초록 ▼

An improved AMPS cellular system where non-interfering digital communication channels are added to the existing analog or digital voice communications channels in the system by utilizing frequency space between channels made possible by the AMPS co-channel and adjacent channel frequency coordination

An improved AMPS cellular system where non-interfering digital communication channels are added to the existing analog or digital voice communications channels in the system by utilizing frequency space between channels made possible by the AMPS co-channel and adjacent channel frequency coordination procedures. Interference is prevented by reduction of power, selection of frequencies, proper modulation and demodulation techniques, and unique allocation to the channels in frequency and location. The system is also applicable in general to the insertion of narrow frequency bandwidth channels in any existing communications system using co-channel and adjacent channel frequency allocation strategies.

대표청구항 ▼

In an advanced mobile phone service system having a plurality of contiguous cells each with a cell site having a radio transceiver with voice and setup channels for communicating with mobile units within the cell, each of said standard voice and setup channels having a predetermined frequency bandwi

In an advanced mobile phone service system having a plurality of contiguous cells each with a cell site having a radio transceiver with voice and setup channels for communicating with mobile units within the cell, each of said standard voice and setup channels having a predetermined frequency bandwidth, a predetermined portion of said channels for each cell having alternate non-used channels between used channels to provide adequate adjacent channel separation while information is being transmitted on a used channel at a predetermined power level, a plurality of said cells being grouped in a cluster to provide a number of disjoint channel sets, such sets avoiding both adjacent channel and co-channel interference while providing for frequency re-use by geographical placement of cells in a cluster having adjacent channels in different cells with at least one intervening cell between them and channels of the same frequency separated by at least one intervening cell between them, characterized by additional data channels for carrying digital data, including means for transmitting said digital data to and from at least one field unit in a cell and said cell site, concurrently with information on a said used channel, each said additional channel having a frequency centered substantially midway between said used and unused channels of the same or adjacent cell and including means for transmitting on said additional channels at a power at least an order of magnitude lower than said predetermined power level and for controlling bandwidth spreading of said additional channels to prevent interference with adjacent used channels.