摘要:
It is the object of the invention to make available a method of transferring user data packets from a terminal to a mainframe of an S-CDMA point-to-multipoint system, in which the data transfer is optimized. The method includes the steps of a repeated transmission of reference data packets coded with pilot codes for the duration of the connections between terminals and a mainframe, wherein the reference data packets contain previously known information, and the transmission of user data packets coded with communication codes include the user information to be transferred. In a preferred embodiment of the invention the user data packets are coded synchronously in time to the reference data packets, superimposed on these, and then modulated. Each terminal is allocated a pilot code, and at least one communication code.
摘要:
A synchronization procedure for a multipoint-to-point CDMA network (2), which minimizes the influence on the information transmission. Instead of interleaving communications and synchronization signals timewise, a simultaneous emission is proposed, in which the synchronization signals are superimposed on the communications signals. The synchronization signals are coded with a special synchronization code (6), which does not correspond to the CDMA communications code of the information signals, e.g Barker code. In addition, the synchronization signals are sent at a lower amplitude compared with the communications signals. The synchronization signals are also modulated (7) prior to sending, in particular using alternating multiplication by +1 and −1. On the receiving side (3), the synchronization signals are detected by demodulation (12; 15), correlation (13; 16) and subsequent accumulation. The transmission capacity for the communications signals is maximized by this procedure and the influence of the synchronization signals on the communications signals minimized.
摘要:
The present invention relates to a method for reducing interference in the downlink direction of a cellular radio communication system comprising base stations communicating with terminals using a frame structure showing a time and frequency extension, said frame comprising a preamble portion and at least one data portion, said terminals being adapted to receive frames for which the receive power of said at least one data portion is varying in a predefined range relative to the receive preamble power of said preamble portion,According to the present invention, the method comprises the steps of: transmitting the part of said data portion destined to said terminal with a transmit power adapted to generate a first receive power (Plow) at said terminal within said range if said terminal belongs to a first group of terminals; transmitting the part of said data portion destined to said terminal with a transmit power adapted to generate a second receive power(Phigh) at said terminal within said range, said second receive power being higher than said first receive power, if said terminal belongs to a second group of terminals.
摘要:
A master clock signal generated at the center (1) of a bidirectional point-to-multipoint network is transmitted in the form of time stamps in an MPEG-2 data format over the downstream channel of the network to a plurality of transmitting/receiving facilities (3). Each transmitting/receiving facility (3) derives the clock signal for the upstream channel from the master clock signal and a local clock signal generated by a reference clock (12). The center (1) compares the clock signal from each transmitting/receiving facility with the master clock signal and derives from the result of this comparison digital phase correction information individual to each transmitting/receiving facility (3), which it transmits to the respective transmitting/receiving facility (3) in the MPEG-2 data stream. The respective transmitting/receiving facility (3) uses the phase correction information to control the clock signal for the upstream channel in a numerically controlled oscillator (13).
摘要:
The invention relates to a multicarrier mobile device comprising a receiver (101) for receiving a first multicarrier signal being associated with a first communication cell and a second multicarrier signal being associated with a second communication cell, an extractor (103) for extracting a first signal portion from the first multicarrier signal and for extracting a second signal portion from the second multicarrier signal and a processor (105) for determining a first interference power on the first signal portion and the second interference power on the second signal portion.
摘要:
The present invention relates to a method for reducing interference in the downlink direction of a cellular radio communication system comprising base stations communicating with terminals using a frame structure showing a time and frequency extension, said frame comprising a preamble portion and at least one data portion, said terminals being adapted to receive frames for which the receive power of said at least one data portion is varying in a predefined range relative to the receive preamble power of said preamble portion,According to the present invention, the method comprises the steps of: transmitting the part of said data portion destined to said terminal with a transmit power adapted to generate a first receive power (Plow) at said terminal within said range if said terminal belongs to a first group of terminals; transmitting the part of said data portion destined to said terminal with a transmit power adapted to generate a second receive power (Phigh) at said terminal within said range, said second receive power being higher than said first receive power, if said terminal belongs to a second group of terminals.