Novel radiation pattern by genetic algorithms, in wireless communication

[[abstract]]The genetic algorithm is used to synthesize the radiation pattern of the directional circular arc array to minimize the bit error rate (BER) performance in an indoor wireless communication system. By using the impulse response of the multipath channel, the performance of the synthesized antenna pattern on a BPSK (binary phase shift keying) system with phase and timing recovery circuits can be calculated. Based on the topography of the antenna and the BER formula, the synthesis problem can be reformulated into an optimization problem and solved by the genetic algorithm. Numerical results show that the synthesized antenna pattern is effective to combat the multipath fading and can increase the transmission rate of the indoor millimeter wave system[[conferencetype]]國際[[conferencedate]]20010506~20010509[[booktype]]紙本[[conferencelocation]]Rhodes, Greec

[[alternative]]Novel Antenna Pattern by the Genetic Algorithm to Minimize Bit Error Rate in Indoor Wireless Communication

計畫編號：NSC89-2213-E-032-037研究期間：2000-08~2001-07研究經費：519,000[[sponsorship]]行政院國家科學委員會[[notice]]補正完

Intégration d'antennes pour objets communicants aux fréquences millimétriques

This PhD thesis investigates the integration of antennas on silicon substrates at millimetre-wave frequencies in order to obtain fully-integrated and packaged transceiver modules using standard technologies in wireless devices. This work is organized in two main parts:In the first part, we investigated the design and realization of integrated antennas in a standard QFN package coupled to a 60 GHz Ultra-Wide-Band (UWB) transceiver chip with two integrated folded-dipole antennas implemented in a 65-nm CMOS-SOI technology on high-resistivity silicon. We defined a simulation model from which we studied the performance of integrated antennas, taking into account the influence of the environment (package, lid, wirebonding and manufacturing technology). Then, we optimized the antenna performances in impedance matching and radiation gain using radiating elements printed on a substrate and coupled to the on-chip folded dipoles. This antenna led to the demonstration of high-data rate communications (up to 2.2 Gbps) with a very low power consumption. We showed that the communication distance can be extended up to several meters using a transmit array printed on a low-loss substrate.In the second part, we investigated the design and realization of multibeam antennas in V-band for long-range applications; it is based on a transmit-array realized in standard printed technologies associated with a focal source array, which consists of a small number of integrated antennas on silicon in order to achieve a good compromise between the radiation gain, the cost and the beam steering capabilities. Several arrays were demonstrated with a circularly-polarized beam, a gain of 18.6 dBi et a beam-steering capability of ±24°.Cette thèse porte sur l'étude d'antennes intégrées sur silicium aux fréquences millimétriques, dans le but d'aboutir à des modules d'émission-réception totalement intégrés et reportés par des technologies standards dans un objet communicant. Ce travail comprend deux axes majeurs: Le première axe traite de l'étude, la conception et la réalisation d'antennes intégrées dans un boitier standard QFN couplées à un circuit émetteur-récepteur Ultra Large Bande (ULB) à 60 GHz comprenant des antennes intégrées de type dipôle replié fabriquées en technologie CMOS SOI 65-nm sur silicium haute résistivité. Dans un premier temps, nous avons défini le modèle de simulation à partir duquel nous avons étudié les performances des antennes prenant en compte l'influence de l'environnement (boitier, capot, fil d'interconnexions et technologie de fabrication). Dans un second temps, nous avons réalisé une optimisation des performances en adaptation et en rayonnement en ajoutant au sein du boitier un substrat et des éléments rayonnants couplés aux antennes intégrées sur la puce. Ce dispositif permet de réaliser des communications très haut débit (jusqu'à 2.2 Gbps) avec une très faible consommation d'énergie. Nous montrons qu'il est possible d'atteindre une distance de communication de plusieurs mètres grâce à un réseau transmetteur réalisé en technologie imprimée.Le deuxième axe porte sur la conception et la réalisation d'antennes multifaisceaux en bande V pour applications à long portée; il propose d'associer un réseau transmetteur réalisé sur technologie imprimée à un réseau focal constitué d'un petit nombre d'antennes intégrées sur silicium afin d'obtenir un compromis intéressant entre le niveau de gain, le coût et les capacités de dépointage de faisceau. Plusieurs réseaux sont démontrés avec un faisceau en polarisation circulaire, un gain de 18.6 dBi et une capacité de dépointage de ±24°

