Question: What type of sequence is used to define pseudo-random sequences in E-UTRA?
Option 1: A length-15 Gold sequence
Option 2: A length-31 Gold sequence
Option 3: A length-63 Gold sequence
Option 4: A length-127 Gold sequence
Explanation: According to the specifications, pseudo-random sequences in E-UTRA are defined by a length-31 Gold sequence. This is used to generate the output sequence of a specific length, which is crucial for various applications in the Evolved Universal Terrestrial Radio Access (E-UTRA) network.