| 摘要 |
<p>The invention is a CDMA spectral shaping technology (116) that attenuates the out-of-band signal power in the CDMA signal. The in-band CDMA signal is attenuated near the corner frequencies to reduce components that provide a disproportionate contribution to the out-of-band signal power. The power amplifier (625) in the CDMA base station (512) can then operate at higher power levels without exceeding out-of-band signal power limitations. As a result, the power amplifier (625) operates more efficiently and extends the range or capacity of the base station. In some examples of the invention, spectral shaping digital filters (516) are placed between the cell site modem (621) and the digital-to-analog converter (623) in the base station. In other examples of the invention, spectral shaping analog filters (516) are placed between the digital-to-analog converter (722) and the low-pass filter (623) in the base station.</p> |
