BACKGROUND

5G networks are digital cellular networks, in which the service area covered by providers is divided into a collection of small geographical areas called cells. Analog signals representing sounds and images are digitized in the phone, converted by an analog to digital converter and transmitted as a stream of bits. All the 5G wireless devices in a cell communicate by radio waves with a local antenna array and low power automated transceiver (transmitter and receiver) in the cell, over frequency channels assigned by the transceiver from a common pool of frequencies, which are reused in geographically separated cells. The local antennas are connected with the telephone network and the Internet by a high bandwidth optical fiber or wireless backhaul connection.

5G uses millimeter waves which have shorter range than microwaves, therefore the cells are limited to smaller size. Millimeter wave antennas are smaller than the large antennas used in previous cellular networks. They are only a few inches (several centimeters) long. Another technique used for increasing the data rate is massive MIMO (multiple-input multiple-output). Each cell will have multiple antennas communicating with the wireless device, received by multiple antennas in the device, thus multiple bitstreams of data will be transmitted simultaneously, in parallel. In a technique called beamforming the base station computer will continuously calculate the best route for radio waves to reach each wireless device, and will organize multiple antennas to work together as phased arrays to create beams of millimeter waves to reach the device. 3GPP defines a Multi-User Superposition Transmission (MUST) feature that allows multi user transmission. In this feature, the Modulation block was modified to allow overlapping modulations (high QAM and low QAM) within the same symbol. The latter enables I/Q outputs different than predefined constellation points.

US8116278 suggests taking time domain represented signals, convert them to frequency domain (e.g. GSM signal from time domain to frequency domain), in the frequency domain a sub-carrier allocation is made and then iFFT is used to move back to time domain. US20110275359A1, US20120140743A1 are talking about serving UE(s) with more than one cellular technology based on carrier aggregation feature defined in LTE but do not suggest running the signal over the same physical radio resource. This is another use of carrier aggregation feature to multiplex various technologies with LTE signal. US20130088983A1 suggest combining of LTE and Wi-Fi over the same HW but the combining is at the MAC/protocol level and not the PHY level. None of the patents or publications described above disclose or suggest the present invention.

SUMMARY

Systems and methods for providing communication signals in a Radio Access Network (RAN) architecture are disclosed.

In one embodiment, a method is disclosed for providing signals for time domain radio access communication over a distributed unit (DU) in a virtual Radio Access Network (RAN) architecture supporting frequency domain signal generation, comprising: dividing a PHY layer between the DU and a Centralized Unit (CU) between an upper PHY and a lower PHY for a first radio access technology in a radio frequency (RF) transmission chain, The first radio access technology may be a frequency domain radio access technology, wherein a PHY layer may be divided between the DU and the CU, The DU may include the lower PHY, and The CU may include the upper PHY; generating time domain radio access communication signals for a second radio access technology; injecting the time domain radio access communication signals into the RF transmission chain; and receiving and transmitting the time domain radio access communication signals in accordance with the selected split option using the DU.

The method may further comprise selecting a split option that splits the CU and DU at the analog to digital conversion (ADC)/digital to analog conversion (DAC) level such that ADC/DAC operation may be performed at the DU and all other PHY operations may be done at the CU. The method may further comprise injecting 2G/3G signals into the DAC, and The method may further comprise extracting 2G/3G signals from the ADC with a 4G/5G DU. The method may further comprise adding configuration options for the DU to modify an ADC/DAC sample rate and adding filters to comply with 2G/3G requirements.

The split option selected may include a time domain part, and The method may further comprise transferring frequency domain samples between the CU and the DU. The method may further comprise: injecting a 2G/3G signal generated in the time domain into a 4G/5G DU while bypassing an inverse Fast Fourier Transform (iFFT) block; and extracting the 2G/3G signal from the 4G/5G DU while bypassing a Fast Fourier Transform (FFT) block. The method may further comprise: generating a 2G/3G signal at the time domain and performing a Fast Fourier Transform (FFT) operation at the CU, and injecting it into a 4G/5G DU as a frequency domain signal; and extracting the 2G/3G signal from the 4G/5G DU after the FFT operation, and processing the signal through the CU. The method may further comprise: generating a 2G/3G signal at the frequency domain and injecting it into a 4G/5G DU; and extracting the 2G/3G signal from the 4G/5G DU and processing the signal in the frequency domain. The method may further comprise performing resource element mapping and demapping. The split option may include the DL stream handled in the DU from a modulation block toward an RF part, and wherein at least one of modulation, layer mapping, precoding, resource element mapping and inverse Fast Fourier Transform (iFFT) may be able to be bypassed.

