CN111757427B

CN111757427B - Channel quality evaluation-based selection method for preferred network of wide-narrow convergence terminal

Info

Publication number: CN111757427B
Application number: CN202010504420.9A
Authority: CN
Inventors: 张宗军; 陈池
Original assignee: Eastern Communication Co Ltd
Current assignee: Eastern Communication Co Ltd
Priority date: 2020-06-05
Filing date: 2020-06-05
Publication date: 2022-11-04
Anticipated expiration: 2040-06-05
Also published as: CN111757427A

Abstract

The invention discloses a selection method of a preferred network of a wide-narrow fusion terminal based on channel quality evaluation, which comprises the steps of evaluating the quality of a B-trunk network signal to obtain a CQI value, evaluating the quality of a PDT network signal to obtain a channel path loss parameter C1 value, comparing the CQI value with the C1 value, and selecting one of the signals as a main network when the signal falls into a judgment range. The invention can reduce the user intervention operation to the maximum extent, improve the convenience of the terminal, expand the use scene of the user for the existing wide and narrow private network, and achieve the purposes of fusion, complementation and multiple guarantee of the two networks. Meanwhile, for private network users, no matter under the PDT network or the B-Trunc network, the use and operation habits of the private network users do not change greatly, and the internal system and the underlying mechanism of the terminal ensure the smoothness of communication and the optimal signal quality.

Description

Channel quality evaluation-based selection method for preferred network of wide-narrow convergence terminal

Technical Field

The invention relates to the field of wide and narrow convergence terminals, in particular to a preferred network selection method of a wide and narrow convergence terminal based on channel quality evaluation.

Background

PDT is a police digital trunking communication system with independent intellectual property rights in China, has a plurality of advantages in function compared with an analog trunking system, but due to the limitation of a technical system, the processing capability for data services is limited, but the service processing in the aspects of images and videos is basically blank, and along with the deepening of police service work, the improvement of social security requirements and the increase of the matching capability of video services are of great importance.

The PDT police digital trunking communication system is designed for commanding and scheduling, and large-area coverage is achieved by using a 12.5KHz carrier 2 time slot TDMA technology. The single-slot voice transmission rate is 2.4Kbps. The data transmission rate is only 4.8Kbps in the case of two-slot combination.

At present, a pure broadband trunking standard (B-Trunc) based on a TD-LTE technology is also established domestically, 20 megabandwidths (1447 to 1467MHz and 1785 to 1805 MHz) are specified by the Ministry of industry and belief as the use frequency of a government broadband private network, and due to the technical system limitation of broadband, large-area coverage cannot be adopted, and huge infrastructure brings unprecedented difficulty to private network construction.

In order to achieve the purpose that both a PDT private network and a pure broadband cluster standard of a TD-LTE technology can be used, a wide-narrow fusion terminal is designed, namely a PDT + LTE wide-narrow band integrated terminal for police is used, so that the public security voice and data service fusion mode can be enriched, interconnection of wide and narrow systems and multimode of application terminals are achieved on the basis of the wide-narrow band fusion technology, and therefore the private network function can be played, the benefit is highlighted, and investment can be saved. The terminal can replace the existing multi-type terminal and is suitable for the multi-form multi-scene use environment of mobile police service.

For a terminal, if two networks meet an access requirement, when a call service is initiated, it is necessary to determine which network to select for communication, and a simpler method is to designate any one of the networks, but this may result in that the network used is not a physically optimal network, so that simply designating one network is simple and easy to use, but is not a good method for operation. Therefore, the mode of the operation of the converged terminal can be more reasonable and feasible by selecting the preferred network through a proper method.

Disclosure of Invention

In order to solve the above technical problems in the prior art, the present invention provides a preferred network selection method for a wide and narrow convergence terminal based on channel quality evaluation, which obtains a CQI value for B-Trunc network signal quality evaluation, obtains a channel path loss parameter C1 value for PDT network signal quality evaluation, compares the CQI value with the C1 value, and selects one of the signals as a main network when the one of the signals falls within a decision range.

Further, in the selection process, if the main network before the conversion is performing the voice or video service, the conversion is performed after the service is completed.

Further, a stable value of the signal lasting for more than 5 seconds is included as a comparison reference.

