Hannu Vilpponen

Channel estimation and signal detection for multi-carrier CDMA systems with pulse-shaping filter

We consider the problem of digital communication in a fading environment using the multi-carrier CDMA technology. By incorporating the effect of the pulse-shaping filter in the channel estimation and signal detection modules, we develop new estimator and detector structures which significantly outperform the commonly used time-domain equalizers and matched filter detector. Our simulation results demonstrate the elimination of some of the error floors which one would experience if usual time-domain techniques were used to cancel the effect of non-ideal pulse-shaping filter.

EDGE circuit switched data-an enhancement of GSM data services

One step in the evolution of the real-time GSM services is the enhanced circuit switched data (ECSD) which is being developed in ETSI as a GSM Phase 2+ work item (EDGE Phase 1) parallel to the Enhanced General Packet Radio Service (EGPRS). The ECSD radio interface deploys 8-PSK modulation in addition to GMSK and thus enables higher data throughput per time slot. This paper gives an overview of the ECSD concept and examples of applications that it supports. The focus is in the link level and the radio network level performance of different ECSD data rates in various test environments. It is shown that by utilising the proper link adaptation mechanism, even demanding transparent high data rate services, like video, can be supported with a good coverage.

Enhanced circuit switched data for real time services over GSM

The deployment of the HSCSD (high speed circuit switched data) is starting in GSM networks. This brings multislot capability to GSM and significantly enhances the available data rates together with the introduction of the 14.4 kbps per time slot data rate. The next step in the evolution of the real-time GSM services is the enhanced circuit switched data (ECSD) which is being developed in ETSI as GSM Phase 2+ work item (EDGE Phase I) parallel to enhanced general packet radio service (EGPRS). The ECSD radio interface deploys 8-PSK modulation in addition to GMSK and thus enables higher data throughput per time slot. The ECSD type radio interface can also be seen as a candidate in the development of real-time services for the evolving mobile networks. This paper focuses on the ECSD concept and presents its essential features as they are defined at the moment, before finalisation of the standard.

Performance comparison between MC-CDMA and 1xEV-DV

This paper presents performance comparison between a cellular system implemented according to the IxEV-DV standard, and a MC-CDMA system with similar parameters. The downlink peak data rate of the IxEV-DV system is 3.0912 Mbps. The proposed MC-CDMA system can provide the same data rates with significantly better performance. The MC-CDMA in this paper is comparable to the IxEV-DV system in the sense that same channel coding, modulation and slot structure as defined for IxEV-DV system are used.