ISSN : 1796-2021
Volume : 3    Issue : 1    Date : January 2008

Combined Packet Retransmission Diversity and Power Adjustment Scheme for High Speed
Wireless Networks
Mikael Gidlund
Page(s): 56-63
Full Text:
PDF (469 KB)

The introduction of High Speed Downlink Packet Access (HSDPA) in the 3GPP R5 standard will
greatly improve the bearer capacity of the mobile network and make the dream of multimedia
communications, anytime and anywhere, come true. One of the central features of HSDPA concept
is advanced physical layer retransmission scheduling employing soft combining gain, incremental
redundancy, and low retransmission delays. This paper studies symbol mapping diversity in
combination with power adjustment for HSDPA. If retransmission are requested, the bit-to-symbol
mapping and transmission power is changed in every retransmission. Compared to the
conventional HARQ schemes, our proposed scheme increases the throughput and decreases the
average number of retransmissions significantly and reduce the power consumption in HSDPA.

Index Terms
Constellation rearrangement, Diversity, LLR, Power adjustment, MQAM, BER