-
1.发明申请METHODS AND APPARATUS FOR PROVIDING ROBUST SYNCHRONIZATION OF RADIO TRANSCEIVERS 审中-公开用于提供无线电收发机的稳健同步的方法和设备
公开(公告)号：WO0011831A3
公开(公告)日：2000-07-06
申请号：PCT/SE9901384
申请日：1999-08-17
Applicant: ERICSSON TELEFON AB L M
Inventor： MATTISSON SVEN , HAARTSEN JAAP , PERSSON JOAKIM
CPC classification number: H04L7/041 , H04L7/046 , H04L25/062 , H04L27/142
Abstract: Methods and apparatus for performing synchronization and DC-offset compensation in FM transmission systems significantly reduce the overhead associated with transmitting a conventional digital preamble at the start of each of a succession of transmitted digital data packets. According to exemplary embodiments, a multi-part digital preamble includes a short, substantially DC-free leading part followed by a code-protected synchronization part which is not necessarily substantially DC-free. The leading part provides for coarse DC offset estimation and synchronization, while the coded synchronization part carries timing and/or other useful information which can be unique for each packet. One or more substantially DC-free trailing parts follow the synchronization part, or are included in the synchronization part itself, and provide for fine tuning of the DC-offset estimate. Since the substantially DC-free leading and trailing parts are extremely short, and since the synchronization part carries useful information, the overhead associated with a preamble according to the invention is significantly reduced as compared to a conventional, entirely DC-free, preamble.
Abstract translation: 用于在FM传输系统中执行同步和DC偏移补偿的方法和设备显着减少了与在传输的数字数据分组的每个开始处传输常规数字前导码相关的开销。 根据示例性实施例，多部分数字前导码包括短的，基本上无DC的前导部分，后面跟着代码保护的同步部分，该部分不一定基本上不含DC。 引导部分提供粗略的DC偏移估计和同步，而编码的同步部分携带对每个分组可能唯一的定时和/或其他有用信息。 一个或多个基本上无DC的尾随部分跟随同步部分，或者包括在同步部分本身中，并且提供DC偏移估计的微调。 由于基本无DC的前导和尾随部分非常短，并且由于同步部分携带有用信息，所以与传统的，完全无DC的前导码相比，与根据本发明的前导码相关联的开销显着降低。
-
公开(公告)号：DE69930612D1
公开(公告)日：2006-05-18
申请号：DE69930612
申请日：1999-01-12
Applicant: ERICSSON TELEFON AB L M
Inventor： ELG JOHANNES , HAARTSEN JAAP
IPC: H04B7/24 , H04B1/713 , H04L12/28 , H04L12/56 , H04W8/26 , H04W52/02 , H04W68/00 , H04W74/06 , H04W84/18
Abstract: A system comprises a wireless master unit and one or more wireless slave units, each having a unique identifier. When a wireless slave unit is active, it is addressed by one of a limited number of temporary addresses. A PARK mode enables a wireless slave unit to be in an idle state during which its temporary address is deallocated, enabling that address to be assigned to another wireless slave unit. To page a parked slave, a paging beacon packet is broadcast to, and received by, each of the wireless slave units at fixed intervals during a master-to-slave time slot. Each wireless slave unit determines whether the received paging beacon packet includes its unique identifier. If so, the wireless slave unit retrieves a temporary address from the paging beacon packet. The wireless unit transmits a response to the wireless master unit during a subsequent slave-to-master time slot if the received paging beacon packet included the unique identifier belonging to the wireless slave unit. Parked wireless slave units are also assigned a unique response number by the master. The master broadcasts a polling beacon packet during a master-to-slave time slot. If the parked slave unit desires access to the channel, it transmits a response in an N:th slave-to-master time slot following the polling beacon packet where N is a function of the slave's unique response number.
-
公开(公告)号：AT292862T
公开(公告)日：2005-04-15
申请号：AT00927201
申请日：2000-05-12
Applicant: ERICSSON TELEFON AB L M
Inventor： HAARTSEN JAAP
Abstract: A method and apparatus for radio communications which uses frequency and time diversity oriented spread spectrum modulation includes adding an additional link depending on interference characteristics. A plurality of data packets may be communicated from a transmitter to a receiver where a first radio link is established by reserving a series of time slots. The radio link, for example, may be one out of every n time slots, where n>1. A second radio link may further be established on a different one out of every n time slots such that each of the plurality of data packets is transmitted over both the first and second radio links resulting in diversity such that the receiver receives each of the data packets twice. Each radio link uses a frequency hopping channel and for each data packet, transmission over the first link occurs on a different frequency than is used for transmission over the second link. The second link may be established in response to detection by the receiver of reception quality problems associated with the first link. Accordingly, the second link may be terminated in response to detection by the receiver of an absence of reception quality problems associated with the first link.
