By the flexible redefinition of frequency-occupation and frequency-collision event, the frequency-(collision) probability of hybrid(DS/FH) spread spectrum network is analyzed. This probability is based on the simultan...By the flexible redefinition of frequency-occupation and frequency-collision event, the frequency-(collision) probability of hybrid(DS/FH) spread spectrum network is analyzed. This probability is based on the simultaneous transmission number threshold and is discussed in synchronous and asynchronous circumstances respectively. And then, the network throughput based on the packet correct reception probability is analyzed. Two models which have finite and infinite population respectively is discussed. At last, the numerical results are given.展开更多
A dual N-ary orthogonal hybrid modulation system is introduced in this paper,which can increasethe data rate greatly compared with conventional N-ary orthogonal spread spectrum system,so it can beused for high rate da...A dual N-ary orthogonal hybrid modulation system is introduced in this paper,which can increasethe data rate greatly compared with conventional N-ary orthogonal spread spectrum system,so it can beused for high rate data communication.Then,three code recognition algorithms are presented for dual N-ary orthogonal hybrid modulation system and the analytic bit error rate(BER)performance of the systemin additive white Gaussian noise(AWGN)and flat Rayleigh fading channel is derived.Finally,the com-puter simulation of the system with three code recognition algorithms is performed,which shows that thesimplified maximum a posteriori(MAP)algorithm is the best for the system with a compromise betweenthe performance and the complexity.展开更多
Hybrid direct sequence and slow frequency hopping spread spectrum multiple access systems (Hybrid DS/SFH SSMA) operating through nonselective slow Rayleigh fading channels was investigated. Multipath and Multiple acce...Hybrid direct sequence and slow frequency hopping spread spectrum multiple access systems (Hybrid DS/SFH SSMA) operating through nonselective slow Rayleigh fading channels was investigated. Multipath and Multiple access interference was taken into account. Expressions of the average error probability for the system were derived. Analytical and numerical results on the average probability of error were presented for the system examined. Random signature sequences and hopping patterns were employed for the system. The numerical results show the effects of the value of M for M ary frequency shift keying (MFSK) modulation and Reed Solomon (RS) coding on the system’s performance. The comparison between RS coded system and noncode system shows that error correction coding is essential to improve the system’s performance.展开更多
文摘By the flexible redefinition of frequency-occupation and frequency-collision event, the frequency-(collision) probability of hybrid(DS/FH) spread spectrum network is analyzed. This probability is based on the simultaneous transmission number threshold and is discussed in synchronous and asynchronous circumstances respectively. And then, the network throughput based on the packet correct reception probability is analyzed. Two models which have finite and infinite population respectively is discussed. At last, the numerical results are given.
基金the National Basic Research Program of China(No5130601)Jiangsu Provincial Natural Science Foundation(NoBK2006701)
文摘A dual N-ary orthogonal hybrid modulation system is introduced in this paper,which can increasethe data rate greatly compared with conventional N-ary orthogonal spread spectrum system,so it can beused for high rate data communication.Then,three code recognition algorithms are presented for dual N-ary orthogonal hybrid modulation system and the analytic bit error rate(BER)performance of the systemin additive white Gaussian noise(AWGN)and flat Rayleigh fading channel is derived.Finally,the com-puter simulation of the system with three code recognition algorithms is performed,which shows that thesimplified maximum a posteriori(MAP)algorithm is the best for the system with a compromise betweenthe performance and the complexity.
文摘Hybrid direct sequence and slow frequency hopping spread spectrum multiple access systems (Hybrid DS/SFH SSMA) operating through nonselective slow Rayleigh fading channels was investigated. Multipath and Multiple access interference was taken into account. Expressions of the average error probability for the system were derived. Analytical and numerical results on the average probability of error were presented for the system examined. Random signature sequences and hopping patterns were employed for the system. The numerical results show the effects of the value of M for M ary frequency shift keying (MFSK) modulation and Reed Solomon (RS) coding on the system’s performance. The comparison between RS coded system and noncode system shows that error correction coding is essential to improve the system’s performance.
