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Reinaldo A Valenzuela - One of the best experts on this subject based on the ideXlab platform.

  • throughput optimal communication strategy for wireless random access channel
    Global Communications Conference, 2013
    Co-Authors: Harpreet S Dhillon, Howard Huang, Harish Viswanathan, Reinaldo A Valenzuela
    Abstract:

    We consider a wireless time-slotted random access channel where user arrivals are characterized by a Poisson process. Each user comes with a fixed payload, which has to be transmitted in the slot in which it arrives. If the transmission is successful, the user leaves the system, else it is dropped. The receiver and users are assumed to have knowledge of the arrival rate λ, but they are not aware of the actual number of users simultaneously attempting to communicate during a given time slot. In contrast to a conventional slotted ALOHA-based strategy where the channel is partitioned into orthogonal subchannels and each user communicates on a randomly chosen subchannel, we propose a novel strategy whereby users transmit simultaneously over the entire channel resource and the receiver jointly decodes the transmissions. Under the proposed strategy, neither users nor the receiver have prior knowledge of the active user set. Our analysis concretely demonstrates that the proposed strategy is optimal in terms of maximizing the average throughput among all uncoordinated strategies. Numerical results show that the proposal provides an order of magnitude throughput improvement compared to slotted ALOHA in a single-cell environment under a 10% maximum outage constraint.

  • GLOBECOM - Throughput optimal communication strategy for wireless random access channel
    2013 IEEE Global Communications Conference (GLOBECOM), 2013
    Co-Authors: Harpreet S Dhillon, Howard Huang, Harish Viswanathan, Reinaldo A Valenzuela
    Abstract:

    We consider a wireless time-slotted random access channel where user arrivals are characterized by a Poisson process. Each user comes with a fixed payload, which has to be transmitted in the slot in which it arrives. If the transmission is successful, the user leaves the system, else it is dropped. The receiver and users are assumed to have knowledge of the arrival rate λ, but they are not aware of the actual number of users simultaneously attempting to communicate during a given time slot. In contrast to a conventional slotted ALOHA-based strategy where the channel is partitioned into orthogonal subchannels and each user communicates on a randomly chosen subchannel, we propose a novel strategy whereby users transmit simultaneously over the entire channel resource and the receiver jointly decodes the transmissions. Under the proposed strategy, neither users nor the receiver have prior knowledge of the active user set. Our analysis concretely demonstrates that the proposed strategy is optimal in terms of maximizing the average throughput among all uncoordinated strategies. Numerical results show that the proposal provides an order of magnitude throughput improvement compared to slotted ALOHA in a single-cell environment under a 10% maximum outage constraint.

Yang Yang - One of the best experts on this subject based on the ideXlab platform.

  • analysis of power ramping schemes for utra fdd random access channel
    IEEE Transactions on Wireless Communications, 2005
    Co-Authors: Yang Yang
    Abstract:

    The random access channel (RACH) in a universal terrestrial radio access-frequency division duplex (UTRA-FDD) system is a contention-based channel mainly used to carry control information from mobile stations (MS) to base stations (BS). The transmission of a random access request contains two steps: preamble transmission and message transmission. In preamble transmission, the power ramping technique is used to favor the delayed preambles by stepping up the transmission power after each unsuccessful access. In doing so, the success of transmitting a long-delayed preamble is increased due to the power capture effect. This paper analyzes the blocking, throughput, and delay performance of preamble transmission under three power ramping schemes with fixed, linear, and geometric step sizes. The interference caused by different power ramping schemes is also compared.

  • Analysis of random access channel in UTRA-TDD on AWGN channel: Research Articles
    International Journal of Communication Systems, 2004
    Co-Authors: Yang Yang, Tak-shing Peter Yum
    Abstract:

    The random access channel (RACH) in UTRA-TDD systems is an uplink contention-based transport channel that is mainly used to carry control information from mobile stations to base stations. In this paper, we study the performance of RACH on an additive white Gaussian noise (AWGN) channel whereby successful transmission of a burst requires the spreading code chosen to be collision-free and the burst is error-free after convolutional decoding. Based on this model, the code-collision probability, the data bit error probability and the RACH channel capacity are derived. The random retransmission delay mechanism is not specified in UTRA-TDD. We therefore choose an access mechanism with binary exponential backoff delay procedure similar to that in IEEE 802.11. Based on that mechanism, the blocking probability and the first two moments of the delay are also derived. Compared with the mean, the standard deviation is found to be very high. Copyright © 2004 John Wiley & Sons, Ltd.

