Unequal power allocation to the turbo-encoder output bits with application to CDMA systems

A Modified Unequal Power Allocation (upa) Scheme for Performance Enhancement in Bit Repetition Turbo Codes in High Speed Downlink Packet Access (hsdpa) System

In this paper, a modified optimal power allocation scheme for different bits in turbo encoder has been proposed to improve the performance of Turbo Codes system in High Speed Downlink Packet Access (HSDPA) service. In a typical turbo code in HSDPA system, an encoder with code rate of 1/3 was used with bit repetition scheme or puncturing system to achieve code rate of 1/4. In this study, the aut...

Optimal Power Allocation for the Proposed Asymmetric Turbo Code for 3G Systems

We proposed a new class of asymmetric turbo encoder for 3G systems that performs well in both “water fall” and “error floor” regions in [7]. In this paper, a modified (optimal) power allocation scheme for the different bits of new class of asymmetric turbo encoder has been investigated to enhance the performance. The simulation results and performance bound for proposed asymmetric turbo code wi...

Turbo-Coded Modulation of EVRC Speech Encoder With Unequal Error Protection For Fading Channels

The Enhanced Variable Rate Codec (EVRC) is a standard for the “Speech Service Option 3 for Wideband Spread Spectrum Digital System,” which has been employed in both IS-95 cellular systems and ANSI J-STC-008 PCS (Personal Communications Systems). This paper investigates the combination of turbo codes with Unequal Error Protection (UEP) and 16-QAM modulation for EVRC codec of Rate 1 to get power ...

Unequal Error Protection on the Turbo-Encoder Output Bits

Multistage Multiuser Detection for Cdma with Space-time Coding

The combination of Turbo codes and space-time block codes is studied for use in CDMA systems. Each user's data are rst encoded by a Turbo code. The Turbo coded data are next sent to a space-time block encoder which employs a BPSK constellation. The space-time en-coder output symbols are transmitted through the fading channel using multiple antennas. A multistage receiver is proposed using non-l...