The exam pattern of bluetooth realizes and also the physical layer is noted (Fig.)
Summary: The exam pattern of bluetooth is part of the Bluetooth Specs, regardless of design or application and growth and development of the bluetooth circuit, can’t test modal use. This text introduction tests the modal laboratory is recognized making the physical layer of bluetooth (base band) within this mode Corrugate observation. Only discuss to transmit and test (transmitter test) here (namely invariable payload) ,Don’t involve loopback test (Loop back test) . Keyword: Test pattern of bluetooth Physical layer waveform Packet format from the data /p>
About test pattern —Bluetooth (Bluetooth) Test pattern test by receiving and dispatching,mainly test employed for showing and cooperating with rf and group belt course, additionally, it can be used as conventional authentication and convey the exam after purchase. The unit underneath the test pattern may not support regular operation. In thought on security, the exam pattern was created to not provide any service for user. So, there’s any machine format import and export around the soft hardware imterface to permit. —It’s examined the modal purpose is based on passing and calculating his air interface’s parameter, for example frequency precision, time precision, modulation parameter and transmitting the bandwidth from the frequency band,etc. prove radio stations frequency and periodic line control layer (LC) Whether it’s in normal operation condition, any bluetooth device can be employed in the exam pattern. Underneath the test pattern, module SUT (suit under test) to become measured In running unconventionally condition, probably the most apparent difference differs from 79 regular frequency-hopping communication, the unit uses the stationary frequency band transmit data. Since the tracing analytical instrument doesn’t need the monitoring signal of frequency hopping, this will make measurement easier.
Setup the needed hardware of test pattern —(1)Adopt the Model R&SPTW60 bluetooth agreement tester that Rohde&Schwarz Company produces, it’s a primary module (master) within the test pattern . This instrument has professional and artificial bluetooth test function, it’s the ideal instrument employed for development and portrayal test. The programming interface due to outfitting with, it’s appropriate for developing the company-new agreement too. —(2)ALPS bluetooth module, because the module to become measured, within the test pattern to be able to be subordinate towards the module (slave) ,Provided energy by HAMGEG three-phase current source. —(3)Four passways of ondoscopes LeCroy figures, can be used for revealing the monitoring signal. —(4)Spectrum analyzer Rohde&Schwarz FSH3, can be used for revealing the energy from the signal is shipped. —(5)Outfitted with PC of software for example FTP-Client, TotalCommander and C ++ editing machine JCreator, employed for getting a glance around, studying, installing and uploading the needed process of various schemes from the test pattern. —Fig. 1 is the fact that every module connects the block diagram within the test pattern.
Test modal setting-up —Usually you will find the next several stages in test designs to create bluetooth products work: —(1)Pass the exam instrument of call establishment (protocol analyzer) Periodic line control layer (LC) And also the periodic line control layer (LC) from the module to become measured Connection. —(2)Test instrument (protocol analyzer) Periodic line administration and supervision government bodies (LM) And also the periodic line administration and supervision government bodies (LM) from the module to become measured Established connection. —(3)Module to become measured makes its way into the exam pattern. —(4)Activate the exam pattern. What this means is testing and waiting for calculating the hyperlink charge of each side (LC) Already have the control information of acceptance test ready. It’s to transmit a hyperlink management (LM) to activate the mode to become measured with the primary module Protocol data unit PDU (protocol data unite) Enable_test_activate gives module to become measured. Receive this data packet to setup the autogenous periodic line control layer because the test pattern within the module to become measured quickly. However, after delivering this protocol data unit in test process of the exam instrument, the periodic line control layer (LC) of test instrument additionally, it setup because the test pattern. —(5)Change to the needed test plan. After initiating the exam pattern, make sure each side to become measured obtain the order which makes them operate in the condition prepared to receive, for instance, alter the communication designs of each side, in order to send and receive employed in exactly the same fixed frequency although not frequency hopping. Because of this, the periodic line administration and supervision government bodies (LM) towards the module to become measured of procedure Send link management (LM) Protocol data unit (PDU) LMP_test_control, this pressure to become measured periodic line control layer (LC) of module Mode searching about from the work. After delivering these details, the process changes the periodic line control layer from the test instrument too, make its operate in the exam pattern. —The above mentioned creates step and order and may be go through the guy-machine interface from the tester R&SPTW60, and all sorts of right single step executive program, observe every layers of execution results. Included in this, step four and 5 passes the handheld remote control from the air interface through the test instrument, to be able to avoid the other bluetooth machines of adjacent place from being set because the test pattern too, the module to become measured is going to be received and are available from HIC (Host Controller Interface, primary control unit interface) Order Enable_Device_Under_Test_Model??,last order,refuse bluetooth module test instruction.
Send and test —This test pattern is pretty easy and ocular. Result in the module of bluetooth within this mode and provide stationary bit payload, periodic conveyance can be used within the slight network (piconet) simultaneously In the module Texas regular up-to-date data packet, the slight network here consists of the tester and module to become measured, it’s identical the test that’s communicated every time is chartered. —Send the main module and appraise the bag (POLL) initially ,Deliver and test that starts, that one that measured and chartered using isn’t the acceptable frequency section within FHP. The tester conveys the control command or measures the bag in Texas time slot, the module to become measured is following to start with time slot the frame has been communicated. Time interval of call from the master unit is determined before which is stationary. The module to become measured hasn’t received the information packet from tester, it will likely be based on delivering its data frame normally regularly. Fig. 2 discloses that send testing the module duration of principal and subordinate cooperate using the situation, reveal within the picture, the frame length may exceed the size of a period slot data packet. Under this case, the tester can be used in calling the next a person’s idle primary Texas time slot.
