Mobile telecommunication system with noise ratio estimation mechanism and method of operation thereof

A method of operation of a mobile telecommunication system includes: measuring a received reference signal; removing a guard portion from the received reference signal; determining a noise variance estimate from both a noise region of the received reference signal and a noise sample in a signal region of the received reference signal, or calculating a dispersion power of a noise region of the received reference signal and determining the noise variance estimate based on at least a dispersion power; and calculating a signal to noise ratio from the noise variance estimate for adjusting a receiver device.

TECHNICAL FIELD

The present invention relates generally to a mobile telecommunication system, and more particularly to a mobile telecommunication system with noise ratio estimation mechanism.

BACKGROUND ART

Modern portable consumer and industrial electronics, especially client devices such as cellular phones, portable digital assistants, navigation systems, and combination devices, are providing increasing levels of functionality to support modern life including mobile data and voice services. Research and development in the existing technologies can take a myriad of different directions.

As users become more empowered with the growth of mobile service devices, new and old paradigms of cellular service stations are becoming essential for users to take advantage of this new mobile data and voice space. Base stations can provide mobile data and voice services. Base stations allow a Mobile Station, such as a User Equipment, to connect to its voice or data services remotely via radio frequency communication. Noise ratio calculation mechanisms help the mobile stations and the base stations manage the communication channel and properly decode symbols transmitted over the radio frequency.

Mobile telecommunication systems have been incorporated in cellphones, handheld devices, automobiles, notebooks, and other portable products. Today, these systems aid users by decoding audio and multimedia data over portable devices and manage the radio frequency communication between the user equipment and the nearby servicing base stations. The proper noise ratio estimation prevents interruption of services because of delay, noise, or interference within the communication channels. However, the accuracy and consistency of these noise ratio estimation mechanisms continue to challenge commercial applicability of these systems.

Thus, a need still remains for a mobile telecommunication system with a noise ratio estimation mechanism to adjust telecommunication receiver for better throughput. In view of the ever-increasing commercial competitive pressures, along with growing consumer expectations and the diminishing opportunities for meaningful product differentiation in the marketplace, it is increasingly critical that answers be found to these problems. Additionally, the need to reduce costs, improve efficiencies and performance, and meet competitive pressures adds an even greater urgency to the critical necessity for finding answers to these problems.

DISCLOSURE OF THE INVENTION

The present invention provides a method of operation of a mobile telecommunication system including: measuring a received reference signal; removing a guard portion from the received reference signal; determining a noise variance estimate from both a noise region of the received reference signal and a noise sample in a signal region of the received reference signal; and calculating a signal to noise ratio from the noise variance estimate for adjusting the receiver device.

The present invention provides a method of operation of a mobile telecommunication system including: measuring a received reference signal; removing a guard portion from the received reference signal; calculating a dispersion power of a noise region of the received reference signal; determining a noise variance estimate based on at least the dispersion power; and calculating a signal to noise ratio from the noise variance estimate for adjusting the receiver device.

The present invention provides a mobile telecommunication system including: a radio frequency module, for measuring a received reference signal; a symbol isolation module, coupled to the radio frequency module, for removing a guard portion from the received reference signal; a noise variance module, coupled to the symbol isolation module, for determining a noise variance estimate from both a noise region of the received reference signal; and a noise sample in a signal region of the received reference signal; and a noise ratio module, coupled to the noise variance module, for calculating a signal to noise ratio from the noise variance estimate for adjusting a receiver device.

The present invention provides a mobile telecommunication system including: a radio frequency module, for measuring a received reference signal; a symbol isolation module, coupled to the radio frequency module, for removing a guard portion from the received reference signal; a leakage estimation module, coupled to a noise variance module, for calculating a dispersion power of a noise region of the received reference signal; the noise variance module, coupled to the symbol isolation module and the leakage estimation module, for determining a noise variance estimate based on at least the dispersion power; and a noise ratio module, coupled to the noise variance module, for calculating a signal to noise ratio from the noise variance estimate for adjusting a receiver device.

BEST MODE FOR CARRYING OUT THE INVENTION

The term “module” referred to herein can include software, hardware, or a combination thereof in accordance with the context in which the term is used. For example, the software can be machine code, firmware, embedded code, and application software. Also for example, the hardware can be circuitry, processor, computer, integrated circuit, integrated circuit cores, a pressure sensor, an inertial sensor, a microelectromechanical system (MEMS), passive devices, or a combination thereof.

