Abstract
Multicarrier systems have become popular for their spectral efficiency and robustness against frequency-selective fading. Multicarrier code-division multiple access (MC-CDMA) is a technique that combines the advantage of multicarrier modulation with that of code-division multiple access (CDMA) to offer reliable high-data-rate downlink cellular communication services. In this paper, we present the architecture of a downlink baseband transceiver using the MC-CDMA technology under the same bandwidth requirement and channel condition as the third-generation wideband CDMA system. In the transmitter, a scrambling code is applied in order to reduce the peak-to-average power ratio (PAPR) of the transmitter output. In the receiver, we use a joint weighted least-squares (WLS) synchronization error estimation algorithm and a novel channel estimator. Both algorithms greatly enhance the system error-rate performance, as indicated by functional simulation. Simulation results also verify maximum aggregate coded data rates of 5.4/10.8Mbps from 32/64 users in mobile/stationary multipath fading channel with a 3/4 convolutional code, respectively.
Highlights
Direct-sequence spread-spectrum (DSSS) code-division multiple access (CDMA) has been adopted in the third-generation (3G) mobile communication standard to provide high capacity and high transmission rate over conventional schemes such as frequencydivision multiple access (FDMA) and time-division multiple access (TDMA)
The channel model that we use is the typical urban power-delay profile specified in a 3GPP technical report, where a large number of paths ensure that correlation properties in the frequency domain are realistic [10]
We proposed the baseband transceiver architecture of a downlink Multicarrier code-division multiple access (MC-CDMA) communication system
Summary
Direct-sequence spread-spectrum (DSSS) CDMA has been adopted in the third-generation (3G) mobile communication standard to provide high capacity and high transmission rate over conventional schemes such as frequencydivision multiple access (FDMA) and time-division multiple access (TDMA). The orthogonality among subcarriers is maintained by EURASIP Journal on Applied Signal Processing setting the frequency spacing to the inverse of the symbol time, as in the case of OFDM [1, 2]. The MT-CDMA transmitter spreads several data streams independently in the time domain and positions the subcarriers that carry those spread signals with a frequency spacing equivalent to the inverse of the symbol time prior to spreading [4]. MC-CDMA signal receiving is susceptible to synchronization errors which have been known to corrupt the orthogonality among subcarriers. MC-CDMA receivers must adopt accurate synchronization error estimation algorithms to attain acceptable performance.
Sign-in/Register to view highlights & summary 
Published Version (
Free)
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call