have the disadvantage of being independent across pcs bands so that they will not track multipath effects the base will transmit reference link maintenance pilots lmps to provide a phase reference for coherent demodulation and an estimate of the desired signal for beamform error estimation reference signals are transmitted on both the forward link and on the reverse link this allows the base to make a measurement of mean square error mse for use in deriving an optimal beamform solution on the reverse link without relying on direction of arrival estimation ru baseband spatial processing techniques ru perform spatial processing at the array aperture to form a continuous beam when a traffic channel is to be established for an ru the base must allocate a channel on which the ru can meet the required grade of service the channel allocation algorithm needs to know information concerning the capabilities of each active and new ru if future equipments operate over different if bandwidths then the channel allocation algorithm needs to know what each equipment can support in the first generation of pwan the ru 39 s support a 1 mhz operating bandwidth this allows operation over any of 16 channels when an ru is identified by its ruid the base searches a data base containing the required information about the ru for the channel allocation algorithm e g frequency if bandwidth bw number of bearer b channels supported type s of voice coding supported etc since the system is dependent on sdma for increasing capacity a very important parameter is the doa.