I. B. Collings

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This paper considers multiple-input multiple-output (MIMO) systems with bit-interleaved coded modulation (BICM). Two receiver structures are considered, one based on zero-forcing, the other on minimum mean square error (MMSE). An approximate log-likelihood (ALL) decoding approach is examined in each case, for PSK and QAM. The resulting receivers are(More)
This paper presents new statistical properties of complex noncentral matrix-variate quadratic forms. In contrast to previous results, the expressions do not involve infinite sums over partitions, or matrix-variate polynomials, and are easily and efficiently computable. These properties are used to derive new upper and lower bounds on the ergodic mutual(More)
We present a novel technique for the detection of spatially multiplexed transmitted symbols in uncoded multiple-input multiple-output orthogonal frequency division multiplexing (MIMO-OFDM) system. The method, termed selective detection, observes errors caused by a simple zero- forcing (ZF) on different OFDM sub-carriers, and selectively performs list sphere(More)
This paper considers the identification of time-varying linear channels using maximum likelihood estimation. The channel is modelled as a tapped-delay line filter with complex coefficients. Due to the complexity of the likelihood function and the large number of parameters to be estimated, an analytical maximization of the likelihood function is infeasible.(More)
This paper considers a signalling scheme for a multi-user wireless broadcast system where the base station has multiple transmit antennas and users can have multiple receive antennas. Independent data streams are transmitted in this system by allocating different transmit antennas to different selected users where multiple transmit antennas may be allocated(More)
Ryan et at. recently described two polynomial time algorithms for noncoherent detection of square QAM in block fading channels with additive white Gaussian noise (AWGN). The first algorithm is optimal with respect to the generalized likelihood ratio test (GLRT) and requires O(T<sup>3</sup>) arithmetic computations, where T is the block length of the(More)
This paper considers wireless broadcast systems with multi-antenna base stations. Preceding at the transmitter reduces interference between users allowing independent data streams to be sent to multiple users simultaneously. With typically more users than transmit antennas, efficient selection of user subsets is important. The paper compares the(More)
This paper presents new statistical properties of complex noncentral Wishart matrices. The properties are then used to derive bounds on the ergodic capacity of single-sided correlated Rician MIMO channels with arbitrary-rank channel mean matrices. We present upper and lower bounds which are computationally efficient and tight
At CSIRO we are engaged in developing enabling technologies for future wireless data communication networks. We have developed a real-time signal processing hardware demonstrator which is suitable for flexible prototyping of new wireless signalling proposals using multiple transmitters and multiple receivers at each end of a communication link, known as(More)
This paper presents performance bounds for block-based detection of PAM and QAM transmitted over non-coherent channels. Such channels give rise to inherent detection ambiguities since multiple possible transmit sequences can have the same likelihood. The number of ambiguous sequences is a function of the block length. In this paper, we derive the(More)