Separation of cochannel signals under imperfect timing and carrier synchronization
Abstract
Separation of co-channel communication signals using multiple antennas and Digital Signal Processing(DSP) based algorithms is a topic of great interest due to its implications for system capacity and frequency reuse. This thesis proposes two methods for timing and carrier recovery, synchronization, spatial signature estimation and separation of co-channel up-link signals. In some propagation scenarios, this is the most general problem possible on this topic. The first method proceeds by using an appropriately designed bank of filters to force a well understood synchronous model on the incoming signal. An extended Kalman Filter is then used to obtain estimates of the spatial signatures and carrier offsets which can then be used to separate the co-channel signals. The second method proceeds by oversampling the antenna base-band signals and uses algebraic properties of statistical quantities associated with the signals to estimate relevant parameters and computationally separate the signals of the different users. The modeling, receiver paradigms, optimizations, tradeoffs and compromises necessary are discussed and simulation results presented.
Degree
Ph.D.
Advisors
Zoltowski, Purdue University.
Subject Area
Electrical engineering|Operations research
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