-
公开(公告)号：DE69910046D1
公开(公告)日：2003-09-04
申请号：DE69910046
申请日：1999-09-14
Applicant: ERICSSON TELEFON AB L M
Inventor： MATTISSON SVEN , HAARTSEN JAAP
Abstract: Transmission power in a frequency-hopping radio system that transmits packets from a sending radio unit to a receiving radio unit, wherein each packet includes an address designating the receiving radio unit, is controlled by measuring received signal strength of packets whose addresses were successfully received in the receiving radio unit, regardless of whether other portions of the respective packets were successfully received. An average signal strength value is generated from the received signal strength measurements. The mathematical difference between the average signal strength value and a target value associated with the receiving radio unit is then determined and used as a basis for deciding whether to send a power control message from the receiving radio unit to the sending radio unit. In order to provide a hysteresis in the power control process, a power control message is sent from the receiving radio unit to the sending radio unit if the mathematical difference is greater than a first decision boundary, or if the mathematical difference is less than a second decision boundary. The power control message may itself include the mathematical difference which, when received by the sending radio unit, is used as a basis for determining a transmission power level adjustment amount. The target value, against which the average signal strength value is compared, may be based on the receiver sensitivity adjusted to account for implementation losses and other inaccuracies.
-
公开(公告)号：EE200000427A
公开(公告)日：2001-12-17
申请号：EEP200000427
申请日：1999-01-12
Applicant: ERICSSON TELEFON AB L M
Inventor： ELG JOHANNES , HAARTSEN JAAP
IPC: H04B7/24 , H04B1/713 , H04L12/28 , H04L12/56 , H04W8/26 , H04W52/02 , H04W68/00 , H04W74/06 , H04W84/18 , H04Q7/22
Abstract: A system comprises a wireless master unit and one or more wireless slave units, each having a unique identifier. When a wireless slave unit is active, it is addressed by one of a limited number of temporary addresses. A PARK mode enables a wireless slave unit to be in an idle state during which its temporary address is deallocated, enabling that address to be assigned to another wireless slave unit. To page a parked slave, a paging beacon packet is broadcast to, and received by, each of the wireless slave units at fixed intervals during a master-to-slave time slot. Each wireless slave unit determines whether the received paging beacon packet includes its unique identifier. If so, the wireless slave unit retrieves a temporary address from the paging beacon packet. The wireless unit transmits a response to the wireless master unit during a subsequent slave-to-master time slot if the received paging beacon packet included the unique identifier belonging to the wireless slave unit. Parked wireless slave units are also assigned a unique response number by the master. The master broadcasts a polling beacon packet during a master-to-slave time slot. If the parked slave unit desires access to the channel, it transmits a response in an N:th slave-to-master time slot following the polling beacon packet where N is a function of the slave's unique response number.
-
Patent Agency Ranking
公开(公告)号：AU4292900A
公开(公告)日：2000-11-14
申请号：AU4292900
申请日：2000-04-10
Applicant: ERICSSON TELEFON AB L M
Inventor： HAARTSEN JAAP
IPC: H04B1/713 , H04B1/7156 , H04B7/26 , H04W48/08 , H04W56/00
Abstract: An uncoordinated frequency hopping cellular system includes a mobile unit and a number of base stations. The mobile unit determines information pertaining to a set of base stations that are within a geographical region defined by a location of the mobile unit, and supplies, to at least one of the base stations in the set, the information pertaining to at least one other base station in the set. The information may include address information corresponding to the set of base stations, and may include clock offset information representing a difference between a clock value associated with at least one of the other base stations in the set. As different mobile units supply information to the base station, the base station accumulates information about other base stations in the system. The base station supplies this accumulated information to mobile units, so that they may readily have information (e.g. address and/or synchronisation information) for more readily establishing communication with base stations that they have not yet encountered.
-
公开(公告)号：SE9800938L
公开(公告)日：1999-09-21
申请号：SE9800938
申请日：1998-03-20
Applicant: ERICSSON TELEFON AB L M
Inventor： HAARTSEN JAAP , MATTISSON SVEN
Abstract: A short-range radio transmitter of a communication device comprising a short-range radio and a long-range radio is controlled to delay packets which are scheduled to be transmitted at the same time as a long-range transmitter of the long-range radio commences or discontinues to transmit. A frequency synthesizer of the short-range radio is thereby not affected by a change in the power supply voltage which otherwise occurs at these moments due to transmission with high power by the long-range transmitter.
-
公开(公告)号：DE69942922D1
公开(公告)日：2010-12-16
申请号：DE69942922
申请日：1999-01-12
Applicant: ERICSSON TELEFON AB L M
Inventor： ELG JOHANNES , HAARTSEN JAAP
-
公开(公告)号：AT364940T
公开(公告)日：2007-07-15
申请号：AT99943582
申请日：1999-08-17
Applicant: ERICSSON TELEFON AB L M
Inventor： MATTISSON SVEN , HAARTSEN JAAP , PERSSON JOAKIM
Abstract: Methods and apparatus for performing synchronization and DC-offset compensation in FM transmission systems significantly reduce the overhead associated with transmitting a conventional digital preamble at the start of each of a succession of transmitted digital data packets. According to exemplary embodiments, a multi-part digital preamble includes a short, substantially DC-free leading part followed by a code-protected synchronization part which is not necessarily substantially DC-free. The leading part provides for coarse DC offset estimation and synchronization, while the coded synchronization part carries timing and/or other useful information which can be unique for each packet. One or more substantially DC-free trailing parts follow the synchronization part, or are included in the synchronization part itself, and provide for fine tuning of the DC-offset estimate. Since the substantially DC-free leading and trailing parts are extremely short, and since the synchronization part carries useful information, the overhead associated with a preamble according to the invention is significantly reduced as compared to a conventional, entirely DC-free, preamble.
-
-
-
-
-
-
-
-
-
Search Results
62
records
(took 0.027 seconds)
