### Abstract

This paper revisits an optimal rate and power allocation problem to maximize throughput in uplink CDMA singlecell packet data communications. First, we show that the widelyaccepted belief that an optimally selected rate always keeps a constant value of the resulting bit energy to the interference plus noise power spectral density ratio is not true in most practical CDMA packet transmission environments, where the packet size varies in proportion to the rate. Then, we derive the rate-dependent optimal bit energy-to-interference- noise power spectral density ratio, based on which we convert the original joint optimization problem of rate and power to an equivalent but simple power allocation problem. Finally, we derive an optimal power allocation strategy by applying the convex optimization theory. Through two instructive examples, we show that the optimality of the well-known bang bang power control, that is, each user (except at most one user) should either transmit his data at the maximum allowed power level or at the minimum required power level meeting the SINR requirement in order to maximize the system throughput, may or may not be true depending on the incorporated channel coding scheme.

Original language | English |
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Title of host publication | IEEE Wireless Communications and Networking Conference, WCNC |

DOIs | |

Publication status | Published - 2009 Sep 22 |

Event | 2009 IEEE Wireless Communications and Networking Conference, WCNC 2009 - Budapest, Hungary Duration: 2009 Apr 5 → 2009 Apr 8 |

### Other

Other | 2009 IEEE Wireless Communications and Networking Conference, WCNC 2009 |
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Country | Hungary |

City | Budapest |

Period | 09/4/5 → 09/4/8 |

### Fingerprint

### ASJC Scopus subject areas

- Engineering(all)

### Cite this

*IEEE Wireless Communications and Networking Conference, WCNC*[4917867] https://doi.org/10.1109/WCNC.2009.4917867

**Optimal rate and power allocation in uplink packet CDMA transmission.** / Kim, Byoung Hoon; Oh, Seong-Jun.

Research output: Chapter in Book/Report/Conference proceeding › Conference contribution

*IEEE Wireless Communications and Networking Conference, WCNC.*, 4917867, 2009 IEEE Wireless Communications and Networking Conference, WCNC 2009, Budapest, Hungary, 09/4/5. https://doi.org/10.1109/WCNC.2009.4917867

}

TY - GEN

T1 - Optimal rate and power allocation in uplink packet CDMA transmission

AU - Kim, Byoung Hoon

AU - Oh, Seong-Jun

PY - 2009/9/22

Y1 - 2009/9/22

N2 - This paper revisits an optimal rate and power allocation problem to maximize throughput in uplink CDMA singlecell packet data communications. First, we show that the widelyaccepted belief that an optimally selected rate always keeps a constant value of the resulting bit energy to the interference plus noise power spectral density ratio is not true in most practical CDMA packet transmission environments, where the packet size varies in proportion to the rate. Then, we derive the rate-dependent optimal bit energy-to-interference- noise power spectral density ratio, based on which we convert the original joint optimization problem of rate and power to an equivalent but simple power allocation problem. Finally, we derive an optimal power allocation strategy by applying the convex optimization theory. Through two instructive examples, we show that the optimality of the well-known bang bang power control, that is, each user (except at most one user) should either transmit his data at the maximum allowed power level or at the minimum required power level meeting the SINR requirement in order to maximize the system throughput, may or may not be true depending on the incorporated channel coding scheme.

AB - This paper revisits an optimal rate and power allocation problem to maximize throughput in uplink CDMA singlecell packet data communications. First, we show that the widelyaccepted belief that an optimally selected rate always keeps a constant value of the resulting bit energy to the interference plus noise power spectral density ratio is not true in most practical CDMA packet transmission environments, where the packet size varies in proportion to the rate. Then, we derive the rate-dependent optimal bit energy-to-interference- noise power spectral density ratio, based on which we convert the original joint optimization problem of rate and power to an equivalent but simple power allocation problem. Finally, we derive an optimal power allocation strategy by applying the convex optimization theory. Through two instructive examples, we show that the optimality of the well-known bang bang power control, that is, each user (except at most one user) should either transmit his data at the maximum allowed power level or at the minimum required power level meeting the SINR requirement in order to maximize the system throughput, may or may not be true depending on the incorporated channel coding scheme.

UR - http://www.scopus.com/inward/record.url?scp=70349191671&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=70349191671&partnerID=8YFLogxK

U2 - 10.1109/WCNC.2009.4917867

DO - 10.1109/WCNC.2009.4917867

M3 - Conference contribution

AN - SCOPUS:70349191671

SN - 9781424429486

BT - IEEE Wireless Communications and Networking Conference, WCNC

ER -