1. A radiation-shielding assembly for holding a container of radioactive material, the assembly comprising:
a body including a radiation shielding material and having a cavity defined therein;
a spacer at least partially disposed in the cavity; and
a base releasably connected to the body, the base having a spacer stowage receptacle defined therein to accommodate the spacer when the spacer is removed from the cavity, and the base is connected to the body.
2. The assembly of claim 1, wherein the base is adapted to releasably secure the spacer in the stowage receptacle.
3. The assembly of claim 1, wherein the base is constructed of a relatively lighter-weight material, and the body is constructed of a relatively heavier-weight material.
4. The assembly of claim 3, wherein the base is constructed of plastic.
5. The assembly of claim 1 further comprising a container of radioactive material disposed in the cavity, the container being in contact with the spacer.
6. Use of the radiation-shielding assembly of claim 1 in eluting a radioisotope from a radioisotope generator.
7. A method of using a radiation-shielding assembly, the method comprising:
placing a spacer in a cavity of a radiation-shielding assembly;
disposing a first container in the cavity while the spacer is in the cavity;
removing the spacer and the first container from the cavity; and
stowing the spacer in a receptacle defined in the assembly.
8. The method of claim 7, wherein the stowing step comprises releasably securing the spacer in the receptacle.
9. The method of claim 7, further comprising:
disposing a second container in the cavity after the removing, wherein the first container is of a first height, the second container is of a second height, and the first height is less than the second height.
10. The method of claim 7, disposing a second container in the cavity after the removing, wherein a mouth of the first container is located at a defined position relative to the radiation-shielding assembly after the disposing of the first container and prior to the removing of the first container, and a mouth of the second container is located at substantially the same defined position relative to the radiation-shielding assembly after the disposing of the second container.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A computer implemented method for estimating at least one offset of a communication in a multicarrier communication system, the method comprising:
receiving a plurality of subcarriers wherein at least one of the plurality of subcarriers contain a subcarrier that is subject to the distortion;
generating a plurality of first channel estimates for a plurality of received subcarriers that are not subject to the distortion;
processing a number of the plurality of first channel estimates for the plurality of received subcarriers that are not subject to the distortion to generate a second channel estimate for the subcarrier that is subject to the distortion; and
estimating an offset associated with the subcarrier that is subject to the distortion by:
receiving a known reference signal transmitted for the subcarrier that is subject to the distortion,
multiplying the second channel estimate with the known reference signal to produce a first value, and
subtracting the first value from the received known reference signal to produce the estimated offset, wherein the estimated offset is a direct current offset estimate of a direct current subcarrier that is subject to distortion and the direct current subcarrier is not nulled and is used for transmission of data.
2. The method of claim 1 wherein processing a number of the plurality of first channel estimates comprises interpolating between a plurality of first channel estimates for at least one subcarrier located higher than the subcarrier that is subject to distortion and for at least one subcarrier located lower than the subcarrier that is subject to distortion.
3. The method according to claim 1 wherein the known reference signal is a known pilot symbol.
4. The method according to claim 1 wherein processing a number of the plurality of first channel estimates comprises interpolating between first channel estimates for received subcarriers other than those received subcarriers located immediately adjacent to the subcarrier that is subject to distortion.
5. The method according to claim 1 wherein processing a number of the plurality of first channel estimates comprises using non-linear interpolation.
6. The method according to claim 1 further comprising determining whether to apply offset compensation based on the estimated offset.
7. The method according to claim 6 further comprising removing the estimated offset from received data on the subcarrier that is subject to the distortion based on determining that offset compensation is to be applied.
8. The method according to claim 7 further comprising removing the estimated offset from a plurality of data symbols successively received on the subcarrier that is subject to the distortion.
9. The method according to claim 8 wherein removing the estimated offset is applied in the frequency domain.
10. The method according to claim 8 wherein removing the estimated offset is applied in the time domain.
11. The method according to claim 10 wherein removing the estimated offset comprises:
scaling the estimated offset according to a size of a corresponding Fast Fourier Transform; and
subtracting the estimated offset from a plurality of received signal time domain samples prior to performing a Fast Fourier Transform.
12. The method according to claim 8 further comprising:
removing an initial estimated offset in a time domain followed by performing compensation in a frequency-domain to remove any residual time domain estimated offset.
13. The method according to claim 1 wherein the multicarrier communication system is arranged to support a variable assignment of symbols to subcarriers, where at least one from a group of: data, pilot symbols, is not always transmitted on the subcarrier that is subject to distortion.
