Research On The Key Technology Of Wideband Digital Receiver

As the increasing complexity of modern electronic warfare environment, the increasingin number of the radiation sources, the increasing in distribution density, the variety of signalparameters, the severe of signal overlap and other features requires electronic warfare receivermuch.Wide open processing bandwidth, large dynamic range, high sensitivity, multi-signalprocessing capabilities and signal real-time processing capabilities will be the direction of thedevelopment of electronic warfare receiver. Wideband digital receiver becomes the inevitabletrend of development of electronic warfare receiver because of its superior performance.However, the sampled data of the existing broadband digital receiver system was too large inamount and too high in rate. The rate bottleneck of high-speed ADC with relatively low-speedDSP, high degree of the system complexity and real-time processing will become the biggestchallenge of wideband digital receiver.This paper expanded research around the key technology of some problem of existingbroadband digital receiver, seeking for each solution. The main content includes:Firstly, for the high sampling rate and sampling interval limit of the traditional low-passand band-pass sampling, using compressed sensing ideological to for cross-Nyquist spacesampling. Broadband signal difference sampling structure was researched and derived, and adual-channel difference sampling structure was deduced. The frequency measurement andparaments estimation was discussed, the folded peaks fuzzy problem was solved by channeladdition.And then, for the contradiction of the frequency measurement accuracy and the responsetime of the FFT receiver, this paper proposed a new FFT structure based on polyphase filterstructure, reducing computing time. Discussed the signal detection and parameter estimationof the structure, by using rife frequency measurement improved the accuracy of frequencymeasurement without time delay.Next, for the increasing of the prototype filter coefficients caused by the increasing in thenumbers of the channel and the narrow transition zone of the channelized receiver, two newchannelized receiver with narrow transition band based on frequency response masking wasproposed, in ensuring narrow transition zone and the amount of computation. Later, for the inflexible of the channel filter, proposed a new reconfigurable filter andfilter bank strcture. The reconfigurable structure was suit for different channel extract, whichhas sharp passband and low coefficients.Finally, for the bandwidth waste and data redundancy in high sampling rate, a conceptionto receive the narrow band signal passband matched was proposed. Through a band-passdecimation and efficient DDC, achieved signal matched receive of different bandwidth andcenter frequency.Simulation and analysis verified the effectiveness and efficiency of each solution.