Generation of BPSK Carrier Modulation Signal and Its Spectrum Analysis with Input Parameters

The process of generating BPSK carrier modulation signals consists of the following steps: First, determine the signal length based on the input data rate and simulation time parameters. This calculation typically involves multiplying the data rate by the simulation duration to obtain the number of symbols. Code implementation would include setting parameters like symbol_count = data_rate * simulation_time. Then, select the intermediate carrier frequency and system sampling rate. These parameters directly affect the spectral characteristics of the signal. In code implementation, the sampling rate should satisfy the Nyquist criterion (typically ≥ 2 × carrier frequency) to avoid aliasing. Next, based on the data rate and simulation time, convert the input data into a digital signal. This involves generating a binary sequence and mapping it to BPSK symbols (typically +1 for binary 1 and -1 for binary 0). The implementation uses digital modulation techniques where each symbol corresponds to a specific phase shift (0° or 180°). The digital signal is then modulated using BPSK modulation technique, converting it into a BPSK signal. This is achieved by multiplying the baseband signal with a carrier wave: bpsk_signal = baseband_signal × cos(2π × carrier_frequency × time). The generated BPSK signal can be analyzed through its time-domain waveform and frequency spectrum. The time-domain waveform shows signal variations over time, while the spectrum displays frequency characteristics. Spectral analysis typically employs FFT algorithms to transform the time-domain signal into frequency domain representation. Therefore, by analyzing both the time-domain waveform and frequency spectrum of the BPSK signal, we can understand its characteristics and performance, including bandwidth efficiency, spectral efficiency, and modulation quality.