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.

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

Abstract: In this paper we investigate the spectrum efficiency gain using transmitting antenna arrays at the base stations of a mobile cellular network. The proposed system estimates the angular positions of the mobiles from the received data, and allows multiple mobiles to be allocated to the same channel within a cell. This is possible by applying a transmit scheme which directs nulls against co-channel users within the cell. It is shown that multiple mobiles per cell is an efficient way of increasing capacity in comparison with reduced channel reuse distance and narrow beams (without directed nulls). The effect of the spatial spread angle of the locally scattered rays in the vicinity of the mobile is also investigated. >

A witness-based approach for data fusion assurance in wireless sensor networks

Abstract: In wireless sensor networks, sensor nodes are spread randomly over the coverage area to collect information of interest. Data fusion is used to process these collected information before they are sent to the base station, the observer of the sensor network. We study the security of the data fusion process in this work. In particular, we propose a witness-based solution to assure the validation of the data sent from data fusion nodes to the base station. We also present the theoretical analysis for the overhead associated with the mechanism, which indicates that even in an extremely harsh environment the overhead is low for the proposed mechanism.

Method and apparatus for controlling power in a variable rate communication system

Abstract: A method and an apparatus for controlling transmission power in a variable rate communication system. A base station (30) monitors the reverse link signal transmitted from a mobile station (50). Base station (30) determines whether mobile station (50) should increase or decrease its power based either upon frame error rates detected by a decoder (44) or by the level of received signal power detected at a receiver (42). In response to this analysis, a control processor (46) generates a power control signal and transmits this signal to mobile station (30).

Power control for a wireless communication system utilizing orthogonal multiplexing

Abstract: Techniques for adjusting transmit power to mitigate both intra-sector interference to a serving base station and inter-sector interference to neighbor base stations are described. The amount of inter-sector interference that a terminal may cause may be roughly estimated based on the total interference observed by each neighbor base station, channel gains for the serving and neighbor base stations, and the current transmit power level. The transmit power may be decreased if high interference is observed by a neighbor base station and increased otherwise. The transmit power may be adjusted by a larger amount and/or more frequently if the terminal is located closer to the neighbor base station observing high interference and/or if the current transmit power level is higher, and vice versa. The intra-sector interference is maintained within an acceptable level by limiting a received SNR for the terminal to be within a range of allowable SNRs.

Spread spectrum apparatus for cellular mobile communication systems

Abstract: An apparatus is disclosed for a cellular mobile communication system utilizing a spread spectrum. A plurality of fixed base stations is connected with a central processor so that calls originating in any cell can terminate in any other cell. The available frequency spectrum is divided such that one-half is used for mobile-to-base station transmission and the other one-half is used for base station-to-mobile unit transmission. A power control/mobile locator system and method is utilized in all mobile units to compensate for changes in signal level and to maintain the average received signal level at the base station constant regardless of the location of the mobile unit within the cell. In addition, each mobile unit has a unique set of time-frequency coded waveforms that are used for both transmission and reception. The waveforms have large time-bandwidth products so that interfering signals are well suppressed, and which provide a large set of signals so that each user can be assigned a unique set of waveforms. Message modulation is accomplished by digitizing the speech and encoding the resulting binary sequences into the set of waveforms available to the user, while detection is accomplished by a demodulation system and method in which the phases of each received waveform are compared with those of the preceding waveform.