Ray Nettleton - Profile on Academia.edu (original) (raw)

Papers by Ray Nettleton

Signal f rocessing For Magnetic Recording

Addressing and Modulation for Frequency-Hopping Multiple Access

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.

Demodulator unit for spread spectrum apparatus utilized in a cellular mobile communication system

Spectral Efficiency in Cellular Land-Mobile Communications: A Spread-Spectrum Approach

Spread spectrum principles for multiple-access systems

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

This paper describes the basic characteristics of the SIP protocol and especially its extension m... more This paper describes the basic characteristics of the SIP protocol and especially its extension mechanism. Several Internet draft specifications are studied in order to get an overall picture of the maturity of the protocol. Some interesting application areas are examined for demonstrating how the SIP protocol suite can be used in a wider context.

Downstream power control for a spread spectrum cellular mobile radio system

Proc. IEEE Globecom, 1982

Demodulator unit for spread spectrum apparatus utilized in a cellular mobile communication system

IEEE Spectrum, 1983

St can greatly expand mobile communications, but some technical and regulatory issues remain unso... more St can greatly expand mobile communications, but some technical and regulatory issues remain unsolved The mobile telephone* used by subscribers in cars or trucks, is a liluitcd Service iii ilie Uniieri $is«îç* ai pitSziH. Eve;: U l^i&C City iike New York has only 7ÔÛ users, and spectral overcrowding has prohibited expansion of the service. But a new technology, cellular mobile radio telecommunications, is about to change this situation radically. With cellular technology, several hundred thousand users can be offered better service than is now available for hundreds. The Federal Communications Commission's decision last year to accept applications for cellular system licenses, which culminated many years of study, has set off a scramble for licenses among dozens of companies in the United States. A major controversy has broken out over the agency's decision to assign half the spectrum being made available for cellular systems to local telephone companies [see "The scramble for cellular radio licenses," p. 33]-competitors to the local phone companies say they can offer the cellular mobile phone service more cheaply. At the same time the type of radio transmission that can best make use of the cellular concept also remains in dispute. While narrowband frequency-modulation systems, the dominant type in mobile communications today, seem likely to be used initially, other modulation techniques may in the end prove superior. Single-sideband amplitude modulation, narrowband digital modulation, and spread-spectrum modulation have advantages over narrowband FM. While narrowband digital modulation and single-sideband AM have been used for quite some time in other civil applications, spread-spectrum faces its own particular regulatory hurdles; it has been used almost solely for military purposes in the past, with only a handful of specialized or experimental uses in the private sector [see "Spread-spectrum regulations taking shape," p. 35]. How these issues are resolved will have a large impact on all land mobile communication systems, for the cellular concept is valid not only for telephone communications, but also for licensed radio links that now serve thousands of users in the country, from police and fire departments to taxi, bus, and truck operators. At the outset, however, the Government is limiting cellular applications to common-carrier mobile telephone communications. To date, cellular systems have been implemented only on an experimental scale in Chicago, with the AT&T Advanced Mobile Phone System. But construction permits have been granted for cellular systems in a number of cities, including Chicago, New York, Boston, and Philadelphia, and initial service could begin before the end of this year. Currently, the majority of permits George R. Cooper Purdue University Ray W. Nettleton Michigan State University have been granted to local telephone companies; permits for two Systems have oeen granted in only two markets.

Probability of error performance of the spread-spectrum mobile communications receiver in a non-Rayleigh fading environment

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

Spread spectrum apparatus for cellular mobile communication systems

Self-organizing channel assignment for wireless systems

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

A high capacity assignment method for cellular mobile telephone systems

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

REACH: a high-performance wireless base station front end

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.

Traffic statistics in a self-organizing cellular telephone system

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

Power control for a spread spectrum cellular mobile radio system

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.

A spread-spectrum technique for high-capacity mobile communications

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 ...

Probability of error performance of the spread-spectrum mobile communications receiver in a non-Rayleigh fading environment

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 effects of the fading distribution on the performance of the Spread-Spectrum receiver. The Spread-Spectrum systems uses transmitter power control to counter the effects of shadow fading in the mobile to base station channel. This study is thus confined to the effects of deviations from the Rayleigh fading assumption. The effects of the distribution of the median are not considered at this time. The design of the signal set used in the spread-spectrum system incorporates inherent diversity into the operation of the receiver. Loose bounds on the probability of error can be set by considering the cases of flat fading over the entire spread-spectrum signal, and independent fading of each component of the spread-spect rural signal. The results of Monte-Carlo computer simulations show that fading distributions that are the result of dominant specular reflections cause deleterious probability of error performance. The result of Jao and Elbaum [7] for single pulse detection in non-Rayteigh fading channels provides the motivation and the genesis for the work presented here.

