Ray Nettleton | University of Colorado, Boulder (original) (raw)
Papers by Ray Nettleton
MILCOM 1982 - IEEE Military Communications Conference - Progress in Spread Spectrum Communications, 1982
This paper describes the common structure of a large class of frequency-hopping multiple-access a... more This paper describes the common structure of a large class of frequency-hopping multiple-access address sequences of the so-called "one-coincidence" type. We show methods for expanding the address sets to great size without compromising performance, and compare frequency and phase modulation methods. We also describe methods for dealing with unsynchronizable signalling alphabets, which arise as a result of expanding the MFSK sets.
Canadian Domestic and International Satellite Communications Conference, 1984
Wireless Technologies and Services for Cellular and Personal Communication Services, 1996
The link budget determines the relationships between range, capacity and transmitted power for an... more The link budget determines the relationships between range, capacity and transmitted power for any wireless technology. In every case it is a key determinant of the system's performance from both an engineering and an economic point of view. Unfortunately, the new 1.9 GHz PCS systems will begin life with an inherent 7 dB disadvantage over the 800 MHz cellular due to propagation differences. Additionally, system wiring and electronics often degrade performance by a further 5 to 10 dB due to long coaxial runs and noisy front end amplification, both of which are harder issues to deal with at 1.9 GHz than at 800 MHz. SCT's REACHTM products address these shortcomings by packaging critical components--front end amplification, filtering, etc.--in a compact cryoelectronic package intended for mounting near the antennas of the base station. In a recent trial with Qualcomm in San Diego, this package improved the CDMA uplink budget by 6 dB--enough to halve the number of base stations that are needed in most areas. This paper examines the technical and economic ramifications of the REACHTM product.
Speech Processing for IP Networks
Proc. IEEE Globecom, 1982
29th IEEE Vehicular Technology Conference, 1979
In previous work to evaluate the probability of error performance of the spread-spectrum mobile c... more In previous work to evaluate the probability of error performance of the spread-spectrum mobile communications receiver the usual assumptions about the 900 MHz urban mobile channel were made [1], [2], [3], [4], [5]. These "usual assumptions" are that the highly frequency-selective fading has Rayleigh statistics with a slowly-changing, non-frequency-selective median, the median has log-normal characteristics [6]. This paper studies the
The authors believe that spread spectrum can substantially improve the spectral efficiency of a c... more The authors believe that spread spectrum can substantially improve the spectral efficiency of a cellular land-mobile radio system.
IEEE Communications Magazine, 1997
CDMA has many benefits compared to TDMA and FDMA systems mainly because it is inherently self org... more CDMA has many benefits compared to TDMA and FDMA systems mainly because it is inherently self organizing. This article shows how the benefits of self organization can be extended to TDMA and FDMA systems also, and describes the results of research conducted by the authors. Self-organizing channel assignment not only increases the capacity and improves the call quality, but also
The authors describe a channel assignment scheme for cellular mobile telephone systems in which a... more The authors describe a channel assignment scheme for cellular mobile telephone systems in which assignment is based on actual field strength measurements performed dynamically on the functioning system. The scheme involves no rigid partitioning of the channel set into geographic patterns, as in conventional systems. A mutual interference criterion is applied to ensure that satisfactory service is maintained throughout the system. The system provides capacity improvements ranging from 100% to 300% depending on the complexity of the implementation. It is implementable using any of the current or proposed modulation schemes
The link budget determines the relationships between range, capacity and transmitted power for an... more The link budget determines the relationships between range, capacity and transmitted power for any wireless technology. In every case it is a key determinant of the system's performance from both an engineering and an economic point of view. Unfortunately, the new 1.9 GHz PCS systems will begin life with an inherent 7 dB disadvantage over the 800 MHz cellular due to propagation differences. Additionally, system wiring and electronics often degrade performance by a further 5 to 10 dB due to long coaxial runs and noisy front end amplification, both of which are harder issues to deal with at 1.9 GHz than at 800 MHz. SCT's REACHTM products address these shortcomings by packaging critical components--front end amplification, filtering, etc.--in a compact cryoelectronic package intended for mounting near the antennas of the base station. In a recent trial with Qualcomm in San Diego, this package improved the CDMA uplink budget by 6 dB--enough to halve the number of base stations that are needed in most areas. This paper examines the technical and economic ramifications of the REACHTM product.
