The performance and efficiency of envelope elimination and restoration transmitters for future multiple-input multiple-output wireless local area networks

The inefficiency of contemporary power amplifiers (PAs), when operating in their linear region, is a major obstacle to mobile operation of wireless local area networks (WLANs) based on IEEE 802.11n. Therefore the use of more efficient envelope elimination and restoration (EER) transmitter architectures is considered. In addition to high efficiency it is also necessary to satisfy the spectral mask and achieve satisfactory link-level performance. Link-level simulations of a contemporary WLAN PA show that, at the power back-offs necessary to achieve sufficient linearity, the power added efficiency (PAE) is only ~1% for a system with four transmit antennas. In contrast, simulations of a phase feedback EER PA architecture show that it is possible to achieve an average PAE of 70%, while satisfying the spectral mask, with only a small degradation in link-level performance.

[1]  Adel A. M. Saleh,et al.  Frequency-Independent and Frequency-Dependent Nonlinear Models of TWT Amplifiers , 1981, IEEE Trans. Commun..

[2]  Alfred Cann.  Nonlinearity Model with Variable Knee Sharpness , 1980, IEEE Transactions on Aerospace and Electronic Systems.

[3]  Steve C. Cripps,et al.  RF Power Amplifiers for Wireless Communications, Second Edition (Artech House Microwave Library (Hardcover)) , 2006 .

[4]  Vahid Tarokh,et al.  A simple encodable/Decodable OFDM QPSK code with low peak-to-mean envelope power ratio , 2001, IEEE Trans. Inf. Theory.

[5]  John F. Sevic,et al.  Statistical characterization of RF power amplifier efficiency for CDMA wireless communication systems , 1997, Proceedings of 1997 Wireless Communications Conference.

[6]  N. O. Sokal.  Class-E switching-mode high-efficiency tuned RF/microwave power amplifier: improved design equations , 2000, 2000 IEEE MTT-S International Microwave Symposium Digest (Cat. No.00CH37017).

[7]  V. Erceg,et al.  TGn Channel Models , 2004 .

[8]  F. Raab.  Intermodulation distortion in Kahn-technique transmitters , 1996 .

[9]  Kevin A Morris,et al.  Gain and phase matching requirements of cubic predistortion systems , 2000 .

[10]  A.A.M. Saleh,et al.  A Statistical Model for Indoor Multipath Propagation , 1987, IEEE J. Sel. Areas Commun..

[11]  Jose C. Pedro,et al.  A comprehensive explanation of distortion sideband asymmetries , 2002 .

[12]  Lawrence E. Larson,et al.  Gain/phase imbalance-minimization techniques for LINC transmitters , 2001 .

[13]  Pb Kenington,et al.  The Effect of Delay Mismatch on a Feedforward Amplifier , 1994 .

[14]  C.A.T. Salama,et al.  Phase-correcting feedback system for class E power amplifier , 1997 .

[15]  D. Rudolph,et al.  Kahn EER technique with single-carrier digital modulations , 2003 .

[16]  Narisi Wang,et al.  60% efficient 10-GHz power amplifier with dynamic drain bias control , 2004, IEEE Transactions on Microwave Theory and Techniques.

[17]  S. C. Cripps,et al.  RF Power Amplifiers for Wireless Communications , 1999 .

[18]  Kevin A Morris,et al.  Removing the effects of baseband impedance on distortion in FET amplifiers , 2006 .

[19]  A. Ghorbani,et al.  The effect of solid state power amplifiers (SSPAs) nonlinearities on MPSK and M-QAM signal transmission , 1991 .

[20]  W. Dehaene,et al.  Energy-scalability enhancement of wireless local area network transceivers , 2004, IEEE 5th Workshop on Signal Processing Advances in Wireless Communications, 2004..

[21]  E. Ballesteros,et al.  Analysis and design of microwave linearized amplifiers using active feedback , 1988 .

[22]  G. Baudoin,et al.  EER architecture specifications for OFDM transmitter using a class E amplifier , 2004, IEEE Microwave and Wireless Components Letters.

[23]  J. S. Kenney,et al.  Behavioral modeling of nonlinear RF power amplifiers considering memory effects , 2003 .

[24]  N. O. Sokal,et al.  RF power amplifiers, classes A through S-how they operate, and when to use each , 1997, Professional Program Proceedings. Electronic Industries Forum of New England.

[25]  Cedric Nishan Canagarajah,et al.  A broadband polynomial predistorter for reconfigurable radio , 2001, IEEE VTS 53rd Vehicular Technology Conference, Spring 2001. Proceedings (Cat. No.01CH37202).

[26]  Hideo Kobayashi,et al.  Uplink Packet Transmission Control for Asymmetric Traffic in CDMA/Shared-TDD Cellular Packet Communications(Wireless Communication Technology) , 2003 .

[27]  K.A. Morris,et al.  Improved EER transmitters for WLAN , 2006, 2006 IEEE Radio and Wireless Symposium.

[28]  W. McFarland,et al.  An IC for linearizing RF power amplifiers using envelope elimination and restoration , 1998, 1998 IEEE International Solid-State Circuits Conference. Digest of Technical Papers, ISSCC. First Edition (Cat. No.98CH36156).

[29]  J. Laskar,et al.  Analysis and design of a high-efficiency multistage Doherty power amplifier for wireless communications , 2005, IEEE Transactions on Microwave Theory and Techniques.