WCDMA uplink capacity and interference statistics of highways cigar-shaped microcells

The capacity and the interference statistics (mean value and variance) of the sectors of the cigar-shaped Wideband Code Division Multiple Access microcells are studied. The two-slope propagation model is used in the analysis. A model of five microcells is used to calculate the uplink capacity and interference statistics assuming highways cigar-shaped microcells. The capacity and the interference statistics of the microcell are studied for different sector range, propagation exponent, antenna side lobe levels and different standard deviation of the power control error. It is noticed that the quasi-maximum uplink sector capacity can be got when the sector range R is between 600 and 1,200 m and the sidelobe level of the directive antenna used in each sector is on the order of −15 dB.     

Zero-Forcing Spatial Interweave with Greedy Scheduling

In this work, the effect of the multipath on the capacity and the interference statistics of the sectors of the highways cigar-shaped W-CDMA microcells is studied. A model of five microcells is used to analyze the uplink. The capacity and the interference statistics of the microcell are studied for different antenna sidelobe levels and different sector ranges. In the study, imperfect power control and limited transmitted power are assumed. Users are assumed to be within equally spaced buses and cars. The uplink capacity of the sector is studied assuming three types of services, namely, voice, 3G data and 3.75G data (representing the High Speed Uplink Packet Access). It is shown that, the sector uplink capacity depends on the buses and cars density within the sector. The capacity is also given as a function of the number of buses and cars within the sector.     

W-CDMA Uplink Capacity and Interference Statistics of a Long Tunnel Cigar-shaped Microcells Using the Hybrid Model of Propagation with Imperfect Power Control

The uplink capacity and the interference statistics (mean and variance) of the sectors of the cigar-shaped W-CDMA microcell are studied. A model with eighteen sectors is used to analyze the uplink. The microcells are assumed to exist in a long tunnel with at least nine base stations. The hybrid model of propagation is used in the calculations. The capacity and the interference statistics of the sectors are studied in terms of the most important parameters: sector radius, specific attenuation factor, antenna sidelobe levels, bend losses and the power control standard deviation error.     

W-CDMA Uplink Capacity and Interference Statistics of a Long Tunnel Cigar-shaped Microcells Using the Hybrid Model of Propagation with Imperfect Power Control

The uplink capacity and the interference statistics (mean and variance) of the sectors of the cigar-shaped W-CDMA microcell are studied. A model with eighteen sectors is used to analyze the uplink. The microcells are assumed to exist in a long tunnel with at least nine base stations. The hybrid model of propagation is used in the calculations. The capacity and the interference statistics of the sectors are studied in terms of the most important parameters: sector radius, specific attenuation factor, antenna sidelobe levels, bend losses and the power control standard deviation error.     

WCDMA Uplink Capacity and Interference Statistics of Highways Shaped Microcells with Imperfect Power Control and Finite Transmitted Power

The capacity and the interference statistics (mean and variance) of the sectors of a Cigar-, Tee-, and Cross-shaped WCDMA microcells are studied. Models of 5, 7, and 9 microcells are used to analyze the uplink capacity of the cigar-, Tee-, and cross-shaped W-CDMA microcell, respectively. The capacity and the interference statistics of the microcell are studied for different sector range and antenna side lobe levels. It is shown that the highest sector capacity is obtained when the microcell is cigar-shaped. For a cross-shaped microcell, the sector capacity is the lowest. Also it is shown that the uplink sector capacity will be very high if synchronous WCDMA is used in the uplink. To get the quasi maximum capacity, the sector range should be (0.6 – 1) km and the side lobe level of the directive antenna used in each sector should be – 15 dBc or lower.     

W-CDMA Uplink Practical Capacity and Interference Statistics of Rural Highways Cigar-Shaped Microcells with Imperfect Power Control and Finite Transmitted Power

The capacity and the interference statistics of the sectors of the cigar-shaped W-CDMA microcell are studied. A model of 5 microcells is used to analyze the uplink. The microcells are assumed to exist in rural zones. The capacity and the interference statistics of the microcell are studied for different sector range, different antenna side lobe levels, different values of the break point distance, different values of the propagation parameter s ₂ and different standard deviation of the power control error.     

W-CDMA Uplink Capacity and Interference Statistics of Rural Highways Cross-Shaped Microcells

The capacity and the interference statistics of the sectors of the cross-shaped W-CDMA cell are studied using an analytical approach. A model of 49 cells is used to analyse the uplink, which limits the capacity. The cells are assumed to exist in rural zones. The capacity and the interference statistics of the microcell are studied for different sector ranges and different antenna sidelobe levels.     

