1. A method of frequency hopping communication, comprising:
a receiver obtaining a frequency hopping sequence, the frequency hopping sequence defining a time sequence of reception through each of a plurality of frequency hopping bands; and
for each of the plurality of frequency hopping bands, the receiver estimating an interference level and assigning a band weight to the frequency hopping band based on the estimated interference level;
the receiver receiving a signal comprising symbols occupying the plurality of frequency hopping bands according to the frequency hopping sequence, and demodulating the symbols producing a stream of estimated bit values and corresponding bit value confidence levels; and
adjusting the bit value confidence levels of each of the estimated bit values according to the band weight of a corresponding frequency hopping band.
2. The method of claim 1, wherein the signal is a multi-carrier signal.
3. The method of claim 2, wherein the receiver estimating an interference level for each of the plurality of frequency hopping bands, comprises:
estimating interference associated with each sub-carrier of multi-carrier symbols transmitted through each of the plurality of frequency hopping bands;
estimating interference of each of the frequency hopping bands based on the estimated interference associated with each sub-carrier of the multi-carrier symbols.
4. The method of claim 2, wherein the multi-carrier signal comprises multi-carrier symbols, and each multi-carrier symbol comprises modulated carrier tones spaced across a frequency hopping band.
5. The method of claim 1, wherein the band weights adjust the bit value confidence levels of estimated bit values that correspond to the frequency hopping bands having an estimated interference level above a threshold to substantially zero.
6. The method of claim 1, wherein the receiver estimating an interference level and assigning a band weight to the frequency hopping band based on the estimated interference level for each of the plurality of frequency hopping bands, further comprises:
for each frequency hopping band, estimating a running percentage of time the estimated interference for the frequency hopping band is greater than the predetermined threshold; and
assigning the band weight for each frequency hopping band based on the running percentage of time.
7. The method of claim 1, wherein the receiver estimating an interference level comprises:
measuring signal energy for each of the plurality of frequency bands.
8. The method of claim 1, wherein the receiver estimating an interference level comprises:
scanning each of the plurality of frequency bands for a UWB signal intended for other receivers.
9. The method of claim 1, wherein the receiver estimating an interference level and assigning a band weight to the frequency hopping band based on the estimated interference level for each of the plurality of frequency hopping bands, further comprises:
for each frequency hopping band, estimating a running percentage of time the estimated interference for the frequency hopping band is less than the predetermined threshold; and
assigning the band weight for each frequency hopping band based on the running percentage of time.
10. The method of claim 1, further comprising setting an automatic gain control (AGC) of the receiver for each of the plurality of frequency hopping bands base at least in part on the estimated interference level of each of the plurality of frequency hopping bands.
11. The method of claim 10, wherein the setting the AGC comprises:
accounting for noise, signal and interference energy within frequency hopping transmission bands that have estimated interference levels below the predetermined threshold for greater than a predetermined percentage of time.
12. A method of communication, comprising:
a receiver receiving a signal with symbols in the presence of interference, wherein the interference is determined to have a repeating pattern over time;
the receiver estimating the repeating pattern of interference and assigning time weights corresponding to an estimated interference level during portions of the pattern in which the interference is above a threshold;
demodulating the symbols producing a stream of estimated bit values and corresponding bit value confidence levels; and
adjusting the bit value confidence levels according to the time weights.
13. A method of frequency hopping communication, comprising:
a receiver obtaining a frequency hopping sequence, the frequency hopping sequence defining a time sequence of reception through each of a plurality of frequency hopping bands; and
for each of the plurality of frequency hopping bands, the receiver estimating an interference level for the frequency hopping band;
the receiver receiving a signal comprising symbols occupying the plurality of frequency hopping bands according to the frequency hopping sequence;
demodulating the symbols producing a stream of estimated bit values and corresponding bit value confidence levels; and
adjusting the bit value confidence levels of each of the estimated bit values according to the estimated interference of a corresponding frequency hopping band.
14. he method of claim 13, wherein for frequency hopping bands having an estimated interference level above a threshold, the bit value confidence levels for estimated bit values corresponding to the frequency hopping bands are adjusted to substantially zero.
15. The method of claim 13, wherein the signal is a multi-carrier signal.
16. The method of claim 15, wherein the receiver estimating an interference level for each of the plurality of frequency hopping bands, comprises:
estimating interference associated with each sub-carrier of multi-carrier symbols transmitted through each of the plurality of frequency hopping bands;
estimating interference of each of the frequency hopping bands based on the estimated interference associated with each sub-carrier of the multi-carrier symbols.
