1. The UMTS UTRA-FDD Uu radio interface diagram is shown below, where a radio frame with a time duration of 10ms contains 38,400 chips. The radio frame consists of 15 time slots, each of which has 2,560 chips and a time duration of 666.7s. Based on the diagram and assume a signal modulation format of 16-QAM, answer the following six questions:

• What is the main functionality of the frame structure?
• State briefly the functionalities of each of the four sections defined in uplink DPCCH.
• If a user would like to upload a file at 2.0Mb/s, work out the spreading factor that the user has to choose, and the corresponding signal bit rate associated with the chosen spreading factor. What is the bandwidth utilisation efficiency?
• For each connection in layer 1, a maximum six DPDCHs may be made available to a single user, work out the maximum theoretical signal bit rate offered to the user.
• Work out all the possible raw signal bit rates offered by downlink DPCH and their corresponding spreading factors.
• Why can UMTS achieve asymmetrical communications and different data rates?

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