GPRS基站次系统介绍.pptVIP

(E) GPRS Base Station Subsystem Legal Notice Intellectual Property Rights All copyrights and intellectual property rights for Nokia training documentation, product documentation and slide presentation material, all of which are forthwith known as Nokia training material, are the exclusive property of Nokia. Nokia owns the rights to copying, modification, translation, adaptation or derivatives including any improvements or developments. Nokia has the sole right to copy, distribute, amend, modify, develop, license, sublicense, sell, transfer and assign the Nokia training material. Individuals can use the Nokia training material for their own personal self-development only, those same individuals cannot subsequently pass on that same Intellectual Property to others without the prior written agreement of Nokia. The Nokia training material cannot be used outside of an agreed Nokia training session for development of groups without the prior written agreement of Nokia. BSS - Content Module objectives After completing this module, the participant should be able to: Explain the air interface principles such as modulation and link adaptation Describe the EDAP interface functionality Depict the PCU functionality Describe the Gb interface main structure GMSK 8-PSK - Phase State Vectors 8-PSK Modulation GMSK and 8PSK Bursts 8-PSK Modulation – Back-off Value Since the amplitude is changing in 8-PSK the transmitter non-linearities can be seen in the transmitted signal These non-linearities will cause e.g. errors in reception and bandwidth spreading. In practice it is not possible to transmit 8-PSK signal with the same power as in GMSK due to the signal must remain in the linear part of the power amplifier Burst Structure Burst structure is similar with current GMSK burst, but term bit is replaced by symbol Training sequence has lower envelope variations Seamless switchover between timeslots In case of max output power only, back-off applied to 8-PSK EDGE Signal GPRS