Referring now toFIG. 1, therein is shown a mobile telecommunication system100with noise ratio estimation mechanism in an embodiment of the present invention. The mobile telecommunication system100includes a receiver device104. The receiver device104can be a user equipment (“UE”), but can also be a base station. The receiver device104can be connected to a transmitter device106via a communication channel108. The transmitter device106can be a base station, but can also be an UE. The receiver device104is defined as an electronic device capable of receiving signals across the communication channel108. The transmitter device106is defined as an electronic device capable of transmitting signals across the communication channel108. The receiver device104can be the same type of device as the transmitter device106.

For example, the communication channel108can be a wireless radio frequency channel, a multi-channel cellular network, an orthogonal frequency division multiplexing (“OFDM”) network, an Evolved High Speed Packet Access (“HSPA+”) network, a Third Generation Partnership Project Long Term Evolution (“3GPP LTE”) network, a 3GPP LTE-Advanced network, or other cellular network.

The communication channel108can be a variety of networks. For example, the communication channel108can include multi-band radio frequency communication, wireless communication, optical, or any combination thereof. Satellite communication, cellular communication, and worldwide interoperability for microwave access (WiMAX) are examples of wireless communication that can be included in the communication channel108.

For example, the receiver device104can be of any of a variety of devices, such as a cellular phone, personal digital assistant, a notebook computer, automotive telematic navigation system, or other multi-functional mobile communication or entertainment device. The receiver device104can also be a device, such as evolve Node B (“eNB”), a cellular radio station, a cell tower, a cellular routing device, a relay station, or other radio receiving devices. The receiver device104can be a standalone device, or can be incorporated with a structure, for example a building, a vehicle, or a tower. The receiver device104can couple to the communication channel108to communicate with the transmitter device106.

The receiver device104can be centralized in a single computer room, distributed across different rooms, attached to a building, distributed across different geographical locations, embedded within a telecommunications network, or attached to a tower. The receiver device104can have a means for coupling with the communication channel108to communicate with the transmitter device106. The receiver device104can also be a mobile type device.

For example, the transmitter device106can be of any of a variety of devices, such as a cellular phone, personal digital assistant, a notebook computer, automotive telematics navigation system, or other multi-functional mobile communication or entertainment device. The transmitter device106can also be a device, such as evolve Node B (“eNB”), a cellular radio station, a cell tower, a cellular routing device, a relay station, or other radio receiving devices. The transmitter device106can be a standalone device, or can be incorporated with a structure, for example a building, a vehicle, or a tower. The transmitter device106can couple to the communication channel108to communicate with the receiver device104.

The transmitter device106can be centralized in a single computer room, distributed across different rooms, attached to a building, distributed across different geographical locations, embedded within a telecommunications network, or attached to a tower. The transmitter device106can have a means for coupling with the communication channel108to communicate with the receiver device104. The transmitter device106can also be a mobile type device.

For illustrative purposes, the mobile telecommunication system100is described with the transmitter device106having a signal transmission function, although it is understood that the transmitter device106can also have a signal receiving function. For illustrative purposes, the mobile telecommunication system100is described with the receiver device104having a signal receiving function, although it is understood that the receiver device104can also have a signal transmission function.

Also for illustrative purposes, the mobile telecommunication system100is shown with the transmitter device106and the receiver device104as end points of the communication channel108, although it is understood that the mobile telecommunication system100can have a different partition between the receiver device104, the transmitter device106, and the communication channel108. For example, the receiver device104, the transmitter device106, or a combination thereof can also function as part of the communication channel108.

The receiver device104can determine a received reference signal110from the communication channel108. The received reference signal110is defined as the reference signal received from the transmitter device106through the communication channel108and determined at the receiver device104. The received reference signal110can be a detected information at the receiver device104corresponding to the resource elements that carry cell-specific reference signals within the considered frequency bandwidth.

The transmitter device106can establish cells by broadcasting their respective cell selection reference signals, such as the received reference signal110. The size of each cell can be defined by the size of an area in which the cell selection reference signal reaches at a predetermined power value. The receiver device104can establish a connection for communication with the transmitter device106from which it can receive the cell selection reference signal, preferably at maximum intensity.