14. The method according to claim 1 wherein the method is applied in an uplink communication channel.
15. The method according to claim 1 wherein the method is applied in a downlink communication channel.
16. The method according to claim 1 wherein the multicarrier communication system employs single carrier frequency division multiple access (SC-FDMA).
17. The method according to claim 1 wherein the multicarrier communication system comprises a third generation partnership project long term evolution communication system.
18. A wireless communication unit comprising:
estimation logic operable to estimate at least one offset in a subcarrier that is subject to distortion in a multicarrier communication system;
receiver logic for receiving a plurality of subcarriers wherein the plurality of subcarriers includes the subcarrier that is subject to the distortion;
estimation generation logic operable to generate a plurality of first channel estimates for a respective plurality of received subcarriers that are not subject to the distortion;
processing logic operable to process a number of the plurality of first channel estimates for the respective plurality of received subcarriers that are not subject to the distortion and to generate a second channel estimate for the subcarrier that is subject to the distortion; and
offset estimation logic operable to estimate an offset associated with the subcarrier that is subject to the distortion by:
receiving a known reference signal transmitted for the subcarrier that is subject to the distortion,
multiplying the second channel estimate with the known reference signal to produce a first value, and
subtracting the first value from the received known reference signal to produce the estimated offset, wherein the estimated offset is a direct current offset estimate of a direct current subcarrier that is subject to distortion and the direct current subcarrier is not nulled and is used for transmission of data.
19. A multicarrier wireless communication system comprising:
a computer memory for storing instructions; and
a processor for executing the instructions, the instructions for:
estimating at least one offset in a subcarrier that is subject to distortion in a multicarrier communication system;
receiving a plurality of subcarriers wherein the plurality of subcarriers includes the subcarrier that is subject to the distortion;
generating a plurality of first channel estimates for a respective plurality of received subcarriers that are not subject to the distortion;
processing a number of the plurality of first channel estimates for the respective plurality of received subcarriers that are not subject to the distortion to generate a second channel estimate for the subcarrier that is subject to the distortion; and
estimating an offset associated with the subcarrier that is subject to the distortion by:
receiving a known reference signal transmitted for the subcarrier that is subject to the distortion,
multiplying the second channel estimate with the known reference signal to produce a first value, and
subtracting the first value from the received known reference signal to produce the estimated offset, wherein the estimated offset is a direct current offset estimate of a direct current subcarrier that is subject to distortion and the direct current subcarrier is not nulled and is used for transmission of data.
20. A semiconductor device comprising:
a receiving logic module arranged to receive a plurality of subcarriers wherein the plurality of subcarriers contain the subcarrier that is subject to the distortion;
an estimation generation logic module arranged to generate a plurality of first channel estimates for a respective plurality of received subcarriers that are not subject to the distortion;
a processing logic module arranged to process a number of the plurality of first channel estimates for the respective plurality of received subcarriers that are not subject to the distortion and to generate a second channel estimate for the subcarrier that is subject to the distortion; and
an offset estimation logic module arranged to estimate an offset associated with the subcarrier that is subject to the distortion by:
receiving a known reference signal transmitted for the subcarrier that is subject to the distortion;
multiplying the second channel estimate with the known reference signal to produce a first value; and
subtracting the first value from the received known reference signal to produce the estimated offset, wherein the estimated offset is a direct current offset estimate of a direct current subcarrier that is subject to distortion and the direct current subcarrier is not nulled and is used for transmission of data.
21. A non-transitory computer readable medium comprising executable program code for:
receiving a plurality of subcarriers wherein the plurality of subcarriers contain the subcarrier that is subject to the distortion;
generating a plurality of first channel estimates for a respective plurality of received subcarriers that are not subject to the distortion;
processing a number of the plurality of first channel estimates for the respective plurality of received subcarriers that are not subject to the distortion to generate a second channel estimate for the subcarrier that is subject to the distortion; and
estimating an offset associated with the subcarrier that is subject to the distortion by:
receiving a known reference signal transmitted for the subcarrier that is subject to the distortion,
multiplying the second channel estimate with the known reference signal to produce a first value, and
subtracting the first value from the received known reference signal to produce the estimated offset, wherein the estimated offset is a direct current offset estimate of a direct current subcarrier that is subject to distortion and the direct current subcarrier is not nulled and is used for transmission of data.
22. The non-transitory computer-readable storage element of claim 21, wherein the computer readable storage medium comprises at least one of a hard disk, a CD-ROM, an optical storage device, a magnetic storage device, a Read Only Memory, ROM, a Programmable Read Only Memory, PROM, an Erasable Programmable Read Only Memory, EPROM, an Electrically Erasable Programmable Read Only Memory, EEPROM, and a Flash memory.