Abstract: The IEEE 802.11a standard uses OFDM, where the transmission is divided into several orthogonal sub-carriers. Here, an algorithm is used for the frame detection; a simplified differentiator obtains an absolute maximum in the differentiated signal at that point where the first plateau in JF(k) starts; a peak detector obtains the position of the absolute maximum in the differentiated signal, divides the problem into relative peak detection and falling edge detection; a simplified XNOR-based crosscorrelator is used, where the simplifications are based on the knowledge of the reference; a particular solution is provided for the CORDIC algorithm in the vectoring mode for arctangent calculation; hardware structuring is presented for the whole synchronizer so as to obtain a simple control mechanism and the separation of this structure into different clock domains, each one being activated only to perform its operation and deactivated afterwards.

Abstract: A method of reducing a phase error caused by a plurality of error sources in a signal in the form of a sequence of a plurality of digital partial signals associated with a number of subcarriers (k) of a carrier, the method including, for each partial signal: equalization of the partial signal (Y(i,k)), estimation of the phase error of the equalized partial signal (X(i,k)), and correction of the estimated phase error of the equalized partial signal. One embodiment provides the equalization with elimination of an accumulation of a phase error over the sequence of the partial signals. In addition the estimation includes detecting a plurality of predetermined pilot signals and determining a phase correction factor on the basis of the detected pilot signals, with at least one multiplication operation carried out solely by means of shift and adding operations. A corresponding apparatus is also described.

Abstract: A method of reducing a phase error caused by a plurality of error sources in a signal which is present in a digital frequency representation in the form of a sequence of a plurality of digital partial signals which are associated with a number of subcarriers (k) of a carrier. The following steps are performed for each partial signal: equalization of the partial signal (Y(i,k)), estimation of the phase error of the equalized partial signal (X(i,k)), and correction of the estimated phase error of the equalized partial signal. An embodiment of that method provides that the equalization step includes the elimination of an accumulation of a phase error of the partial signal, caused by a sampling frequency error, over the sequence of the partial signals, such that the accumulation is negligible.

Abstract: The IEEE 802.11a standard uses OFDM, where the transmission is divided into several orthogonal sub-carriers. Here, an algorithm is used for the frame detection; a simplified differentiator obtains an absolute maximum in the differentiated signal at that point where the first plateau in JF(k) starts; a peak detector obtains the position of the absolute maximum in the differentiated signal, divides the problem into relative peak detection and falling edge detection; a simplified XNOR-based crosscorrelator is used, where the simplifications are based on the knowledge of the reference; a particular solution is provided for the CORDIC algorithm in the vectoring mode for arctangent calculation; hardware structuring is presented for the whole synchronizer so as to obtain a simple control mechanism and the separation of this structure into different clock domains, each one being activated only to perform its operation and deactivated afterwards.