摘要:
A method for closed loop link adjustment based on a Request To Send-Clear To Send (RTS-CTS) channel access scheme includes the following steps. Designating a station as an originating station. Transmitting a RTS frame with predetermined transmit power from an originating station, prior to an intended DATA transmission, sounding the channel such that reception characteristics can be evaluated at a designated receiving station. Transmitting, in response to the originating station, a CTS frame with a predetermined transmit power from the receiving station with directives of link adjustments. Transmitting a DATA frame from the originating station to the receiving station frame complying with link adjustment directives to the extent of the originating stations capabilities. And, transmitting an acknowledge (ACK) frame in response to the originating stations from the receiving station indicating result of DATA frame reception.
摘要:
In a multihop communications network a cost determination method includes determining a plurality of simultaneously potential or favorable next hop nodes for at least one of the nodes between a source and a destination node pair, whereby a mesh-like path comprising a plurality of simultaneously potential routes or paths is defined between the source and destination node. This mesh-like structure is typically determined in a distributed manner and results from a cost optimization process. The cost optimization should preferably consider stochastic variations that for example are caused by the wireless medium.
摘要:
A sending node (405) is adapted for communication with several receiving nodes (410, 420) by transmitting information in the form of a regular data packet to at least one intended receiving nodes, said sending node comprising—means to receive, identify and store a priori information in feedback from receiving nodes (410, 420); —means (905) for forming a composite data packet from at least two regular data packets, said means arranged to use a priori information from said a priori information storage module (910) and to determine which multiple individual data packets to retrieve from a buffer module (920) for use in the composite data packet, said means being arranged to form a composite data packet from which the intended receiving node for each of the at least two regular packets can decode the composite packet to obtain at least one packet intended for it.
摘要:
Each receiving node (120) of a plurality of receiving nodes (120-1, 120-2 and 120-3) such as base stations in a wireless network converts a superposition of signals received from a plurality of transmitting nodes such as mobile terminals (10) to produce soft complex signal information. The soft complex signal information associated with the considered plurality of receiving nodes are collected, for example in a central node (130) and jointly detect signal information transmitted from at least a subset of the plurality of transmitting nodes (10) based on the collected soft complex signal information. The collected soft signal information generally retains phase and amplitude information, and the transmitted signals are preferably detected in a joint detection process based on a complex channel representation and collected soft signal information. In a truly distributed realization, adjacent receiving nodes or base stations exchange soft complex signal information with each other, thus forming at least partially overlapping groups for distributed collection of information, detection and subsequent decoding in each base station.
摘要:
The present invention relates to methods and arrangements in a relaying radio node and/or in a sending/receiving radio node, adapted for use in a relaying communication system. The relaying node is in bidirectional communication with at least a first and a second sending/receiving radio node, and the relaying radio node receives at least a first signal carrying at least first data and a second signal carrying at least second data. The relaying node generates a reduced representation of at least the first and second signal, with a reduced information content as compared to the first and second data, by a joint non-linearly encoding operation, and transmits the reduced representation to at least the first and the second communication node. The first and second sending/receiving node can extract data from the reduced representation by a non-linear decoding operation using stored a priori information.
摘要:
A wireless relaying network having a number of network nodes including a designated originating node, at least one relaying node, and at least two receiving nodes. The designated originating node transmits a pilot signal, and the relaying node(s) receives and forwards the pilot signal to the receiving nodes, each of which measures channel quality based on the received pilot signal. At least part of the receiving nodes feed information on the measured channel quality all the way back to the designated originating node, and the originating node then schedules data for transmission to at least one selected node of the receiving nodes based on the received channel quality information. Subsequently, the designated originating node transmits data to the selected receiving node(s) via the same relaying node(s) that forwarded the pilot signal. In this way, multi-user diversity scheduling is introduced to relaying networks that provides significant data rate enhancements.
摘要:
The method and arrangement according to the present invention relates to scheduling and coding in communication systems utilizing automatic repeat request (ARQ) and/or multihop scheduling and forwarding. According to the inventive method the receiving nodes selectively stores received information, also overheard information, as a priori information and feed back information about their respective stored a priori information to a sending node. The sending node forms composite data packets by jointly encoding and scheduling multiple multicast data packets, and subsequently transmits the composite data packets to the receiving nodes. Upon receiving a composite data packet the receiving nodes uses their stored a priori information, comprising of regular multicast packets, or full or partly decoded composite packets comprised of regular multicast packets, in the process of extracting multicast data packets from the composite data packets.
摘要:
A method for closed loop link adjustment based on a Request To Send-Clear To Send (RTS-CTS) channel access scheme includes the following steps. Designating a station as an originating station. Transmitting a RTS frame with predetermined transmit power from an originating station, prior to an intended DATA transmission, sounding the channel such that reception characteristics can be evaluated at a designated receiving station. Transmitting, in response to the originating station, a CTS frame with a predetermined transmit power from the receiving station with directives of link adjustments. Transmitting a DATA frame from the originating station to the receiving station frame complying with link adjustment directives to the extent of the originating stations capabilities. And, transmitting an acknowledge (ACK) frame in response to the originating stations from the receiving station indicating result of DATA frame reception.
摘要:
The present invention relates to relay supported wireless communication to enhance communication performance. In the wireless communication system according to the invention neighboring relay stations are arranged with substantially overlapping coverage. In the method according to the invention mobile stations makes soft association to relay stations. The mobile stations feed back the selection of relay stations and channel quality measures to the base station. The base station adapts the transmission to the relay stations based on each mobile stations reported soft associations and channel quality measures. In this way the control signaling to and from the relay stations can be very limited.
摘要:
A multiple path information transfer system in a cellular radio network includes several receivers (BS-1, . . . , BS-N) for receiving radio signals representing digital information from at least one signal source. From each received radio signal a corresponding digitized baseband signal that contains soft information is extracted. Compressing units (10) compress the soft information to produce compressed baseband signals. These compressed signals are forwarded to a combining unit over a transport network. A de-compressor (16) de-compresses the forwarded signals to at least approximately restore the baseband signals. The de-compressed signals are combined (18-22) and the combined signal is decoded to at least approximately restore the digital information.