Adaptive quantization for third-generation TDMA transmitters

Pulse-amplitude modulation is used extensively in digital wireless systems, due to the need for spectral efficiency. An example of such systems is the third-generation time-division multiple access (TDMA) system known as EDGE. In this work, optimal quantization of pulse amplitude-modulated systems is analyzed and applied to an EDGE uplink transmitter. Of particular interest is how uplink data is scaled prior to subsequent quantization as a result of digital-to-analog conversion. Through analysis, two methods of quantization are presented-fixed and adaptive. Simulations are provided which show that adaptive quantization provides a performance benefit over fixed methods in terms of baseband SNR