An apparatus (12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32), comprising: a baseband processing module adapted to generate a signal including a preamble in accordance with either a first preamble type or a second preamble type, wherein: the first preamble type corresponds only to open loop single user, SU, transmissions without beamforming; and the second preamble type corresponds to either SU beamforming transmissions or multiple user, MU, transmissions; and at least one antenna (82, 84, 86) adapted to transmit the signal, or at least one additional signal derived from the signal, to at least one wireless communication device (12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32); and wherein: the first preamble type includes at least one short training field, followed by at least one long training field, followed by one signal field, followed by at least one additional long training field; the second preamble type includes at least one short training field, followed by at least one long training field, followed by one signal field, followed by at least one additional short training field, followed by at least one additional long training field; and the preamble is followed by a data field, characterised in that: when the second preamble type corresponds to MU transmissions, the second preamble type includes: the at least one additional long training field followed by at least one additional signal field, and the signal field indicating a first modulation coding set, MCS, associated with the at least one additional signal field, and the signal field further indicating a difference between the first modulation coding set and a modulation coding set associated with the data field, such that the first modulation coding set and the difference between the first modulation coding set and the modulation coding set associated with the data field is used for processing the data field. a baseband processing module adapted to generate a signal including a preamble in accordance with either a first preamble type or a second preamble type, wherein: the first preamble type corresponds only to open loop single user, SU, transmissions without beamforming; and the second preamble type corresponds to either SU beamforming transmissions or multiple user, MU, transmissions; and the first preamble type corresponds only to open loop single user, SU, transmissions without beamforming; and the second preamble type corresponds to either SU beamforming transmissions or multiple user, MU, transmissions; and at least one antenna (82, 84, 86) adapted to transmit the signal, or at least one additional signal derived from the signal, to at least one wireless communication device (12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32); and wherein: the first preamble type includes at least one short training field, followed by at least one long training field, followed by one signal field, followed by at least one additional long training field; the second preamble type includes at least one short training field, followed by at least one long training field, followed by one signal field, followed by at least one additional short training field, followed by at least one additional long training field; and the first preamble type includes at least one short training field, followed by at least one long training field, followed by one signal field, followed by at least one additional long training field; the second preamble type includes at least one short training field, followed by at least one long training field, followed by one signal field, followed by at least one additional short training field, followed by at least one additional long training field; and the preamble is followed by a data field, characterised in that: when the second preamble type corresponds to MU transmissions, the second preamble type includes: the at least one additional long training field followed by at least one additional signal field, and the signal field indicating a first modulation coding set, MCS, associated with the at least one additional signal field, and the signal field further indicating a difference between the first modulation coding set and a modulation coding set associated with the data field, such that the first modulation coding set and the difference between the first modulation coding set and the modulation coding set associated with the data field is used for processing the data field. when the second preamble type corresponds to MU transmissions, the second preamble type includes: the at least one additional long training field followed by at least one additional signal field, and the signal field indicating a first modulation coding set, MCS, associated with the at least one additional signal field, and the at least one additional long training field followed by at least one additional signal field, and the signal field indicating a first modulation coding set, MCS, associated with the at least one additional signal field, and the signal field further indicating a difference between the first modulation coding set and a modulation coding set associated with the data field, such that the first modulation coding set and the difference between the first modulation coding set and the modulation coding set associated with the data field is used for processing the data field.