A novel family of techniques for assigning channels to calls in a cellular mobile telephone syste... more A novel family of techniques for assigning channels to calls in a cellular mobile telephone system based on real-time measurements of signal strength is introduced. A discussion of the behavior of the system using self-organizing techniques is presented. Results are presented for traffic distribution per channel, traffic distribution per cell site, mean time between handoffs, and mean signal-to-interference ratio. In each case, it is shown that the system behavior is progressive and degrades gracefully with increasing traffic; there is, for example, no threshold behavior in signal-to-interference ratio. This suggests that the concept can be introduced in stages as the traffic demand increases, without abrupt changes in system behavior
In two earlier papers (ICC'80 [3] and GLOBECOM'82 [6]) two power control schemes for spread spect... more In two earlier papers (ICC'80 [3] and GLOBECOM'82 [6]) two power control schemes for spread spectrum cellular land mobile radio have been described, one for the upstream (mobile to base) link and one for the downstream link. Here we compare the power control problem for the upstream and the downstream links and show that using simple algebra we can equalize the signal-to-interference ratio for each mobile in a given cell in both links and thereby increase the capacity by 30 to 100% compared with a system with no power control. We also show that the SIR values can be equalized system-wide for both link directions by means of a nontrivial eigenvalue problem, which results in a further capacity improvement of 10 to 15%. Denial statistics are also presented.
IEEE Transactions on Vehicular Technology, 1978
264 IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY, VOL. ... [4] EV Jull, Finite-Range gain of sector... more 264 IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY, VOL. ... [4] EV Jull, Finite-Range gain of sectoral and pyramidal horns, Electron. Lerr., vol. 6, pp. 680-681, Oct. 15,1970. ... 1 Harold E. Taggart (58-SM'78) received the BS degree in chemistry from the Uni-versity of ...
MILCOM 1982 - IEEE Military Communications Conference - Progress in Spread Spectrum Communications, 1982
This paper describes the common structure of a large class of frequency-hopping multiple-access a... more This paper describes the common structure of a large class of frequency-hopping multiple-access address sequences of the so-called "one-coincidence" type. We show methods for expanding the address sets to great size without compromising performance, and compare frequency and phase modulation methods. We also describe methods for dealing with unsynchronizable signalling alphabets, which arise as a result of expanding the MFSK sets.
Canadian Domestic and International Satellite Communications Conference, 1984
Wireless Technologies and Services for Cellular and Personal Communication Services, 1996
The link budget determines the relationships between range, capacity and transmitted power for an... more The link budget determines the relationships between range, capacity and transmitted power for any wireless technology. In every case it is a key determinant of the system's performance from both an engineering and an economic point of view. Unfortunately, the new 1.9 GHz PCS systems will begin life with an inherent 7 dB disadvantage over the 800 MHz cellular due to propagation differences. Additionally, system wiring and electronics often degrade performance by a further 5 to 10 dB due to long coaxial runs and noisy front end amplification, both of which are harder issues to deal with at 1.9 GHz than at 800 MHz. SCT's REACHTM products address these shortcomings by packaging critical components--front end amplification, filtering, etc.--in a compact cryoelectronic package intended for mounting near the antennas of the base station. In a recent trial with Qualcomm in San Diego, this package improved the CDMA uplink budget by 6 dB--enough to halve the number of base stations that are needed in most areas. This paper examines the technical and economic ramifications of the REACHTM product.
Speech Processing for IP Networks
Proc. IEEE Globecom, 1982
29th IEEE Vehicular Technology Conference, 1979
In previous work to evaluate the probability of error performance of the spread-spectrum mobile c... more In previous work to evaluate the probability of error performance of the spread-spectrum mobile communications receiver the usual assumptions about the 900 MHz urban mobile channel were made [1], [2], [3], [4], [5]. These "usual assumptions" are that the highly frequency-selective fading has Rayleigh statistics with a slowly-changing, non-frequency-selective median, the median has log-normal characteristics [6]. This paper studies the
The authors believe that spread spectrum can substantially improve the spectral efficiency of a c... more The authors believe that spread spectrum can substantially improve the spectral efficiency of a cellular land-mobile radio system.
