The terminal equipment of mobile station mobile users can be divided into vehicle mounted, portable and handheld types.The handheld type is commonly known as "mobile phone".It is controlled by the mobile user, and establishes a two-way wireless telephone circuit with the base station to communicate.
Mobile stations are vehicle mounted, hand-held, portable and fixed for ships and special areas.At the beginning, it was mainly vehicle mounted. Handheld type developed rapidly because of its small size, light weight, convenient carrying and low price.
Mobile station is the part of mobile customer equipment, which consists of two parts, mobile terminal (MT) and customer identification card (SIM).
Figure 1 Mobile Station
Mobile terminals are "machines", which can complete voice coding, channel coding, information encryption, information modulation and demodulation, information transmission and reception.
constitute
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It is mainly composed of operation part, control unit, receiving and transmitting unit, duplex filter and power supply.
① The operation part is usually installed in the telephone.It consists of a button type keyboard, a dial display and a microprocessor. The key discrimination and LCD display are controlled by the microprocessor.
② The control unit is composed of microprocessor, whose function is to control the start of the transmitter, select the channel, release the channel, and decide whether to loop back the monitoring tone sent by the base station.
③ The receiving and transmitting unit sends or receives voice and signaling information to the base station and displays the received field strength.
④ Duplex filter is generally composed of a circulator and a filter to separate the transmission signal and reception signal of the mobile station.
⑤ The power supply is generally charged, which can be used for one hour of continuous communication. The hand-held power supply can be combined with the telephone, and the vehicle mounted power supply is often installed separately.
SIM card
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The SIM card is an "identity card", which is similar to the current IC card, so it is also called a smart card. It contains all the information needed to authenticate the customer's identity, and can implement some important information related to security and confidentiality to prevent illegal customers from entering the network.The SIM card also stores management data related to the network and customers. The mobile terminal can access the network only after inserting the SIM card, but the SIM card itself is not a gift card.
In a typical mobile communication system such as GSM, mobile users and mobile stations are completely independent.Any mobile user can use different mobile stations as long as he has his own subscriber identity card (SIM).The SIM card is a "smart" card conforming to the ISO standard. It contains information related to the user on the side of the stored user's wireless interface, including authentication and encryption information.All mobile stations using GSM standard need to insert a SIM card. Only when dealing with abnormal emergency calls, the mobile station can be operated without a SIM card.The application of SIM card makes mobile station not tied to one user. Therefore, GSM system identifies mobile phone users through SIM card, which lays the foundation for the development of personal communication.
classification
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Mobile station is the user equipment of GSM system, including vehicle mounted station, portable station and handset.Mobile stations can be divided into the following three types:
MT0 includes data terminal function and terminal adaptation function;MT1 includes ISDN terminal adaptation function;MT2 includes the adaptation function of CCTV series or X series terminals.
The mobile terminal is not fixed to a user. On any mobile station in the system, the user can be identified by the SIM card (Subscriber Identity Module). The Personal Identification Number (PIN) can prevent unauthorized use of the subscriber identity card.
On board mobile station
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Fully compatible with mobile WiMAX, supporting wireless broadband access in high-speed mobile situations.At the same time, the mobile station also integrates encoder, WIFI and other functional modules to support ultra long distance (more than 20 km) coverage.
Portable mobile station
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The portable emergency mobile FM relay station relates to the technical field of mobile communication.It is to solve the problem of inconvenient traffic flow in the wild forest
Figure 3 Mobile Station
In case of emergency, the total weight of the existing repeater is more than 50 kg, which brings inconvenience to human transportation, and the installation time is more than one hour, which delays the time.The programming control I/O port of the first handheld interphone 1 is connected to the transmission control I/O port of 4, the receiving control I/O port of 4 is connected to the programming control I/O port of the second handheld interphone 2, the FM signal output end of 1 is connected to the input end of duplexer 3, the FM signal input end of 2 is connected to the output end of 3, and the antenna end of 3 is connected to the antenna.The total weight of the portable emergency mobile FM relay station is less than 10 kg, the installation time is less than 10 minutes, and the working time is more than 10 hours. It can realize one or two times of ultrashort wave relay. The relay communication between different frequency bands of ultrashort wave can also be realized between the two relay stations.
Handheld mobile station
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Small size, easy to carry, within a certain distance, both sides can talk to each other.There is no need to pay for the walkie talkie. The talk distance of a conventional walkie talkie is 3-5 kilometers. With network support, the talk range of the walkie talkie can reach tens of kilometers.
Features: long call distance, clear voice;High reliability, strong anti-interference ability, especially suitable for variable frequency elevator;Small size, car roof and pit auxiliary machine are hands-free with call function, easy to install and use.
Velocity estimation
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Figure 4 Mobile Station
The mobile speed estimation method of mobile station: sampling multiple complex value fading factors of wireless channel;Calculate the multi order complex number domain autocorrelation values of the above multiple fading factor samples;Calculate the relative change of each order autocorrelation value;According to the calculated autocorrelation change value, find the comparison table or comparison curve between the autocorrelation change value of the fading factor and the mobile station's mobile speed estimation, and estimate the current mobile speed of the mobile station.The method of the invention can realize high-precision mobile station moving speed estimation with a small amount of calculation.
