一个四用户的扩频通信系统，扩频增益为N=16，采用Walsh码进行直接序列扩频，BPSK调制，无线信道为AWGN(加性高斯白噪声信道)信道(AWGN信道：不考虑通信信道信号时，由宽频范围描述的统计随机无线噪声。)。在接收端进行解扩，解调，判决，通过仿真得到其中一个用户的误比特率与信噪比的仿真结果。,A four-user spread spectrum communication system, spreading gain for N = 16, using Walsh code Direct

dspbuilder中用spectrum scope来查看波形的频谱，一些参数需要正确设置，一些模块需要正确添加-dspbuilder using spectrum scope to see the waveform of the spectrum, some parameters need to properly set up, a number of modules required to add the correct

fftcode_scope computes and displays spectrum of a signal stored in a Structure with Time format (Format used to save signals in Simulink Scope block and in To Workspace block). The signal must be sampled at fixed step. PSBFFT_SCOPE perf