detect the corresponding Pcell Id value; the eMTC PBCH data block correlation calculation module extracts an eMTC PBCH repeated data block 1 and a repeated data block 2 according to the time-frequency position determined by the PSS/SSS detection result and the time-frequency distribution relation determined by the eMTC PBCH under different modes and cyclic extension prefixes, and then performs correlation calculation; and the eMTC PBCH analysis module is used for starting an eMTC PBCH analysis process by the eMTC terminal if the correlation peak value of the eMTC PBCH exists in the calculation result of the eMTC PBCH data block correlation calculation module, wherein the process is the same as the conventional eMTC PBCH analysis method, and the eMTC PBCH analysis is carried out by adopting a merging mode.

The above provides the modules involved in detecting whether a cell has a valid eMTC PBCH signal, and a specific implementation procedure is given below according to the definition procedure of the present invention.

Step 1: the eMTC terminal is powered on, and performs broadband scanning on each frequency band according to the frequency bands supported by the terminal, and measures the RSSI signal quality at each frequency point, as in the RSSI measurement module in fig. 3. If the eMTC supports a plurality of frequency bands, after one frequency band is scanned, the other frequency band is continuously scanned, and then all the RSSI frequency points to be measured are sequenced from large to small according to the strength of the RSSI. As shown in

steps

1 and 2 in fig. 4.

Step 2: the eMTC terminal determines whether there is an effective PSS/SSS signal on the frequency point in turn according to the sequence of the RSSI signal strength from large to small, and performs radio frequency front end setting after the RSSI measurement module determines the frequency point according to fig. 3, so that the time frequency data of the frequency point is obtained after the FFT. And the PSS/SSS module searches the PSS/SSS synchronization signal in the received time-frequency data. In the process, the eMTC terminal needs to detect a network identifier 1 (NID (1)) and a network identifier 2 (NID (2)) and then forms a Pcell Id, a cell cyclic prefix mode is synchronously checked according to the positions of a PSS and a SSS, the blind detection process is completely the same as an LTE method, and a local PSS/SSS signal and a received PSS/SSS signal are adopted for carrying out correlation calculation. As in steps 3.1 and 3.2 of figure 4.

And step 3: according to the detected PSS/SSS signals on the frequency point and the detected cyclic prefix mode (CP mode for short), corresponding eMTC PBCH data can be extracted according to the eMTC PBCH distribution definition in 36.211 and the eMTC PBCH data block correlation calculation module. And if the frequency point belongs to the FDD frequency point, referring to the resource particle position relation determined in the table 1. Therein_lIndicating an eMTC PBCH symbol number.

Table 1. eMTC PBCH occupies slot, symbol distribution relation table in FDD mode.

And if the frequency point belongs to the TDD frequency point, referring to the position relation of the resource particles determined in the table 2.

TABLE 2 eMTC PBCH occupying time slot, symbol distribution relation table in FDD mode

According to the FDD or TDD property of the frequency point and the detected CP mode, the eMTC PBCH time-frequency distribution mode corresponding to the table 1 or the table 2 is selected, and a first repeated PBCH block and a second repeated PBCH block of the eMTC PBCH are taken out from the corresponding positions. As in step 4.1 of figure 4.

And 4, step 4: in the eMTC PBCH data block correlation calculation module, correlation calculation is directly carried out on a first repeated data block and a second repeated data block of the eMTC PBCH, and if a correlation peak value exists, the cell supports the eMTC service. Otherwise, directly judging that the cell does not support the eMTC service, and entering the search process of the next frequency point. As in step 4.2 of figure 4.

And 5: if the cell supports the eMTC service in the process of performing eMTC PBCH data block correlation calculation in step 4, the eMTC PBCH analysis module determines cell parameters according to the PSS/SSS detection module, extracts a related reference signal CRS, performs channel estimation, then performs combination analysis on repeated eMTC PBCH transmission, and finally analyzes the eMTC PBCH data. Such as steps 5.1, 5.2 and 6 in fig. 4.

Step 6: in the eMTC PBCH analysis process, as long as the requirement is not met, the frequency point is reselected, the detection of the eMTC PBCH is continued, and if all the frequency points are not met, the eMTC PBCH directly exits. As shown in step 7 of fig. 4. The above examples are to be construed as merely illustrative and not limitative of the remainder of the disclosure. After reading the description of the invention, the skilled person can make various changes or modifications to the invention, and these equivalent changes and modifications also fall into the scope of the invention defined by the claims.

