In this paper, we study high reliability, low latency and cost effective network planning for industrial wireless mesh networks. Based on the requirements of routing reliability, minimum end-to-end delay and reduced deployment cost in wireless mesh networks, such as WirelessHART network, we propose three network planning approaches following the principles of the shortest hops, the least routers and balance of the shortest hops and the least routers, respectively. We then implement the proposed algorithms respectively to generate the network deployment for a given factory layout. Simulation results show that there exists a performance trade-off between these three algorithms. The proposed algorithms have also been implemented and validated in an NS-2 WirelessHART network simulator.

In this paper, we study automated network planning for industrial wireless mesh networks. Based on the requirements of routing reliability in WirelessHART network, we propose two network planning approaches following the principles of the shortest hops and the least routers, respectively. We then implement them in Algorithms 1 and 2 respectively to automatically generate the network deployment for a given factory layout. Simulation results show that there exists a performance tradeoff between the two algorithms. The proposed algorithms have also been implemented and validated in an NS-2 WirelessHART network simulation.

As Gaussian minimum shift keying (GMSK) modulation scheme is adopted for wireless body area network (WBAN) applications, simple and noise-robust synchronisation algorithms for GMSK are desired to meet the limited resources of power, storage and size in WBAN. However, the current synchronisation algorithms for GMSK are either too complicated or have unsatisfactory performance for low signal-to-noise ratio (SNR), especially for coded GMSK systems. The authors will propose the synchronisation algorithms for general GMSK systems with three unknown synchronisation parameters, namely, timing, frequency and phase offsets estimation. By incorporating noise/interference-reduction methods, the authors propose low-complexity synchronisation algorithms for GMSK that can achieve satisfactory performance in low SNR region. Furthermore, their new feedforward timing and frequency recovery algorithms can provide much better performance than those in the literature by using reliability-measuring mechanism for timing estimation and two-phase frequency estimation. The data-aided Cramer–Rao bounds (CRBs) for the joint estimation of GMSK synchronisation parameters are also derived. The numerical results show that the performance of their proposed synchronisation algorithms is close to the CRBs. The overall bit error rate performance for both uncoded and Bose-Chaudhuri-Hocquenhem BCH-coded GMSK systems are examined. The performance loss owing to synchronisation errors can be reduced to about 1 dB with their proposed algorithms.

We propose a symbol-by-symbol (SBS) detector for Gaussian minimum shift keying (GMSK) signals in body area networks (BAN). Our detector exploits the orthogonality between adjacent GMSK-modulated symbols. By dividing the received signals into inphase-/quadrature-channels and odd-/even-streams, the strongest inter-symbol interference (ISI) from the adjacent symbols is removed. A whitened matched filter is designed, and a decision-feedback scheme is proposed to further reduce the residue ISI. This SBS detector has much lower complexity than the conventional maximum likelihood sequence detection schemes using the Viterbi algorithm. Its performance can approach the MSK/BPSK performance which results in high energy efficiency. Thus, our proposed energy-efficient, low-complexity, SBS GMSK demodulator is suitable for BAN which have very limited resources. Based on our demodulator's structure, several other SBS detectors can be obtained straightforwardly.

The problem of carrier and clock synchronization without a training sequence for a robust receiver working at low signal-to-noise (SNR) ratios is considered. Both short packet and long burst transmission scenarios are taken into account. A low-complexity iterative symbol timing and carrier synchronization algorithm making use of the extrinsic information from the soft- input soft-output (SISO) decoder is proposed. The non-data-aided (NDA) algorithms are used for initial synchronization. In order to solve the phase ambiguity problem inherent in the NDA phase synchronization algorithm, two SISO decoders denoted by I and Q decoders, respectively, along with a differential decoder are proposed. The simulation results show that the proposed iterative synchronizer and decoder can reach the ideal performance at very low SNR with an increased allowed residual frequency offset and [-pi,pi] phase uncertainty region.

We consider the problem of carrier frequency and phase synchronization at low SNR without a training sequence for short packet transmission. A low-complexity iterative joint symbol timing and carrier synchronization algorithm making use of the extrinsic information from the soft-input soft-output (SISO) decoder is proposed. The non-data-aided (NDA) algorithms are used for initial synchronization. The simulation results show that the frequency offset estimation is the most critical problem in low SNR region. The proposed low-complexity algorithm can reach the ideal performance with perfect synchronization in the absence of frequency offset at very low SNR. When the frequency offset exists, the proposed algorithm can work effectively and improve the performance significantly.

