资源描述
Introduction PHS phones
PHS phone is a miniature of the 1900 MHz radio transceiver call machine. Transmitting power only 10 mw, minimal radiation, the only mobile phone handset 1/200, it is "green communications tool," said.
1, features
①, murmur of small, clear sound quality, can the city and sound quality comparable to fixed telephone, and confidentiality than fixed telephone strong.
②, p call can be called anytime, anywhere, and with other PHS phone calls directly.
⑧, LCD displays are a number of background light, easy to watch.
④, a telephone directory function, ringing sound choice, volume control, and other functions.
⑤, have a button on the redial function.
⑥, the largest PHS phones can be a feature of the home phone or office phone has a phone number, from one side of the other party can automatically cut off, to prevent eavesdropping. PHS phones can also have a virtual number, so home or office phone and PHS phones can call each other.
2, the band
①, 1895 MHz-1906.1MHz allocated to the private network
②, 1906.1 MHz-1918.1MHz distribution to the public network
Each carrier frequency of 300 KHz bandwidth is available on the band frequency is 77, each district station used by the carrier frequency of: f = 1895.1 +0.36 X (N-1) MHz in the N-type for the carrier frequency, , The range is 1-77, f for the use of the air with the corresponding frequency N
For example:
Carrier frequency N = I f = 1895.1MHz
Carrier frequency N: 2 f = 1895.46MHz
Carrier frequency N = 3 f - 1895.82MHz
Carrier frequency N = 77 f = 1922.46MHz
3, the phone modeling
①, the total weight: 80 ~ 90 g (plus panels of less than 200 g)
②, size: two small boxes so much firewood
⑧, power supply capacity: continuous talk time of about 8 h, in a state reception for 500 h
④, the PHS models currently available in the market mainly UTS702-P, UTS602-A, UTS702-S331, UTS708-J, UTS708-SY, and so on.
4, "Little Smart" mobile phone functions
PHS phones there are three main series:
1), UTS700 (popular) series of mobile phones, a low-cost mobile phones, LCD smaller, only figures show that there are four kinds of ringing and 20 kinds of music, can store five calls have been recorded and five pulling phone records, phone book can be Store 20 phone numbers. The phone has been eliminated.
2), UTS702 (charisma) phones, mobile phones are mid-range and medium-sized LCD Chinese / English, in addition to 700 series, also a function of time, vibration, hands-free, voice recording, voice and data communications. Representative models have 702,702-331.
3), UTS708 (scenery) phones, a high-end mobile phones, large-screen LCD Chinese / English, can store 500 phone numbers, text message to support the Chinese character input.
Second, the PHS mobile phone technology with the principle of indicators
1), the technical indicators PHS
Transmitting power: 10 mw (average), 80 mw (peak)
Frequency: 1895.150 ~ 1917.950 MHz
Sensitivity: less than 16 db ~ V (≤ 97 dbm)
Air interface: RCR STD-28 Version 2
Carrier interval: 300 KHz
Communication: TDMA / TDD
Modulation: n/4QPSK
Transfer rate: 384 Kbps
Voice encoding: 32 K bps ADPCM
Melody output: in the great volume when> 73 db
Tone frequency: 2800 HZ, 1800HZ
Zhenchang: 5 ms
2), PHS phone calls were working principle of breath
1, PS PHS breath process
①, when - • users to call in the PS on the dial-up and sent out if all the wireless channel are already occupied, it will hear the voices, otherwise PS exhaled information put into the agreement PHS phone number, and The information transmitted to the RP.
②, RP PS to receive wireless link came through the information.
⑧, RP will receive information through wired connections to the RPC (base station controllers).
④, RPC PHS agreement information will be converted to an agreement Q.931 information. In addition, RPC (base station controllers) from the output of information extracted dial-up code and put it into DTMF (dual-tone multi-frequency) signals, Q.931 agreement by a E1 line of the D-channel sent to the RT (infrastructure equipment ).
⑤, when RT (infrastructure equipment) to receive information breath, it translates the information to select and connect to the local exchange, the corresponding analog line interface, and access to information given to the RPC. RPC path through the voice of the DTMF (dual-tone multi-frequency) dial-up signal to the Central Bureau of switches, after the completion of dial-up, RPC and RP Centre will switch between the PS and the path to link up all the voice. Called party phone ringing and pick, exhaled the end of the process, and the main call can be called mutual conversation.