The communication channel108from the transmitter device106to the receiver device104can include characteristics such as Gaussian noise, dispersion, path loss, shadow fading, fast fading, other interference or noise, or a combination thereof. These characteristics can cause the received reference signal110to be attenuated, phase-shifted, or delayed, resulting in decrease in the quality of the signal seen by the receiver device104.

The transmitter device106can transmit a reference element count112of reference symbols114to the receiver device104. The reference symbols114are defined as resource elements each corresponding to one complex-valued modulation symbol. The reference element count112is defined as the number of the reference symbols114in symbol duration116for transmission. The reference element count112can be the number of m-th cell specific reference signal (CRS) resource element (RE) in the symbol duration116. The symbol duration116is defined as a unit time block for transmission from the transmitter device106to the receiver device104. The symbol duration116can be an inverse to the symbol rate of the transmitter device106.

The receiver device104can measure the radio link quality through the communication channel108from the transmitter device106. The radio link quality can be generally represented as a form of a signal to noise ratio118. The signal to noise ratio118can be, for example, a signal-to-interference-plus-noise ratio (SINR), a signal-to-noise ratio (SNR). In a system with multiple carriers such as OFDM, the signal to noise ratio118can also represent the carrier-to-noise ratio (CNR) or the carrier-to-interference-plus-noise ratio (CINR).

The signal to noise ratio118can be measured in either frequency domain or in time domain. The signal to noise ratio118can be measured with a channel impulse response (CIR) of the received reference signal110in time domain. The signal to noise ratio118can be the ratio of a received signal power120over a total noise variance122. The total noise variance122is defined as the total variance of noise within the symbol duration116. In an OFDM system, multiple frequency domain samples are assigned as the received reference signal110. Hence, calculation of the received signal power120and the total noise variance122can be done in the time domain by taking an inverse fast Fourier transform (IFFT) on the received reference signal110in the symbol duration116. The signal to noise ratio118can be averaged with an adaptive filter or an infinite impulse response filter.

The received signal power120is defined as received power based on a message sent from the transmitter device106for the symbol duration116. The received signal power120can include the received power on specific resources such as reference symbols, pilot symbols, allocated data symbols, or a combination thereof. The total noise variance122can be calculated based on noise variance noise samples found throughout the symbol duration116.

The transmitter device106can send the received reference signal110to the receiver device104for the purpose of measuring the signal to noise ratio118. The received reference signal110can include multiple reference symbol elements and its spacing is related to the expected coherence bandwidth of the channel, which is in turn related to a delay spread. The receiver device104can calculate the signal to noise ratio118on the reference symbol elements of the received reference signal110in time domain.

The receiver device104can compute the received signal power120for processing symbols from the transmitter device106based on a total power124of the received reference signal110and the signal to noise ratio118. The total power124is defined as total received power in the symbol duration116including noise, interference, and signal. For example, the receiver device104can compute the received signal power120based on the total power124minus the total noise variance122. The receiver device104can combine the signal to noise ratio118in each of OFDM symbol, and utilize it as the mean/average SNR for decoding symbols from the received reference signal110. The receiver device104can combine instances of the signal to noise ratio118computed per antenna on the receiver device104, and use it to calculate the mean/average SNR.

The physical transformation of adjusting the receiver device104based on estimation of the signal to noise ratio118results in activations of displays, signal decoding hardware, or audio components in the receiver device104in the physical world. Further, as a result of the adjustment based on the signal to noise ratio118, the mobile telecommunication system100will physically change the operation of its symbol decoding module, radio link management module, and the downlink quality reporting module. Based on the change of symbol decoding, radio link management, and downlink reporting, the voice and data quality heard and displayed on the receiver device104is changed. Thus, the quality and delay of the receiver device104, such as a mobile device output, can change and improve based on those adjustments due to accurate estimation of the signal to noise ratio118by the mobile telecommunication system100.

Referring now toFIG. 2, therein is shown an exemplary block diagram of the mobile telecommunication system100. The receiver device104can send information in a first device transmission202over the communication channel108to the transmitter device106ofFIG. 1. The receiver device104can receive information in a second device transmission204over the communication channel108from the transmitter device106.

