Patent ID: 6570842
Filing Date: 2003-05-27
Classification: H04B

Abstract:
A method of determining a pulse shape having a Fourier transform for use in a DS-CDMA (direct sequence code division multiple access) communication system comprising:projecting said Fourier transform onto a truncated set of basis functions fI(&ohgr;), thus expressing the Fourier transform as a sum of M+1 terms of the form xifi(&ohgr;), where the xi are unknown coefficients, M being an integer selected to result in a sufficiently accurate approximation, &ohgr; being an angular frequency, and i being an indexing subscript; expressing a cost function which is either an acquisition Signal to Noise Ratio (SNR) or an interference power as a function of the set of basis functions and the unknown coefficients; expressing as a first constraint, in terms of the set of basis functions and the unknown coefficients, the remaining one of the acquisition SNR and the interference power; solving numerically for the unknown coefficients such that the cost function is optimized and subject to the first constraint; forming the Fourier transform by adding up the basis functions multiplied by the respective solved coefficients; creating a pulse shaping circuit adapted to produce said pulse shape.