IMO, the reference signals for users involved should be distinct and should have good cross-correlation properties. If two or more UEs in one sector are assigned to the same resource blocks, their reference signals are derived from the same sequence with cyclic-shift in the time-domain. In 3GPPLTE, the cyclic-shifts for a UE's reference signal can take eight different values. These values can ideally support uplink MU-MIMO with two to six UEs. However, in practice, only two users are paired to lower the receiver complexity. It may be noted that the length of the reference signals are based on the number of resource blocks allocated to a user. In general, reference signals of 36 or more in length are based on extended Zadoff- Chu sequences, while reference signals of length 12 and 24 are computer generated sequences. The interference seen by a user's signal comprises two parts: the intra-cell interference due to other users' involved in the uplink MU-MIMO; and inter-cell interference due to users in other sectors. As the UEs in a sector can operate at different MCS levels and multipath can create nulls and peaks in one transmission, the inter-cell interference due to these UEs seen at neighboring sectors can be quite irregular in the frequency-domain. One can choose to estimate the spatial pattern of the inter-cell interference over one or multiple resource blocks. There are a number of uplink MIMO receiver 10.9 Multi-antenna techniques in 3GPP LTE algorithms which can be used for 3GPP LTE uplink MIMO. Using MU-MIMO, two UE's transmit on the same frequency sub-carriers and at the same time. Thus, there is cross-user interference between these two UEs. Using a MMSE receiver at the BS, the interference between these two UEs can be significantly reduced. The 3GPP LTE Release 8 supports downlink transmissions on one, two, or four cell-specific antenna ports, each corresponding to one, two, or four cell-specific reference signals, where each reference signal corresponds to one antenna port. An additional antenna port, 