Methods and apparatus for establishing a communication link between a first user equipment and at least one other user equipment in a radio communication cell using a radio frequency spectrum divided into a plurality of channels. The first user equipment comprises a tuner configured to tune a communication unit to channels of a channel sequence vector in order. The channel sequence vector comprises at least a partial vectorization of a symmetric Toeplitz matrix formed from a set of the plurality of channels. The communication unit is configured, at each channel, to receive link data for establishing a communication link with the at least one other user equipment. A link establisher is configured to establish a communication link with the at least one other user equipment over the tuned channel if the link data is received.