Title :
DADS with short spreading sequences for high data rate communications or improved BER performance
Author :
Le Nir, V. ; Scheers, B.
Author_Institution :
Dept. Commun., Inf. Syst. & Sensors (CISS), Brussels, Belgium
Abstract :
In this paper, a method is proposed to improve the performance of the delay and add direct sequence (DADS) modulation scheme. On one hand, the selection of a short pseudonoise (PN) sequence is used to improve the data rate performance. On the other hand, when high data rates are not required, the same short PN sequence is replicated to form a long PN sequence. In this case, noise reduction by averaging is used to improve the bit error rate (BER) for high spreading factors. Theoretical BER formulas are derived and verified by simulations in additive white Gaussian noise (AWGN) and frequency selective Rayleigh channels. The proposed DADS modulation scheme is implemented using the CogWave software to allow the exchange of video, audio and text between two USRPs through a graphical user interface (GUI) developed in Qt4.
Keywords :
AWGN channels; Rayleigh channels; delays; error statistics; pseudonoise codes; AWGN; BER performance; CogWave software; DADS modulation scheme; additive white Gaussian noise; bit error rate; delay and add direct sequence modulation scheme; frequency selective Rayleigh channels; graphical user interface; high data rate communications; short pseudonoise sequence; short spreading sequences; AWGN channels; Bit error rate; Delays; Frequency modulation; Noise; Noise reduction; Spread spectrum modulation scheme; noncoherent detection; transmit reference;
Conference_Titel :
Military Communications and Information Systems Conference (MCC), 2013
Conference_Location :
St.-Malo
Print_ISBN :
978-83-934848-8-1
