rf校準(zhǔn)軟件設(shè)計(jì)

1、手機(jī)射頻校準(zhǔn),什么是射頻校準(zhǔn)？,The process of obtaining RF parametric data to be used by the phone for the purpose of compensating for non-linear devices, frequency variations, and temperature variationsOutput from the calibration pro

2、cess is stored in non-volatile (NV) memoryDMSS uses RF NV items during normal operation to ensure system performance is met.,射頻校準(zhǔn)的意義? (1),Subscriber units have differing RF characteristics.-Some characteristics vary f

3、rom one unit to the next-Other characteristics vary from one design to the next,射頻校準(zhǔn)的意義? (2),The subscriber unit must estimate the Rx power properly to maximize signal to noise ratios and to provide a basis for Tx powe

4、r output.The subscriber unit must transmit at correct Tx power level over its large dynamic range.,射頻校準(zhǔn)的意義? (3),The MSM device and system software combination must “know” the RF characteristics of the particular unit. T

5、his information is known as RF calibration data.Failure to compensate for differing RF characteristics may cause the unit to fail minimum performance specifications.,射頻校準(zhǔn)的意義? (4),Calibration Consideration: - Some NV

6、Items will be static per phone design » Ex: NV_CDMA_ENC_BTF - Other NV items will vary from one phone to the next and need to be calibrated » Ex: NV_CDMA_TX_LIN_MASTER_1,射頻校準(zhǔn)的信號流圖,射頻校準(zhǔn)工位搭建,,

7、NV項(xiàng),Calibration compensates for nonlinear characteristics, and temperature and frequency variations in the performance of the Tx and Rx path components in a subscriber unitOutput from the calibration process are stored

8、in nonvolatile (NV) memory items in AMSS softwareDMSS software loads calibration values into MSM registers or uses them for software processing during normal DMSS operationNV items can be accessed using raw DIAG comman

9、ds or using DIAG-based tools, such as the QPST RF Calibration Tool? Some NV items will be static per the hardware designOther NV items will vary from one unit to the nextSome elements within an NV item can be extrap

10、olated,NV項(xiàng)類型,Static RF NV Items: Value is determined by design and does not change for the same design. Ex: NV_CDMA_NONBYPASS_TIMER_ICalculated RF NV Items: Value is calculated based on other parameters of the

11、 design configuration and value does not change for a given configuration. Ex: NV_CDMA_LNA_RANGE_RISE_IMeasured RF NV Items: Value is defined by RF calibration process and each device may have a different valu

12、e. Ex: NV_CDMA_TX_LIN_MASTER_0_I,FTM介紹,FTM is expandable, allowing customers to build onto the functions for manufacturer-specific testingFTM is now a part of QPSTExtensive documentation is available for customer re

13、ference– 80-V4690-25 Rev. B MSM 6250 RF NV Items– CL-93-V5368-1 Rev. C Factory Test Mode WCDMA Commands– CL93-V5370-1 Rev. F Factory Test Mode GSM Commands– 80-V5359-1 Rev. E FTM Overview,運(yùn)行FTM,Released DMSS ca

14、n be made to boot up in one of two operatingmodes– Normal “DMSS” mode with regular cellular operation– FTM mode with no cellular system determination and call-processingBy default, DMSS will power up in normal mod

15、eAMSS software is also capable of switching modes at run-time (no reset required)– To switch from online to FTM, send a “Mode FTM” command to the phone.– To switch from FTM to online, send a “Mode Online” command.T

16、o activate FTM:– Send Off_line command to target– Send Diag Command NV_WRITE and set NV item NV_FTM_I to 1.– Reset target by sending a MODE_RESET command. Target will boot up inFTM mode. Target LCD screen should

17、display “Factory Test Mode” At this point the unit is ready to receive FTM commands,FTM命令介紹（1）,Bool Set PDM(pdm_id_type type) – This command sets the value of a PDM output, based on PDM_ID such asTx_Agc_Pdm or Rx_Agc

18、_PdmByte Get ADC(adc_id_type type, word* data = NULL) This command returns the value of the specified analogto- digital converter (ADC) channels.Word GetCAGC_RX_AGC() – This command returns the 10-bit 2’s comp