We detail a code mapping scheme designed especially for devices in the enhanced wireless personal area networks operating in both the 868 MHz and 915 MHz bands for the emerging IEEE 802.15.4b standard. This carefully designed coding scheme, called cyclic odd bit inversion length 16 (COBI-16), meets all the following three essential criteria: (a) no spikes in the frequency spectrum, (b) low complexity correlation operations and (c) simple frequency offset and DC compensation operations. The scheme is tested in both AWGN and Rayleigh fading (flat and frequency selective) channels. Both coherent and non-coherent demodulations are investigated. Also investigated are the synchronous false alarm rate and synchronous miss rate in the AWGN channel. The results show that the scheme conforms to all the stringent requirements defined by the IEEE 802.15.4b protocol. The scheme has been accepted by the IEEE 802.15.4b task group as the standard for data transmission.

IEEE 802.15.4b is an enhanced standard to the IEEE 802.15.4, addressing the needs for high-data rate transmission using 868 or 915 MHz band in the wireless personal area networks. This paper details a modulation and code mapping scheme designed specifically for the standard's high rate transmission schemes operating in the 868 MHz and 915 MHz bands; which leads to efficient transmission and low implementation complexity. The code mapping scheme is called Quadrature Cyclic Odd Bit Inversion length 16 or Quad COBI-16. Among the scheme's desirable properties is that the total phase rotation in the I/Q plane accumulates to 0 degree over the complete symbol. The scheme is tested in both AWGN and Rayleigh frequency selective fading channels. The results show that it conforms to all the stringent requirements defined by the standard.

IEEE 802.15.4b is an enhanced standard to the IEEE 802.15.4, addressing the need for high-data rate transmissions in the 868 and 915 MHz band in the wireless personal area networks. This paper details a code mapping scheme designed specifically for the standard's 915 MHz band that leads to efficient transmission and low implementation complexity. The scheme is called quadrature cyclic odd bit inversion length 16 or Quad COBI-16 and one of its desirable properties is that the total phase rotation in the I/Q plane accumulates to 0 degree over the complete symbol. The scheme is tested in both AWGN and Rayleigh fading (flat and frequency selective) channels. Both coherent and non-coherent demodulations are investigated. Also investigated are the synchronous false alarm rate and synchronous miss rate in the AWGN channel. The results show that the scheme conforms to all the stringent requirements defined by the IEEE 802.15.4b protocol.

This paper addresses the issue of blind channel estimation (BCE) in a SIMO FIR channel. This is an issue arising in e.g. mobile communication systems using digital signaling. It also arises in the presence of frequency selective fading, when training (reference/pilot) symbols are unavailable. In this contribution we analyze the performances of two types of channel coding schemes; turbo coding and serial concatenated convolutional coding with two types of second order statistical BCE algorithms. The first BCE algorithm is the subspace decomposition algorithm (SSDA) and the second is the outer product decomposition algorithm (OPDA). The object of this contribution is to investigate the performances of the coded scheme with these two types of BCE algorithms in order to characterize a possible and realistic scenario. The results show that the coded schemes using the SSDA can outperform the scheme using the OPDA by as much as 7 dB

We detail a cyclic odd bit inversion length 16 (COBI-16) code mapping scheme designed especially for devices in the enhanced wireless personal area networks operating in the 915 MHz for the emerging IEEE 802.15.4b standard. This carefully designed coding scheme meets all the following three essential criteria: (a) no spikes in the frequency spectrum, (b) low complexity correlation operations and (c) simple frequency offset and DC compensation operations. The scheme is tested in both AWGN and Rayleigh flat and frequency selective fading channels. Both coherent and noncoherent demodulations are investigated. Also investigated are the synchronous false alarm rate and synchronous miss rate in the AWGN channel. The results show that the scheme conforms to all the stringent requirements defined by the IEEE 802.15.4b protocol. The scheme has been accepted by the IEEE 802.15.4b task group as the standard for data transmission

In this paper, a pulse UWB system based on 16-ary ternary orthogonal keying (TOK) is proposed for low power low data rate wireless personal area networks (WPAN). The novel ternary sequence based common signaling in the UWB system is proposed to support efficient implementation for both simple energy detectors and complex coherent detectors. Three variants on different pulse compression and clustering are also discussed and simulations have been conducted for both additive white Gaussian noise channels, UWB line-of-sight and non-line-of-sight fading channels. The results have demonstrated the superior performance of the proposed UWB system over other systems.