The receiver device104can include a first control unit206, a first storage unit208, a first communication unit210, and a first user interface212. The first control unit206can include a first control interface214. The first control unit206can execute a first software216to provide the intelligence of the mobile telecommunication system100. The first control unit206can be implemented in a number of different manners. For example, the first control unit206can be a processor, an embedded processor, a microprocessor, a hardware control logic, a hardware finite state machine (FSM), a digital signal processor (DSP), or a combination thereof. The first control interface214can be used for communication between the first control unit206and other functional units in the receiver device104. The first control interface214can also be used for communication that is physically separated from the receiver device104.

The first control interface214can receive information from the other functional units or from external sources, or can transmit information to the other functional units or to external destinations. The external sources and the external destinations refer to sources and destinations physically separated from the receiver device104.

The first control interface214can be implemented in different ways and can include different implementations depending on which functional units or external units are being interfaced with the first control interface214. For example, the first control interface214can be implemented with a pressure sensor, an inertial sensor, a microelectromechanical system (MEMS), optical circuitry, waveguides, wireless circuitry, wireline circuitry, or a combination thereof.

The first storage unit208can store the first software216. The first storage unit208can also store the relevant information, such as advertisements, points of interest (POI), navigation routing entries, or any combination thereof.

The first storage unit208can include a first storage interface218. The first storage interface218can be used for communication between the first storage unit208and other functional units in the receiver device104. The first storage interface218can be used for communication that is external to the receiver device104.

The first storage interface218can receive information from the other functional units or from external sources, or can transmit information to the other functional units or to external destinations. The external sources and the external destinations refer to sources and destinations physically separated from the receiver device104.

The first storage interface218can include different implementations depending on which functional units or external units are being interfaced with the first storage unit208. The first storage interface218can be implemented with technologies and techniques similar to the implementation of the first control interface214.

The first communication unit210can enable external communication to and from the receiver device104. For example, the first communication unit210can permit the receiver device104to communicate with the transmitter device106ofFIG. 1, such as a peripheral device or a computer desktop, and the communication channel108.

The first communication unit210can also function as a communication hub allowing the receiver device104to function as part of the communication channel108and not limited to be an end point or terminal unit to the communication channel108. The first communication unit210can include active and passive components, such as microelectronics or an antenna, for interaction with the communication channel108.

The first communication unit210can include a first communication interface220. The first communication interface220can be used for communication between the first communication unit210and other functional units in the receiver device104. The first communication interface220can receive information from the other functional units or can transmit information to the other functional units.

The first communication interface220can include different implementations depending on which functional units are being interfaced with the first communication unit210. The first communication interface220can be implemented with technologies and techniques similar to the implementation of the first control interface214.

The first user interface212allows a user (not shown) to interface and interact with the receiver device104. The first user interface212can include an input device and an output device. Examples of the input device of the first user interface212can include a keypad, a touchpad, soft-keys, a keyboard, a microphone, or any combination thereof to provide data and communication inputs.

The first user interface212can include a first display interface222. The first display interface222can include a display, a projector, a video screen, a speaker, or any combination thereof.

The first control unit206can operate the first user interface212to display information generated by the mobile telecommunication system100. The first control unit206can also execute the first software216for the other functions of the mobile telecommunication system100. The first control unit206can further execute the first software216for interaction with the communication channel108via the first communication unit210.

The transmitter device106can be optimized for implementing the present invention in a multiple device embodiment with the receiver device104. The transmitter device106can provide the additional or higher performance processing power compared to the receiver device104. The transmitter device106can include a second control unit224, a second communication unit226, and a second user interface228.

The second user interface228allows a user (not shown) to interface and interact with the transmitter device106. The second user interface228can include an input device and an output device. Examples of the input device of the second user interface228can include a keypad, a touchpad, soft-keys, a keyboard, a microphone, or any combination thereof to provide data and communication inputs. Examples of the output device of the second user interface228can include a second display interface230. The second display interface230can include a display, a projector, a video screen, a speaker, or any combination thereof.

The second control unit224can execute a second software232to provide the intelligence of the transmitter device106of the mobile telecommunication system100. The second software232can operate in conjunction with the first software216. The second control unit224can provide additional performance compared to the first control unit206.

The second control unit224can operate the second user interface228to display information. The second control unit224can also execute the second software232for the other functions of the mobile telecommunication system100, including operating the second communication unit226to communicate with the receiver device104over the communication channel108.

The second control unit224can be implemented in a number of different manners. For example, the second control unit224can be a processor, an embedded processor, a microprocessor, a hardware control logic, a hardware finite state machine (FSM), a digital signal processor (DSP), or a combination thereof.