Mobile station - application
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9.1 Mobile station test device
Provide a set of main measurement items to test the performance of dual-mode CDMA mobile stations operating in the 500 to 1000 MHz frequency band.With the 83236BPCS interface, the 8924C also adds the CDMA test capability in the 1700 to 2000 MHz frequency band.As a calibrated high-performance CDMA base station, 8924C can not only test the parameter characteristics of CDMA phones, but also test the functional aspects of phone performance.
Figure 5 Mobile Station
The mobile station test device has all the test capabilities of AMPS, NAMPS, EAMPS, EAMPS, TACS, NTACS, ETACS and JTACS, allowing you to conduct analog and CDMA digital mobile station measurements with the same instrument, thus saving your space, costs and training expenses.In order to perform a complete call processing inspection, the mobile station test device supports the connection and hanging up of outgoing calls between the mobile station and the base station.Once a telephone call is established, it is very simple to check all functions of CDMA mobile station by using voice loopback mode of mobile station test device.For testing various protocol modes, the mobile station test device provides six protocol stacks that users can choose: IS-95, IS-95A-TSB-74, J-STD-008, ARIBT53 and KOREANPCS8924C. It also supports several service options, including 9600BPS and 14400BPS service channel configurations.The mobile station test device provides a group of main measurement items to test the performance of dual-mode CDMA mobile stations operating in the 500 to 1000 MHz frequency band.Due to the 83236BPCS interface, the mobile station test device has also added the CDMA test capability of 1700 to 2000 MHz frequency band.As a calibrated high-performance CDMA base station, the mobile station test device can not only verify the parameter characteristics of the CDMA phone, but also verify the various functional aspects of the phone performance.
Performance Main technical performance of TACS (E-TACS) mobile station is shown in the table.
Table 1 Performance Table
(Mobile station power control)
High accuracy CDMA source suitable for CDMA receiver test: The simulation of the effective active base station in the mobile station test device is provided by sector A, which supports the following CDMA channels: pilot channel, synchronization channel, paging channel, traffic channel and orthogonal channel noise source (OCNS).In addition, the 8924C also has a second sector B source for testing soft handovers.Sector source B is a local sector source with pilot channel, traffic channel and OCNS channel.The mobile station test device also includes an additive white Gaussian noise (AWGN) source to provide interference generated by adjacent cells in a working CDMA network.The mobile station test device can measure the frame error rate (FER) of the receiver at all four rates of full rate, half rate, 1/4 rate and 1/8 rate used in the CDMA system.The confidence limit technique is used to reduce the receiver test time to an absolute minimum.
CDMA transmitter measurement: the mobile station test device provides average power measurement based on DSP technology.The channel power measurement based on DSP enables the mobile station test device to achieve accurate low-level CDMA power measurement.The wave mode quality transmitted by the access test power measurement is also called p (rho) measurement.In addition, the p (rho) measurement also reports/records frequency errors, modulation phase and amplitude errors, and carrier feed leakage (pass).
Handover inspection: In order to improve the test speed, the mobile station test device supports hard handover between RF channels, and also supports the handover from the CDMA cellular and PCS dual band to the analog system.With two configurable CDMA sector sources, 8924C can check the CDMA mobile station support software.The test devices of two mobile station test devices can be synchronized with each other, which is suitable for completing the test of idle and soft handover.
Authentication and short message service support: The mobile station test device provides various necessary features to test the ability of CDMA mobile stations to realize call processing under the conditions of Korean and American authentication.The mobile station test device also supports the short message service (SMS) terminated by the mobile station.
9.2 For cruise at sea
The wireless mobile stations that are specially used for maritime navigation and are used for wireless communication on maritime ships and shore are called maritime wireless mobile stations, also known as ship stations.Marine wireless mobile station is a mobile station with strong professionalism. Its use environment is harsh, the range of ship activities is wide, and the sea temperature changes greatly. To meet the needs of global maritime safety navigation, its product design is very professional,The working frequency is also unified according to the unified provisions of international maritime communications. The working frequency range of mobile radio vendors for marine use is from 156.025MHz to 157.425MHz TX and 156.025MHz to 163.275MHz RX.The working channels are divided into international channels, American channels and Canadian channels, and there are 10 weather channels (8 of which are American weather channels and 2 are Canadian weather channels).The three working channels are the three standard versions of channels, and all kinds of marine interphones have three standard versions.According to the use requirements, users can choose different versions of frequency while purchasing marine mobile stations.There are many countries that use the American frequency standard version, and most Chinese marine mobile stations use the American version. It is said that the American frequency version has more same frequency points and less different frequency points.In addition to the above frequency points, some maritime mobile stations have 10 frequency points that can be defined by users themselves, which is convenient for users to use internally.There are same frequency points and different frequency points in the frequency of marine mobile station.The cutout frequency difference at the different frequency point is 4.6MHz instead of 5.7MHz for the conventional unit.
