In this letter, we propose a multi-cell cooperation method for broadcast packet transmission in the OFDM-based cellular system with multiple transmit antennas. In the proposed method, to transmit two streams of spatially demultiplexed or transmit diversity coded symbols, we divide a coded packet into subparts to each of which different cell group and antenna pairs are assigned. It is shown that the proposed method reduces the outage probability with only negligible increase in channel estimation.