Abstract
Hierarchical quadrature amplitude modulation (HQAM) allows for transmission of multiple classes of data (such as voice, video and file transfer), provides flexibility in terms of coverage area and allows for network upgrades while maintaining backwards compatibility. However, the addition of hierarchical layers leads to higher-order modulation schemes which make the system increasingly susceptible to noise and fading. To mitigate fading while maintaining backwards compatibility, maximum ratio transmission (MRT) is incorporated into the HQAM system to maximise signal-to-noise ratio for a given number of diversity branches. This study presents a theoretical bit error rate (BER) performance analysis of an MRT enhanced HQAM (MRT-HQAM) system in Rayleigh fading. The BER performance gains of the proposed system over single-input–single-output and single-input–multiple-output HQAM systems are shown. The HQAM hierarchical modulation parameter is varied and the effects are presented. Furthermore, the authors present the effects of varying the number of antennas on the transmitting and receiving ends and discuss the optimal antenna configuration. The theoretical BER expressions used in the performance analysis are verified using simulation results.
Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
