At least some reference symbols dedicated to a particular communication device are transmitted in resource blocks allocated to other devices. This way, reference symbol assignments are not unduly restricted by other constraints placed on the boundary elements of a resource block. According to an embodiment, data and reference signals are transmitted by transmitting a resource block allocated to a first communication device. The resource block includes a plurality of resource elements, each resource element corresponding to a modulation symbol. At least one reference symbol associated with the resource block and dedicated to the first communication device is transmitted in a resource block allocated to a second communication device. On the receive side, the communication device can perform channel estimation based on reference symbols dedicated to the device that are transmitted in resource blocks allocated to the device and in resource block(s) allocated to other communication device(s).