The exemplary and non-limiting embodiments of this invention relate generally to wireless communications, and more specifically to using a common local oscillator for multiple transceivers (e.g., in a base station transceiver unit).
This section is intended to provide a background or context to the invention that is recited in the claims. The description herein may include concepts that could be pursued, but are not necessarily ones that have been previously conceived, implemented or described. Therefore, unless otherwise indicated herein, what is described in this section is not prior art to the description and claims in this application and is not admitted to be prior art by inclusion in this section.
The following abbreviations that may be found in the specification and/or the drawing figures are defined as follows:
3GPP third generation partnership project
BB baseband
BS base station
BST base station transceiver
BW bandwidth
CDMA code divisional multiple access
CMOS complimentary metal-oxide semiconductor
DL downlink
E-UTRA evolved universal terrestrial radio access
eNB evolved node B/base station in an E-UTRAN system
LO local oscillator
LTE long term evolution
LTE-A long term evolution advanced
PCB printed circuit board
RF radio frequency
RFM radio frequency module
Rx receiver, receive
SWCR software change request
Tx transmitter, transmit
UE user equipment
UL uplink
UTRAN universal terrestrial radio access network
A cellular base station transceiver (BST) may typically contain multiple transmit (Tx) and receive (Rx) paths, and each path may contain its own frequency sources (local oscillators) to allow up and down conversion of RF signals (to and from the RF band of interest, relative to baseband signal processing). For example, the base station radio may comprise N radio pipes/branches (N being a finite integer of more than one) which can convert corresponding radio frequency signals provided to/from antennas from/to baseband signals. Each pipe/branch may comprise a pair of a transmitter and a receiver and a pair of local oscillators (LOs), where one LO provides an oscillator signal to the transmitter of the pair and another LO provides an oscillator signal to the receiver of the pair (the first and second oscillator signals may have the same or different frequencies in general).
This is illustrated in
According to a first aspect of the invention, a method, comprising: generating in a wireless radio device one or more oscillator signals by one or two local oscillators; providing in the wireless radio device corresponding portions of the one or two oscillator signals generated by the one or two local oscillators to multiple transmitters and to multiple receivers through corresponding paths in the wireless radio device.
According to a first aspect of the invention, an apparatus, comprising: one or two local oscillators configured to generate corresponding one or more oscillator signals; multiple transmitters and multiple receivers; and multiple paths through which the one or two local oscillators are configured to send corresponding portions of the one or two oscillator signals to the multiple transmitters and to the multiple receivers.
For a better understanding of the nature and objects of the present invention, reference is made to the following detailed description taken in conjunction with the following drawings, in which:
As noted herein, in a conventional approach typically a frequency source/local oscillator (LO) can be used for each pipe/branch in the BST. Such an approach shown in
A new method and apparatus are presented for using a common local oscillator for multiple transceivers (e.g., in a base station transceiver unit). According to embodiments of the invention one or two shared LOs/frequency sources in a wireless radio device (e.g., transceiver) may be configured to generate corresponding one or more oscillator signals, so that the corresponding portions of the one or two oscillator signals generated by the one or two LOs may be provided to multiple transmitters and to multiple receivers through corresponding paths in the wireless radio device. For example it may be a shared use of frequency sources/LOs between multiple pipes/branches of the BST (one local oscillator for all transmitters, and another local oscillator for all receivers in the multiple pipes/branches). The implementation of the embodiments described herein may require proper routing, and amplification and/or frequency conversion/shifting if necessary, of the shared LO signals as further described herein. It is noted that for the purposes of this invention the term “pipe” is equivalent to the term “branch”.
The wireless radio device may be a BST or a wireless transceiver comprised in an access node/network element such as eNB and the like in LTE/LTE-A systems or even in a UE such as a mobile phone, a camera mobile phone, a wireless video phone, a portable device or a wireless computer, etc. The key advantages in this new shared approach may be space savings on a PCB, and cost savings of removed/unnecessary components.
According to one embodiment, the wireless radio device (transceiver) may comprise two shared LOs each generating one oscillator signal, where the portions of the first generated oscillator signal are provided to the multiple receivers (e.g., in multiple pipes) and the portions of the second generated oscillator signal are provided to the multiple transmitters (in these multiple pipes). The two oscillator signals generated by the two LOs (one oscillator signal for transmitters and another oscillator signal for receivers) in general may have different frequencies (but also may have a same frequency) based on specific applications. Proper routing the portions of the one or two oscillator signals may be implemented using one or more radio frequency (microwave) signal splitters. Also, as stated herein, all or selected corresponding portions of oscillator signals may be amplified in the corresponding paths.
Moreover, in a wireless radio device multiple transmitters and multiple receivers may be parts of multiple pipes (e.g., see
According to a further embodiment, the wireless radio device (transceiver) with multiple pipes may have only one LO generating one oscillator signal to provide corresponding portions of this one generated oscillator signal to both the multiple receivers and to the multiple transmitters in the multiple pipes (see an example shown in
In a method according to this exemplary embodiment, as shown in
In a next step 54, amplifying in the wireless radio device, if necessary, at least selected portions of oscillator signals in the corresponding paths using corresponding amplifiers (optional step). In a next step 56, frequency converting/shifting in the wireless radio device, if necessary, at least selected portions of oscillator signals in the corresponding paths using corresponding frequency converters (optional step).
In a next step 58, providing in the wireless radio device corresponding portions of the one or two oscillator signals, amplified and/or frequency shifted if necessary, to multiple transmitters and to multiple receivers (e.g., in multiple pipes).
It is noted that various non-limiting embodiments described herein may be used separately, combined or selectively combined for specific applications.
Further, some of the various features of the above non-limiting embodiments may be used to advantage without the corresponding use of other described features. The foregoing description should therefore be considered as merely illustrative of the principles, teachings and exemplary embodiments of this invention, and not in limitation thereof.
It is to be understood that the above-described arrangements are only illustrative of the application of the principles of the present invention. Numerous modifications and alternative arrangements may be devised by those skilled in the art without departing from the scope of the invention, and the appended claims are intended to cover such modifications and arrangements.