**4. WiMAX with compander for PAPR reduction**

The system will be used in this work is shown in Figure 13. The transmitter section maps a random data bit sequence, into a sequence of QAM symbols. The QAM symbols are partitioned into N-length blocks and modulated onto the sub-carriers of an OFDM modulator via the inverse Fast Fourier Transform (IFFT). Before guard interval insertion, prior to transmission, the signal is companded with µ-law compander. The companded signal is then passed through the amplifier at the transmitter, which distorts the signal according to nonlinear solid state power amplifier models. After transmission, the signal is passed through SUI channels and corrupted with AWGN, compensation, µ-law expansion, and OFDM demodulation.

**Figure 13.** Simulation model of WiMAX system.

Compander (µ) was described in detail in chapter 3 where µ is the parameter controls the amount of compression.