  • Analysis of random access channel in UTRA‐TDD on AWGN channel
    International Journal of Communication Systems, 2004
    Co-Authors: Yang Yang, Tak-shing Peter Yum
    Abstract:

    The random access channel (RACH) in UTRA-TDD systems is an uplink contention-based transport channel that is mainly used to carry control information from mobile stations to base stations. In this paper, we study the performance of RACH on an additive white Gaussian noise (AWGN) channel whereby successful transmission of a burst requires the spreading code chosen to be collision-free and the burst is error-free after convolutional decoding. Based on this model, the code-collision probability, the data bit error probability and the RACH channel capacity are derived. The random retransmission delay mechanism is not specified in UTRA-TDD. We therefore choose an access mechanism with binary exponential backoff delay procedure similar to that in IEEE 802.11. Based on that mechanism, the blocking probability and the first two moments of the delay are also derived. Compared with the mean, the standard deviation is found to be very high. Copyright © 2004 John Wiley & Sons, Ltd.

  • GLOBECOM - Analysis of power ramping schemes for UTRA-FDD random access channel
    IEEE Global Telecommunications Conference 2004. GLOBECOM '04., 1
    Co-Authors: Yang Yang, Tak-shing, Peter Yum
    Abstract:

    The random access channel (RACH) in a universal terrestrial radio access frequency division duplex (UTRA-FDD) system is a contention-based channel mainly used to carry control information from mobile stations to base stations. The transmission of a random access request contains two steps, preamble transmission and message transmission. In preamble transmission, a power ramping technique is used to favor the delayed preambles by stepping up the transmission power after each unsuccessful access. In doing so, the success of transmitting a long-delayed preamble is increased due to the power capture effect. We analyze the blocking and throughput performance of preamble transmission under three power ramping schemes with fixed, linear and geometric step sizes. Also, we compare the interference caused by different power ramping schemes.

H. Boujemaa - One of the best experts on this subject based on the ideXlab platform.

Harpreet S Dhillon - One of the best experts on this subject based on the ideXlab platform.

  • throughput optimal communication strategy for wireless random access channel
    Global Communications Conference, 2013
    Co-Authors: Harpreet S Dhillon, Howard Huang, Harish Viswanathan, Reinaldo A Valenzuela
    Abstract:

    We consider a wireless time-slotted random access channel where user arrivals are characterized by a Poisson process. Each user comes with a fixed payload, which has to be transmitted in the slot in which it arrives. If the transmission is successful, the user leaves the system, else it is dropped. The receiver and users are assumed to have knowledge of the arrival rate λ, but they are not aware of the actual number of users simultaneously attempting to communicate during a given time slot. In contrast to a conventional slotted ALOHA-based strategy where the channel is partitioned into orthogonal subchannels and each user communicates on a randomly chosen subchannel, we propose a novel strategy whereby users transmit simultaneously over the entire channel resource and the receiver jointly decodes the transmissions. Under the proposed strategy, neither users nor the receiver have prior knowledge of the active user set. Our analysis concretely demonstrates that the proposed strategy is optimal in terms of maximizing the average throughput among all uncoordinated strategies. Numerical results show that the proposal provides an order of magnitude throughput improvement compared to slotted ALOHA in a single-cell environment under a 10% maximum outage constraint.

  • GLOBECOM - Throughput optimal communication strategy for wireless random access channel
    2013 IEEE Global Communications Conference (GLOBECOM), 2013
    Co-Authors: Harpreet S Dhillon, Howard Huang, Harish Viswanathan, Reinaldo A Valenzuela
    Abstract:

    We consider a wireless time-slotted random access channel where user arrivals are characterized by a Poisson process. Each user comes with a fixed payload, which has to be transmitted in the slot in which it arrives. If the transmission is successful, the user leaves the system, else it is dropped. The receiver and users are assumed to have knowledge of the arrival rate λ, but they are not aware of the actual number of users simultaneously attempting to communicate during a given time slot. In contrast to a conventional slotted ALOHA-based strategy where the channel is partitioned into orthogonal subchannels and each user communicates on a randomly chosen subchannel, we propose a novel strategy whereby users transmit simultaneously over the entire channel resource and the receiver jointly decodes the transmissions. Under the proposed strategy, neither users nor the receiver have prior knowledge of the active user set. Our analysis concretely demonstrates that the proposed strategy is optimal in terms of maximizing the average throughput among all uncoordinated strategies. Numerical results show that the proposal provides an order of magnitude throughput improvement compared to slotted ALOHA in a single-cell environment under a 10% maximum outage constraint.

M. Siala - One of the best experts on this subject based on the ideXlab platform.