Polar transmitter for wireless communication system

Polar modulation techniques offer the capability of multimode wireless system and the potential for the high efficiency power amplifier (PA). Any input baseband complex signal is decomposed into magnitude and phase signal, and goes through envelope modulator and phase modulator respectively. The modulated envelope and phase message signals are combined and amplified by switched-mode PA. In this paper, we will focus on the rectangular-to-polar converter, envelope modulator and phase modulator of polar transmitter for EDGE (2.5G) system. The analog part includes open-loop envelope modulator. The digital part includes rectangular-to-polar converter and digital phase modulator. We employ the coordinate rotation digital computer (CORDIC) and direct digital frequency synthesizer (DDFS) techniques in this part. A prototype chip has been designed and fabricated in UMC 0.18 /spl mu/m CMOS process with 1P6M technology.

[1]  F. Elguibaly,et al.  A fast parallel multiplier-accumulator using the modified Booth algorithm , 2000 .

[2]  J. Vankka.  Digital frequency synthesizer/modulator for continuous-phase modulations with slow frequency hopping , 1997 .

[3]  D. De Caro,et al.  Direct digital frequency synthesizers using high-order polynomial approximation , 2002, 2002 IEEE International Solid-State Circuits Conference. Digest of Technical Papers (Cat. No.02CH37315).

[4]  A. Torosyan,et al.  A 300 MHz quadrature direct digital synthesizer/mixer in 0.25 /spl mu/m CMOS , 2002, 2002 IEEE International Solid-State Circuits Conference. Digest of Technical Papers (Cat. No.02CH37315).

[5]  A. Chen,et al.  Reduced complexity CORDIC demodulator implementation for D-AMPS and digital IF-sampled receiver , 1998, IEEE GLOBECOM 1998 (Cat. NO. 98CH36250).

[6]  P.J. Nagle,et al.  A wideband linear amplitude modulator for polar transmitters based on the concept of interleaving delta modulation , 2002, 2002 IEEE International Solid-State Circuits Conference. Digest of Technical Papers (Cat. No.02CH37315).

[7]  Jorge L. C. Sanz,et al.  Fast least-squares curve fitting using quasi-orthogonal splines , 1994, Proceedings of 1st International Conference on Image Processing.

[8]  D. Rudolph.  Out-of-band emissions of digital transmissions using Kahn EER technique , 2002 .

[9]  D. Al-Khalili,et al.  Low power direct digital frequency synthesizers in 0.18 /spl mu/m CMOS , 2003, Proceedings of the IEEE 2003 Custom Integrated Circuits Conference, 2003..

[10]  Dengwei Fu,et al.  A 300MHz quadrature direct digital synthesizer/mixer in 0.25μm CMOS , 2002 .

[11]  Stephan V. Schell,et al.  Polar modulator for multi-mode cell phones , 2003, Proceedings of the IEEE 2003 Custom Integrated Circuits Conference, 2003..