Sökning: "code-division multiple access system"

Visar resultat 16 - 20 av 26 avhandlingar innehållade orden code-division multiple access system.

1. 16. Multiuser Serially Concatenated Continuous Phase Modulation

   Författare :Pär Moqvist; Chalmers tekniska högskola; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : A multiuser communication system using serially concatenated and randomly interleaved continuous phase modulation (SCCPM) over the additive white Gaussian noise (AWGN) channel is investigated. The users, which may be asynchronous, are allowed to have individual energy levels as well as carrier frequencies and phases. LÄS MER

3. 17. On the Design of Error Control Coding for Wireless Communication Systems

   Författare :Carl Fredrik Leanderson; Institutionen för elektro- och informationsteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; joint source-channel decoding; Electrical engineering; Elektroteknik; a posteriori probability; soft decoding; list sequence decoding; incremental redundancy; retransmission; low-rate; parallel concatenated; convolutional codes; Turbo codes; Wireless; error correction;

   Sammanfattning : New wireless services such as mobile Internet, multimedia streaming and high speed packet data access are making their way to the market. Availability of low-cost equipment providing high transmission quality and efficient spectrum utilization is crucial to the success of these services. LÄS MER

4. 18. On interference suppression techniques for communication systems

   Författare :Hongxia Zhao; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; CDMA; QPSK; fixed-point implementation; DQPSK; rapid single flux quantum RSFQ ; MUD; unequal BER; fiber-optic communications; unequal SER; ISI;

   Sammanfattning : The work presented in this thesis concerns interferencesuppression techniques in two different communication systems.In the first part we study fiber-optic systems with practical non-ideal transmitters and receivers, which give rise to intersymbol interference (ISI). LÄS MER

5. 19. Aspects of Fixed-point Implementation of Multiuser Detctors in WCDMA

   Författare :Hongxia Zhao; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

   Sammanfattning : Wideband code-division multiple-access (WCDMA) has been selected as the radio technique standard for the 3G mobile communication systems. However, it is well known that the conventional single-user detector, which is commonly used in CDMA systems, suffers from multiple-access interference (MAI). LÄS MER

7. 20. Multirate Codes and Multicarrier Modulation for Future Communication Systems

   Författare :Pål Frenger; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; channel estimation; code-spread CDMA; DS-CDMA; convolutional codes; interference cancellation; nested convolutional codes; multicarrier modulation; optimum distance spectrum ODS ; rate-compatible punctured convolutional codes RCPC-codes ; OFDM; turbo decoding; rate matching; parallel combinatory signaling; Rayleigh fading;

   Sammanfattning : In this thesis, new detection and modulation methods for multicarrier systems are presented. The proposed multicarrier detectors are based on feedback of previously detected symbols and the idea is to exploit the correlation, both in time between consecutive symbols, and in frequency between neighboring sub-carriers. LÄS MER