WCDMA Uplink Capacity of a Long Tunnel Cigar-shaped Microcells for Underground Train Service

In this paper, the capacity and the interference statistics of the sectors of the cigar-shaped WCDMA microcells are studied using the hybrid model of propagation. A model of nine microcells in a metro tunnel is used to analyze the uplink capacity and the interference statistics. The capacity and the interference statistics of the microcells in metro tunnels are studied in this work for different propagation parameters, antenna side lobe levels, sector ranges and bends losses.

Uplink Multi-service Capacity and Interference Statistics of City Streets WCDMA Cross-shaped Microcells with Imperfect Power Control and Finite Transmitted Power

The multi-service (combination of more than one service) capacity and interference statistics (mean and variance) of the sectors of the street cross-shaped Wide Band Code Division Access (WCDMA) microcell are studied. A model of 21 cross-shaped microcells is used to analyze the uplink. The two slope propagation model is used to analyze the uplink. The capacity and interference statistics of the sectors are studied for different sector ranges, side lobe levels and power control (PC) standard deviation errors. It is noticed that, increasing the sector range will increase the sector capacity, reducing the side lobe level will also increase the sector capacity. Also it is noticed that, increasing the propagation exponent s ₂ will increase the sector capacity, reducing the standard deviations of the shadowing parameters σ₁ and σ₂ will increase the sector capacity and that reducing the power control standard deviation error σ_c will increase the sector capacity.

WCDMA Uplink Capacity of Highways Cigar-Shaped Microcells with Incorporated HSUPA Service

The multi-service (voice, data and HSUPA) uplink capacity and the interference statistics of the sectors of the cigar-shaped WCDMA microcell are studied using a model of 5 highway microcells. The two-slope propagation loss model with lognormal shadowing is used in the analysis. It is concluded that the voice and data service are significantly affected by HSUPA users and sector capacity decreases dramatically when one of these users gets connected to a given sector or to one next to it. Also it has been concluded that the capacity decrement is highly sensitive to the location of the HSUPA users. Thus, no more than one HSUPA with a process gain of 16 can be connected to a given base station. In this case, the HSUPA user should interrupt its transmission when it is near to the sector border. No more than one HSUPA user with a process gain of 8 is permitted in a given sector and the sector next to it. When the HSUPA user is at the sector border, its transmission should be disabled.     

Uplink user capacity in a CDMA system with hotspot microcells: effects of finite transmit power and dispersion

This paper examines the uplink user capacity in a two-tier code division multiple access (CDMA) system with hotspot microcells when user terminal power is limited and the wireless channel is finitely-dispersive. A finitely-dispersive channel causes variable fading of the signal power at the output of the RAKE receiver. First, a two-cell system composed. of one macrocell and one embedded microcell is studied and analytical methods are developed to estimate the user capacity as a function of a dimensionless parameter that depends on the transmit power constraint and cell radius. Next, novel analytical methods are developed to study the effect of variable fading, both with and without transmit power constraints. Finally, the analytical methods are extended to estimate uplink user capacity for multicell CDMA systems, composed of multiple macrocells and multiple embedded microcells. In all cases, the analysis-based estimates are compared with and confirmed by simulation results.     

Multiservice capacity and interference statistics of the uplink of high altitude platforms (HAPs) for asynchronous and synchronous WCDMA system

In this work, the capacity and the interference statistics of the uplink of high-altitude platforms (HAPs) for asynchronous and synchronous WCDMA system assuming finite transmission power and imperfect power control are studied. Propagation loss used to calculate the received signal power is due to the distance, shadowing, and wall insertion loss. The uplink capacity for 3- and 3.75-G services is given for different cell radius assuming outdoor and indoor voice users only, data users only and a combination of the two services. For 37 macrocells HAP, the total uplink capacity is 3,034 outdoor voice users or 444 outdoor data users. When one or more than one user is an indoor user, the uplink capacity is 2,923 voice users or 444 data users when the walls entry loss is 10?dB. It is shown that the effect of the adjacent channels interference is very small.     

WCDMA downlink capacity of cigar-shaped microcells for long tunnels

In this paper, the Wideband Code Division Multiple Access (WCDMA) downlink capacity and the interference statistics of long tunnel cigar-shaped microcells are analyzed. The hybrid model of propagation is used in the analysis where a model of 10 cigar-shaped microcells is used. The downlink capacity is given for different sector radio R, break point distance R _b and propagation parameters (s and γ). It is found that the effect of changing the value of the propagation parameter s is very small. Also, it is noticed that, increasing the propagation parameter γ will increase the sector downlink. It is found that, the effect of changing the break point distance R _b is quasi null. Finally it is noticed that the imperfect power control reduces the downlink capacity by 4 %.     