Further, the decision rule is specifically as follows:

(1) When PDT network 10 is less than or equal to C1 and less than 20, if the B-Trunc network can carry out 64QAM communication and CQI is more than or equal to 10, selecting the B-Trunc network as a preferred network, and if the CQI of the B-Trunc network is less than or equal to 10 at the moment, still using the PDT network;

(2) When PDT networks 5 & ltc & gt C1 & lt & gt are less than or equal to 10, if the CQI of the B-Trunc network is detected to be more than or equal to 7 and the B-Trunc network can carry out 16QAM communication, the B-Trunc network is selected as a preferred network, and if the CQI of the B-Trunc network is less than 7, the PDT network is still used;

(3) When PDT networks 0 and C1 are less than or equal to 5, if the CQI of the B-Trunc network is detected to be more than or equal to 3 and the B-Trunc network can carry out qpsk communication, the B-Trunc network is selected as a preferred network, and if the CQI of the B-Trunc network is less than 3, the PDT network is still used.

Further, in the case of rule (3), the wireless signal of the network is constantly monitored, and the network is immediately accessed as soon as improvement.

Furthermore, the CQI of the C1 and B-Trunc networks of the PDT network is used as a two-dimensional parameter, and a working state diagram of the fusion terminal is given on a coordinate axis to compare and judge.

Furthermore, the CQI value is measured and reported by the user equipment UE, and the eNodeB selects a proper downlink scheduling algorithm and a downlink data block size according to the CQI information.

Further, the CQI value is related to SINR of the downlink reference signal, sensitivity of a UE receiver, MIMO transmission mode, and radio link characteristics.

Further, the path loss parameter C1 is calculated as follows:

C1 = A-B-Max (0，C-D )

a: RSSI = average signal strength of the downlink signal received by the mobile station from the base station of the cell;

b: MIN _ RXLEV = minimum allowed signal reception strength of the mobile station within the cell;

c: MAX _ TXPWR = maximum allowed signal transmission strength of the mobile station in the cell;

d: PMS = maximum emission level value of the mobile station itself;

wherein Max (0, C-D) is the maximum between 0 and C-D;

the higher the value of C1 is, the better the field intensity signal of the serving cell of the mobile station is, when the value of C1 is faded to a certain threshold value, the mobile station starts to measure and calculate the values of the adjacent cells, continuously compares the values with the value of C1 of the serving cell, and switches according to the actual situation by combining the cell reselection parameters preset in the system.

Further, when the wide-narrow convergence terminal is in a dual coverage network of PDT and B-Trunc, after the wide-narrow convergence terminal is started up, the PDT network needs to be searched, the B-Trunc network also needs to be searched, and when the two networks meet the network access conditions of the terminal, the terminal can be registered under the corresponding PDT and B-Trunc networks in sequence.

The invention provides a selection method of a preferred network of a wide and narrow converged terminal, which is based on dynamic evaluation of signal quality of a B-Trunc network and a PDT network, samples evaluation values into different quantization spaces, compares channel signal evaluation values of the two networks, selects one signal as a main network when the signal falls into a judgment range based on the method, and simultaneously, in the selection process, if the main network before conversion is in voice or video service, the conversion must be carried out after the service is finished, and in order to avoid accidental signal interference or mutation, a stable value which can last for more than 5 seconds is ensured for a measurement value of the signal to be included into a comparison reference.

The invention provides a feasible network selection method for the converged multi-mode private network terminal by adopting a signal dynamic evaluation method based on the converged terminal, can reduce user intervention operation to the maximum extent, improves the convenience of the terminal, expands the use scene of a user for the existing wide and narrow private network, and achieves the purposes of convergence, complementation and multiple guarantee of two networks. Meanwhile, for private network users, no matter under a PDT network or a B-trunk network, the use and operation habits of the private network users do not change greatly, only the use of the terminal needs to be concerned, the selection of different networks does not need to be concerned, and the internal system and the bottom layer mechanism of the terminal ensure the smoothness and the optimal signal quality of communication.

Drawings

FIG. 1 is a flow chart of a terminal network access process of a B-trunk network;

fig. 2 is a flow chart of a PDT terminal network access process;

FIG. 3 is a graph of PDT parameters C1 and CQI values versus network selection;

fig. 4 is a schematic diagram of a preferred network decision tree.

Detailed Description

The invention will be further explained with reference to the drawings.

