An apparatus and method transmits a packet data symbol in a high-rate packet data (HRPD) mobile communication system for broadcasting service. A transmission processor generates a modulated symbol by encoding, interleaving and modulating a physical layer packet to be transmitted, and arranges the modulated symbol in a data tone. A tone inserter inserts a guard tone and a pilot tone into the data tone. A tone power allocator sets a different pilot-to-data tone power ratio according to a position of a slot, in which the packet data symbol is included, and allocates power according to the pilot-to-data tone power ratio. A transmitter transmits the packet data symbol.