The second control unit224can include a second control interface234. The second control interface234can be used for communication between the second control unit224and other functional units in the transmitter device106. The second control interface234can also be used for communication that is external to the transmitter device106.

The second control interface234can be implemented in different ways and can include different implementations depending on which functional units or external units are being interfaced with the second control interface234. For example, the second control interface234can be implemented with a pressure sensor, an inertial sensor, a microelectromechanical system (MEMS), optical circuitry, waveguides, wireless circuitry, wireline circuitry, or a combination thereof.

A second storage unit236can store the second software232. The second storage unit236can also store the relevant information, such as advertisements, points of interest (POI), navigation routing entries, or any combination thereof. The second storage unit236can be sized to provide the additional storage capacity to supplement the first storage unit208.

For illustrative purposes, the second storage unit236is shown as a single element, although it is understood that the second storage unit236can be a distribution of storage elements. Also for illustrative purposes, the mobile telecommunication system100is shown with the second storage unit236as a single hierarchy storage system, although it is understood that the mobile telecommunication system100can have the second storage unit236in a different configuration. For example, the second storage unit236can be formed with different storage technologies forming a memory hierarchal system including different levels of caching, main memory, rotating media, or off-line storage.

The second storage unit236can include a second storage interface238. The second storage interface238can be used for communication between the second storage unit236and other functional units in the transmitter device106. The second storage interface238can be used for communication that is external to the transmitter device106.

The second storage interface238can include different implementations depending on which functional units or external units are being interfaced with the second storage unit236. The second storage interface238can be implemented with technologies and techniques similar to the implementation of the second control interface234.

The second communication unit226can enable external communication to and from the transmitter device106. For example, the second communication unit226can permit the transmitter device106to communicate with the receiver device104over the communication channel108.

The second communication unit226can also function as a communication hub allowing the transmitter device106to function as part of the communication channel108and not limited to be an end point or terminal unit to the communication channel108. The second communication unit226can include active and passive components, such as microelectronics or an antenna, for interaction with the communication channel108.

The second communication unit226can include a second communication interface240. The second communication interface240can be used for communication between the second communication unit226and other functional units in the transmitter device106. The second communication interface240can receive information from the other functional units or can transmit information to the other functional units.

The second communication interface240can include different implementations depending on which functional units are being interfaced with the second communication unit226. The second communication interface240can be implemented with technologies and techniques similar to the implementation of the second control interface234.

The first communication unit210can couple with the communication channel108to send information to the transmitter device106in the first device transmission202. The transmitter device106can receive information in the second communication unit226from the first device transmission202of the communication channel108.

The second communication unit226can couple with the communication channel108to send information to the receiver device104in the second device transmission204. The receiver device104can receive information in the first communication unit210from the second device transmission204of the communication channel108. The mobile telecommunication system100can be executed by the first control unit206, the second control unit224, or a combination thereof.

For illustrative purposes, the transmitter device106is shown with the partition having the second user interface228, the second storage unit236, the second control unit224, and the second communication unit226, although it is understood that the transmitter device106can have a different partition. For example, the second software232can be partitioned differently such that some or all of its function can be in the second control unit224and the second communication unit226. Also, the transmitter device106can include other functional units not shown inFIG. 2for clarity.

The functional units in the receiver device104can work individually and independently of the other functional units. The receiver device104can work individually and independently from the transmitter device106and the communication channel108.

The functional units in the transmitter device106can work individually and independently of the other functional units. The transmitter device106can work individually and independently from the receiver device104and the communication channel108.

For illustrative purposes, the mobile telecommunication system100is described by operation of the receiver device104and the transmitter device106. It is understood that the receiver device104and the transmitter device106can operate any of the modules and functions of the mobile telecommunication system100. For example, the receiver device104is described to operate the first communication unit210, although it is understood that the transmitter device106can also operate the first communication unit210.

Referring now toFIG. 3, therein is shown an example of the received reference signal110from a channel impulse response measured by the receiver device104ofFIG. 1. The received reference signal110can include intervals of the symbol duration116. The symbol rate can be measured as a subcarrier spacing of the received reference signal110in frequency domain. The symbol duration116can include a signal region302, and a noise region304. The symbol duration116can be surrounded by a guard portion306.

