Final answer:
BPSK provides the lowest bit rate but is most resilient to noise. QPSK doubles the bit rate of BPSK with moderate noise resilience, and 16-QAM has the highest bit rate but is the least robust against noise among the three modulation schemes.
Step-by-step explanation:
When comparing BPSK, QPSK, and 16-QAM in terms of bit rate and bandwidth in an AWGN (Additive White Gaussian Noise) channel with the same power consumption and the same Bit Error Rate (BER), we must consider the differences in their signal constellations and spectral efficiencies. BPSK (Binary Phase Shift Keying) transmits one bit per symbol, so it has the lowest bit rate among the three given equal bandwidth conditions. However, BPSK has the highest resilience to noise given its simpler modulation.
QPSK (Quadrature Phase Shift Keying) transmits two bits per symbol, effectively doubling the bit rate of BPSK for the same bandwidth. It has a denser constellation than BPSK and hence, under the same power, experiences more errors than BPSK in a noisy channel, but this disadvantage is offset by achieving a higher bit rate.
16-QAM (16-point Quadrature Amplitude Modulation) transmits four bits per symbol. It has the highest spectral efficiency among the three, hence providing the highest bit rate for the same amount of bandwidth. However, because of its denser constellation, it is more susceptible to errors due to noise compared to BPSK and QPSK.
In summary, assuming the same power and BER, BPSK offers the lowest bit rate and is the most robust against noise. QPSK offers a middle ground with doubled bit rate and moderate noise performance. 16-QAM, however, offers the highest bit rate at the cost of being less robust against noise than BPSK and QPSK.