Abbreviations and explanations of terms used in the present invention:

PDT: police Digital Trunking

SIC: system Information Code, system Information codeword

TDMA: time division multiple access

LTE: long Term Evolution, long Term Evolution

MME: mobile Management Entity

TD-LTE: time Division LTE

B-Trunc: broadband Trunking, broadband cluster

CQI: channle Quality Indication, channel Quality Indication

UE: user Equipment, user machine

QAM: quadrature Amplitude Modulation

QPSK: quadrature Phase Shift Keying (QPSK) modulation

PDSCH: physical Downlink Shared Channel, physical Downlink Shared Channel

BLER: block Error Rate, decoded Block Error Rate

SINR: signal to Interference plus Noise Ratio

PRB：Physical Resource Block

RE: resource Element, resource Element

Physical Downlink Control Channel (PDCCH)

MIMO: multi Input Multi Output, multiple Input multiple Output

TBS: transport Block Size, transport Block Size

CFI: control Format indicator, control Format indication

DwPTS: downlink Pilot Time Slot, downlink Pilot Time Slot

C1: channel path loss parameter

IMSI: international Mobile Subscriber Identity (IMSI)

eNodeB: evolved Node B, evolved base station

eNB: evolved Node B, evolved base station

EPC: evolved Packet Core, evolved Packet Core network

TM: transfer Mode, antenna port Transfer Mode

GUTI: global Unique temporal UE Identity, globally Unique Temporary UE Identity

RRC: radio Resource Control, radio Resource Control

TAU: tracking Area Update

NAS: non-Access Stratum, non-Access Stratum

MCS: modulation and Coding Scheme, modulation and Coding strategy

E-UTRAN: E-UTRAN evolution type Universal Terrestrial Radio Access Network

GSM: global System for Mobile Communication

Enhanced Data Rate for GSM Evolution for Enhanced Data Rate for GSM Evolution

GERAN: GSM EDGE Radio Access Network, GSM/EDGE wireless communication Network

S1: the interface between EPC and E-UTRAN is called S1 interface

MNC: mobile Network Code, mobile area Code

RSSI: received Signal Strength Indication, the mobile station receives the Signal Strength Indication.

MIN _ RXLEV: minimum Received signal level, minimum allowed signal Received strength.

MAX _ TXPWR: maximum Transmission Power, the Maximum allowable signal Transmission strength of a mobile station within a cell.

PMS: power of Mobile Station, maximum transmission level value of the mobile Station itself.

Terminal network access process of network

As shown in fig. 1, when a user equipment UE is just powered on, the UE first performs physical downlink synchronization, searches and measures to perform cell selection, and after selecting a suitable or acceptable cell, performs a camping and attaching process, which specifically includes:

1) Step 1-5 will establish RRC connection, step 6, 9 will establish S1 connection, and completing these procedures will mark NAS signaling connection establishment completion.

2) Description of message 7: the user and the UE are just started and attached for the first time, the IMSI is used, and the verification process is not needed; subsequently, if there is a valid GUTI, the core network will initiate the validation procedure (for uplink and downlink direct transfer messages) using the GUTI attach.

3) Description of messages 10 to 12: if the message 9 carries the UE wireless capability information, the eNB cannot send the UE capability query message to the UE, namely, 10 to 12 processes do not exist; otherwise, the UE sends the wireless capability information, and the eNB sends the UE capability information indication again to report the wireless capability information of the UE to the core network. To reduce air interface overhead, the MME may store the UE radio capability information in the EPC idle, and the eNB may be brought in an initial context setup request message unless the UE performs an attach or "first TAU with GERAN/UTRAN attach" or "UE radio capability update" TAU procedure (i.e., these procedures the MME does not bring the UE radio capability information to the eNB and may delete the locally stored UE radio capability information, and the eNB may query the UE capability information and report it to the MME in the EPC). The E _ UTRAN radio capability information of the UE needs to be attached first and then attached if it changes.

4) Description of messages 13 to 15: the eNB has finished sending the message 13 and does not need to wait for the message 14 to be received and sends the message 15 directly.

5) If the IMSI of the UE is duplicated with the IMSI of another UE when the IMSI attach is initiated, and other UEs are already attached, the core network releases the previous UE. If the MNC in the IMSI is inconsistent with the configuration of the core network, the core network replies attachment rejection.

6) Description of message 9: the message is an initial context establishment request initiated by the MME to the eNB, requests the eNB to establish bearer resources, and simultaneously has security context and possibly parameters such as user wireless capability, a handover restriction list and the like. The security capability parameters of the UE are brought to the core network via the attach request message, which is then sent to the eNB via the message. The TAU needs to be initiated if the network capability (security capability) information of the UE changes.

