The present disclosure provides a radio communication method, a user equipment, and a network side device, the radio communication method includes: receiving, by a network side device, a random access preamble signal transmitted by a user equipment, where duration of the random access preamble signal is one SC-FDMA symbol or one OFDM symbol, thus air interface overhead of random access can be greatly reduced in a condition that a user equipment can access a cell randomly. The cell may be a microcell or other similar cells.