tailieunhanh - Modulation and coding course- lecture 3

Transforming the information source to a form compatible with a digital system -Sampling -Aliasing -Quantization -Uniform and non-uniform -Baseband modulation -Binary pulse modulation -M-ary pulse modulation -M-PAM (M-ay Pulse amplitude modulation) | Digital Communication I Modulation and Coding Course ------- -------------- Period 3 - 2007 Catharina Logothetis Lecture 3 Last time we talked about Transforming the information source to a form compatible with a digital system Sampling Aliasing Quantization Uniform and non-uniform Baseband modulation Binary pulse modulation M-ary pulse modulation M-PAM M-ay Pulse amplitude modulation Lecture 3 2 Formatting and transmission of baseband signal r Digital info. Bit stream Pulse waveforms Data bits baseband signals Textual Format Pulse modulate I Sampling at rate I i fs 1 T s s sampling time Ts Quantizing each sampled value to one of the I L levels in quantizer. I I Encoding each q. value to l log2 L bits Data bit duration Tb Ts l l Mapping every m log2 M data bits to a I symbol out of M symbols and transmitting a baseband waveform with duration T Information data rate Rb 1 Tb bits sec Symbol rate R 1 T symbols sec For real time transmission Rb mR Lecture 3