ability > -1%). For uplink with two receive antennas, a similar requirement states SNR of -3 to -4 dB for PUCCH CQI report and the initial RRC message in connection setup procedure (random access message 3 sent on PUSCH). Thus in the absence of better receiver performance test results, it is usually not advisable to use SNR targets approximately below -3 dB in either uplink or downlink. This also has some implications on handover offset planning since if intra-frequency A3 offset higher than 3 dB is used; this risks having SNR of below -3 dB in case one or more neighbour cells become fully loaded. For this reason, it is not in general recommended to use intra-frequency handover margins much higher than 3 dB. Mapping Throughput to RSRQ While SINR can in principle be estimated from reported RSRQ and own cell PRB utilization, most eNodeB implementations do not implement such option for downlink. Downlink SINR can be calculated from the relation RSRQ = RSRP/RSSI, where RSSI is the total received power normalized to 1 PRB bandwidth. 11 The goal is to define an RSRQ threshold that corresponds to downlink throughput that is below a target value. When downlink average subcarrier activity factor is y the RSRQ can be written as RSRQ = 2RSRP + 121oth +12N 11 The number of PRBs in the 3GPP definition of RSSI in 3GPP TS 36.214 can be dropped to simplify notation. The RSSI in this section is normalized to one PRB bandwidth. LTE Small Cell Optimization The average subcarrier activity factor y is defined for orthogonal frequency division multi- plexing (OFDM) symbols that carry RS of the first two transmit antennas and hence for a 1Tx cell the minimum value of y is 2/12 = 1/6 since there are always 2 RS symbols in the OFDM symbol even if the cell carries no PDSCH or PDCCH traffic. The maximum value is = 1 for the case when all PRBs in the 1Tx cell are utilized. The other cell interference (10th) and thermal noise power (N) have been normalized to subcarrier bandwidth. The equation can be related to SINR by rewriting it as - 121o