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公开(公告)号：AT303023T
公开(公告)日：2005-09-15
申请号：AT99957511
申请日：1999-11-03
Applicant: LUCENT TECHNOLOGIES INC
Inventor： BALACHANDRAN KRISHNA , EJZAK RICHARD P , NANDA SANJIV
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公开(公告)号：DE60100981T2
公开(公告)日：2004-08-12
申请号：DE60100981
申请日：2001-06-18
Applicant: LUCENT TECHNOLOGIES INC
Inventor： GOPALAKRISHNAN NANDU , KADABA SRINIVAS R , ULLAH KHAN FAROOQ , NANDA SANJIV , SUNAY MEHMET OGUZ , SUNDARAM GANAPATHY SUBRAMANIAN
Abstract: Data rate determination is provided in a system where the available power fraction and available Walsh codes in each active leg are dynamically changing over time. This method adapts the rate (modulation and coding) based on the combined resource (power & code space) levels seen at each cell. The method results in maximization of the rate supportable by each cell given their resource constrained situation while meeting the constraints of target packet or frame error rate and orthogonality. Furthermore, improved fast cell selection by the mobile results due to this approach that is based on knowledge of combined resource (power & code space) levels across the cells in the active set.
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公开(公告)号：CA2263060C
公开(公告)日：2003-12-09
申请号：CA2263060
申请日：1999-02-26
Applicant: LUCENT TECHNOLOGIES INC
Inventor： NANDA SANJIV , EJZAK RICHARD PAUL , BALACHANDRAN KRISHNA , KADABA SRINIVAS R
IPC: H04B17/00 , H03M13/23 , H04B1/10 , H04B7/26 , H04L1/00 , H04L1/12 , H04L1/20 , H04L27/00 , H04L27/18 , H04L27/34 , H04W36/30 , H04W72/08
Abstract: A system and method to measure channel quality in terms of signal to interference plus noise ratio for the transmission of coded signals over fading channels in a communication system. A Viterbi decoder metric for the Maximum Likelihood path is used as a channel quality measure for coherent and non-coherent transmission schemes. This Euclidean distance metric is filtered in order to smooth out short term variations. The filtered or averaged metric is a reliable channel quality measure which remains consistent across different coded modulation schemes speeds. The filtered metric is mapped to the signal to interference plus noise ratio per symbol using a threshold based scheme. Use of this implicit signal to interference plus noise ratio estimat e is used for the mobile assisted handoff in a cellular system, power control and data rat e adaptation in the transmitter.
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公开(公告)号：CA2296137C
公开(公告)日：2003-10-28
申请号：CA2296137
申请日：2000-01-14
Applicant: LUCENT TECHNOLOGIES INC
Inventor： BUDKA KENNETH C , NANDA SANJIV , SCHEFCZIK HANS PETER
Abstract: In a wireless data network, such as a General Packet Radio Service (GPRS ) network, a transmitter uses one of k coding/modulation schemes for transmitting data. The transmitter initially selects a coding/modulation scheme, C, as a functi on of carrier-to-interference ratio (C/I) measurements. The transmitter then calculates the number of blocks, B, required to transmit a number of data packets, D, using the coding/modulation scheme C. In addition, the transmitter calculates the number of blocks required to transmit the number of data packets, D, for each coding/modulation scheme th at is stronger than the selected coding/modulation scheme C. The transmitter final ly selects that coding/modulation scheme that results in transmitting the number of dat a packets D in B blocks using the strongest coding/modulation scheme. As a result, each block is transmitted using the strongest coding/modulation scheme available.
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公开(公告)号：CA2341917A1
公开(公告)日：2002-06-29
申请号：CA2341917
申请日：2001-03-19
Applicant: LUCENT TECHNOLOGIES INC
Inventor： CHANG KIRK K , EJZAK RICHARD PAUL , LUO WEI , NANDA SANJIV , BALACHANDRAN KRISHNA
Abstract: Unlike earlier methods and systems in which Radio Link Control (RLC) performance was characterized in terms of the throughput, and the size of th e higher layer Protocol Data Units (PDUs) or packets to be transferred was ignored, a method and apparatus is provided that is based on the delay of a higher layer PDU o r packet. A method and apparatus so based have less delay than a method and apparatus based on employing adaptive coding and modulation to achieve the greatest mean throughput of a data block.
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Patent Agency Ranking
公开(公告)号：AU9344601A
公开(公告)日：2002-05-30
申请号：AU9344601
申请日：2001-11-26
Applicant: LUCENT TECHNOLOGIES INC
Inventor： KHAN FAROOQ ULLAH , NANDA SANJIV
Abstract: Disclosed is an ARQ technique that efficiently utilizes channel resources while allowing for scheduling flexibility. The ARQ technique is an asynchronous parallel packet transmission technique which utilizes packet identifiers, sequence identifiers and user identifiers. The ARQ technique does not require a strict timing relationship to exist between parallel channels and physical layer frames because the identifiers would indicate to the user the user to whom a sub-packet is intended, the identity of the sub-packet and the sequence of the sub-packet.
