Methods and apparatus for mobile station to mobile station communications in a mobile satellite communication system

Claim 2

In a mobile satellite communications system, a method for providing communications via a communications satellite relay station between a first mobile station conditioned to transmit a first signal having a first TDMA signal format and a first bandwidth and a second mobile station conditioned to receive a second signal having a second TDMA signal format, the method comprising: receiving in the satellite relay station the first signal having the first TDMA signal format and the first bandwidth from the first mobile station; sampling the received first signal at a first rate to produce a first bitstream having a first number of samples per second; storing, in a buffer, the first bitstream; clocking out of the buffer the first bitstream at a second rate, which is different from the first rate, to produce a second bitstream having a second number of samples per second which is different from the first number of samples per second of the first bitstream, the samples in both the first and second bitstreams being representative of the received first signal; and transmitting from the satellite relay station to the second mobile station the second bitstream as the second signal using the second TDMA format at a second bandwidth which is different from the first bandwidth of the first signal.

Claim 3

The method of claim 1, wherein the number of time slots in the first TDMA format and the second TDMA format may be varied with different frames.

Claim 4

A method according to claim 1, wherein the second bitstream is multiplexed with Slow Associated Control Channel (SACCH) information to provide the second signal using the second TDMA format.

Claim 5

A method according to claim 3, wherein the SACCH information is provided to the satellite relay station by a ground station in the mobile satellite communications system.

Claim 6

A communications satellite relay station for providing communications between a first mobile station conditioned to transmit a first signal having a first TDMA format and a first bandwidth and a second mobile station conditioned to receive a second signal having a second TDMA format, the satellite relay station comprising: a receiver for receiving the first signal having the first TDMA signal format and the first bandwidth; an analog to digital converter for sampling the received first signal at a first rate to produce a first bitstream having a first number of samples per second; a buffer for receiving the first bitstream and clocking out the first bitstream at a second rate, which is different from the first rate, to produce a second bitstream having a second number of samples per second which is different from the first number of samples per second of the first bitstream, the samples in both the first and second bitstreams being representative of the received first signal; and a transmitter for transmitting the second bitstream as the second signal using the second TDMA format at a second bandwidth which is different from the first bandwidth of the first signal.

Claim 7

A communications satellite relay station for providing communications between a first mobile station conditioned to transmit a first signal having a first TDMA format and a first bandwidth and a second mobile station conditioned to receive a second signal having a second TDMA format, the satellite relay station comprising: a receiver for receiving the first signal having the first TDMA signal format and the first bandwidth; an analog to digital converter for sampling the received first signal at a first rate to produce a first bitstream having a first number of samples per second; a buffer for receiving the first bitstream and clocking out the first bitstream at a second rate, which is different from the first rate, to produce a second bitstream having a second number of samples per second which is different from the first number of samples per second of the first bitstream, the samples in both the first and second bitstreams being representative of the received first signal; and a transmitter for transmitting the second bitstream as the second signal using the second TDMA format at a second bandwidth which is different from the first bandwidth of the first signal.

Claim 8

The satellite relay station of claim 5, where said buffer is a shift register.

Claim 9

The satellite relay station of claim 5, where said second TDMA format is a GSM format.

Claim 10

A satellite relay station according to claim 5, wherein the second bitstream is multiplexed with Slow Associated Control Channel (SACCH) information to provide the second signal using the second TDMA format.

Claim 11

A satellite relay station according to claim 8, wherein the SACCH information is provided to the satellite relay station by a ground station in the mobile satellite communications system.

Claim 12

In a mobile satellite communications system, a method for providing communications via a communications satellite relay station between a first mobile station conditioned to transmit a first signal having a first TDMA format and a first bandwidth BW and a second mobile station conditioned to receive a second signal having a second TDMA format, the method comprising: receiving, in the satellite relay station the first signal having the first TDMA signal format and the first bandwidth BW from the first mobile station; downconverting the first signal to a first IF signal; sampling the first IF signal at a rate N×BW, where N is greater than or equal to 2, to produce a first bitstream having at least N×BW samples per second with the samples being representative of the received first signal; storing, in a buffer, the first bitstream; clocking out of the buffer the first bitstream at a rate M×N×BW, where M is greater than or equal to 2 to produce a second bitstream having at least M×N×BW samples per second with the samples being representative of the received first signal; filtering the second bitstream to produce a second IF signal; upconverting the second IF signal to produce an output signal; formatting the output signal into the second TDMA format to produce the second signal; and transmitting the second signal from the satellite relay station to the second mobile station.

