Operating Manual Vol 1 - ES Documentation

SMIQDigital Standard IS-95 CDMA(CLOCK...) CLOCK SOURCE Selection of clock source.INTSMIQ uses internally generated clocksignals.EXT An external chip clock is fed in at connectorSYMBOL CLOCK. Multifolds of thechip clock are fed in at connector BITCLOCK .The clock synthesizer on the modulationcoder is synchronized to this clock.Parameter CHIP RATE has to be set withan accuracy of ± 1 %.The polarity, the trigger threshold and theinput resistance of the SYMBOL CLOCKinput can be modified in menu DIGITALMOD - EXT INPUTS.IEC/IEEE-bus :SOUR:IS95:CLOC:SOUR INTDELAYSetting the delay of generated modulation signal toan external clock.This can be used, for example, for synchronizationwith a second unit to achieve time synchroneitybetween the modulation signals of the two units.The displayed setting resolution of 1/100 symbol isonly attained for symbol-clock frequencies below100 kHz.The resolution is reduced with increasing frequency.At a chip rate of 1.2288 Mcps, the resolution equalsthe chip duration × 0.1.IEC/IEEE-bus :SOUR:IS95:CLOC:DEL 0.5TOTAL POWERDisplay of the total power of all active code channels. The TOTAL POWER iscalculated when the modulation is active (STATE = ON). It is the sum of thechannel power of all active channels. If the value is not equal 0 dB then all activechannel power were internally adjusted so that the total power equals 0 dB (thepower relation between single code channels is not affected!) This is nessessaryto keep the setted output power (LEVEL) constant. In addition to this averagepower (LEVEL) the peak envelope power (PEP) is also indicated in the header ofthe display. The value for PEP is calculated based on a worst case. The actualpeak powers are mostly smaller.IEC/IEEE-bus command :SOUR:IS95:POW?ADJUSTTOTAL POWERChanges the power of every code channel switched on. After this adjustmentthe total power is 0 dB. The power relation between single active codechannels is not affected.IEC/IEEE-bus command :SOUR:IS95:POW:ADJ1125.5555.03 2.143E-9