19、lement output of the RX AGC loopBool GetSynthLockState() – This command returns thestate of the RF synthesizers.,FTM命令介紹（2）,Bool SetCDMAWaveCW(bool on_off) – This command sets the modulation ON/OFF for the uplink wav

20、eform. Pass in “true” for CW waveform and “false” for WCDMA uplink waveformBool SetChannel(word channel) – This command sets the uplink and downlink channelBool SetLNAOffset(byte index, int value) – This command sets

21、 the LNA offset registerBool SetLNARange(lna_range_type range) – This command sets the LNA range state machine to the specified state,FTM命令介紹（3）,Bool SetMode(mode_id_type mode) – This function makes a selection

22、 between GSM and WCDMA operating modes. It initializes all of the necessary registers to place the phone in the requested modeBool SetPARange(pa_range_type range) – This command sets the PA range state machine to t

23、he specified stateBool SetTxOFF() – This command turns off the phone’s transmit chain including the power amplifier and the MSM Tx clocksBool SetTxON() – This command turns on the phone’s transmit chain including the

24、 power amplifier and the MSM Tx clock,FTM命令介紹（4）,Word GetCDMAIM2(byte* Idac, byte* Qdac, byte* Trans) – This command returns the optimum IM2 value for the current mode and channel of the mobile. Rx signal input are requi

25、red to be set before issuing this command or results will not be accurate. The resulting word contains two values: – The most significant byte contains the I value – The middle byte contains the Q value – The

26、 least significant byte contains the transconductance valueBool SetDVGAOffset(word offset) – This function sets the DVGA (Digital VGA) offset registerWord GetDVGAOffset(void) – This function gets the DVGA offset regi

27、ster value,Automatic Gain Control (AGC),The phone does not use dB and dBm to manage power.In the embedded software, all power is defined in terms of AGC units– AGC units» AGC is stored as 10-bit number»

28、Range is 210,1024 total units» dB/AGC = Dynamic Range (dB) / 1024» For Dynamic Range = 85.3 dBThere are 12 AGC units per dB– Both RX and TX use AGC units for all power calculations» E.g. Rx must m

29、easure power and determine RX AGC.» E.g. Tx AGC units are used to calculate transmit power (e.g. max power and access probe step sizes).,RX AGC和dBm的轉(zhuǎn)換,Given– Min RSSI = -106 dBm– AGC/dB conversion = 12 AGC /

30、 1 dB– dB/AGC conversion = 0.08 dB / 1 AGC,TX AGC和dBm的轉(zhuǎn)換,Given– Min MSM Tx linearizer power = -57.3 dBm– AGC/dB conversion = 12 AGC / 1 dB– dB/AGC conversion = 0.08 dB / 1 AGC,HDET,Phone looking up HDET to get power

31、:– Upper 25% of the Tx dynamic is used to obtain power vs. HDET curve.– HDET dynamic range = 0.25 * 85.3 =21.33– HDET dynamic range is divided into 16 segments.– HDET max table power = 28.0 dBm– HDET mi

32、n table power = 6.67 dBmHDET offset and span– Offset and span define the range in which the power-limiting algorithm is active– Offset: Lowest HDET value used for power limiting = HDET reading at

33、 (max Tx power limit - 6dB)– Span: Highest HDET value used for power limiting = HDET reading at (max Tx power limit + 2dB) - offset,Rx Calibration (1),,Rx Calibration (2),,Rx Calibration- IM2 (3),IM2 cali

34、bration is done to improve reception in certain types of jamming situations. Improper IM2 calibration may cause the mobile station’s FER to increase in these jamming situations.,Rx Calibration- IM2 (4),Using a signal ge

35、nerator, place an AM modulated carrier with the following characteristics at the input to the antenna »The frequency of the carrier must be offset from the Rx reference frequency by 5.0 MHz. »Program

36、the modulation tone be sinusoidal and to have a frequency of 20 kHz. »Program the signal generator such that the AM modulation depth is 56 %. »Program the signal strength to be –25 dBm at the antenna’s

37、 input. »Check the RSSI using the FTM function Get RX AGC. If the RSSI is saturated (at the extreme limit), adjust the signal’s strength accordingly until the RSSI is no longer saturated.Call the FTM function Get

