Patent ID: 7283790

Claim:
A blind or partially blind process to determine characteristic space-time parameters of a propagation channel in a system comprising at least one reception sensor, the process comprising: receiving a signal y(t) with the at least one reception sensor; determining antenna vectors (a) and time vectors (τ) starting from second order statistics of the received signals based on a specular structure of the propagation channel; selecting a length of the propagation channel {circumflex over (L)} such that {circumflex over (L)}≧Lg+Δτ max , where Lg denotes a filter length and Δτ max denotes a largest possible value of a relative delay between two paths, and a value of a number of observations K satisfies K≧{circumflex over (L)}; determining a sub-space criterion matrix Q {circumflex over (L)} ({circumflex over (R)}), where {circumflex over (R)} denotes a covariance matrix; estimating a number of paths {circumflex over (d)}; estimating delays {circumflex over (τ)}, where τ ^ = ar ⁢ g ⁢ ⁢ min ⁢ τ ⁢ J L ^ . d ^ ⁡ ( τ ) , where J L ^ . d ^ ⁡ ( τ ) = λ min ⁡ ( G L ^ . d ^ ⁡ ( τ ) H ⁢ Q L ^ ⁡ ( R ) ⁢ G L ^ . d ^ ⁡ ( τ ) ) λ min ⁡ ( G L ^ . d ^ ⁡ ( τ ) H ⁢ G L ^ . d ^ ⁡ ( τ ) ) , λ min denotes a smallest eigenvalue of a matrix, and (G {circumflex over (L)},{circumflex over (d)} (τ)) denotes a matrix containing delayed sampled versions of the received signal; estimating a value of an antenna vector â by â=vp min (G {circumflex over (L)},{circumflex over (d)} (τ) H Q {circumflex over (L)} ({circumflex over (R)})G {circumflex over (L)},{circumflex over (d)} (τ)), where vP min denotes an eigenvector associated with λ min ; and forming an estimate of a pulse response ĥ such that ĥ=G {circumflex over (L)},{circumflex over (d)} (τ)â.