Method for transmission power shaping and communications apparatus utilizing the same

A communications apparatus, comprising:

• an RF signal processing device, capable of supporting carrier aggregation and configured to process RF signals;
• at least a baseband signal processing device, configured to process baseband signals;
• and
• a processor, configured to control operations of the RF signal processing device and the baseband signal processing device,
• wherein the processor further receives a power control signal from a peer communications apparatus, obtains an assigned transmission power which is assigned by the peer communications apparatus for the communications apparatus to transmit a reference signal for uplink carrier selection according to information carried in the power control signal, determines a spectral efficiency estimation value of the communications apparatus and directs the RF signal processing device to transmit the reference signal with a reduced transmission power or the assigned transmission power according to the determined spectral efficiency estimation value;
• wherein the reference signal is transmitted with the reduced transmission power in a physical uplink shared channel (PUSCH).