Function of the modem in WirelessUSB LP devices

Question: What is the function of the modem in WirelessUSB LP devices ?

 

Answer:

The modem implements the coding layer that converts the stream of data in the data buffers to sequences of chips. It works with the framer to provide start of packet markers and other structures necessary to packetize the data. The modem also decodes received data, using a correlator function to center and decode the chip sequence. Various data modes are supported by the modem, configured by register settings. These modes, in conjunction with

a user specified 32 or 64 chip PN code, implement a variety of data rates