Multiple access wireless communications using a non-gaussian manifold
A method and apparatus for multiple-access wireless transmission is disclosed. The method involves mapping a plurality of signals onto a multi-dimensional non-Gaussian source manifold, the plurality of signals including signals targeted for transmission to a plurality of receivers. The method also involves transforming the source manifold into a multi-dimensional target manifold using a polarization stream network. The method further involves generating a multiple-access transmission waveform for transmission to the plurality of receivers, the multiple-access transmission waveform being based on the target manifold.
1. A method for multiple-access wireless transmission, the method comprising:
mapping a plurality of signals onto a multi-dimensional non-Gaussian source manifold, the plurality of signals including signals targeted for transmission to a plurality of receivers;
transforming the source manifold into a multi-dimensional target manifold using a polarization stream network, the polarization stream network including a plurality of transformations for shaping between the non-Gaussian source manifold and the multi-dimensional target manifold that are configured in a training exercise; and
generating a multiple-access transmission waveform for transmission to the plurality of receivers, the multiple-access transmission waveform being based on the target manifold.
2. The method of claim 1 wherein the target manifold comprises a multi-dimensional Gaussian manifold.
3. The method of claim 1 further comprising transmitting configuration information defining the polarization stream network to the plurality of receivers.
4. The method of claim 1 further comprising selecting the source manifold from a plurality of source manifolds in response to a channel condition determined for the transmission.
5. The method of claim 4 wherein some regions of the source manifold are associated with increased signal attenuation and wherein mapping the plurality of signals comprises mapping the plurality of signals onto regions of the source manifold not associated with increased signal attenuation.
6. The method of claim 1 wherein the source manifold comprises an N-dimensional manifold and wherein transforming the signals comprises transforming the signals into an M-dimensional target manifold.
7. The method of claim 6 wherein the dimension N associated with the source manifold is equal to the dimension M associated with the target manifold.
8. The method of claim 6 wherein the multiple-access transmission waveform comprises an orthogonal frequency-division multiple access (OFDMA) transmission waveform including M sub-carriers.
9. The method of claim 6 wherein the polarization stream network is configured for transforming between an N-dimensional source manifold and M-dimensional target manifold, and wherein the dimension N of the source manifold exceeds the dimension M of the target manifold, and wherein excess dimensions of the target manifold are held constant when transforming signals from the source manifold to the target manifold.
10. The method of claim 9 further comprising transmitting information to the plurality of receivers identifying the excess dimensions on the target manifold that are held constant.
11. The method of claim 9 wherein the multiple-access transmission waveform comprises a sparse code multiple access (SCMA) transmission waveform.
12. The method of claim 6 wherein the polarization stream network is configured for transforming between an N-dimensional source manifold and M-dimensional target manifold and wherein the dimension M associated with the target manifold exceeds the dimension N associated with the source manifold by at least one excess dimension.
13. The method of claim 12 further comprising transmitting information to the plurality of receivers identifying the at least one excess dimension.
14. The method of claim 12 wherein the multiple-access transmission waveform comprises a code-division multiple access (CDMA) transmission waveform and wherein the at least one excess dimension comprises a spreading code.
15. The method of claim 6 wherein the polarization stream network comprises at least one neural network and wherein the method further comprises training the neural network to determine a set of weights for the at least one neural network that are operable to configure the polarization stream network to perform the transformation between the source manifold and the target manifold.
16. The method of claim 15 wherein training the at least one neural network comprises training the neural network to transform from the target manifold to the source manifold to determine the set of weights for the at least one neural network, the polarization stream network being reversible to provide parameters for a reversed polarization stream network operable to transform from the source manifold to the target manifold.
17. The method of claim 15 wherein training the at least one neural network comprises causing the transmitter to train the at least one neural network and further comprising transmitting information to the plurality of receivers defining a configuration of the polarization stream network and the set of weights for the least one neural network.
18. The method of claim 15 wherein training the neural network comprises causing one of the plurality of receivers to train the neural network and further comprising transmitting information to the plurality of receivers defining a configuration of the polarization stream network and the set of weights for the least one neural network.
19. The method of claim 1 wherein the polarization stream network comprises a cascade of one or more polarization stages, each polarization stage including at least a shuffle function that shuffles signal data in accordance with a shuffle order, and further comprising transmitting information identifying the shuffle order to the plurality of receivers.
20. The method of claim 1 further comprising receiving the multiple-access transmission waveform at one of the plurality of receivers and using the polarization stream network to transform the multiple-access transmission waveform from the target manifold to the source manifold to facilitate recovery of signals targeted for transmission to the one of the plurality of receivers.
21. An apparatus for multiple-access wireless transmission, the apparatus comprising a transmitter operably configured to:
map a plurality of signals onto a multi-dimensional non-Gaussian source manifold, the plurality of signals including signals targeted for transmission to a plurality of receivers;
transform the source manifold into a multi-dimensional target manifold using a polarization stream network, the polarization stream network including a plurality of transformations for shaping between the non-Gaussian source manifold and the multi-dimensional target manifold that are configured in a training exercise; and
generate a multiple-access transmission waveform for transmission to the plurality of receivers, the multiple-access transmission waveform being based on the target manifold.