Receiver DC-offset reduction method
Original Publication Date: 2001-Dec-01
Included in the Prior Art Database: 2003-Jul-23
For the existing Global System of Mobile Communi- cation (GSM) a new radio interface technology called EDGE (Enhanced Data Rates for GSM evolution), also known as EGPRS, will enable large scale mobile videos and internet applications. In order to achieve this, EDGE allows for an increased data throughput up to around 384 kbits/s per carrier using 8PSK modulation scheme instead of binary GMSK (Gaus- sian Minimum Shift Keying) modulation. In general mobile cellular phone receivers introduce impairments due to the receiving process e.g. direct conversion receivers have DC-offsets that shifts the received base band signal from the origin. Since 8PSK modulation has constellation points with low distance to each other compared to GMSK, this modulation type is more sensitive against DC-shifts. This means that DC-offset compensation algorithms usually used for GMSK are not sufficient for EDGE receivers in order to achieve adequate receiver per- formance.