Design And Realization Of The Key Modules In The GSM/EDGE Baseband System

The technology of link adaption (LA), automatic gain control (AGC) and 8PSK demodulation is the core technology in GSM/EDGE baseband system. Based on the study of the technology above and the requirements of chip design for GSM/EDGE baseband system of a certain company tightly, this paper specializes the low-power design and optimization technology for these key modules, accomplishes their structure and RTL design, and verifies them at last.For the research and design of LA, the correlation protocol and mechanism are analyzed in this paper first. According to the parameter provided by the correlation modules, a method of measuring channel quality by BEP (Bit Error Probability) is proposed. The QI (Quality Indicator) will be accurate to reflect the channel quality through the optimized filter, together with the current codec mode of the MS, an appropriate CMR (Codec Mode Request) is generated. Secondly, it combines the processes of the phase register configuration and the ACS register configuration by the RATSCCH mechanism, which can predigest the processes and reduce the realization complexity.Another issue of this paper is the design and optimization of the AGC system. First of all, the filters of order 2 are suggested to improve the response time and stability of the system. Secondly, to reduce the area and power consumption, this paper changes the comparison circuit into coder and encoder structure, which can optimize the area and power performance greatly. Thirdly, considering the universality, the design adds AGC tables of some master RFs into the lookup-table to support the different RFs for the choices of different clients.The third work of this paper is the design and optimization of the 8PSK module. This paper proposes a structure which is similar to DSP by the characteristic that there is much of the same computation in the module. So the data operation can be done with a CMU (Common Manipulation Unit), and the FSM (Finite State Mechanism) will control the data storage. The benefit of the area and the performance improves greatly after synthesis.The research of this paper meets the chip design requirements for GSM/EDGE Baseband System of a certain company, and the three key modules designed have already applied on the chip and passed the relational verification.