This paper presents a new spreading matrix for block spread OFDM (BSOFDM) to improve the performance of the system by increasing the correlation between the symbols. This is achieved by rotating the modulation scheme used at the transmission, say QPSK, into a higher order modulation scheme, for example 16QAM. By this the correlation between the transmitted symbols is increased. The advantage of this new spreading matrix over more traditional spreading matrices is its flexibility in achieving different higher order modulation schemes during transmission depending on the angle alpha. This is compared to other spreading matrices in frequency selective channel environment.
This paper presents a study into different angles for the New spread matrix developed for BSOFDM. It varies the angles for the matrix to develop different constellation schemes which are useful in overcoming the frequency selective channels which are encountered in mobile communication systems. Previously it has been discussed that this new matrix (the rotation matrix) has some advantages over Hadamard and the rotated Hadamard matrix in certain channels. This paper presents a study of varies angles with this new matrix over the UWB channels CM1 to CM4.
Disciplines
Physical Sciences and Mathematics
Publication Details
This paper continues the work on the new Rotation matrix developed for BSOFDM which showed improvement in frequency selective channels such as the UWB IEEE defined CM1 to CM4 and overall system performance. This paper presents a method by which higher order Rotation matrix can be derived and simulation results are used to show that the higher order Rotation matrix outperforms the Hadamard matrix in frequency selective channels.
KeywordsRotation spreading matrix, BSOFDM, Frequency selective channel
Disciplines
Physical Sciences and Mathematics
This paper presents an implementation of turbo codes test bed developed in Matlab's Simulink which will aid researchers in the field of turbo codes.It discusses the design, implementation and presents the validation results.
Disciplines
Physical Sciences and Mathematics
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