This paper addresses the issue of blind channel estimation (BCE) in a SIMO FIR channel. This is an issue arising in e.g. mobile communication systems using digital signaling. It also arises in the presence of frequency selective fading, when training (reference/pilot) symbols are unavailable. In this contribution we analyze the performances of a 1/2 and 1/3 rate turbo code of various frame lengths with two types of second order statistical BCE algorithms. The first algorithm is the subspace decomposition algorithm (SSDA) and the second is the outer product decomposition algorithm (OPDA). The object of this contribution is to investigate the performances of the turbo coded system with these two types of BCE algorithms in order to characterize a possible and realistic scenario. The results show that the turbo coded schemes using the SSDA can outperform the scheme using the OPDA by as mush as 7 dB.

In this paper, a new pulse-based UWB system is proposed with low power ranging. The ternary sequence based common signaling is proposed to support power efficient energy detectors, differential detectors, and coherent detectors simultaneously. The preamble for ranging is designed to have good autocorrelation properties. The on-off keying based power efficient modulation is combined with chip mapping/spreading to provide robust system performance even in a multipath fading channel. Furthermore, a low complexity energy detection receiver structure is elaborated for leading edge detection in a multipath rich channel. System simulations are performed to demonstrate the promising performance of the proposed system

We detail a cyclic odd bit inversion length 16 (COBI-16) code mapping and modulation scheme designed especially for devices in the enhanced wireless personal area networks (WPAN) operating in the 868 MHz for the emerging IEEE 802.15.4b standard. This COBI-16 scheme has been accepted and incorporated in the draft IEEE 802.15.4b standard. This carefully designed coding and modulation scheme meets all the following three essential criteria: (a) no spikes in the frequency spectrum, (b) low complexity correlation operations and (c) simple frequency offset and DC compensation operations. The transmitted signal meets all the IEEE standard's stringent PSD mask requirements. The system is tested in both AWGN and Rayleigh fading (flat and frequency selective) channels. Both coherent and non-coherent demodulations are investigated. Also investigated are the synchronous false alarm rate and synchronous miss rate in the AWGN channel

We present a mobility model for simulations of scenarios in UMTS networks. This new model has been developed to overcome the shortcomings of previous models in capturing mobile user behavior. The proposed model strikes a balance between the abstraction level of purely stochastic models which lack certain important properties of the real world and completely deterministic models. The proposed model generates destinations of the mobile users based on the maximization of entropy of the gravity model which was first used in transportation planning and which has proven invaluable in urban planning. Subsequently, the model then allows the detailed tracking of users, in particular, the path of mobile users based on some known statistical behaviors of the mobile users, such as service arrival rates, service holding times, velocities, etc. As tracking is done on a microscopic level, it is possible to simulate and collect parameters which are important for wireless network planning and optimization, without the use of unrealistic assumptions.

In universal mobile telecommunication system (UMTS), the interference caused by location management procedures is expected to have an impact on the capacity of the network, since it is an interference-limited system. The grouping of the cells into LAs, RAs and URAs will affect the amount of paging and thus, will have an impact on the capacity of the network. In this work, we set up a simulation platform to study the effects of paging procedures in the Release 99 version of UMTS on the network capacity. Simulation results show how the capacity of the system changes as the paging load is increased. The results presented are important in providing an insight into the impact of paging procedures on the system throughput and capacity of the UMTS forward link.

Blind channel estimation (BCE) of multi channel FIR filters is an issue arising in e.g. mobile communication systems using digital signaling. It also arises in the presence of frequency selective fading, when training (reference/pilot) symbols are unavailable. In this contribution we analyze the performances of two types of channel coding schemes; turbo coding and serial concatenated convolutional coding (SCCC), with BCE. The BCE technique used here is a second order statistics algorithm based on subspace decomposition (SSD). The coding schemes are combined with this BCE technique to characterize a realistic scenario: in that we do not assume the transmitted signal to be white. Two types of blind equalizers are investigated; the zero forcing and the minimum mean squared error equalizers. The results show that the turbo-coding scheme performs better than the SCCC scheme by an average of 1-1.5dB.