Title :
Signal generation algorithm for digital polar transmitters with reduced receive band noise
Author :
Nakatani, Takeshi ; Gheidi, H. ; Leung, V.W. ; Kimball, D.F. ; Asbeck, P.M.
Author_Institution :
Univ. of California San Diego, La Jolla, CA, USA
Abstract :
Digital polar transmitters are under development for multiband handset applications, but typically lead to excess Rx band noise (RxBN). In this paper, a technique to improve the RxBN of a digital polar transmitter is demonstrated. Linear phase FIR filters are applied to both envelope and phase signals, so that the RxBN becomes relatively insensitive to transmitter non-idealities. At the same time, there is only small degradation of ACLR and EVM. Noise shaping algorithms are also applied to reduce the envelope quantization noise. For a WCDMA signal at 1.75 GHz, with a corresponding Rx band at 1.845 GHz, we demonstrate RxBN of -142 dBm/Hz in simulation and -125 dBm/Hz in experimental measurements.
Keywords :
FIR filters; code division multiple access; linear phase filters; quantisation (signal); radio transmitters; signal generators; Rx band noise; WCDMA signal; bandwidth 1.75 GHz; bandwidth 1.845 GHz; digital polar transmitters; envelope quantization noise; linear phase FIR filters; multiband handset applications; noise shaping algorithms; phase signals; reduced receive band noise; signal generation algorithm; transmitter nonidealities; Bandwidth; Finite impulse response filters; Noise; Noise shaping; Power generation; Quantization (signal); Transmitters; Power amplifiers; digital pulse width modulation; linear phase FIR filter; noise shaping; polar transmitters; receive band noise;
Conference_Titel :
Power Amplifiers for Wireless and Radio Applications (PAWR), 2014 IEEE Topical Conference on
Conference_Location :
Newport Beach, CA
Print_ISBN :
978-1-4799-2298-7
DOI :
10.1109/PAWR.2014.6825738
