1. What is the Walsh—Hadamard sequence H64(1)? What does your answer imply about the modulation of the pilot channel at the baseband output of Fig. 5.39? How would this be useful for synchronizing the receiver?
2. In- the IS-95 uplink, instead of using complete on/off voice activation, the transmitter user simply lowers the data rate and transmit power level, so that the receiver can maintain lock. Comment on how this approach will affect both multiple-access interference and the tracking performance requirements of the receiver.