Showing papers by "Amitava Ghosh published in 1997"
Patent•
27 Aug 1997TL;DR: In this paper, a method for determining a subscriber unit location in a communication system including the steps of receiving a signal from the subscriber unit (1390) at a first base station, determining a first receive time of the signal based on a sequence of spreading symbols at the first base stations, determining the first angle of arrival of a signal at the second base station and determining the location of the SU from the first received time, the first arrival time, and further predetermined information about the first BS.
Abstract: A method for determining a subscriber unit location in a communication system including the steps of receiving a signal from the subscriber unit (1390) at a first base station, determining a first receive time of the signal based on a sequence of spreading symbols at the first base station, determining a first angle of arrival of the signal at the first base station, and determining the location of the subscriber unit from the first received time, the first angle of arrival, and further predetermined information about the first base station. The signal is formed via modulation by the sequence of spreading symbols.
217 citations
Patent•
24 Apr 1997TL;DR: In this article, a method and apparatus for determining the location of a communication unit in a CDMA system includes in a first embodiment, sending a location request via a spread spectrum signal to the subscriber (140), and receiving in return a subscriber signal including a response message showing a receive time of a particular symbol of the base's spreading sequence and a transmit time of the subscriber's transmission sequence.
Abstract: A method and apparatus for determining the location of a communication unit in a CDMA system includes in a first embodiment, sending a location request via a spread spectrum signal to the subscriber (140), and receiving in return a subscriber signal including a response message showing a receive time of a particular symbol of the base's spreading sequence and a transmit time of a particular symbol of the subscriber's spreading sequence. The base (130), along with other receiving base(s) (140), also receives a predetermined symbol of the subscriber spreading sequence, and each determines a respective receive time of the predetermined symbol. The received information is then processed, along with known base location and delay information, to determine the subscriber location. If insufficient number of bases are capable of communicating with the subscriber, for example due to high loading/interference, auxiliary bases (121) are also provided for receiving from or transmitting to the subscriber.
41 citations
Patent•
03 Jan 1997
TL;DR: In this paper, les groups of commande de puissance recus sont analyses and compares a plusieurs niveaux de seuil d'energies (73, 75, 77, 79, 80, 81).
Abstract: Un emetteur transmet le signal desire a l'aide d'un cycle de fonctionnement en continu a des vitesses de transmission inferieures a la pleine vitesse L'energie utilisee dans chaque groupe de commande de puissance est liee a la vitesse de transmission En repetant les groupes de commande de puissance, on obtient une diversite de division dans le temps Dans le recepteur, les groupes de commande de puissance recus sont analyses et compares a plusieurs niveaux de seuil d'energie (73, 75, 77, 79) Les resultats des comparaisons sont convertis en un signal de commande de puissance (74, 76, 78, 80, 81) puis sont retournes au poste mobile Les postes mobiles peuvent selectionner le bit adapte et regler leur puissance En option, un indicateur de la vitesse de transmission peut etre achemine en avance sur la trame Le recepteur compare une estimation de puissance avec le seuil pour la vitesse de transmission indiquee
2 citations
Patent•
02 Sep 1997
1 citations