Network access process of terminal

After the mobile station is started, the mobile station firstly scans to a PDT network to obtain system access information including access parameters, system access authority, system codes and the like, then the mobile station sends an access signaling to start a registration process, the level parameters include 16 bits lower than a network address, a system information code SIC of the network where the mobile station is located is filled, 8 bits higher than the network address is all 0, and whether a security module is carried or not is indicated.

During registration, the base station may make a device number query to the mobile station.

Message process of registration as shown in fig. 2, after the registration is successful, the terminal can initiate PDT cluster service.

When the terminal accesses the PDT network, the signal measurement is continuously carried out, and the current channel path loss parameter C1 value is obtained according to the measurement result and is used as the quality basis for the terminal to evaluate the current PDT network.

B-Trunc network signal quality evaluation method

CQI value determination

The B-trunk network quality uses CQI as a channel quality estimation parameter, the CQI is measured by the UE, and the CQI refers to downlink channel quality. Since the B-Trunc network is physically the same as the LTE network, but the cluster function is extended, the CQI parameter is used in the B-Trunc network for network quality assessment. And the eNodeB selects a proper scheduling algorithm and the size of the downlink data block according to the CQI information so as to ensure that the UE obtains the optimal downlink performance under different wireless environments. The eNodeB selects a suitable downlink scheduling algorithm and a transmission coding mode according to the CQI information, and different channel conditions are also different for the selection of modulation modes, and the higher the coding mode (QPSK < 1694am and 64qam), the higher the channel condition requirements.

Since the downlink scheduling is determined by the eNodeB, which is the transmitting end and does not know the quality of the channel, the quality of the channel is measured by the UE. The eNodeB determines what coding scheme is to be used, and needs the UE to feed back the quality of the channel, and the LTE protocol quantizes the quality of the channel into a sequence of 0 to 15 (carried by 4 bits), and defines the channel quality as CQI.

The CQI value is measured and reported by the UE. The CQI selection criterion in the LTE specification is to ensure that the decoding error rate (i.e., BLER) of the PDSCH is less than 10% of the CQI value used. That is, the UE needs to evaluate the downlink characteristics according to the measurement result (such as SINR), determine the BLER value that can be obtained under this SINR condition, and report the corresponding CQI value according to the limitation that BLER is less than 10%. The CQI values and coding schemes used are shown in table 1.

TABLE 1 CQI VALUES AND CORRESPONDING CODING MODES THEREOF

The modulation scheme determines the modulation order, which represents the number of bits transmitted in each 1 symbol. QPSK corresponds to a modulation order of 2, 16QAM of 4 and 64QAM of 6. The code rate is the ratio of the information bit number to the total physical channel bit number in the transport block, that is:

code rate = number of information bits/total number of physical channels bits in transport block = number of information bits/(total number of symbols of physical channels × modulation order) = efficiency/modulation order

Therefore, different values of the CQI determine the difference between the downlink modulation mode and the transport block size. The larger the CQI value is, the higher the modulation and coding scheme used is, the higher the efficiency is, and the larger the corresponding transport block is, so that the higher the downlink peak throughput provided is, the better the quality of the radio channel is.

CQI influencing factor

The UE determines the available CQI from the measured SINR value and reports to the eNodeB, so the CQI value is mainly related to the SINR of the downlink reference signal.

The CQI is related to, among other things, the UE receiver sensitivity, MIMO transmission mode and radio link characteristics. The concrete expression is as follows:

under the same channel quality condition, the higher the sensitivity of the UE receiver, the higher the measured SINR value, and therefore the larger the reported CQI value.

The MIMO mode, number of retransmissions, and number of antennas all affect BLE performance. Since the CQI corresponds to the SINR value required for 10% BLER, the CQI value is higher for 3 retransmissions than for 0 retransmissions, TM3/4 is higher than TM2 CQI, and 4 antennas is higher than the CQI for 2 antennas under the same SINR condition.

Effect of CQI on Performance

As can be seen from the above analysis, the CQI plays a very critical role in downlink scheduling. The UE estimates CQI according to the SINR value and reports the CQI in a periodic or aperiodic mode, and the eNodeB extracts corresponding broadband or sub-band CQI information according to different CQI modes to obtain the interference situation of the UE on a specific frequency band and realize frequency selective or non-selective scheduling. Importantly, the eNodeB acquires MCS and TBS information according to CQI and PRB information, which directly affects downlink throughput.

