Tuyển tập báo cáo các nghiên cứu khoa học quốc tế ngành hóa học dành cho các bạn yêu hóa học tham khảo đề tài: Generalized Alamouti Codes for Trading Quality of Service against Data Rate in MIMO UMTS | EURASIP Journal on Applied Signal Processing 2004 5 662-675 2004 Hindawi Publishing Corporation Generalized Alamouti Codes for Trading Quality of Service against Data Rate in MIMO UMTS Christoph F. Mecklenbrauker Forschungszentrum Telekommunikation Wien ftw Donau-City Strafie 1 1220 Vienna Austria Email cfm@ Markus Rupp Institutfur Nachrichtentechnik und Hochfrequenztechnik Technische Universitat Wien Gusshausstrafie 25-29 1040 Vienna Austria Email mrupp@ Received 17 December 2002 Revised 26 August 2003 New space-time block coding schemes for multiple transmit and receive antennas are proposed. First the well-known Alamouti scheme is extended to NT 2m transmit antennas achieving high transmit diversity. Many receiver details are worked out for four and eight transmit antennas. Further solutions for arbitrary even numbers NT 2k of transmit antennas are presented achieving decoding advantages due to orthogonalization properties while preserving high diversity. In a final step such extended Alamouti and BLAST schemes are combined offering a continuous trade-off between quality of service QoS and data rate. Due to the simplicity of the coding schemes they are very well suited to operate under UMTS with only very moderate modifications in the existing standard. The number of supported antennas at transmitter alone is a sufficient knowledge to select the most appropriate scheme. While the proposed schemes are motivated by utilization in UMTS they are not restricted to this standard. Keywords and phrases mobile communications space-time block codes spatial multiplexing. 1. INTRODUCTION One of the salient features of UMTS is the provisioning of moderately high data rates for packet switched data services. In order to maximize the number of satisfied users an efficient resource assignment to the subscribers is desired allowing flexible sharing of the radio resources. Such schemes must address the extreme variations of the link quality. Standardization .
