A TDD-CDMA system with pre-phase subcarrier equalizer using asymmetric modulation scheme in duplex channel

Author

Jeong, Incheol ; Nakagawa, Masao

Author_Institution

Dept. of Electr. Eng., Keio Univ., Yokohama, Japan

fYear

1999

fDate

1999

Firstpage

122

Abstract

A multicarrier (MC) signal has a large peak to mean envelope power ratio, so that the MC signal suffers from a high level of intermodulation distortion due to the non-linearity of the power amplifier stage. For portable terminals, it is difficult to adopt a linear amplifier because high power efficiency is needed. To solve the problem mentioned above, we propose a time division duplex (TDD) code division multiple access (CDMA) communication system which uses an asymmetric modulation between the forward and the reverse link. The system consists of multicarrier modulation for the forward link and single carrier modulation for the reverse link. A pre-equalization method for the forward link transmission is also presented in this paper. In frequency selective fading, the system achieves the frequency diversity effect without any channel estimation unit at the mobile station by using the pre-subcarrier equalizer

Keywords

code division multiple access; diversity reception; equalisers; fading channels; intermodulation distortion; land mobile radio; modulation; multipath channels; multiuser channels; radio links; TDD-CDMA system; asymmetric modulation; code division multiple access; duplex channel; forward link transmission; frequency diversity; frequency selective fading; high power efficiency; intermodulation distortion; mobile station; multicarrier signal; multipath channel model; nonlinear power amplifier stage; peak to mean envelope power ratio; portable terminals; pre-equalization method; pre-phase subcarrier equalizer; reverse link; single carrier modulation; time division duplex system; Channel estimation; Distortion; Equalizers; Fading; Frequency diversity; High power amplifiers; Multiaccess communication; OFDM; Phase shift keying; System performance;

fLanguage

English

Publisher

ieee

Conference_Titel

Global Telecommunications Conference, 1999. GLOBECOM '99

Conference_Location

Rio de Janeireo

Print_ISBN

0-7803-5796-5

Type

conf

DOI

10.1109/GLOCOM.1999.831620

Filename

831620