Title :
Effective implementation of the OFDM/CDMA base station transmitter using joint FHT and IFFT
Author_Institution :
Inst. of Electron. & Telecommun., Poznan Univ. of Technol., Poland
Abstract :
In the paper, a multicarrier CDMA (OFDM/CDMA) technique for application in mobile radio communication systems is considered. In the base station (BS) transmitter, the orthogonal modulation of Walsh sequences can effectively be realized by fast Hadamard transform (FHT), while the orthogonal multicarrier modulation is implemented by inverse fast Fourier transform (IFFT). In the paper, the possibility of joining FHT and IFFT is shown. The fast algorithm for this new joint transform is presented. It is based on junction of the “butterfly” operations performed by FHT and IFFT, which is equivalent to a pair of simple multiplications. This algorithm is low computationally complex, and simplifies implementation of the BS transmitter. The computational complexity as the number of arithmetic operations is calculated for the presented method
Keywords :
Hadamard transforms; OFDM modulation; Walsh functions; code division multiple access; computational complexity; fast Fourier transforms; land mobile radio; radio transmitters; FHT; IFFT; OFDM/CDMA base station transmitter; Walsh sequences; arithmetic operations; computational complexity; effective implementation; fast Hadamard transform; fast algorithm; inverse fast Fourier transform; joint transform; mobile radio communication systems; multicarrier CDMA technique; orthogonal modulation; orthogonal multicarrier modulation; simple multiplications; Arithmetic; Base stations; Computational complexity; Fast Fourier transforms; Frequency division multiplexing; Frequency modulation; Land mobile radio; Multiaccess communication; OFDM modulation; Radio transmitters;
Conference_Titel :
Signal Processing Advances in Wireless Communications, 1999. SPAWC '99. 1999 2nd IEEE Workshop on
Conference_Location :
Annapolis, MD
Print_ISBN :
0-7803-5599-7
DOI :
10.1109/SPAWC.1999.783044
