Simulation Of Data Transmission In Physical Layer With Different Channel Models

By adopting multiple-input multiple-output (MIMO) and orthogonal frequency-division multiplexing (OFDM) technologies, indoor wireless systems could reach data rates up to several hundreds of Mbits/s and achieve spectral efficiencies of several tens of bits/Hz/s, which are unattainable for conventional single-input single-output systems. The enhancements of data rate and spectral efficiency come from the fact that MIMO and OFDM schemes are indeed parallel transmission technologies in the space and frequency domains, respectively. Using a block diagram of the transmitter and receiver of IEEE 802.11n standard, It contains four RFs, four analog-to-digital converters (ADCs), four FFTs, a MIMO equalizer, four de- Quadrature Amplitude Modulation and de-interleaver, a de-spatial parser, a de-puncturer, a channel decoder, a synchronization block, and a channel estimation block. This model is used to develop and explore a continuous (not"bursty") carrier and timing tracking synchronization scheme. Techniques incorporated can then likely be extended and modified to suite specific communications standards. The model uses an"acquisition"technique that exploits the correlation properties of the cyclic prefix to get a rough estimate of the frame boundary before attempting to accomplish the fine tracking algorithms. The model implements a 64 carrier OFDM waveform with a 16 point cyclic prefix. The OFDM symbol has 16 pilots, 3 guard tones (0 amplitude at band edge) and uses 4 QAM for the 45 remaining data streams.