Topic
Frequency sharing
About: Frequency sharing is a research topic. Over the lifetime, 308 publications have been published within this topic receiving 2000 citations.
Papers published on a yearly basis
Papers
Patent•
18 Mar 1991
TL;DR: In this article, a frequency-hopping packet communication system without a master clock or master control unit is based on use of a receiver's frequency hopping timing and identification to control communication.
Abstract: A frequency-hopping packet communication system without a master clock or master control unit is based on use of a receiver's frequency hopping timing and identification to control communication. A frequency-hopping band plan, involving the number of channels and the pseudo-random pattern of frequency change and nominal timing of changes, is universally known to each node in the network. Frequency-hopping is implemented by the division of communication slots and the accumulation of slots into epochs, wherein each epoch equals the total number of available slots (number of channels times the number of time frames per channel). A transmitting node tracks the preestablished frequency-hopping pattern for its target receiver based on previously-acquired information. The transmission node identifies a receiver node and a current frequency channel of such receiver node. The transmission node then checks the frequency channel to determine if available (e.g., not in use and within an acceptable noise margin). If unavailable, the transmission node delays transmission to the identified node to a later slot. During the delay, the transmission node identifies another receiver node and a corresponding current frequency channel. The steps of identifying a receiver node and checking the corresponding current frequency channel are repeated until a node having an available frequency channel is identified. The transmission node then sends a packet to the selected receiver node at a frequency and for a duration defined according to the current slot. Such transmission node tracks the changing frequency of the selected receiver node to maintain frequency synchronization.
136 citations
Patent•
27 May 1993
TL;DR: In this paper, a frequency agile spread spectrum radio system which is capable of efficient frequency re-use and frequency sharing is proposed, where the receiver adaptively learns which frequencies to avoid and sends redundant transmissions on widely separated pseudo-random carrier frequencies to overcome jammed channels.
Abstract: A frequency agile spread spectrum radio system which is capable of efficient frequency re-use and frequency sharing. The receiver (101) adaptively learns which frequencies to avoid. The transmitter (104) sends redundant transmissions on widely separated pseudo-random carrier frequencies to overcome jammed channels. A coded preamble is used to provide a greatly enhanced hybrid form of Time Division Multiple Access/Frequency Division Multiple Access for co-existence and frequency re-use with nearby systems. Anti-jam margins of 60 to 90 dB can be inexpensively achieved, far exceeding that of traditional direct sequence systems.
129 citations
TL;DR: This paper carries out interference analysis between GEO and MEO satellite systems considering the case of the O3b satellite system and proposes an adaptive power control technique for both the uplink and downlink scenarios in order to mitigate the in-line interference.
Abstract: The interest towards the deployment of Low Earth Orbit LEO/Medium Earth Orbit MEO satellite systems in several frequency bands is increasing due to the requirement of low latency for real-time systems and high demand of broadband data When the number of usable Non-Geostationary NGEO satellites, that is, LEO/MEO in space, increases, the frequency coexistence between the NGEO satellite systems with the already existing geostationary GEO satellite networks becomes a requisite In this context, it is crucial to explore interference mitigation techniques between GEO and NGEO systems in order to allow their spectral coexistence More specifically, in the coexistence scenario of GEO and NGEO satellite networks, in-line interference may be a serious problem, especially in the equatorial region In this paper, we provide several frequency sharing studies in the context of the coexistence of an NGEO satellite link with another NGEO/GEO satellite link Furthermore, we carry out interference analysis between GEO and MEO satellite systems considering the case of the O3b satellite system and propose an adaptive power control technique for both the uplink and downlink scenarios in order to mitigate the in-line interference Moreover, we suggest several cognitive solutions for mitigating the in-line interference and provide future research issues Copyright © 2014 John Wiley & Sons, Ltd
108 citations
Patent•
24 Jun 1994
TL;DR: In this paper, the receiver at each node is assigned a seed value and is provided with a channel punchout mask, which is used to generate a specific randomly ordered channel hopping band plan on which to receive signals.
Abstract: In a wireless packet communication system having a plurality of nodes, each having a transmitter and a receiver, the receiver at each node is assigned a seed value and is provided with a channel punchout mask. A node uses its seed value and punchout mask to generate a specific randomly ordered channel hopping band plan on which to receive signals. A node transmits its seed value and punchout mask to target nodes with which it wants to establish communication links, and those target nodes each use the seed value and punchout mask to generate the randomly ordered channel hopping band plan for that node. Subsequently, when one of the target nodes wish to transmit to the node, the target node changes frequency to the frequency of the node according to that node's band plan.
91 citations
1 Jun 2008
TL;DR: In the proposed system, OFDM hotspot communication is overlapped to the uplink of MC-DS-CDMA cellular system in the same frequency band and the beam-forming method is applied to eliminate inter-system interference and the orthogonality of each user is kept.
Abstract: In multi-carrier CDMA cellular systems, hotspot communication can be established to support the high-traffic areas by using the same frequency band of the original cellular systems. However, interference from the hotspots deteriorates the communication performance of the original cellular system. In this paper, in order to decrease the interference, we set up the access point (AP) of hotspots with the adaptive array antenna and code assignment method between the cellular and the hotspot communication is considered. In the proposed system, OFDM hotspot communication is overlapped to the uplink of MC-DS-CDMA cellular system in the same frequency band and the beam-forming method is applied to eliminate inter-system interference. Moreover, by allocating orthogonal variable spreading factors (OVSF) code to the both hotspot users and cellular users in the hotspot uplink period, the orthogonality of each user is kept. As a result, we can embed many hotspots into the cellular system with very small interference toward the uplink communication of the cellular system and we can improve the throughput of total system. The performance of the proposed system is evaluated by computer simulation under additive white Gaussian noise (AWGN) and Rayleigh fading environment. Copyright © 2007 John Wiley & Sons, Ltd.
90 citations
Related Topics (5)
Performance Metrics
| Year | Papers |
|---|---|
| 2021 | 5 |
| 2020 | 5 |
| 2019 | 7 |
| 2018 | 15 |
| 2017 | 16 |
| 2016 | 19 |