—Can test the needed correlation parameter after delivering off testing to setup, for example output energy, energy density, amount of sensitivity of numerous time slots,etc., only discuss oscillogram and energy are distributed here. —Theory structure and test result research into the data packet —Data packets namely canonial bluetooth data packets underneath the test pattern. Within the disposition, the tester (master) Define two parameters: Data packet kind and loaded length that be utilized. The burden length needs according with and become limit towards the norm of base band, the loaded structure of ACL data packet defined is stored within the norm of base band. —In delivering the exam pattern, are only able to make use of the data packet format of without FEC error correction, for example packet format for example HV3, DH1, DH3, DH5 and AUX1, supports probably the most lengthy data packet using these forms. Within this mode, haven’t became a member of the variety of making an uproar within the tester and knowledge packet to become exchanged while analyzing module useless. Here when analyzing the module and entering the exam pattern, this function is forbidden, launch within the test pattern from the backout again. — Physical layer (base band) in Bluetooth Specs Packet format from the data —Supply the agreement specs format here, to be able to match up against the exam result. The center is bit length. —The information packet format of normal bluetooth consists of the lots of mind and – 2745bit of determining code of 72bit, 54bit. —Determining code (Assess Code) ,Employed for moving ahead concurrently, Electricity makes up and proves, its form is the following. Included in this, header (Preamble) Comprised of fixed 4bit, convenient Electricity makes up Syncing code (Sync word) Comprised of 64bit, can be used for moving ahead concurrently regularly Trailer (Trailer) Comprised of stationary 4bit, can be used in Electricity to pay too.
Preamble/ Sync word/ Trailer
//—Mind form (Header) Range from the control signal from the periodic line, the shape is the following. Included in this, AM_ADDR is 3bit lengthy activity member’s address, details are employed for broadcasting news, 7 for the most part TYPE is really a kind code of information packet, you will find 16 kinds in most FLOW may be the flow charge of 1bit ARQN may be the acknowledgement code of 1bit, shows success from the data packet is communicated SEQN is really a sequence code of 1bit, guarantees the back and front order from the data packet HEC is really a forward error fixing code of 8bit, guarantees the exactness from the mind.
AM-ADDR/ TYPE/ FLOW/ ARQN/ SEQN/ HEC
/////Load (Payload) Employed for transporting the voice texting or data information from the upper strata. —Some that must also explain, this test has selected 2 kinds of different bit samples because the load, including alternative 01 (0101010 …)And 4 alternative 10 (111100001111 …). The reason behind choosing these 2 kinds of loaded samples is, because base band and rf layer of bluetooth choose Gaussian minimum frequency change typing (GMSK) ,The amplitude peak has saved the bandwidth, but introduced intersymbol interference (ISI) simultaneously . In other words, within the code sequence waveform released in demodulation, or 1 seems continuously, can make its frequency drift accumulate while increasing constantly. If gain to noise temperature ratio may cause error code while being past the scope of receiver while receiving, this phenomenon could be observed ocularly under test. — Resulting waveform research into the test —3 following pictures were written here the exam pattern with four passways of ondoscopes LeCroy figures, do a comparison briefly using the data packet format from the theory here. —When for 1111 and 0000 data packet that appear alternatively load, signal the intersection of occupied bandwidth and relation as time passes is show as with Fig. 3. More standard packet format can discover the determining code, mind and cargo. Since the mind includes information, has utilized 1/3FRC, namely every information bit continuous repetition is distributed for several occasions, taken about 1 s (effective data rates are 721kb/s) by just such as this ,Can prevent within the mind every information bit occupies 3 s. With this characteristic, can see in this situation the very first three AM_ADDR within the mind is 111, namely No. 7 comes from the module. 4 TYPE yards later may also be read out for 0010, three later were successively FLOW, ARQN and SEQN, included in this SEQN was constant jump transfer underneath the normal conditions. The bandwidth adopted may also be read out, it’s about – 150kHz- +150kHz. —When for 01 data packet that appear alternatively load, signal the intersection of occupied bandwidth and relation as time passes is show as with Fig. 4. Structure its and three Fig. similar overall, it marks out 9 s to become a beginning reason for mind in within the picture, AM_ADDR in the module within this example is 101. There’s apparent difference, namely within the loaded part. 01 appear alternatively, compare 1111 to possess example until 0000 replace, appear intersymbol interference clearly reduce, the crest value the frequency occupies is reduced (the intensive small sawtooth part within the picture) ,It’s about – 75Hz- +75Hz.
—The power distribution from the data packet of bluetooth is proven as with Fig. 5. Getting used we’ve got the technology of frequency hopping partially within the rf of bluetooth, in ISM frequency band, have divided 79 frequency channels, the bandwidth of each and every passway is 1MHz. Within the communication of actual bluetooth, the regularity has been designated to those 79 frequency channels evenly, they begin from 2.402GHz, 2.480GHz finally. This type of frequency hopping technologies have contained the selective interference from the frequency and wet the affect on interacting effectively. Because test pattern focus on FHP, can discover energy its to distribute one the intersection of fixed frequency and piece over evenly going after. Went after knowingly, center frequency is 2.452GHz, it’s the frequency funnel No. 50 which use.
Conclusion —This text features the exam pattern from the module of bluetooth, has submit a concrete test method and evaluated the exam result. The study in this way will lead to technical further knowledge of bluetooth, popularization and application. Communication Center News Information world wide web.CCNinfo.com