Base station

About: Base station is a research topic. Over the lifetime, 85883 publications have been published within this topic receiving 1019303 citations. The topic is also known as: Mobile phone base stations & BS.

Radio range adjustment for energy efficient wireless sensor networks

Abstract: In wireless ad hoc sensor networks, energy use is in many cases the most important constraint since it corresponds directly to operational lifetime. Topology management schemes such as GAF put the redundant nodes for routing to sleep in order to save the energy. The radio range will affect the number of neighbouring nodes, which collaborate to forward data to a base station or sink. In this paper we study a simple linear network and deduce the relationship between optimal radio range and traffic. We find that half of the power can be saved if the radio range is adjusted appropriately compared with the best case where equal radio ranges are used.

Communication system with fast control traffic

Abstract: A method and system for conducting rapid control traffic in a time division multiple access (TDMA) communication system comprises a base station communicating with a plurality of user stations in assigned time slots of a time frame. For bearer traffic, time slots are assigned to particular user stations for an extended duration. In unassigned time slots, the base station transmits a general polling message indicating availability of the time slot. A user station desiring to hand off communication from one base station to another uses multiple available time slots at the target base station for exchanging control traffic messages with the target base station. The next available time slot is indicated by a slot pointer in the header of each general polling message to facilitate rapid exchange of control traffic messages. During handover, the user station may establish a new link with the target base station before relinquishing the existing communication link with the old base station.

Array antenna system of wireless base station

Abstract: An array antenna system of a wireless base station in CDMA mobile communications combines signals, which have been received by a plurality of antenna elements of an array antenna, upon subjecting the signals to amplitude and phase-rotation control, and despreads the combined signal. A searcher has matched filters which apply correlation operations to output signals from respective antenna elements to thereby calculate correlation signals that are correlated with a signal transmitted from a mobile station of interest. An adaptive weight calculating unit calculates adaptive weights for obtaining in-phase correlation signals from the respective antenna outputs. A beam former multiplies, by the adaptive weights, output signals from the corresponding antenna elements and combines the resulting products to output a combined signal. The combined signal is found for each path of multipaths and is input to a Rake receiver, which proceeds to identify data.

Smart antenna CDMA wireless communication system

Abstract: A TDD antenna array S-CDMA system for increasing the capacity and quality of a wireless communications is disclosed. By simultaneous exploiting the spatial and code diversities, high performance communications between a plurality of remote terminals and a base station is achieved without sacrificing system flexibility and robustness. The time-division-duplex mode together with the inherent interference immunity of S-CDMA signals allow the spatial diversity to be exploited using simple and robust beamforming rather than demanding nulling. Measurements from an array of receiving antennas at the base station are utilized to estimate spatial signatures, timing offsets, transmission powers and other propagation parameters associated with a plurality of S-CDMA terminals. Such information is then used for system synchronization, downlink beamforming, as well as handoff management. In an examplary embodiment, the aforementioned processing is accomplished with minimum computations, thereby allowing the disclosed system to be applicable to a rapidly varying environment. Among many other inherent benefits of the present invention are large capacity and power efficiency, strong interference/fading resistance, robustness power control, and easy hand-off.

The spectrum efficiency of a base station antenna array system for spatially selective transmission

Abstract: The goal of this paper is to estimate the gain, in terms of system capacity at a given outage probability, which can be obtained by applying antenna arrays in the base stations of a mobile cellular network. For this purpose a propagation model which incorporates the angular distribution of the rays in the vicinity of the mobile is postulated. Also included in the model is the interference from co-channel cells. With the aid of the model, a weight selection algorithm is derived. The proposed system is simulated with different numbers of mobiles per channel in each cell and different numbers of antenna elements in the arrays. Also varied is the cluster size. This is done to determine the optimal trade-off between reduced cluster size and multiple mobiles per channel in each cell. The results show that it is possible to increase capacity between two and twelve times depending on the number of antennas in the arrays and the spread of the local scattering. >