Satu pertanyaan dari catatan saya adalah seperti ini.
Consider a communication channel with a bandwidth of 2400Hz. If QPSK technique is
used, what is the possible transmission rate? (Assume that rectangular
pulses are used in the baseband signals, and that 90% energy preservation is
required.)
For a baseband system, a bipolar signal of bandwidth B can support a rate of B
with 90% energy preservation (since bandwidth =1/τ in this case).
For a bandpass system, a BPSK signal of bandwidth of B can support a rate of B/2.
This is because, after modulation, the bandwidth is 2/τ.
For QPSK, rate can be doubled using the same bandwidth. Therefore the
supported rate is 2400bps.
Mengapa sinyal BPSK bandwidth 2 / τ dapat mendukung flatate B / 2? dan apa hubungan antara bandwidth dan datarate? dan mengapa di QPSK, kurs dapat digandakan menggunakan bandwidth yang sama?