38、CDMA IM2. It may take approximately 5 seconds before the function returns a value.Store the two values in NV_CDMA_IM2_I_VALUE and NV_CDMA_IM2_Q_VALUE.,Rx Calibration (5),FTM command sequence-1.SET_MODE {FTM}-2.RESET

39、-3.TEST_SET_MODE {PHONE_MODE_CDMA_800}-4.TEST_SET_CHANNEL {CDMA reference=202} -5.Input CDMA waveform at ref. channel and at LNA_FALL1 power.-6.TEST_GET_DVGA_OFFSET-7.TEST_GET_LNA_OFFSET {ID=0}-8.Change input

40、 power level to LNA_FALL2.-9.TEST_GET_LNA_OFFSET {ID=1}-10.Change input power level to LNA_FALL3.-11.TEST_GET_LNA_OFFSET {ID=2}-12.Repeat steps 4 through 11 for all 16 channels.,Rx Calibration (6),Stored in follo

41、wing NV items: NV_CDMA_VGA_GAIN_OFFSETNV_CDMA_VGA_OFFSET_VS_FREQNV_LNA_RANGE_OFFSETNV_CDMA_LNA_RANGE_OFFSET_VS_FREQNV_LNA_RANGE_12_OFFSETNV_CDMA_LNA_RANGE_12_OFFSET_VS_FREQNV_CDMA_LNA_3_OFFSETNV_CDMA_LNA_

42、 3_OFFSET_VS_FREQNV_CDMA_LNA_ 4_OFFSETNV_CDMA_LNA_ OFFSET_VS_FREQNV_CDMA_IM2_I_VALUENV_CDMA_IM2_Q_VALUENV_CDMA_IM2_TRANSCONDUCTOR_VALUE,Tx Calibration (1),,Tx Calibration (2),Nonlinear RF characteristics of the

43、 Tx AGC amplifier are captured in linearizer tables,Tx Calibration (3),FTM command sequence1.SET_MODE {FTM}2.RESET3.TEST_SET_MODE {PHONE_MODE_CDMA_800}4.TEST_SET_CHANNEL {CDMA reference=202} 5.TEST_SET_TX_ON6.TEST_

44、SET_PA_RANGE {LOW_POWER}7.Measure Tx power and use TEST_SET_PDM {Tx_AGC,x} to adjust until the desired Tx power for index 0 is achieved. Record Tx_AGC PDM.8.Repeat Step 7 for all other indices from 1 to 36.9.TEST_SET_

45、PA_RANGE {HIGH_POWER}10.Adjust the Tx power as described in Step 7, and record Tx AGC PDMs and HDET values for all 37 indices.,Tx Calibration (4),Stored in the following NV items:NV_CDMA_TX_LIN_MASTER0NV_CDMA_TX_LIN

46、_MASTER1NV_TX_COMP0NV_TX_COMP1NV_HDET_OFFNV_HDET_SPNNV_CDMA_TX_LIM_VS_FREQNV_CDMA_EXP_HDET_VS_AGC,RF Calibration-硬件設(shè)備接口 (1),GPIB硬件接口-GPIB接口是一個(gè)數(shù)字化24腳并行總線，其中16根為TTL并行總線，包括8根雙向數(shù)據(jù)線、5根控制線、3根握手線，另8根為地線和屏蔽線。-GPI

47、B卡作為計(jì)算機(jī)與測量儀表之間的橋梁，主要承擔(dān)著命令、數(shù)據(jù)的傳送功能，計(jì)算機(jī)通過控制GPIB卡向測試儀表發(fā)送控制命令，控制測試儀表執(zhí)行相應(yīng)的動作、進(jìn)行相應(yīng)的測試；計(jì)算機(jī)向測試儀表發(fā)送數(shù)據(jù)讀取命令，控制測試儀表將測試數(shù)據(jù)通過GPIB接口送入計(jì)算機(jī)；,RF Calibration-硬件設(shè)備接口 (2),NI公司提供的常用IEEE488.2函數(shù) -viOpenDefaultRM (ViPSession vi) -viOpen(ViSe