Claims

1. a method for quickly determining whether a cell supports eMTC, comprising the following steps:

Step 1: The eMTC terminal is powered on, determines the terminal's ability to support eMTC, and initializes the supported frequency band;

Step 2: According to the determination of the frequency band capability supported by eMTC, blindly scan the signal strength in the supported frequency band, measure the signal strength of each frequency point, and then sort from large to small according to the signal strength;

Step 3: In the list of frequency points with signals, take out the frequency points in descending order according to the signal strength, and then detect the PSS/SSS on the frequency point to detect whether there is a physical signal to identify the Pcell Id, if not detected. If the PcellId is valid, select the second strongest frequency point and continue to detect PSS/SSS;

Step 4: If a valid Pcell Id is detected at a frequency point, at the time-frequency position determined by the PSS/SSS signal, the first time of the eMTC PBCH is extracted according to the PBCH data of each eMTC occupying 4 symbol lengths. Repeated and second repeated PBCH data blocks;

Step 5: The two extracted eMTC PBCH data are respectively composed of two complete PBCH data, and then the correlation calculation is performed. If there is a correlation peak, it indicates that the cell supports the eMTC service, otherwise it does not support the eMTC service;

Step 6: If it is determined in Step 5 that the cell supports the eMTC service, the content of the eMTC PBCH is interpreted using the conventional method according to the PBCH combining algorithm of the eMTC. Make sure that the cell supports the eMTC service, otherwise, continue to search for the next frequency point until all the frequency points with signal strength have been searched.

2. a kind of method for quickly determining whether a cell supports eMTC according to claim 1, is characterized in that, described step 2 is based on determining the frequency band capability that eMTC supports, carries out signal strength blind scan in the supported frequency band, and measuring gives The signal strength of each frequency point, and then sorted according to the signal strength, from large to small, including:

According to the frequency band supported by the eMTC terminal, perform broadband scanning on each frequency band, and measure the RSSI signal quality on each frequency point. If the eMTC supports multiple frequency bands, after scanning one frequency band, continue to scan another frequency band, and then The measured RSSI frequency points are sorted in descending order according to the strength of the RSSI.

3. The method for quickly determining whether a cell supports eMTC according to claim 2, wherein the step 3 specifically comprises:

The eMTC terminal determines whether there is a valid PSS/SSS signal on the frequency point according to the RSSI signal strength in descending order. After the RSSI measurement module determines the frequency point, the RF front-end setting is performed, which is the frequency point after the FFT. Perform the blind detection process: search the PSS/SSS synchronization signal in the received time-frequency data, the eMTC terminal needs to detect the network ID 1 and the network ID 2, and then form the Pcell Id, and synchronize according to the PSS and SSS The location check cell cyclic prefix mode, the blind detection process is exactly the same as the LTE method, and the correlation calculation can be performed by using the local PSS/SSS signal and the received PSS/SSS signal.

4. a kind of method for quickly determining whether the cell supports eMTC according to claim 3, is characterized in that, in described step 4, the PBCH data block of the first repetition and the second repetition of the eMTC PBCH is extracted, specifically comprising : According to the PSS/SSS signal detected on the frequency point and the detected cyclic prefix pattern, the corresponding eMTC PBCH can be taken out according to the PBCH distribution definition about eMTC and the eMTC PBCH data block correlation calculation module in 3GPP TS 36.211 Data, if the frequency point belongs to the FDD frequency point, determine the location relationship of the resource particles, select the eMTC PBCH time-frequency distribution method according to whether the frequency point is FDD or TDD, and the detected CP mode, and take out the eMTC PBCH in the corresponding position. The first repetition of the PBCH block and the second repetition of the PBCH block.

5. a kind of method for quickly determining whether the cell supports eMTC according to claim 4, it is characterized in that, in the eMTCPBCH data block correlation calculation module, to the eMTC PBCH repeating data block for the first time and repeating the data block for the second time directly. The correlation calculation is performed, if there is a correlation peak, it indicates that the cell supports the eMTC service; otherwise, it is directly determined that the cell does not support the eMTC service, and the process of searching for the next frequency point is entered.

6. a kind of method for quickly determining whether the cell supports eMTC according to claim 5, it is characterized in that, if in carrying out eMTC PBCH data block correlation calculation process, it is determined that this cell supports eMTC service, then eMTC PBCH parsing module then according to PSS /SSS detection module, determine the cell parameters, extract the relevant reference signal CRS, perform channel estimation, and then combine and parse the repeated eMTC PBCH transmission, and finally parse the eMTC PBCH data. If the CRC check is correct, it is finally determined that the cell supports the eMTC service, otherwise, it continues to try other frequencies.