IEEE Communications Magazine, 1997
CDMA has many benefits compared to TDMA and FDMA systems mainly because it is inherently self org... more CDMA has many benefits compared to TDMA and FDMA systems mainly because it is inherently self organizing. This article shows how the benefits of self organization can be extended to TDMA and FDMA systems also, and describes the results of research conducted by the authors. Self-organizing channel assignment not only increases the capacity and improves the call quality, but also
The authors describe a channel assignment scheme for cellular mobile telephone systems in which a... more The authors describe a channel assignment scheme for cellular mobile telephone systems in which assignment is based on actual field strength measurements performed dynamically on the functioning system. The scheme involves no rigid partitioning of the channel set into geographic patterns, as in conventional systems. A mutual interference criterion is applied to ensure that satisfactory service is maintained throughout the system. The system provides capacity improvements ranging from 100% to 300% depending on the complexity of the implementation. It is implementable using any of the current or proposed modulation schemes
The link budget determines the relationships between range, capacity and transmitted power for an... more The link budget determines the relationships between range, capacity and transmitted power for any wireless technology. In every case it is a key determinant of the system's performance from both an engineering and an economic point of view. Unfortunately, the new 1.9 GHz PCS systems will begin life with an inherent 7 dB disadvantage over the 800 MHz cellular due to propagation differences. Additionally, system wiring and electronics often degrade performance by a further 5 to 10 dB due to long coaxial runs and noisy front end amplification, both of which are harder issues to deal with at 1.9 GHz than at 800 MHz. SCT's REACHTM products address these shortcomings by packaging critical components--front end amplification, filtering, etc.--in a compact cryoelectronic package intended for mounting near the antennas of the base station. In a recent trial with Qualcomm in San Diego, this package improved the CDMA uplink budget by 6 dB--enough to halve the number of base stations that are needed in most areas. This paper examines the technical and economic ramifications of the REACHTM product.
A novel family of techniques for assigning channels to calls in a cellular mobile telephone syste... more A novel family of techniques for assigning channels to calls in a cellular mobile telephone system based on real-time measurements of signal strength is introduced. A discussion of the behavior of the system using self-organizing techniques is presented. Results are presented for traffic distribution per channel, traffic distribution per cell site, mean time between handoffs, and mean signal-to-interference ratio. In each case, it is shown that the system behavior is progressive and degrades gracefully with increasing traffic; there is, for example, no threshold behavior in signal-to-interference ratio. This suggests that the concept can be introduced in stages as the traffic demand increases, without abrupt changes in system behavior
In two earlier papers (ICC'80 [3] and GLOBECOM'82 [6]) two power control schemes for spread spect... more In two earlier papers (ICC'80 [3] and GLOBECOM'82 [6]) two power control schemes for spread spectrum cellular land mobile radio have been described, one for the upstream (mobile to base) link and one for the downstream link. Here we compare the power control problem for the upstream and the downstream links and show that using simple algebra we can equalize the signal-to-interference ratio for each mobile in a given cell in both links and thereby increase the capacity by 30 to 100% compared with a system with no power control. We also show that the SIR values can be equalized system-wide for both link directions by means of a nontrivial eigenvalue problem, which results in a further capacity improvement of 10 to 15%. Denial statistics are also presented.
IEEE Transactions on Vehicular Technology, 1978
264 IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY, VOL. ... [4] EV Jull, Finite-Range gain of sector... more 264 IEEE TRANSACTIONS ON VEHICULAR TECHNOLOGY, VOL. ... [4] EV Jull, Finite-Range gain of sectoral and pyramidal horns, Electron. Lerr., vol. 6, pp. 680-681, Oct. 15,1970. ... 1 Harold E. Taggart (58-SM'78) received the BS degree in chemistry from the Uni-versity of ...