A method for broadcasting system information via a broadcast channel (BCH) in an OFDMA system is provided. The BCH comprises one or more two-dimensional resource blocks. A plurality of pilot tones and a plurality of data tones are positioned within each resource block. The system information is mapped onto the plurality of data tones. In one embodiment, the plurality of pilot tones are located in configurable positions such that pilot tones of the same resource blocks transmitted by different base stations in the OFDMA system are interlaced to reduce pilot-to-pilot collision. In another embodiment, data tones that are located in pilot positions of other adjacent cells are nullified to reduce data-to-pilot collision. In one novel aspect, the property of interlaced pilot patterns and tone nullification is leveraged to estimate interference second-order statistics, which facilitates receiver implementation and improves receiver performance.