Random Access Preamble for Minimizing PA Backoff

A method, in a user equipment, the method comprising:

• generating a Single-Carrier Frequency-Division Multiple Access (SC-FDMA) random access preamble signal comprising consecutive preamble symbol groups, each preamble symbol group comprising a cyclic prefix portion and a plurality of identical symbols, every second one of the preamble symbol groups corresponding to a second subcarrier frequency and each of the remaining preamble symbol groups corresponding to a first subcarrier frequency;
• and
• transmitting the SC-FDMA random access preamble signal.

A method, in a base station, the method comprising:

• receiving a radio-frequency signal;
• and
• detecting, in the radio-frequency signal, a first Single-Carrier Frequency-Division Multiple Access (SC-FDMA) random access preamble signal, transmitted by a first remote user equipment, wherein the first SC-FDMA random access preamble signal comprises consecutive preamble symbol groups, each preamble symbol group comprising a cyclic prefix portion and a plurality of identical symbols, every second one of the preamble symbol groups corresponding to a second subcarrier frequency and each of the remaining preamble symbol groups corresponding to a first subcarrier frequency.

A user equipment comprising:

• one or more processing circuits configured to
• generate a Single-Carrier Frequency-Division Multiple Access (SC-FDMA) random access preamble signal comprising consecutive preamble symbol groups, each preamble symbol group comprising a cyclic prefix portion and a plurality of identical symbols, every second one of the preamble symbol groups corresponding to a second subcarrier frequency and each of the remaining preamble symbol groups corresponding to a first subcarrier frequency, and
• transmit the SC-FDMA random access preamble signal from the user equipment to a base station.