1. Introduction. 2. Propagation Path Characteristics for Wireless Communication Systems. 3. Modulation and Demodulation Techniques. 4. Anti-Flat Fading Techniques. 5. Anti-Frequency-Selective Fading Techniques. 6. Error Control Techniques. 7. Access and Duplex Techniques. 8. Synchronization for Digital Wireless Transmission Systems. 9. System Performance Evaluation for the Development of Air Interfaces. 10. Radio Link Design. 11. Personal Digital Cellular (PDC) Telecommunication System. 12. Personal Handyphone System (PHS). 13. Digital Multichannel Access (MCA) System. 14. Digital Public PMR System. 15. System Design Strategy for TDMA-Based Systems. 16. System Design Strategy for CDMA-Based Systems. 17. Flexible Radio Interface Design Strategy for Future Wireless Multimedia Communications Systems. Abbreviations and Acronyms. Index.

Applications of digital wireless technologies to global wireless communications

Cyclic codes are an interesting type of linear codes and have wide applications in communication and storage systems due to their efficient encoding and decoding algorithms. In this paper, let \(\Bbb F_r\) be a finite field with \(r=q^m\) . Suppose that \(g_1, g_2 \in \Bbb F_r^*\) are not conjugates over \(\Bbb F_q\) , \( \operatorname {ord}(g_1)=n_1\) , \( \operatorname {ord}(g_2)=n_2\) , \(d=\gcd (n_1, n_2)\) , and \(n={n_1n_2}/ d\) . Let \(\Bbb F_q(g_1)=\Bbb F_{q^{m_1}}, \Bbb F_q(g_2)=\Bbb F_{q^{m_2}}\) , and \(\text{T}_i\) denote the trace function from \(\Bbb F_{q^{m_i}}\) to \(\Bbb F_q\) for \(i=1, 2\) . We define a cyclic code \(\mathcal C_{(q, m, n_1, n_2)}=\{c(a,b) : a \in \Bbb F_{q^{m_1}}, b \in \Bbb F_{q^{m_2}}\},\) where \(c(a,b)=(\text {T}_1(ag_1^0)+\text {T}_2(bg_2^0), \text {T}_1(ag_1^1)+\text {T}_2(bg_2^1), \ldots , \text {T}_1(ag_1^{n-1})+\text {T}_2(bg_2^{n-1})).\) We mainly use Gauss periods to present the weight distribution of the cyclic code \(\mathcal C_{(q, m, n_1, n_2)}\) . As applications, we determine the weight distribution of cyclic code \(\mathcal C_{(q, m,q^{m_1}-1,q^{m_2}-1)}\) with \(\gcd (m_1,m_2)=1\) ; in particular, it is a three-weight cyclic code if \(\gcd (q-1,m_1-m_2)=1\) . We also explicitly determine the weight distributions of some classes of cyclic codes including several classes of four-weight cyclic codes.

Hamming Weights of the Duals of Cyclic Codes With Two Zeros

Spread Spectrum Communications Handbook

In this paper, a new generalized cyclotomy with respect to a positive odd integer is introduced, and a construction of frequency hopping sequence sets and two constructions of frequency hopping sequences are proposed as its applications. The frequency hopping sequence sets and frequency hopping sequences obtained in this paper can be optimal with respect to the Peng-Fan bound and Lempel-Greenberger bound, respectively. Further, the length of sequences in the optimal frequency hopping sequence sets can be any odd integer larger than 3. Some of them have new parameters.

Optimal Frequency Hopping Sequences of Odd Length

Cyclic codes are a subclass of linear codes and have applications in consumer electronics, data storage systems, and communication systems as they have efficient encoding and decoding algorithms. In this paper, a family of p-ary cyclic codes whose duals have three pairwise nonconjugate zeros is proposed. The weight distribution of this family of cyclic codes is determined. It turns out that the proposed cyclic codes have five nonzero weights.

A Family of Five-Weight Cyclic Codes and Their Weight Enumerators

In communication systems, frequency hopping spread spectrum and direct sequence spread spectrum are two main spread coding technologies. Frequency hopping sequences are used in FH-CDMA systems. In this paper, an earlier idea of constructing optimal sets of frequency hopping sequences is further investigated. New optimal parameters of sets of frequency hopping sequences are obtained with subcodes of the Reed-Solomon codes. Optimal sets of frequency hopping sequences are constructed with a class of irreducible cyclic codes. As a byproduct, the weight distribution of a subclass of irreducible cyclic codes is determined.

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Optimal Sets of Frequency Hopping Sequences From Linear Cyclic Codes

In this paper, we derive a new bound on maximum nontrivial Hamming correlation of frequency hopping (FH) sequences from the Singleton bound in error correcting code literature, and we discuss the relation between the new bound and the known ones on FH sequences. Further, we construct two classes of FH sequences from punctured Reed-Solomon codes and one class of FH sequences from polynomial functions, which meet the new bound.

New Bound on Frequency Hopping Sequence Sets and Its Optimal Constructions

Golay sequences have been studied for more than five decades since Golay first discovered those sequences. However, the periodic autocorrelation of a single Golay sequence is unknown. In this paper, for H≥ 2 being an arbitrary even integer, we show there exist three different constructions of H-ary Golay sequences with a zero autocorrelation zone (ZACZ) of length approximately an half, a quarter or one eighth of their period. Those new discoveries on Golay sequences can be explored during synchronization and detection at the receiver end and thus improve the performance of the communication system. We present the application of binary Golay sequences with ZACZ for intersymbol interference (ISI) channel estimation. Compared with m-sequences, Golay-sequence-aided channel estimation has perfect autocorrelations within the zone. Compared with Frank-Zadoff-Chu sequences, Golay-sequence-aided channel estimation requires much lower hardware and computational complexity. We also discuss the performance of Golay-sequence-aided channel estimation in terms of its error variance. Finally, simulations are conducted to show the performance of our proposed scheme against m-sequences and FZC sequences in terms of symbol error rate. The simulations also confirm with our theoretical results.

Large Zero Autocorrelation Zones of Golay Sequences and Their Applications

Frequency-hopping sequences (FHSs) with favorable partial Hamming correlation properties have important applications in many synchronization and multiple-access systems. In this paper, lower bounds on the partial Hamming correlation of FHSs and FHS sets are proposed. They slightly improve the known bounds by Eun et al. and Zhou et al. A construction of FHSs and FHS sets having optimal partial Hamming correlation with respect to the improved bounds is also presented based on the theory of generalized cyclotomy. Our construction yields optimal FHSs and FHS sets with new and flexible parameters not covered in this paper.

Yang Yang

Papers

Optimal Sets of Frequency Hopping Sequences From Linear Cyclic Codes

Optimal Frequency Hopping Sequences of Odd Length

New Bound on Frequency Hopping Sequence Sets and Its Optimal Constructions

Large Zero Autocorrelation Zones of Golay Sequences and Their Applications

A New Construction of Frequency-Hopping Sequences With Optimal Partial Hamming Correlation