TDMA/FDMA/CDMA hybrid radio access methods

• US 5,566,168 A
• Filed: 06/07/1995
• Issued: 10/15/1996
• Est. Priority Date: 01/11/1994
• Status: Expired due to Term

• Current Assignee: Ericsson GE Mobile Communications Inc (Telefonaktiebolaget LM Ericsson)
• Original Assignee: Ericsson GE Mobile Communications Inc (Telefonaktiebolaget LM Ericsson)
• Inventors: Dent, Paul W.
• Primary Examiner(s): MARCELO, MELVIN C
• Application Number:
  US08/475,303
• Time in Patent Office: 496 Days
• Field of Search: 370/50, 370/75, 370/95.1, 370/95.3, 370/97, 370/104.1, 370/18, 455/12.1, 455/13.1, 455/13.3, 455/13.4, 455/33.1, 455/33.3
• US Class Current: 370/323
• CPC Class Codes: H04B 7/18532 Arrangements for managing transmission, i.e. for transporting data or a signalling message
• CPC Class Codes: H04B 7/18539 Arrangements for managing radio, resources, i.e. for establishing or releasing a connection

Abstract

A radio access method for facilitating communication between at least one first station and a plurality of second stations is disclosed. First, each signal intended for transmission is buffered at a first station. The signals are then divided into equal length segments. The signal segments intended for a particular one of the second stations is transmitted using a corresponding time slot in a regularly repeating time multiplex frame. The signal segments transmitted by the first station are received at at least one of the second stations and the signal segments are assembled from successive corresponding time slots to reconstruct said intended signal. A transmit frequency channel uniquely associated with the corresponding receive time slot is determined at the second station. Finally, a signal intended for transmission to the first station is buffered in the second station and compressed for transmission using the transmit frequency channel during substantially the entire time period that the second station is not receiving.

Claims

1. A communication system for providing telephone communications between a number of outstations in a subscriber and a public switched telephone network comprising at least one orbiting satellite and at least one hubstation in communication with said satellite and said public switched telephone network comprising:

at least one orbiting satellite in communication with at least one of said outstations and said hubstation, said satellite including;

multiple beam antenna means for illuminating different areas on the earth with signals to be transmitted from said satellite to said outstations;

multiple transmitter means for generating said transmit signals associated with respective beams of said multiple beam antenna means; and

multiple receiver means for receiving signals from said hubstation to be retransmitted by said multiple transmitter means and respective beams of said multiple beam antenna;

at least one hubstation in communication with at least one orbiting satellite, comprising;

multiple multiplexed means for multiplexing signals intended for retransmission from said satellite using a particular beam of said multiple beam antenna into respective active time slots of a corresponding time division multiplex frame also including inactive time slots to produce corresponding TDM signals;

multiple transmitter means in radio communication respectively with said multiple satellite receiver means for transmitting said corresponding TDM signals such that each TDM signal is retransmitted from a corresponding one of said multiple satellite antenna beams; and

time slot allocating means to allocate said active time slots in each beam so that they coincide with inactive time slots in neighboring beams.

2. A satellite communication system according to claim 1, wherein said satellite multiple transmitter means comprise saturated travelling wave tubes.

3. A satellite communication system according to claim 1, wherein said satellite multiple transmitter means comprise class C transmit power amplifiers operated at maximum efficiency.

4. A satellite communication system according to claim 3, wherein said transmit power amplifiers are powered down to a low current during inactive or unallocated time slots of the respective TDM signals.

5. A satellite communication system according to claim 4, wherein said active time slots of any TDM signal are packed together to occupy adjacent time slots in a subframe period being a portion of said TDM frame period and said inactive time slots form the rest of said TDM frame period.

6. A satellite communication system according to claim 5, wherein said subframe of any one TDM signal retransmitted in one of said multiple satellite antenna beams does not overlap the subframes of the TDM signals transmitted in the neighboring beams.

7. A communication satellite system for providing telephone communications between a number of outstations and a subscriber in a public switched telephone network comprising at least one orbiting satellite and at least one ground control station in communication with said satellite and the public switched telephone network, comprising:

at least one orbiting satellite in communication with at least one of said outstations and said control station, said satellite comprising;

multiple beam antenna means for receiving uplink signals from groups of said outstations located in respective regions of the earth and transmitting corresponding downlink signals to said outstations;

first multiple receiver means each associated with one of said multiple antenna beams for receiving said uplink signals;

first multiple transmitter means coupled to said first multiple receiver means for relaying said received signals to said control station;

second multiple receiver means for receiving time division multiplex signals from said control station; and

second multiple transmitter means each associated with one of said multiple antenna beams and coupled to said second multiple receiver means for relaying said TDM signal to said outstation;

at least one control station in communication with said at least one orbiting satellite, comprising;

multiple receiver means for receiving said relayed uplink signals from said satellite;

multiple transmitter means for transmitting time division multiplex signals to said satellite for retransmission by said satellite to said outstations in corresponding downlink satellite antenna beams; and

time slot and frequency allocating means to associate uplink channel frequencies used by said outstations for transmitting with downlink time slots used by said outstations for receiving such that allocated downlink time slots and associated uplink frequencies in one of said multiple antenna beams correspond to unallocated time slots and frequencies in neighboring beams.