The method may further comprise using a Multi-User Superposition Transmission (MUST) feature to manipulate a modulator In-phase/Quadrature (I/Q) output such that I/Q output samples reflect a desired 2G/3G signal. The split option may be done between the Media Access Control (MAC) layer and the Physical (PHY) layer. The method may further comprise injecting a 2G/3G signal generated at the time domain into a 4G/5G DU while bypassing Encoder, Rate Matching, Scrambling, Modulation, Layer Mapping, Precoding, RE mapping and iFFT blocks. The method may further comprise passing a 2G/3G signal generated in a frequency domain through De-Scrambling into a 4G/5G DU split option 6 while bypassing an Encoder and/or Rate Matching.

In another embodiment, a non-transitory computer-readable medium is disclosed containing instructions for providing 2G/3G communication over 4G/5G distributed unit (DU) in a virtual Radio Access Network (RAN) architecture, which, when executed, cause a system to perform steps comprising: dividing a PHY layer between the DU and a Centralized Unit (CU) between an upper PHY and a lower PHY for a first radio access technology in a radio frequency (RF) transmission chain, The first radio access technology may be a frequency domain radio access technology, wherein a PHY layer may be divided between the DU and the CU, The DU may include the lower PHY, and The CU may include the upper PHY; generating time domain radio access communication signals for a second radio access technology; injecting the time domain radio access communication signals into the RF transmission chain; and receiving and transmitting the time domain radio access communication signals in accordance with the selected split option using the DU.

The non-transitory computer-readable medium of claim15, the steps The method may further comprise selecting the split option to split the CU and DU at an Analog to Digital Conversion (ADC)/Digital to Analog Conversion (DAC) level such that ADC/DAC operation may be performed at the DU and all other PHY operations may be done at the CU. The non-transitory computer-readable medium of claim15, The split option selected may include a time domain part and wherein frequency domain samples may be transferred between the CU and the DU. The non-transitory computer-readable medium of claim15, the steps The method may further comprise including a DL stream handled in the DU from a modulation block toward an RF part, and bypassing at least one of modulation, layer mapping, precoding, resource element mapping and inverse Fast Fourier Transform (iFFT). The non-transitory computer-readable medium of claim15, wherein a split option may be selected to split the Media Access Control (MAC) layer and the Physical (PHY) layer.

In another embodiment, a system is disclosed for providing 2G/3G communication over 4G/5G distributed unit (DU) in a virtual Radio Access Network (RAN) architecture, comprising: at least one processor at a RAN node in communication with a 2G/3G core network and a 4G/5G core network; and at least one memory in communication with the processor, The processor enables selecting at least one split option between an upper PHY and lower PHY; The PHY layer may be divided between the DU and a Centralized Unit (CU); The DU may include a lower PHY and the CU may include an upper PHY; and The processor enables receiving and transmitting 2G/3G signals in the virtual RAN in accordance with the selected split option using the 4G/5G DUs.

In another embodiment a method is disclosed that includes selecting at least one split option between an upper PHY and lower PHY and between a PHY layer and a MAC layer; wherein the PHY layer is divided between the DU and a Centralized Unit (CU), wherein the DU includes a lower PHY and the CU includes an upper PHY; and receiving and transmitting 2G/3G signals in the virtual RAN in accordance with the selected split option using the 4G/5G DUs.

In some embodiments, a method includes: selecting at least one split option between an upper PHY and lower PHY and between a PHY layer and a MAC layer; wherein the PHY layer is divided between the DU and a Centralized Unit (CU), wherein the DU includes a lower PHY and the CU includes an upper PHY; and receiving and transmitting 2G/3G signals in the virtual RAN in accordance with the selected split option using the 4G/5G DUs.

In some embodiments, the split option comprises option 8, wherein the split option selected splits the CU and DU at the ADC/DAC level where ADC/DAC operation is performed at the DU and all other PHY operations are done at the CU.

In some embodiments, the split option comprises option 7 which includes option 7.1, 7.2, and 7.3. In option 7.1 and wherein the split option selected includes a time domain part and wherein frequency domain samples are transferred between the CU and the DU. Option 7.1 includes comprising injecting the 2G/3G signal generated in the time domain into the 4G/5G DU while bypassing an inverse Fast Fourier Transform (iFFT) block; and extracting the 2G/3G signal from the 4G/5G DU while bypassing a Fast Fourier Transform (FFT) block. Option 7.2 includes generating the 2G/3G signal at the frequency domain and injecting it into the 4G/5G DU; and extracting the 2G/3G signal from the 4G/5G DU and processing the signal in the frequency domain. Option 7.3 includes the DL stream handled in the DU from a modulation block toward an RF part and wherein at least one of modulation, layer mapping, precoding, resource element mapping and inverse Fast Fourier Transform (iFFT) are able to be bypassed.

In some embodiments the split option comprises option 6, wherein the split option is done between the Media Access Control (MAC) layer and the Physical (PHY) layer.