Claim 13

In a mobile satellite communications system, a method for providing communications via a communications satellite relay station between a first mobile station conditioned to transmit a first signal having a first TDMA format and a first bandwidth BW and a second mobile station conditioned to receive a second signal having a second TDMA format, the method comprising: receiving, in the satellite relay station the first signal having the first TDMA signal format and the first bandwidth BW from the first mobile station; downconverting the first signal to a first IF signal; sampling the first IF signal at a rate N×BW, where N is greater than or equal to 2, to produce a first bitstream having at least N×BW samples per second with the samples being representative of the received first signal; storing, in a buffer, the first bitstream; clocking out of the buffer the first bitstream at a rate M×N×BW, where M is greater than or equal to 2 to produce a second bitstream having at least M×N×BW samples per second with the samples being representative of the received first signal; filtering the second bitstream to produce a second IF signal; upconverting the second IF signal to produce an output signal; formatting the output signal into the second TDMA format to produce the second signal; and transmitting the second signal from the satellite relay station to the second mobile station.

Claim 14

The method of claim 10, wherein the number of time slots in the first TDMA format and the second TDMA format may be varied with different frames.

Claim 15

The method of claim 10, wherein N, in the sampling rate of the first IF signal, is an integer.

Claim 16

The method of claim 10, wherein M, in the rate at which the first bitstream is clocked out of the buffer, is an integer.

Claim 17

A method according to claim 10, wherein the second bitstream is multiplexed with Slow Associated Control Channel (SACCH) information to provide the second signal using the second TDMA format.

Claim 18

A method according to claim 14, wherein the SACCH information is provided to the satellite relay station by a ground station in the mobile satellite communications system.

Claim 21

A method according to claim 16, wherein the stored signals are multiplexed with Slow Associated Control Channel (SACCH) information to provide the wideband time division multiple access format.

Claim 22

A method according to claim 17, wherein the SACCH information is provided to the satellite relay station by a ground station in the satellite communication system.

Claim 23

A satellite transponder for supporting calls between two mobile stations within a satellite communication system, comprising: receiving means for receiving signals being transmitted using a narrowband time division multiple access transmission format; means for sampling and digitizing said received signals; means for storing said sampled and digitized signals at a first rate; means for reading out said stored signals at a faster rate than said first rate and modulating said stored signals onto a downlink frequency to create a wideband time division multiple access transmission format; and transmitting means for transmitting said modulated signals to a second mobile station.

Claim 24

A satellite transponder for supporting calls between two mobile stations within a satellite communication system, comprising: receiving means for receiving signals being transmitted using a narrowband time division multiple access transmission format; means for sampling and digitizing said received signals; means for storing said sampled and digitized signals at a first rate; means for reading out said stored signals at a faster rate than said first rate and modulating said stored signals onto a downlink frequency to create a wideband time division multiple access transmission format; and transmitting means for transmitting said modulated signals to a second mobile station.

Claim 25

A satellite transponder according to claim 19, wherein the stored signals are multiplexed with Slow Associated Control Channel (SACCH) information to provide the wideband time division multiple access format.

Claim 26

A satellite transponder according to claim 20, wherein the SACCH information is provided to the satellite transponder by a ground station in the satellite communication system.

Claim 29

A method according to claim 22, wherein said other signals from said at least one ground station are Slow Associated Control Channel Information (SACCH) signals.

Claim 30

A method according to claim 23, wherein said SACCH signals are computed based upon the received narrowband signals relayed to said at least one ground station.

Claim 31

A method according to claim 23, wherein said SACCH signals control transmit timing at said mobile stations.

