Sökning: "Direct sequence code division multiple access DS-CDMA"

Visar resultat 1 - 5 av 15 avhandlingar innehållade orden Direct sequence code division multiple access DS-CDMA.

1. 1. Successive Interference Cancellation in DS-CDMA Systems

   Författare :Ann-Louise Johansson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; group-wise detection; direct-sequence code division multiple access DS-CDMA ; multiuser detection; multirate schemes; weighted cancellation; successive interference cancellation;

   Sammanfattning : There is every indication that direct-sequence code division multiple access (DS-CDMA) will be one of the multiple access schemes for the third generation wireless mobile systems. CDMA is a flexible multiple access method suitable for supporting many new services (speech, data, video, etc), which are becoming increasingly important for mobile communications. LÄS MER

3. 2. Interference Cancellation for DS/CDMA Systems in Flat Fading Channels

   Författare :Ann-Louise Johansson; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; mixed modulation; direct-sequence code division multiple access DS CDMA ; multiuser detection.; multiple data rates; parallel channels; multicode; interference cancellation;

   Sammanfattning : This thesis investigates interference cancellation in direct-sequence codedivision multiple access (DS/CDMA) systems that support multiple data rates.Two approaches for implementing multiple data rates are considered. Oneis the use of mixed modulation. The second is the use of parallel channels. LÄS MER

4. 3. Multirate Schemes and Multiuser Decoding in DS/CDMA Systems

   Författare :Tony Ottosson Gadd; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; multi processing-gain; multi-channel; soft decoding; vector quantization.; joint optimization; Direct-Sequence Code Division Multiple-Access DS CDMA . multirate; multi-modulation; multiuser detection;

   Sammanfattning : Direct-Sequence Code Division Multiple-Access (DS/CDMA) has for some yearsbeen considered as a candidate for future personal and mobile communications.The reasons are mainly the properties of universal frequency reuse andthe multi-path mitigation. LÄS MER

5. 4. Coding for multiple-access and fading channels

   Författare :Leif Wilhelmsson; Institutionen för elektro- och informationsteknik; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Systems engineering; Gilbert-Elliott channel model; Imperfect interleaving; Fading; Error correcting codes; Pre-coding; Channel capacity; Direct-sequence code-division multiple-access DS-CDMA ; Frequency-hopped code-division multiple-access FH-CDMA ; computer technology; Data- och systemvetenskap; Telecommunication engineering; Telekommunikationsteknik;

   Sammanfattning : This thesis treats some information-theoretical and coding aspects of communication over multiple-access and fading channels. It consists of a general introduction and seven papers. In code-division multiple-access (CDMA) communication, many users have access to the channel simultaneously. LÄS MER

7. 5. Coding, Decoding and Multiuser Detection for Wireless CommunicationsCoding, Decoding and Multiuser Detection for Wireless Communications

   Författare :Pål Orten; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; direct-sequence code division multiple access DS-CDMA ; sequential decoding; Rayleigh fading; multirate DS-CDMA; optimum distance spectrum; rate matching; rate compatible punctured convolutional codes; multiuser detection; nested codes;

   Sammanfattning : In the strive for making the Universal Mobile Telecommunication System(UMTS) a reality, concepts and techniques are to be developed which canprovide both high system capacity and sufficient quality for the increasingnumber of mobile users. To obtain these objectives, powerful and flexibleerror control coding is needed, as well as efficient means for many usersto share the same commmication medium. LÄS MER