G100 Wireless Handheld Functional Description

The G100 consists of a receiver, a transmitter, and host processor functions. The receiver is used to translate the RF signal into useful information from the base station to the processor where it is converted to user messages. The transmitter up-converts and amplifies data packets generated by the GMSK data pump to the base station. We will discuss the receiver and transmitter separately. Both of these sections depend upon the host processor for communications and control to support their operations.

G100 Transmitter Functional Description

The G100 transmitter is used to transmit data to the base station when the user sends an email message or data. The host processor formats the information to send to the base station in small packets. These are passed to the encoder circuitry where it is turned into a GMSK voltage that represents +/- 2 kHz modulating voltage waveform. This is passed through DAC controlled conditioning buffers to provide the proper voltage levels to modulate the Voltage Controlled Oscillator (VCO) to +/- 2 kHz centered at the transmit frequency. 

G100 Receiver Functional Description

The G100 receiver is used to receive data from the base station when email or data is sent to the user. The receiver is tuned to its proper frequency listening at the appropriate time for any valid incoming traffic. A valid frequency detected at a sufficient power level to drive the Receive Signal Strength Indicator (RSSI) circuitry causes the processor to attempt to decode the signal. The signal is demodulated to a GMSK voltage and passed through the conditioning circuitry to trigger the pattern detection circuit. 

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