Claim 32

A communications satellite relay station for providing communications between a first mobile station conditioned to transmit a first signal having a first TDMA format and a second mobile station conditioned to receive a second signal having a second TDMA format, the satellite relay station comprising: a receiver for receiving the first signal having the first TDMA signal format and a first bandwidth BW and downconverting the first signal to a first IF signal; an analog to digital converter for sampling the first IF signal at a rate N×BW, where N is greater than or equal to 2 to produce a first bitstream having at least N×BW samples per second with the samples being representative of the received first signal; a buffer for receiving the first bitstream and clocking out the first bitstream at a rate M×N×BW, where M is greater than or equal to 2 to produce a second bitstream having at least M×N×BW samples per second with the samples being representative of the received first signal; a low pass filter for filtering the second bitstream to produce a second IF signal; an upconverter for upconverting the second IF signal to produce an upconverted output signal; and a transmitter for transmitting the upconverted output signal using the second TDMA format.

Claim 33

A communications satellite relay station for providing communications between a first mobile station conditioned to transmit a first signal having a first TDMA format and a second mobile station conditioned to receive a second signal having a second TDMA format, the satellite relay station comprising: a receiver for receiving the first signal having the first TDMA signal format and a first bandwidth BW and downconverting the first signal to a first IF signal; an analog to digital converter for sampling the first IF signal at a rate N×BW, where N is greater than or equal to 2 to produce a first bitstream having at least N×BW samples per second with the samples being representative of the received first signal; a buffer for receiving the first bitstream and clocking out the first bitstream at a rate M×N×BW, where M is greater than or equal to 2 to produce a second bitstream having at least M×N×BW samples per second with the samples being representative of the received first signal; a low pass filter for filtering the second bitstream to produce a second IF signal; an upconverter for upconverting the second IF signal to produce an upconverted output signal; and a transmitter for transmitting the upconverted output signal using the second TDMA format.

Claim 34

The satellite relay station of claim 26, where said buffer is a shift register.

Claim 35

The satellite relay station of claim 26, where said second TDMA format is a GSM format.

Claim 36

The satellite relay station of claim 26, wherein the number of time slots in the first TDMA format and the second TDMA format may be varied with different frames.

Claim 37

The satellite relay station of claim 26, wherein N, in the sampling rate of the first IF signal, is an integer.

Claim 38

The satellite relay station of claim 26, wherein M, in the rate at which the first bitstream is clocked out of the buffer, is an integer.

Claim 39

A satellite relay station according to claim 26, wherein the second bitstream is multiplexed with Slow Associated Control Channel (SACCH) information to provide the second signal using the second TDMA format.

Claim 40

A satellite relay station according to claim 32, wherein the SACCH information is provided to the satellite relay station by a ground station in the mobile satellite communications system.

Claim 41

A satellite transponder for supporting calls between two mobile stations within a satellite communication system, comprising: means for receiving narrow band time division multiple access (TDMA) signals from said mobile stations at a satellite relay station; means for relaying the received narrowband TDMA signals to at least one ground station; means for digitizing some of the received narrowband signals; means for time compressing said digitized signals; means for multiplexing said time compressed signals into a wideband TDMA downlink format along with other signals from said at least one ground station; and means for transmitting said multiplexed signals to one of said mobile stations.

Claim 42

A satellite transponder for supporting calls between two mobile stations within a satellite communication system, comprising: means for receiving narrow band time division multiple access (TDMA) signals from said mobile stations at a satellite relay station; means for relaying the received narrowband TDMA signals to at least one ground station; means for digitizing some of the received narrowband signals; means for time compressing said digitized signals; means for multiplexing said time compressed signals into a wideband TDMA downlink format along with other signals from said at least one ground station; and means for transmitting said multiplexed signals to one of said mobile stations.

Claim 43

A satellite transponder according to claim 34, wherein said other signals from said at least one ground station are Slow Associated Control Channel Information (SACCH) signals.

Claim 44

A satellite transponder according to claim 35, wherein said SACCH signals are computed based upon the received narrowband signals relayed to said at least one ground station.

Claim 45

A satellite transponder according to claim 35, wherein said SACCH signals control transmit timing at said mobile stations.