The Development Of The Wcdma Digital If Receiver

The 3G mobile-communication systems should make use of frequency resource efficiently enough, supply the high-quality and multi-rate multimedia operations as the highly capacious traditional operations, can run in the multi communication conditions and multi communication nets. This will result in the appearance of multi communication protocols and multi bands, and is quite difficult and inconvenient for manufactures and consumers. Fortunately, software radio is a powerful tool to resolve this problem, and is the core of the future radio communication designs. Additionally, another advantage of software radio is that it can process multi-carrier, decrease the RF channel, lessen the devices'solidity, and save the its cost.Due to the constraint of the actual devices, software radio changes the sampling speed of IF or RF signal flow for the sequent signal processing by using the special digital convertor . In this dissertation, the application of software radio in the 3G mobile communication is investigated, and the realization of digital IF receiver by using special DDC is focused on. The first chapter introduce the 3G actuality , analyze the digital-down converting's research actuality in software radio and introduce WCDMA briefly. The second chapter study the signal processing of digital-down converting , which mostly includes down-sampling technology, multi-rate signal processing and orthonormal digital mixer technology .etc . and analyze the DDC's configuration and performance due to the special DDC. The third chapter mostly research the design and realization of WCDMA's digital IF receiver using DDC, design a digital channels and do simulation which indicate that the design of the digital channels can satisfy the requirement. The forth chapter investigate the realization of the digital IF receiver, bring forward a scheme for the channels'coherence emendation and realize it, finish the test of the channel characteristic and sensitivity. The test achievement make know that the channels design and the sensitivity is enough for the requirement.