2, PS people process called PHS
This feature provides a PS to the basic process of incoming terminals. Through the establishment of a functional equivalent of incoming RT regional paging service area.
①, incoming, the simulation of a particular line ringing.
②, RT-detected bell and the incoming flow of information, together with Q.931 agreement gave the call number RPC.
⑧, when the RPC received from the RT-sent to the information, it will Q.931 agreement gave the call number RPC.
④, these calls all the mobile phone base stations (PS) and FSU, when the pager number and the corresponding PS received from the RP of the paging information, it immediately ringing.
If the destination telephone pick, pick signal through the RP, RPC and RT transmitted to the central switch, all the voice path has already established, so the users connected to each other on both sides of the call.
3, Authentication
Authentication function for the prevention of private users was the right number of officers. Authentication function in the breath, incoming and location of the implementation of the registration process. Telephone users in the application, operating Chamber of Commerce for distribution of a user's phone number only authentication code. RT-all the authentication code stored in its database, PS each have their own authentication code. When the RPC received from the RT-after an authentication code, will perform the following functions:
①, generate a random code-based authentication and to send it to the PS
②, to receive the results from the PS
⑧ findings and the results sent to the RT and inspection results.
4, the handoff
This feature for mobile phones from the state of the RT service area of a region moving to other areas to provide continuous communications services. The RPC services in the same region of the handoff, do not have any RT-operation can be connected to the communication channel to switch to another RP control of the region. RPC in different areas between the switch, the new RT-RPC to send instructions to establish the handoff of information, RT and then sent to the new RPC to connect information, and to send the original RPC rewirable information.
PHS handset itself has many automatic features, in the original call cut off before the channel, they will choose a new base stations, re-establish a connection channel, in this process does not require a network-monitoring wireless links. This re-establish the connection channel, even in RP call services due to inconsistency in the border caused serious quality wireless links and vicious, can provide a stable communication services.
C), the PHS mobile phone circuit principle
PHS phones principle circuit diagram shown in Figure 1-1:
Picture this subject are as follows:
PHS phones is the work in the 1900 MHz band digital phone, with its circuit structure is very similar to the GSM handsets, base circuit can be roughly divided into three parts: a high-frequency part of the launch and receive parts: a control logic part of the transmission The interface, man-machine dialogue segment, followed by the power part. PHS phones because of the degree of integration very good, in many parts of a complete integrated circuits.
1, RF System
(1), part of the transmitter
Transmitters in part by quadrature modulator fired power amplifiers, transceivers switch and band-pass filter components.
① quadrature modulator (1 C101)
Quadrature modulator from quadrature modulator integrated circuit components. By orthogonal frequency modulation integrated circuits enter basic instruction signal, after two mixer output, has received a transfer quadrature modulator output. Quadrature modulator integrated circuits using a DC voltage output unit (automatic level control) control the output intensity. Through the cycle of control, get a constant intensity of the output. If it has the best DC voltage on the output from the control module.
② fired power amplifier (1 C051)
Quadrature modulator output into the monolithic microwave integrated circuits, and then enlarge it to send the necessary strength. Monolithic microwave integrated circuits by changing the threshold voltage, can control the output power and current consumption levels.
⑧ transceiver Switching (1 C001)
Transceiver circuit switch connections, may choose to send or receive the time switch, to connect with the antenna.
④ band-pass filter (FL051)
So that by orthogonal modulator signal in the terminal before they reach the antenna through the band-pass filter to reduce interference, such as the mirror interference, nonlinear harmonic interference, and so on.
(2) of the receiver
To receive part of the band-pass filter front-end integrated circuit, mixing three components.
① band-pass filter
Band-pass filter including dielectric filters (FL00t), SAW filter surface acoustic (FL033), ceramic filters, etc. (FLl01).
Dielectric filters filtering IF signal at every level to reduce do not want to receive the signal from the band.
Ceramic filter made of ceramic materials used high Q band-pass filter filter second-class IF signal to reduce do not want to receive, such as adjacent channel interference.