Signal f rocessing For Magnetic Recording

Addressing and Modulation for Frequency-Hopping Multiple Access

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.

Demodulator unit for spread spectrum apparatus utilized in a cellular mobile communication system

Spectral Efficiency in Cellular Land-Mobile Communications: A Spread-Spectrum Approach

Spread spectrum principles for multiple-access systems

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

This paper describes the basic characteristics of the SIP protocol and especially its extension m... more This paper describes the basic characteristics of the SIP protocol and especially its extension mechanism. Several Internet draft specifications are studied in order to get an overall picture of the maturity of the protocol. Some interesting application areas are examined for demonstrating how the SIP protocol suite can be used in a wider context.

Downstream power control for a spread spectrum cellular mobile radio system

Proc. IEEE Globecom, 1982

Demodulator unit for spread spectrum apparatus utilized in a cellular mobile communication system

IEEE Spectrum, 1983

St can greatly expand mobile communications, but some technical and regulatory issues remain unso... more St can greatly expand mobile communications, but some technical and regulatory issues remain unsolved The mobile telephone* used by subscribers in cars or trucks, is a liluitcd Service iii ilie Uniieri $is«îç* ai pitSziH. Eve;: U l^i&C City iike New York has only 7ÔÛ users, and spectral overcrowding has prohibited expansion of the service. But a new technology, cellular mobile radio telecommunications, is about to change this situation radically. With cellular technology, several hundred thousand users can be offered better service than is now available for hundreds. The Federal Communications Commission's decision last year to accept applications for cellular system licenses, which culminated many years of study, has set off a scramble for licenses among dozens of companies in the United States. A major controversy has broken out over the agency's decision to assign half the spectrum being made available for cellular systems to local telephone companies [see "The scramble for cellular radio licenses," p. 33]-competitors to the local phone companies say they can offer the cellular mobile phone service more cheaply. At the same time the type of radio transmission that can best make use of the cellular concept also remains in dispute. While narrowband frequency-modulation systems, the dominant type in mobile communications today, seem likely to be used initially, other modulation techniques may in the end prove superior. Single-sideband amplitude modulation, narrowband digital modulation, and spread-spectrum modulation have advantages over narrowband FM. While narrowband digital modulation and single-sideband AM have been used for quite some time in other civil applications, spread-spectrum faces its own particular regulatory hurdles; it has been used almost solely for military purposes in the past, with only a handful of specialized or experimental uses in the private sector [see "Spread-spectrum regulations taking shape," p. 35]. How these issues are resolved will have a large impact on all land mobile communication systems, for the cellular concept is valid not only for telephone communications, but also for licensed radio links that now serve thousands of users in the country, from police and fire departments to taxi, bus, and truck operators. At the outset, however, the Government is limiting cellular applications to common-carrier mobile telephone communications. To date, cellular systems have been implemented only on an experimental scale in Chicago, with the AT&T Advanced Mobile Phone System. But construction permits have been granted for cellular systems in a number of cities, including Chicago, New York, Boston, and Philadelphia, and initial service could begin before the end of this year. Currently, the majority of permits George R. Cooper Purdue University Ray W. Nettleton Michigan State University have been granted to local telephone companies; permits for two Systems have oeen granted in only two markets.

Probability of error performance of the spread-spectrum mobile communications receiver in a non-Rayleigh fading environment

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

Spread spectrum apparatus for cellular mobile communication systems

Self-organizing channel assignment for wireless systems

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

A high capacity assignment method for cellular mobile telephone systems

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

REACH: a high-performance wireless base station front end

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.

Traffic statistics in a self-organizing cellular telephone system

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

Power control for a spread spectrum cellular mobile radio system

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.

A spread-spectrum technique for high-capacity mobile communications

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 ...

Probability of error performance of the spread-spectrum mobile communications receiver in a non-Rayleigh fading environment

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 effects of the fading distribution on the performance of the Spread-Spectrum receiver. The Spread-Spectrum systems uses transmitter power control to counter the effects of shadow fading in the mobile to base station channel. This study is thus confined to the effects of deviations from the Rayleigh fading assumption. The effects of the distribution of the median are not considered at this time. The design of the signal set used in the spread-spectrum system incorporates inherent diversity into the operation of the receiver. Loose bounds on the probability of error can be set by considering the cases of flat fading over the entire spread-spectrum signal, and independent fading of each component of the spread-spect rural signal. The results of Monte-Carlo computer simulations show that fading distributions that are the result of dominant specular reflections cause deleterious probability of error performance. The result of Jao and Elbaum [7] for single pulse detection in non-Rayteigh fading channels provides the motivation and the genesis for the work presented here.