Method of blind transport format detection based on power transition

1. A method of format detection for information having an information rate and received over a communication channel of a communication system, the method comprising the steps of:

measuring the time period during which the information was received at a power level that is equal to or above a defined threshold wherein the time period is measured by detecting transitions in the power level of the received information, and

calculating the amount of information in said received information during the measured time period as a function of said information rate and said measured time period,

the amount of information received during the measured time period being dependent on which of a plurality of information formats is the format of said received information, and said method further comprising determining the format of said received information from said calculated amount of information.

2. The method of claim 1 wherein said transitions are detected by

a) measuring the average power of a received signal carrying said information over a first time window of a certain time width,

b) measuring the average power of said received signal over a plurality of second time windows of said certain time width, each said second time window beginning at a respective time after the start of said first time window,

c) comparing the power measured in step a with each of the powers measured in step b, and

d) identifying the occurrence of said transitions as a function of the results of said comparing.

3. The method of claim 1 wherein said communication channel is a guiding channel, wherein said guiding channel contains blocks of data with a unique format, and wherein the format of other channels is associated with said unique format of said guiding channel.

4. A method of format detection for information having an information rate and received over a communication channel of a communication system, the method comprising the steps of:

determining the format of the received information from the information rate and a measurement of a time period during which the information was received at a power level that is equal to or above a defined threshold wherein the time period is measured by detecting transitions in the power level of symbols carrying the information,

wherein the communication channel is a guiding channel and the received information is extracted from the guiding channel, and

determining the format of information in other channels based on the format of said guiding channel, wherein M information blocks of defined size for said guiding channel are associated with M information blocks of defined size for each of said other channels where M is an integer.

5. The method of claim 4 where said communication channel carries 3 GPP compliant UTMS communication signals.

6. The method of claim 4 wherein the step of determining said format of said received information comprises the steps of:

calculating an estimated information size value for information extracted from said guiding channel by multiplying said information rate by said measured time period;

selecting at least one information size value candidate from M information size values for said guiding channel based on the calculated estimated information size value; and

applying the selected candidates to an algorithm for determining an actual information size value of said information extracted from said guiding channel when said estimated information size value is not equal to any of said M information size values for said guiding channel.

7. The method of claim 6 wherein the step of calculating an estimated information size value further comprises rounding off said calculated information size value to a nearest integer value.

8. The method of claim 6 wherein the format of the extracted information is determined from said calculated estimated information size value when that value is equal to one of said M information size values for said guiding channel.

9. The method of claim 6 wherein the step of applying the selected candidates to said algorithm for determining an actual information size value comprises performing an error correcting decode operation on said extracted information that yields a result on which a tail bit test and an error detecting decode operation are performed.

10. The method of claim 3 wherein the transitions in said power level occurs at the beginning and end of received blocks of data.

11. A method for use in a system in which information is communicated between communicating entities via a plurality of signals each transmitted over respective one of a plurality of channels using a selected one of a plurality of formats, there being for each format a respective information block size for each of said channels, the power of the signal transmitted over at least a particular one of said channels, serving as a guiding channel, being equal to or above a defined threshold when a block is being transmitted over that channel, the method comprising:

identifying said selected format in response to a determination of the block size being used in said guiding channel, and

determining the block size being used in the others of said channels based on the identified format,

wherein the determination of the block size being used in said guiding channel is made by measuring the time period during which at least a complete one of said blocks of information was received over said guiding channel by detecting transitions in the power level of the signal on that channel, and

determining said block size as a function of said information rate and said measured time period.

12. The invention of claim 11 wherein said determining said block size as a function of said information rate and said measured time period comprises:

calculating an estimated block size by multiplying said information rate by said measured time period;

selecting at least one block size candidate from among the block sizes specified by said formats for said guiding channel, said selecting being based on said estimated block size; and

identifying as the actual block size being used in said guiding channel by attempting to decode information communicated in said guiding channel utilizing the block size candidates and determining which of said block size candidates gives rise to a correct decode.