智能天线对LTE上行链路干扰及容量的影响

为了从根本上降低LTE上行链路的干扰,提高系统的容量,从理论上分析了终端使用主瓣宽度为60°的智能天线对上行链路干扰及容量的影响。通过计算得出,系统内所有的终端均使用主瓣宽度为60°的智能天线时,可使相邻小区的干扰功率与本小区干扰功率的比值降低到10-2量级以下,可使多小区的容量达到单小区容量的98.6%以上。     

Capacity and interference statistics of highways W-CDMAcigar-shaped microcells (uplink analysis)

The capacity and the interference statistics of the sectors of the shaped W-CDMA cell are studied. A model of five cells is used to analyze the uplink. The cells are assumed to exist in rural zones. The capacity and the interference statistics of the cell are studied using a two-slope propagation model. The expected value and the variance of the interference are given for different propagation exponent     

Bit rate of HSDPA in tunnel’s cigar-shaped microcells

This paper presents the bit rate of High Speed Downlink Packet Access (HSDPA) mode for cigar-shaped microcells deployed at tunnels. The hybrid propagation loss model with log-normal shadowing is used to calculate the signal to interference plus noise ratio taking into account the expected value and the variance of the interference. A model of ten cigar-shaped microcells is used in the analysis. The effect of the propagation parameters on the HSDPA performance (coverage and bit rate) is studied. It is found that, with a sector transmitted power of 1 W, a sector with a range of 1 km can be deployed with the worst case propagation parameters values. It is shown that it is impossible to support more than 6 HSDPA codes for full coverage within the sector what ever the power assigned to the HSDPA service.     

Capacity analysis for underlaying CDMA microcell/macrocell systems

The CDMA system can provide more capacity than the conventional AMPS system and the hierarchical layer of cells is required for system design in the future. However, the problem is whether the same RF channels used in a CDMA underlaying macrocell/microcell structure also obtain high capacity as in the homogeneous structure. This paper investigates the interference of uplink and downlink from both the microcell and macrocell in a hierarchical structure. Downlink power control is also considered. The results show that the capacity of microcell in a hierarchical structure is 23 per cent less than in homogeneous cells. The capacity of macrocell in a hierarchical structure decreases dramatically in proportion to the number of microcells. The capacities of the microcell and macrocell are limited in downlink, and uplink, respectively. In addition, more efforts for microcell should be made, such as more power is transmitted by microcell basestation if the same RF channel is used in a hierarchical structure. The results suggest that different RF channels are used in a two‐tier cellular environment. Copyright © 2001 John Wiley & Sons, Ltd.     

Joint optimal power control and beamforming in wireless networksusing antenna arrays

The interference reduction capability of antenna arrays and the power control algorithms have been considered separately as means to increase the capacity in wireless communication networks. The minimum variance distortionless response beamformer maximizes the signal-to-interference-and-noise ratio (SINR) when it is employed in the receiver of a wireless link. In a system with omnidirectional antennas, power control algorithms are used to maximize the SINR as well. We consider a system with beamforming capabilities in the receiver, and power control. An iterative algorithm is proposed to jointly update the transmission powers and the beamformer weights so that it converges to the jointly optimal beamforming and transmission power vector. The algorithm is distributed and uses only local interference measurements. In an uplink transmission scenario, it is shown how base assignment can be incorporated in addition to beamforming and power control, such that a globally optimum solution is obtained. The network capacity and the saving in mobile power are evaluated through numerical study     

多约束条件下的阵列天线方向图可重构设计

介绍了一种多个约束条件下的阵列天线方向图可重构设计方法。在阵列激励功率种类与仅相位加权等条件的限制下,优化后的阵列天线多种方向图均满足了预设目标。首先,建立了多目标优化求解模型;然后,针对不同的问题采用了不同的优化方法进行求解。优化后的阵列采用了三种不同的功率组件,并在同一功率激励情况下采用不同的相位分布分别实现了低副瓣笔形波束、45°余割平方与22°扇形方向图的可重构设计,而且优化后的总输入功率较相同副瓣电平下的泰勒加权的总功率增加了约13%。     

Modeling and computer simulation of wave propagation in linealline-of-sight microcells

The model and implementation principles governing the computer simulation of line-of-sight (LOS) microcell wave propagation are presented. Multiray propagation above a plane earth constitutes the basic model. For rural microcells, two rays are used while, for urban microcells, 10 rays are used propagating in a dielectric canyon. The model is applied to two relevant problems. In the first, control of electric field falloff with distance, r, is studied. ln the second, the advantages of switched transversal antenna diversity are demonstrated. Power falloff rates of 1/r⁴ and 1/r⁶ were obtained for simple two-element array structures. This may provide an additional interference control tool in the layout and design of microcells. The interference between the various rays propagating in lineal urban microcells results in deep nulls at various locations. The deleterious effects of these nulls can be eliminated by employing simple switched transverse antenna diversity