Performance Limits of Microwave and Dual Microwave/Millimeter Wave Band Networks

Traditionally, wireless networks communicate over the conventional microwave band (sub-6 GHz) as it supports reliable communication over a large geographic area. The ever increasing demand for bandwidth to support the rising number of consumers and services, however, is fast depleting the available microwave spectrum. As such, complementing the microwave spectrum with additional bandwidth from the millimeter-wave (mm-wave) band has been envisioned as a promising solution to this problem. Since transmissions in the mm-wave band are typically achieved with highly directional steerable antenna arrays to counter the severe path-loss in mm-wave frequencies, the resulting mm-wave links are typically rendered highly directional, which can often be modeled as directional point-to-point links. However, mm-wave transmissions are inherently unreliable compared to those in the microwave band. Hence, communicating simultaneously over both bands in an integrated mm-wave/microwave dual-band setup is emerging as a promising new technology. In this dual-band setting, high-rate data traffic can be carried by relatively unreliable high-bandwidth mm-wave links, while control signals and moderate-bandwidth traffic can be communicated over the relatively reliable microwave band. In this thesis, we first study two dual-band multi-user networks that model two important aspects of wireless communication: inter-user interference and relay-cooperation. The broad goal of this study is to characterize information-theoretical performance limits of such networks, which can then be used to obtain insights on the optimal encoding/decoding strategy, effective resource allocation schemes, etc. In the first part of this thesis, we study a two-transmitter two-receiver dual-band Gaussian interference channel (IC) operating over an integrated mm-wave/microwave dual-band. This channel models a setting where a pair of single-transmitter single-receiver links communicate simultaneously, and thus mutually interfere. Here, transmissions in the underlying microwave band are modeled as a two-user conventional Gaussian IC (GIC). In contrast, a transmitter in the mm-wave band is assumed to be capable of communicating to either the desired destination or the interfered destination via a point-to-point direct-link or a cross-link, respectively. The dual-band IC is first classified into 3 classes according to the interference level in the underlying microwave GIC, and then sufficient channel conditions are obtained under which the capacity region of the 3 classes are characterized. For cases in which the sufficient conditions do not necessarily hold, approximate capacity results are obtained that characterizes the capacity region to within 1/2 bit per channel use per user. The performance of the dual-band IC is likely to be impacted significantly by the point-to-point nature and large bandwidth of the mm-wave links, and specifically by whether the mm-wave spectrum is used as direct-links or cross-links. Transmitting in either the direct-links only or the cross-links only is not optimal for all channel conditions, and there exists a non-trivial trade-off between the two modes. To understand the impact of this trade-off on the performance of the dual-band IC, we study the power allocation scheme over the mm-wave direct and cross-links that maximizes the sum-rate of the channel. The resulting power allocation strategy is characterized in closed form, which possesses rich properties and reveals useful insights into the trade-offs in such networks. In the second part of this thesis, we study a fading Gaussian multiple-access relay channel (MARC) over an integrated mm-wave/microwave dual-band, where two sources communicate to a destination with the help of a relay. In the dual-band MARC, transmission in the underlying microwave band is modeled as a conventional Gaussian MARC. However, similar to that in the dual-band IC, a mm-wave transmitter in this channel is modeled as being able to communicate to either the destination or the relay by creating a direct-link or a relay-link, respectively. For dual-band MARC, we characterize an achievable region and a set of rate upper bounds, and then obtain sufficient channel conditions under which its capacity region is characterized. Similar to the dual-band IC, the performance of the dual-band MARC will likely be significantly affected by whether the mm-wave band is used as direct-links or relay-links, and a non-trivial trade-off between the two modes exists in this case as well. To understand this trade-off, we study the transmission power allocation scheme over the mm-wave direct and relay-links that maximizes the sum-rate of the dual-band MARC. The resulting power allocation scheme, characterized in closed form, is observed to have rich structural properties, which reveal insights into the trade-offs in relay cooperation in dual-band networks. While dual-band communication is a promising technology, currently the bulk of the connectivity is still supported by the microwave band. However, the problem of interference mitigation for conventional microwave bands is still open even for the basic case of a two-user IC. Motivated by this, in the third part of the thesis, we study the performance limits of the multiple-access interference channel (MAIC) which models the interference during cellular uplink over the conventional single band. Focusing on the weak interference case, which provides a more realistic model of the inter-cell interference, we characterize an achievable strategy and 3 novel upper bounds on the sum-rate in the partially symmetric case, thereby providing improved sum-rate upper and lower bounds in these cases