The guard portion306is defined as a portion of the received reference signal110for ensuring distinct transmissions in the received reference signal110do not interfere with one another and for introducing resistance or immunity to propagation delays, echoes, and reflections. The guard portion306can be between transmitted pulses in time domain. The guard portion306can be removed in frequency domain as described inFIG. 4.

A cyclic prefix308can be a form of the guard portion306. The cyclic prefix308can be part of the guard portion306. The cyclic prefix308is defined as a portion of the received reference signal110before a symbol that is a repetition of the end of the symbol. The cyclic prefix308can allow the linear convolution of a frequency-selective multipath channel to be modeled as circular convolution, which in turn may transform to the frequency domain using a discrete Fourier domain. The cyclic prefix308can be for eliminating intersymbol interference and for channel estimation and equalization.

The signal region302is defined as a time duration of the received reference signal110during which a transmitted pulse of symbol or symbols and its multipath components are received. The signal region302can be a time duration of the received reference signal110during which a channel impulse and its multipath components are received. The signal region302can have a duration equal to the duration of the cyclic prefix308or double the duration of the cyclic prefix308.

The signal region302can also include shifted samples310. Because the mobile telecommunication system100may zero-pad the channel impulse response in frequency domain, the received signal power120ofFIG. 1can spread in time domain. The received signal power120can also have a sync-like shape due to windowing or zero-padding.

Some of the received signal power120can leak outside an interval of time more than the duration of the cyclic prefix308. The shifted samples310is defined as last time domain samples in the symbol duration116that are circularly shifted to the beginning of the symbol duration116. A shift size312is defined as the size of the shifted samples310. A prefix sample size314is defined as the sample size of the cyclic prefix308. For example, the signal region302can have a duration equal to the prefix sample size314plus the shift size312.

Noise is a characteristic of the communication channel108ofFIG. 1, and hence is throughout the received reference signal110. The received reference signal110can include the noise region304in time domain, where the transmitter device106ofFIG. 1has not encoded any signal symbol in the region and where the received reference signal110includes only noise, interference, or both noise and interference. The noise region304and the signal region302can be separated by data segmentation mechanisms, including thresholding by a power or voltage amplitude, peak counting, or comparing the average power of intervals within the symbol duration116. The noise region304can be identified by taking the symbol duration116minus a time interval equal to the duration of the cyclic prefix308and the duration of the shifted samples310.

Most of the received signal power120can be in the first half of the symbol duration116, mainly within a time interval equal to the duration of the cyclic prefix308. Noise of the communication channel108can be in the entirety of the symbol duration116. The total noise variance122ofFIG. 1can be estimated by calculating a noise region variance316in the noise region304or a noise variance estimate318in both the noise region304and the signal region302.

The noise region variance316is a calculated variance of noise samples in the noise region304. The noise variance estimate318is a calculated variance of noise samples, which can be in the noise region304, the signal region302, or both. The total noise variance122can be estimated as a summation of the absolute square value of all noise samples in the signal region302and the noise region304multiplied by a scaling factor of total number of samples in the symbol duration116divided by number of noise samples in the noise region304and the signal region302.

The symbol duration116can include a noise sample size320of instances of a noise sample322. The noise sample322is defined as a discrete noise sample in the symbol duration116in time domain which contains only noise, interference, or a combination thereof. While the signal region302contains reference symbols, the signal region302can also contain the noise sample322. The noise sample322can be noise symbols within the signal region302received as a characteristic of the communication channel108. The noise sample size320is defined as the number of the instances of the noise sample322in the symbol duration116.

The received reference signal110can be represented in frequency domain, such as by a Fourier transform324. The Fourier transform324is defined as a collection of discrete frequencies and corresponding amplitudes to those frequencies.

The received reference signal110can be converted back to time domain following a frequency domain operation by an inverse Fourier transform326. The inverse Fourier transform326is defined as a discrete time domain representation of a discrete Fourier transform. The size of the inverse Fourier transform326can be a number that is an order of 2, where the size is greater than the number of reference symbol elements. The size of the inverse Fourier transform326can be an order of 2 just above the number of reference symbol elements, or any order of 2 above the number of reference symbol elements.