Surface Acoustic SAW filter, the frequency with specific characteristics can replace the traditional LE absorption and single-loop, double-tuned circuit.
② front-end mixer IC (1 C00 Asia)
LNA IC including front-end mixer and a mixer.
The one-output Ⅱ. 6GHz band and receive the 1.9 GHz band signal mixing, mixing, was an intermediate frequency signal losers
Out through the media filter to the next level after mixing circuit.
⑧ mixing two parts (1 C Ⅱ 01)
Part two includes a mixer IF amplifier, two mixers, two intermediate frequency amplifiers, limiting amplifier and receiver carrier identification signals, and other functions. 2 IF 10.8 MHz, the signal through ceramic filters, IF amplification and limiting amplifier in the enlarged, the final signal from the intermediate frequency signal transmitted to the control unit. RSSI (received signal strength) to receive signals through Level
Into a DC voltage through this value to identify a carrier signal.
2, logic control system (1 C80 b)
Part of the agreement, including control unit, voice processing part of the subsidiary unit.
(1) agreement unit
Agreement by the channel decoder unit, conditioning unit, the central processing unit, read-only memory, random access memory components.
① channel decoder unit
Channel decoder modules are as follows: modulation of the radio frequency modulation unit sent to the intermediate frequency signal, TDMA / TDD units to deal with the collection of data transmission and reception of data separation, from time to time through the control of the radio frequency modules Ⅱ 9.2 MHz output The clock frequency, in control of operations at the same time, the power control unit to provide power control signals in the output, such as PLL-3V, PTX-3V, RX-3V, TCXO-3V, to provide radio frequency modules transmit and receive the support of Power , PLL unit used to exchange all kinds of control signals: If LE, CLK, PS Ⅱ, PS2, LD, and so on. RF modules for the PLL frequency integrated circuits provide settings.
② conditioning unit
Conditioning units from the following components: for π / 4 frequency shift keying signal to provide identification to receive signal strength of the carrier to identify the management unit, and transmit power control unit.
③ central processing unit, read-only memory, random access memory (1 C804 1c803)
CPUs for external flash and a built-in (address) of random access memory to provide agreement. It also provides the interface with other units, such as voice codecs modules and related modules.
(2), voice processing part
Voice processing part by the decoding unit and a voice interface circuit components:
① voice decoder unit
Voice decoding unit negative voice is encoded signal decoder, it also provides a data error when the mute control and suppression, sent transmission tone output, such as dial tone, busy tone-Yinhe. In addition, by reducing the consumption of current, suspended for each unit of the clock signal, so as to achieve energy-saving purposes.
② interface circuit
Interface circuits, including ringing and handset power control unit, ring tones control unit, and other control circuits. They control by subsidiary units.
(3), the subsidiary unit
Subsidiary units including the application of CPU unit IC804, electrical erasable read-only memory, IC803 chip (address code, authentication code) and man-machine interface modules.
① Application Processor unit
Application Processor unit used to control protocol modules and voice coding interface, also used to control wireless calls to accept control unit, keyboard input modules, liquid crystal display modules and peripheral circuits, such as lighting, and other background.
② Electrically Erasable read-only memory (1 C804)
Electrically Erasable memory stored large amounts of data, such as codes, telephone directory information, hardware data, data terminals, and other parameters. Through the 3-wire type of interface and application of microprocessors to maintain communications.
③ man-machine interface unit
Man-machine interface unit including the display unit, keyboard scanning, data interface connector.
Parametric data terminals
LCD display unit and a liquid crystal display driver in two parts. It controlled by the application of microprocessors, is to display some of the wireless receiver and personal portable telephone to receive the information, internal state, and the response to the external operating information. Can display three lines of 11 numbers, and direct the status shows 0.
Keyboard scan by a 6:4 composition of the matrix, through the central processing unit to detect external input keys. Arbitrary key response by the central processing unit is also testing a key input from the disruption of the signal to achieve.
Data interface connector box data connectivity through the data interface connector (1 C601), the central processing unit in the serial and individuals can maintain communications between computers. This will be able to convert a set
展开阅读全文
浙ICP备2021020529号-1 | 浙B2-20240490 
