Performance of Gaussian waveform in OvTDM

Waveforms play a key role in overlapping time division multiplexing （OvTDM） system. The OvTDM has been proved to be a novel transmission technique that can utilize time diversity to improve the bit error ratio （BER） performance in Rayleigh channel. According to the resulted law, the BER performance of Gaussian waveform in OvTDM also improves with the increase in the waveform parameter monotonically, and the rectangular waveform is the worst case of Gaussian waveform. In contrast, the spectrum effectiveness of Gaussian waveform OvTDM decreases with the increase in the waveform parameter. In the study, it is obtained that waveforms can achieve the best performance when the smallest correlation coefficient between neighbor symbols is e^-1 .

Downlink scheduling of multiuser MIMO systems with transmit beamforming

This article deals with downlink scheduling for multiuser multiple-input multiple-output （MIMO） systems, where the base station communicates with multiple users simultaneously through transmit beamforming. Most of the existing transmission schemes for multiuser MIMO systems focus on optimizing sum rate performance of the system. The individual quality of service （QoS） requirements （such as packet delay and minimum transmission rate for the data traffic） are rarely considered. In this article, a novel scheduling strategy is proposed, where we try to optimize the global system performance under individual QoS constraints. By performing scheduling into two steps, namely successive user selection and power allocation, the scheduler can achieve efficient resource utilization while maintaining the QoS requirements of all users. Extensive simulations and analysis are given to show the effectiveness of the proposed scheduler.

Decoding OvTDM with sphere-decoding algorithm

Overlapped time division multiplexing （OvTDM） is a new type of transmission scheme with high spectrum efficiency and low threshold signal-to-noise ratio （SNR）. In this article, the structure of OvTDM is introduced and the sphere-decoding algorithm of complex domain is proposed for OvTDM. Simulations demonstrate that the proposed algorithm can achieve maximum likelihood （ML） decoding with lower complexity as compared to traditional maximum likelihood sequence demodulation （MLSD） or viterbi algorithm （VA）.

Ad-hoc network DOA tracking via sequential Monte Carlo filtering

A novel sequential Monte Carlo （SMC） algorithm is provided for the multiple maneuvering Ad-hoc network terminals direction of arrival （DOA） tracking. A nonlinear mobility and observation model is adopted, which can describe the motion features of the Ad-hoc network terminal more practically. The algorithm does not need any additional measurement equipment. Simulation result shows its significant tracking accuracy.

Near theoretical upper bound new loosely synchronous complementary spreading sequences

A new class of loosely synchronous(LS)spreading sequences with zero correlation window(ZCW)was presented.It was constructed by making Kronecker product of orthogonal matrix and ZCW complementary sequences.This new LS sequence increases the number of perfect complementary pairs and extends ZCW within the same group.Moreover,both auto-correlation and cross-correlation of ZCW in the same group remain identical.The minimum ZCW among different groups is the same as that of basic LS sequences.The method for constructing these new LS sequences is presented and ZCW properties are also verified.The number of these new LS sequences is only smaller than theoretical upper bound by one.