Abstract: There is provided apparatus for propagation of a wireless signal through a barrier comprising a first antenna for location on a first side of the barrier, a second antenna for location on a second side of the barrier and a waveguide. The waveguide comprises a conducting member passing through the barrier between the first and second sides. The conducting member is held within an insulator sleeve such that it is spaced from a surrounding metal wall of the waveguide. A wireless signal received by the waveguide on the first side of the barrier is transmitted through the barrier by Transverse Electro-Magnetic (TEM) mode propagation along the waveguide is re-radiated on the second side.

Abstract: There is provided apparatus for propagation of a wireless signal through a barrier comprising a first antenna for location on a first side of the barrier, a second antenna for location on a second side of the barrier and a waveguide. The waveguide comprises a conducting member passing through the barrier between the first and second sides. The conducting member is held within an insulator sleeve such that it is spaced from a surrounding metal wall of the waveguide. A wireless signal received by the waveguide on the first side of the barrier is transmitted through the barrier by Transverse Electro-Magnetic (TEM) mode propagation along the waveguide is re-radiated on the second side.

Abstract: The apparatus for symbol boundary synchronization in one embodiment includes on the receive path of a multi-tone modem a window synchronizer, a converter and a symbol boundary component. The window synchronizer obtains windowed portions of the received datastream which includes symbols each expressed with a corresponding set of tones in a time domain. The windowed portions obtained in the training phase exhibit varying degrees of misalignment with the corresponding symbol boundaries. The window synchronizer is responsive to an alignment signal to obtain succeeding windowed portions of the incoming datastream aligned with the corresponding symbol boundaries therein. The converter couples to the window synchronizer to convert the set of tones from each windowed portion from the time domain to a frequency domain.

Abstract: An apparatus and concomitant method for selecting a macroblock coding mode based upon the quantization scale selected for the macroblock. The total number of bits needed to code each macroblock consists of two parts, bits needed for coding motion vectors and bits for coding the predictive residual. The number of bits for coding the motion vectors is generally obtained from a look-up table. The number of bits for coding the predictive residual is obtained by an estimation which assumes that the number of bits for encoding the predictive residuals is directly proportional to the value of its variance and inversely proportional to the value of quantizer steps (quantizer scale). Using this estimation, the total number of bits necessary to code a macroblock is calculated and compared for each coding mode. By selecting the coding mode with the least number of bits, a near-optimal solution of low complexity for practical implementation is acquired.

Abstract: A method and apparatus for selecting a quantizer scale for each macroblock to maintain the overall quality of the video image while optimizing the coding rate. A quantizer scale is selected for each macroblock such that target bit rate for the picture is achieved while an optimal quantization scale ratio is maintained for successive macroblocks to produce a uniform visual quality over the entire picture. One embodiment applies the method to the frame level while another embodiment applies the method in conjunction with a wavelet transform.

Abstract: A video decompression system includes block error concealment means for generating substitute data for lost blocks of pixel data. An interpolator generates both spatially and temporally interpolated or predicted blocks of data for concealing a lost block. Pixel data in the respective blocks of spatially and interpolated data are transformed to coefficients representing frequency spectra. A substitute block of coefficients is assembled from coefficients from both the transformed blocks, according to a predetermined criteria. The substitute block is transformed back to the spatial domain for substitution of lost pixel values.