The CQI evaluation and measurement mechanism in the UE and eNodeB scheduling algorithms has a direct impact on system performance. If the CQI reported by the UE is low but the system erroneously sends a large TBS, the UE may fail to decode and send acknowledgement information, thereby generating retransmission and affecting the resource utilization of the system. On the contrary, if the actual radio environment is poor but the CQI value reported by the UE is high, the network selects a larger TBS according to the CQI, which may also cause the UE to fail decoding, resulting in a decrease in the utilization of system resources.

PDT network signal quality evaluation method

PDT refers to the practice of general networks. That is, the parameter determining the signal quality of the mobile station cell is the current path loss parameter C1. Here, C1 also represents to some extent the signal quality of the current cell.

The path loss parameter C1 is calculated by the following method:

C1 = A-B-Max (0，C-D )

a: RSSI = average signal strength of the downlink signal received by the mobile station from the base station of the cell.

B: MIN _ RXLEV = minimum allowed signal reception strength of the mobile station in the cell.

C: MAX _ TXPWR = maximum allowed signal transmission strength of the mobile station in the cell.

D: PMS = maximum emission level value of the mobile station itself.

Where Max (0, C-D) is the maximum between 0 and C-D.

The specific value of a is measured by the mobile station.

The specific values of B and C are preset by the system and are given by the broadcast form through the cell base station. The specific value of D is given by the mobile station itself.

C1 Is in dB and all parameters in the C1 calculation are in dBm.

In summary, the higher the value of C1, the better the field strength signal representing the serving cell of the mobile station. The value of C1 provides a basis for the field strength for cell reselection by the mobile station. No matter the mobile station is in an idle state or a call state, the mobile station can constantly monitor downlink signals of the base stations of the serving cell and the adjacent cell, when the C1 value is faded to a certain threshold value, the mobile station starts to measure and calculate the value of the adjacent cell, constantly compares the value with the C1 value of the serving cell, and switches according to actual conditions and the combination of cell reselection parameters preset in the system.

When the terminal is in a dual coverage network of PDT and B-Trunc, for the terminal, after the terminal is started, the PDT network needs to be searched, the B-Trunc network also needs to be searched at the same time, and after the two networks meet the network access conditions of the terminal, the terminal can be registered under the corresponding PDT and B-Trunc networks in sequence.

PDT and B-Trunc network selection criteria

As shown in fig. 3 and 4, for the convergence terminal, based on the selection principle of signal quality and network preference, the preferred network selection method of the wide-narrow convergence terminal based on channel quality evaluation is proposed:

when C1 of the PDT network is larger than or equal to 20, the PDT network is selected as the preferred network for communication.

When PDT network 10 is less than or equal to C1<20, B-Trunc network can carry out 64QAM communication, CQI is more than or equal to 10, B-Trunc network is selected as preferred network, if terminal is carrying out voice call through PDT network at the moment, then corresponding preferred network mode switching process can be carried out after the call is finished. If the B-Trunc network or the CQI is less than or equal to 10 at the moment, the PDT network is used;

when PDT network 5 & lt C1 & gt is less than or equal to 10, the CQI of the B-Trunc network is detected to be more than or equal to 7, the B-Trunc network can carry out 16QAM communication, the B-Trunc network is selected as a preferred network, and if the terminal carries out voice call through the PDT network at the moment, a corresponding preferred network mode switching process can be carried out after the call is finished. If the B-Trunc network is also CQI <7 at the time, the PDT network is used;

when PDT networks 0 & lt & gt C1 & lt & gt are less than or equal to 5, the CQI of the B-trunk network is detected to be more than or equal to 3, the B-trunk network can carry out qpsk communication, the B-trunk network is selected as a preferred network, and if the terminal carries out voice call through the PDT network at the moment, a corresponding preferred network mode switching process can be carried out after the call is finished. If the B-Trunc network is also CQI <3 at this time and the PDT network is still used, the radio signals of the network are constantly monitored even if communication has hardly been possible at this time, an improved immediate access network.

In order to avoid frequent mode switching of the convergence terminal, it is set that when the stabilization time of the detection value is not less than 5 seconds, that is, for the PDT network, the C1 value in a certain range should satisfy the duration of 5 seconds, and correspondingly the corresponding CQI of the B-trunk network should also last 5 seconds, which can be measured by setting a duration timer.

