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The parametric (or model-based) methods of signal processing require often not only the estimation of a vector of real-valued parameters but also the selection of one or several integer-valued parameters that are equally important for the specification of a data model. Examples of these integer-valued parameters of the model include the orders of an autoregressive moving average model, the number of sinusoidal components in a sinusoids-in-noise signal, and the number of source signals impinging on a sensor array. In each of these cases, the integer-valued parameters determine the dimension of the parameter vector of the data model, and they must be estimated from the data.

In a recent work space-time block codes were introduced to obtain coded diversity for a multiple-antenna communication system. In this work, we cast space-time codes in an optimal signal-to-noise ratio (SNR) framework and show that they achieve the maximum SNR and, in fact, they correspond to a generalized maximal ratio combiner. The maximum SNR framework also helps in calculating the distribution of the SNR and in deriving explicit expressions for bit error rates. We bring out the connection between the theory of amicable orthogonal designs and space-time codes. Based on this, we give a much simpler proof to one of the main theorems on space-time codes for complex symbols. We present a rate $1/2$ code for complex symbols which has a smaller delay than the code already known. We also present another rate $3/4$ code which is simpler than the one already known, in the sense it does not involve additions or multiplications. We also point out the connection between generalized real designs and generalized orthogonal designs., Addresses: Ganesan G, Uppsala Univ, Dept Syst & Control, SE-75103 Uppsala, Sweden. Uppsala Univ, Dept Syst & Control, SE-75103 Uppsala, Sweden.

In this correspondence, we consider the case of multiple-antenna transmission diversity. We outline a recent result on the maximum possible performance (in terms of mutual information) and show that it can be achieved using scaler codes instead of vector, Addresses: Ganesan G, Univ Uppsala, Dept Syst & Control, SE-75103 Uppsala, Sweden. Univ Uppsala, Dept Syst & Control, SE-75103 Uppsala, Sweden.

In this paper we consider the utilization of multiple transmitter and receiver antennas for space-time diversity. The optimal SNR scheme, which also provides the best diversity, is outlined. This scheme however involves a reduction in the data rate. Codin, Addresses: Ganesan G, Uppsala Univ, Dept Syst & Control Informat Technol, POB 27, SE-75103 Uppsala, Sweden. Uppsala Univ, Dept Syst & Control Informat Technol, SE-75103 Uppsala, Sweden.

In this paper we consider the use of multiple antennas for wireless communication over fading channels. The fading we consider is quasi-static Bat Rayleigh fading. For such a scenario optimal SNR schemes are derived when the transmitter knows the channel, Addresses: Ganesan G, Uppsala Univ, Dept Syst & Control Informat Technol, POB 27, SE-75103 Uppsala, Sweden. Uppsala Univ, Dept Syst & Control Informat Technol, SE-75103 Uppsala, Sweden.

A worst case lower bound (WCLB) result obtained by Nemirovskii suggests that a potentially significant estimation accuracy enhancement may be achieved provided the true parameter vector is known to belong to a ball. In this paper we discuss the many facet, Addresses: Ganesan G, Syst & Control Grp, POB 27, S-75103 Uppsala, Sweden. Syst & Control Grp, S-75103 Uppsala, Sweden.

In this paper a new method, based on subspaces of a cumulant matrix, is proposed for the blind identification of an ARMA system which is driven by white non-Gaussian noise. The relationship between the cumulants and the impulse response is exploited to ar, Addresses: Ganesan G, Uppsala Univ, Dept Syst & Control, POB 27, S-75103 Uppsala, Sweden. Uppsala Univ, Dept Syst & Control, S-75103 Uppsala, Sweden.