Beyond 3G wireless communication system prototype

Abstract

Modern wireless systems have to achieve very high data rates over noisy channels. Channel codes are usually used to guarantee reliable communication, but validating a system with extremely low Bit Error Rate (BER) requires the simulation of a huge number of samples. The simulation complexity furtherly increases if we want to take into account the joint effect of channel codes and complex modulation techniques, such as Orthogonal Frequency Division Multiplexing (OFDM), over multi-path fading channel. The use of software simulators to evaluate system performance in several scenarios may result in unacceptably long times and a reconfigurable hardware prototyping environment may be an effective solution. This paper describes the implementation of a complete real-time, fully digital, flexible high performance hardware/software prototype for beyond 3G wireless communications. The transmitter/receiver chain includes several innovative characteristics: Serial Concatenated Convolutional Codes (SCCC) Turbo Encoder/Decoder, adaptive OFDM modulation, versatile multiple user access scheme and a sophisticated, real-time power control.Optimal choices for partitioning and internal data representation have been described as well as internal architecture and measurement environment. Our programmable prototype ensures high flexibility and speedup of more than 4000 times compared with the software version.