In this thesis, a novel training sequence is proposed for timing offset estimation in orthogonal frequency division multiplexing (OFDM) systems. The proposed training sequence and the derived timing offset estimator are proved to outperform traditional schemes. In timing estimation of OFDM systems, the scheme proposed by Schmidl [4,5] is perhaps the most well-known one. However, Schmidl¡¦s scheme has a plateau in timing metric, which substantially degrades system performance. In this thesis, simulation experiments are conducted to evaluate the performance of the proposed timing offset estimator and the mean square error (MSE) is adopted as the performance measure. Simulation results demonstrate that the performance of the proposed scheme not only improves Schmidl¡¦s scheme, but also outperforms Minn¡¦s [9] and Park¡¦s [10] schemes.

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This dissertation explores the application of Silvester's space-time block code to the multi-index CPM called "ARTM CPM" in the IRIG 106 standard to solve the "two antenna problem"---the use of two transmit antennas to provide full spatial coverage on an airborne test article and the accompanying self interference due to different delays between the two transmit antennas and the ground-based receive antenna. A symbol-level encoding scheme is derived that allows the burst-based space-time block code to operate in a continuously streaming mode. The results show that the space-time block code can solve the two antenna problem with differential delays, but that the differential delays generate a substantial increase in the computational complexity of the detector. Complexity-reducing techniques are applied and analyzed. The results show that the complexity reductions required to produce a practically realizable detector render the bit error probability performance sensitive to the differential delay. Numerical results are presented to quantify the performance loss due to the differential delay. The use of space-time coded ARTM CPM to solve the two-antenna problem in aeronautical mobile telemetry requires estimates of the parameters that define the propagation environment. The maximum likelihood estimator problem is defined and used to motivate reduced-complexity estimators suitable for use in a real system. A modified gradient descent algorithm performs the search required to find the delay parameters. An "inner" phase lock loop operating with an "outer" frequency lock loop computes decision-directed estimates of the frequency offset. Computer simulations were used to assess the impact on bit error rate performance introduced by the estimators. The simulation results show the combined joint estimator for the delays, channel gains, and frequency offset imposes a 1.15 dB loss in performance. This loss is approximately the same as the 1.1 dB loss due to the complexity-reducing techniques used by the decoder/detector.