17. The method of claim 15, wherein the multi-carrier signal comprises multi-carrier symbols, and each multi-carrier symbol comprises modulated carrier tones spaced across a frequency hopping band.
18. The method of claim 13, wherein the receiver estimating an interference level for each of the plurality of frequency hopping bands, further comprises:
for each frequency hopping band, estimating a running percentage of time the estimated interference for the frequency hopping band is greater than the predetermined threshold; and
estimating the interference level for each frequency hopping band based on the running percentage of time.
19. The method of claim 13, wherein the receiver estimating an interference level for each of the plurality of frequency hopping bands, further comprises:
for each frequency hopping band, estimating a running percentage of time the estimated interference for the frequency hopping band is less than the predetermined threshold; and
estimating the interference level for each frequency hopping band based on the running percentage of time.
20. The method of claim 13, further comprising setting an automatic gain control (AGC) of the receiver for each of the plurality of frequency hopping bands base at least in part on the estimated interference level of each of the plurality of frequency hopping bands.
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. An image forming apparatus comprising:
a memory unit having a common storage area which temporarily stores data in an intermediate form between data in a form of page description language and data in a bitmap form, and the data in a bitmap form generated based on the data in an intermediate form, and which includes a rasterization area used when the data in a bitmap form are generated based on the data in an intermediate form and temporarily stored therein;
a control unit which generates the data in a bitmap form based on the data in an intermediate form and temporarily stores in the rasterization area;
an image processing unit which executes image processing on the data in a bitmap form stored in the rasterization area by the control unit, and which stores the image-processing completed bitmap data in the storage area; and
a memory area control section which expands the rasterization area according to a used state of the rasterization area.
2. The image forming apparatus of claim 1, wherein the memory area control section determines whether a usable area exists in the rasterization areas when generating the data in a bitmap form based on the data in an intermediate form, and expands the rasterization area according to a result of the determination.
3. The image forming apparatus of claim 1, wherein the memory area control section determines whether it is possible for the image processing unit to execute image processing on the data in a bitmap form, and expands the rasterization area according to a result of the determination.
4. The image forming apparatus of claim 1, wherein the memory area control section releases, out of the expanded rasterization area, an expanded rasterization area portion in which the data in a bitmap form generated based on the data in an intermediate form are not stored.
5. The image forming apparatus of claim 4,
wherein the storage area includes the rasterization area in advance, and
the memory area control section releases an expanded rasterization area portion when there exists, in the rasterization area included in advance, the rasterization area portion that does not store the data in a bitmap form generated based on the data in an intermediate form.
6. The image forming apparatus of claim 4, wherein the memory area control section determines whether the image-processing executed data in a bitmap form can be stored in the storage area, and releases the expanded rasterization area according to a result of the determination.
7. The image forming apparatus of claim 1,
wherein the control unit includes a CPU to execute a computer program, and
the memory area control section is configured to be a part of the control unit as a function implemented with the computer program executed by the CPU.
8. An image forming method comprising:
a rasterization step to generate data in a bitmap form based on data in an intermediate form and to store the data in a bitmap form in a rasterization area of a memory unit, the memory unit having a common storage area which temporarily stores the data in an intermediate form between data in a form of page description language and data in a bitmap form, and the data in a bitmap form generated based on the data in an intermediate form, and which includes a rasterization area used when the data in a bitmap form are generated based on the data in an intermediate form and temporarily stored therein;
an image processing step to execute image processing on the data in a bitmap form stored in the rasterization area in the rasterization step, and which stores the image-processing completed bitmap data in the storage area; and
a memory area control step to expand the rasterization area according to a used state of the rasterization area.
9. The image forming method of claim 8, wherein the memory area control step determines whether a usable area exists in the rasterization areas when generating the data in a bitmap form based on the data in an intermediate form, and expands the rasterization area according to a result of the determination.
10. The image forming method of claim 8, wherein the memory area control step determines whether it is possible for the image processing unit to execute image processing on the data in a bitmap form, and expands the rasterization area according to a result of the determination.
11. The image forming method of claim 8, wherein the memory area control step releases, out of the expanded rasterization area, an expanded rasterization area portion in which the data in a bitmap form generated based on the data in an intermediate form are not stored.
12. The image forming method of claim 11, wherein the storage area includes the rasterization area in advance, and
the memory area control step releases an expanded rasterization area portion when there exists, in the rasterization area included in advance, the rasterization area portion that does not store the data in a bitmap form generated based on the data in an intermediate form.
13. The image forming method of claim 11, wherein the memory area control step determines whether the image-processing executed data in a bitmap form can be stored in the storage area, and releases the expanded rasterization area according to a result of the determination.