SMIQ
Digital Standard PHS
1125.5555.03
E-9
2.115
2.11
Digital Standard PHS
With the options Modulation Coder (SMIQB20) and Data Generator (SMIQB11) provided, modulation
signals according to the Japanese PHS standard
1
can be generated. PHS is a TDMA standard for
private and public cordless phones.
SMIQ can generate both the transmit signal of a cell station (CS) and the transmit signal of a personal
station (PS). Transmission from CS to PS is called "downlink", "uplink" being used for transmission in
the opposite direction.
Uplink and downlink are transmitted in the separate time slots of a frame using the time duplex method.
Each frame consists of 8 slots. The data contents of each slot can be defined individually by SMIQ by
means of a slot editor. SMIQ can generate a control physical slot and also a communication physical
slot. Each slot can be switched on or off. A defined intermediate level can also be set.
A burst type has to be defined to configure a slot. The following burst types can be selected:
•
TCHFULL
simulation of a communication channel for a speech coder rate of 32 kbit/s,
•
TCHHALF
simulation of a communication channel for a speech coder rate of 16 kbit/s,
•
VOX
simulation of a communication channel in non-speech intervals with uplink
transmission only in every fourth frame,
•
SYNC,
simulation of a sync channel and
•
ALL_DATA
burst type for test purposes with freely programmable data contents in the selected
slot.
The following internal modulation sources are available:
•
different PRBS generators with a sequence length between 2
9
-1 and 2
23
-1 and
•
data lists, ie freely programmable data sequences from the data generator memory.
For generating the PHS signals, SMIQ inserts the modulation data continuously (in real time) into the
selected slots. Using a digital signal processor the data generator generates a data sequence with
modulation data and control signals for envelope control.
The data generator in SMIQ generates a data stream which is converted into IQ signals in the
modulation coder. According to the PHS standard, the modulation type is
π
/4 DQPSK at a symbol rate of
192 ksymbol/s and
√
COS filtering. Symbol rate and filtering can be changed in SMIQ.
1
Personal Handy Phone System ARIB Standard (RCR STD-28)