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公开(公告)号：CA2316722A1
公开(公告)日：2001-03-07
申请号：CA2316722
申请日：2000-08-25
Applicant: LUCENT TECHNOLOGIES INC
Inventor： WEAVER CARL FRANCIS , NANDA SANJIV , REGE KIRAN M
Abstract: A method and apparatus to quickly adjust a targeted E b/N0 (270, 470) in a wireless communication system by using an effective E b/N0 (310, 510) for each frame. The E b/N0 distribution of a frame produces a certain frame error rate. Effective E b/N 0 (310, 510) is the E b/N0 that would produce the same frame error rate in a model channel, such as an additive white Gaussian noise (AWGN) channel. The effective E b/N0 (310, 510) for eac h frame is obtained and compared to a model targeted E b/N0 (250, 480). The E b/N0 for all of the power control groups in one frame compose the vector E b/N0 (300, 500). The effective E b/N0 (310, 510) for the frame is obtained by mapping a vector E b/N0 (300, 500) into a scalar. The model targeted E b/N0 (280, 480) is the E b/N0 value that produces a desired frame error rate in the model channel. The targeted E b/N0 (270, 280) is increased by one up step si ze when the effective E b/N0 (310, 510) is smaller than the model targeted E b/N0 (280, 480) and i s decreased by one down step size when the effective E b/N0 (310, 510) is larger than the model targeted E b/N0 (280, 480). E b/N0 (290, 490) are measured for each power control group in a frame . The wireless communication system includes a transmitter (400) to transmit a signal, a receiver (320) to receive the signal, and an outer control loop (250, 450) to adjust the targeted E b/N0 (270, 470) based on a comparison of the effective E b/N0 (310, 510) of the signal to th e model targeted E b/N0 (280, 480). Preferably, the outer control loop (250, 450) is implemented in software, although it can be implemented in hardware. Obtaining an effective E b/N0 (310, 510) for each time period allows quicker adjustments of the targeted E b/N0 (270, 470). Th is permits the targeted E b/N0 (270, 470) to be closer to an E b/N0 that produces a desired frame error rate, especially if the mobile is moving. This allows the transmitted power to be closer to the power needed to produce the desired frame error rate, permitting an increase in th e capacity of the wireless communication system while still maintaining an acceptable number o f errors.
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公开(公告)号：BR0003310A
公开(公告)日：2001-02-20
申请号：BR0003310
申请日：2000-06-06
Applicant: LUCENT TECHNOLOGIES INC
Inventor： KUMAR SARATH , NANDA SANJIV , RUBIN HARVEY , VITEBSKY STANLEY
Abstract: A back haul architecture effectively reduces the reactivation times for both forward-link and reverse-link data transmissions over CDMA wireless communications systems, by relying on packet-mode transmissions over the back haul between a frame selection/distribution (FSD) function and the appropriate base stations for both forward-link data and reverse-link data. In particular, for the forward direction, the FSD function transmits forward-link data only to one base station (i.e., the primary base station), which is solely responsible for controlling the forward-link air interface with the corresponding mobile unit. As such, the forward link always operates in simplex mode for data transmissions, independent of how many base stations are operating in soft handoff for the reverse link with the same mobile unit. For the reverse direction, each base station that receives frames of reverse-link data from the mobile unit, assigns a time tag to the frame, divides the frame into one or more data packets, assigns a different sequence number to each data packet, and transmits the data packets to the FSD function over the back haul, all without first synchronizing time with any other base station that is also operating in reverse-link soft hand-off with that mobile unit. The FSD function (or preferably the radio link protocol (RLP) function) is then responsible for selecting packets of reverse-link data for subsequent processing (e.g., transmission to the network end of the connection). By limiting forward-link data transmissions to simplex mode and using packet-mode transmissions for reverse-link data, the need to first synchronize timing between the various base stations is eliminated for both forward-link and reverse-link data transmissions. As a result, reactivation delays are greatly reduced.
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公开(公告)号：BR0003063A
公开(公告)日：2001-02-06
申请号：BR0003063
申请日：2000-05-10
Applicant: LUCENT TECHNOLOGIES INC
Inventor： KNISELY DOUGLAS N , NANDA SANJIV , KUMAR SARATH , KHAN FAROOQ ULLAH , MEDAPALLI KAMESWARA RAO
Abstract: A variable length sequence number is used to identify data units in a communication channel. The sequence number associated with the most recent data that has been received successfully and the sequence number expected with the next new data message to be received are examined to determine the minimum size sequence number necessary to unambiguously identify to the transmitter incorrectly received data that must be retransmitted in a later message. The receiver provides the transmitter with the sequence number associated with the last successfully received byte of data and the sequence number associated with the next expected byte of data. The receiver communicates this information to the transmitter using a NAK control message. The transmitter then uses the sequence number of the next byte of data to be transmitted and the information received in the control message from the receiver to determine the smallest number of bits necessary to represent the sequence numbers for both data transmissions and the retransmission of data that was not received properly by the receiver.
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公开(公告)号：AU3024700A
公开(公告)日：2000-11-16
申请号：AU3024700
申请日：2000-05-02
Applicant: LUCENT TECHNOLOGIES INC
Inventor： KHAN FAROOQ ULLAH , KNISELY DOUGLAS N , KUMAR SARATH , MEDAPALLI KAMESWARA RAO , NANDA SANJIV
Abstract: A variable length sequence number is used to identify data units in a communication channel. The sequence number associated with the most recent data that has been received successfully and the sequence number expected with the next new data message to be received are examined to determine the minimum size sequence number necessary to unambiguously identify to the transmitter incorrectly received data that must be retransmitted in a later message. The receiver provides the transmitter with the sequence number associated with the last successfully received byte of data and the sequence number associated with the next expected byte of data. The receiver communicates this information to the transmitter using a NAK control message. The transmitter then uses the sequence number of the next byte of data to be transmitted and the information received in the control message from the receiver to determine the smallest number of bits necessary to represent the sequence numbers for both data transmissions and the retransmission of data that was not received properly by the receiver.
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