Methods of data allocation and signal receiving, a wireless transmitting apparatus, and a wireless receiving apparatus are provided based on orthogonal frequency division multiplexing (OFDM) technology. The wireless transmitting apparatus obtains a data stream and allocates the data stream to a first sub-carrier set. Each of the first sub-carrier set and a second sub-carrier set has sub-carriers with opposite frequencies to each other, respectively. The second sub-carrier is emptied or allocated according the data stream allocated to the first sub-carrier set. The data stream is converted into an OFDM signal transmitted through a transmitting module. The wireless receiving apparatus includes a single branch receiver for receiving a radio frequency (RF) signal and outputting a baseband signal. Subsequently, the data stream is restored from the baseband signal.