The present invention relates to the field of wireless access systems and more particularly to a broadband wireless access system and a transmission method for such system. At least two data streams (2, 3, 4) are simultaneously transmitted in a multi-user channel (1) having a location dependent capacity. The data streams (2, 3, 4) are transmitted on the same radio resources. Preferably, the data streams are combined in a transmitter and separated in a receiver using different modulation and/or coding for the data streams.