In the above process, if the converged terminal operates in the B-Trunc mode, when the preferred network is switched to the PDT mode, if the terminal is performing the voice or video service, the terminal may switch the PDT mode only if the current service state is ended, so as to ensure the smoothness of the ongoing service.

According to the principle, CQI of C1 and B-trunk of PDT can be used as two-dimensional parameters, a working state diagram of the converged terminal is given on a coordinate axis, the problem of a network selection principle in actual work is solved by optimizing signal quality of PDT and B-trunk networks, and meanwhile, by the method, a main network can be dynamically selected according to the signal quality of the two networks, so that the conversation effect is improved, and the communication quality is ensured.

Claims

1. A preferred network selection method of a wide and narrow converged terminal based on channel quality assessment is characterized by comprising the following steps: evaluating the quality of the B-Trunc network signals to obtain a CQI value, evaluating the quality of PDT network signals to obtain a channel path loss parameter C1 value, comparing the CQI value with the C1 value, and selecting one of the signals as a main network when the signal falls into a judgment range;

the decision rule is as follows:

(1) When the PDT network 10 is less than or equal to C1 and less than 20, if the B-Trunc network can carry out 64QAM communication and the CQI is more than or equal to 10, selecting the B-Trunc network as a preferred network, and if the CQI of the B-Trunc network is less than or equal to 10, still using the PDT network;

(3) When PDT networks 0 & ltc & gt C1 & lt & gt are less than or equal to 5, if CQI of a B-trunk network is detected to be more than or equal to 3 and the B-trunk network can carry out qpsk communication, the B-trunk network is selected as a preferred network, and if CQI of the B-trunk network is less than 3, the PDT network is still used;

the path loss parameter C1 is calculated as follows:

C1 = A-B-Max (0，C-D )

a: RSSI = average signal strength of downlink signals received by the mobile station from the cell base station;

d: PMS = maximum emission level value of the mobile station itself;

wherein Max (0, C-D) is the maximum between 0 and C-D;

the higher the value of C1 is, the better the field intensity signal of the serving cell of the mobile station is, when the value of C1 is faded to a certain threshold value, the mobile station starts to measure and calculate the value of the adjacent cell, continuously compares the value with the value of C1 of the serving cell, and switches according to the actual situation by combining the cell reselection parameters preset in the system.

2. The channel quality estimation-based selection method for a preferred network of a wide-narrow convergence terminal according to claim 1, characterized in that: in the selection process, if the main network before conversion is carrying out voice or video service, the conversion is carried out after the service is completed.

3. The method for selecting a preferred network of a wide-narrow converged terminal based on channel quality assessment according to claim 1 or 2, wherein: the steady value of the signal lasting more than 5 seconds is taken as a measured value as a comparison reference.

4. The channel quality estimation-based selection method for a preferred network of a wide-narrow convergence terminal according to claim 1, characterized in that: in the case of rule (3), the wireless signals of the network are constantly monitored, and the network is immediately accessed as soon as improvement.

5. The method for selecting a preferred network for a wide-narrow converged terminal based on channel quality assessment as claimed in claim 1, wherein: and taking the CQI of the C1 and B-Trunc networks of the PDT network as a two-dimensional parameter, and giving a working state diagram of the fusion terminal on a coordinate axis for comparison and judgment.

6. The channel quality estimation-based selection method for a preferred network of a wide-narrow convergence terminal according to claim 1, characterized in that: and the CQI value is measured and reported by the user equipment UE, and the eNodeB selects a proper downlink scheduling algorithm and a downlink data block size according to the CQI information.

7. The channel quality estimation-based selection method for a preferred network of a wide-narrow converged terminal according to claim 6, wherein: the CQI value is related to the SINR of the downlink reference signal, the sensitivity of the UE receiver, the MIMO transmission mode and the radio link characteristics.

8. The method for selecting a preferred network for a wide-narrow converged terminal based on channel quality assessment as claimed in claim 1, wherein: when the wide-narrow fusion terminal is under a dual coverage network of PDT and B-Trunc, after the wide-narrow fusion terminal is started, the PDT network needs to be searched, the B-Trunc network also needs to be searched, and when the two networks meet the network access conditions of the terminal, the terminal can be registered under the corresponding PDT and B-Trunc networks in sequence.