Abstract: A method for performing magnetic resonance measurements on a sample includes applying a first predetermined number of pulse trains for excitation, each pulse train having a constant amplitude and including a second predetermined number of pulses spaced by a predetermined time interval. The pulse trains are modulated by a bent function. After each pulse, data is sampled. Preferably a square number of pulses is generated being constant in power, and the Walsh transform of the sequence of their phases is constant in power, so that the power of the excitation in time and frequency domain is constant. The method can reduce power requirements and may permit undercutting specific absorption rate (SAR) limits due to the small excitation power necessary to create time signals with reasonable signal to noise ratio.

Abstract: A method for performing magnetic resonance measurements on a sample includes applying a first predetermined number of pulse trains for excitation, each pulse train having a constant amplitude and including a second predetermined number of pulses spaced by a predetermined time interval. The pulse trains are modulated by a bent function. After each pulse, data is sampled. Preferably a square number of pulses is generated being constant in power, and the Walsh transform of the sequence of their phases is constant in power, so that the power of the excitation in time and frequency domain is constant. The method can reduce power requirements and may permit undercutting specific absorption rate (SAR) limits due to the small excitation power necessary to create time signals with reasonable signal to noise ratio.

Abstract: There is disclosed a method of creating an LDPC code that is defined by a parity-check matrix H. The parity-check matrix H is derived from a (0,1)-geometry which is induced by a finite inversive space. This inversive space has an order q where every circle in the inversive space contains exactly q+1 points, q is preferably even, and most preferably equal to 2. Where the inversive space has a dimension n. Where the (0,1)-geometry is formed as a derived geometric structure based on pencils of degree m?n in the inversive space. The method includes construction of a binary K by N matrix H labelled by K circles and N pencils of the inversive space, wherein the (i, j)-entry of the matrix is 1 if circle i belongs to pencil j, and 0 otherwise. If the degree of the pencil is given by 2 then the parity-check matrix H needs to be transposed, i.e. HT is used instead of H. A method of transmitting a message, a coder, a decoder and a data transmission system using such codes are also disclosed.