Referring now toFIG. 4, therein is shown a control flow of the mobile telecommunication system100. The mobile telecommunication system100can include a radio frequency module402. The radio frequency module402is for receiving and measuring radio waves from at least one antenna. The radio frequency module402can receive and output the received reference signal110ofFIG. 1for other modules of the mobile telecommunication system100to process. The radio frequency module402can measure the received reference signal110at the receiver device104.

The mobile telecommunication system100can include a symbol isolation module404. The symbol isolation module404can be coupled with the radio frequency module402to receive the received reference signal110from the radio frequency module402. The symbol isolation module404is for isolating the symbol duration116ofFIG. 1from the received reference signal110. The symbol isolation module404can isolate the symbol duration116by removing the guard portion306ofFIG. 3of the received reference signal110or removing the cyclic prefix308ofFIG. 3of the received reference signal110. The symbol isolation module404can isolate the symbol duration116in time domain or in frequency domain.

The symbol isolation module404can include a Fourier transform module406. The Fourier transform module406is for calculating the Fourier transform324ofFIG. 3of the received reference signal110by performing a discrete Fourier transformation on the received reference signal110. The Fourier transform module406can also be for removing the guard portion306from the received reference signal110. The Fourier transform module406can remove the guard portion306from the received reference signal110including removing the cyclic prefix308from the received reference signal110. The Fourier transform module406can remove the guard portion306in the Fourier transform324of the received reference signal110. The Fourier transform module406can calculate a flat-fading channel frequency response.

The symbol isolation module404can include a smooth module408. The smooth module408can be coupled to the Fourier transform module406to receive the Fourier transform324from the Fourier transform module406. The smooth module408is for smoothing the received reference signal110for preventing fading of the received reference signal110. The smooth module408can smooth the received reference signal110by zero-padding the Fourier transform324of the received reference signal110for non-symbol frequencies.

The smooth module408can smooth the received reference signal110by windowing the received reference signal110, such as a band-pass filter, a rectangular window function, a Hann window, a Hamming window, a Raised-Cosine window, an apodization function, or other windowing function. The smooth module408can smooth the received reference signal110by interpolation. For example, the smooth module408can insert samples between reference symbol elements in the Fourier transform324, where the magnitude of the inserted samples is an average of the neighboring reference symbol elements.

For example, when rectangular windowing is applied, the noise region304ofFIG. 3and the signal region302ofFIG. 3can be fixed. As a specific example, the noise region304and the signal region302can be segregated based on the longest channel delay profile that the receiver device104ofFIG. 1can support. For another example, when non-rectangular windowing is applied, the noise region304can be widened from the fixed size because signal leakage to the noise region304can be significantly reduced.

The symbol isolation module404can include an inverse Fourier module410. The inverse Fourier module410can be coupled to the smooth module408to receive the Fourier transform324after processing by the smooth module408. The inverse Fourier module410is for calculating the inverse Fourier transform326ofFIG. 3from the Fourier transform324of the received reference signal110. The inverse Fourier module410can calculate the inverse Fourier transform326from the Fourier transform324with the guard portion306removed. By taking the inverse Fourier transform of the Fourier transform324, the inverse. Fourier module410can determine the channel impulse response in time domain. The received reference signal110can be interpolated in time domain after the inverse Fourier transform326is calculated, where samples of the inverse Fourier transform326that is not a reference symbol element can be estimated as an average between the neighboring reference symbol elements.

The mobile telecommunication system100can include a sample shift module412. The sample shift module412can be coupled to the symbol isolation module404to receive the inverse Fourier transform326ofFIG. 3of the received reference signal110with the guard portion306removed. The sample shift module412is for circular shifting samples in the inverse Fourier transform326of the received reference signal110within the symbol duration116. The sample shift module412can move the shifted samples310ofFIG. 3from an end portion of the inverse Fourier transform326to a beginning portion of the inverse Fourier transform326.

The mobile telecommunication system100can include a noise variance module414. The noise variance module414can be coupled to the symbol isolation module404to receive the inverse Fourier transform326of the received reference signal110. The noise variance module414can be coupled to the sample shift module412to receive the inverse Fourier transform326of the received reference signal110after circular shifting the shifted samples310. The noise variance module414is for determining or estimating the noise variance estimate318ofFIG. 3of the received reference signal110. The noise variance estimate318can be estimated with the channel impulse response in time domain.

The noise variance module414can calculate the noise region variance316ofFIG. 3from the noise region304. The noise variance module414can output the noise region variance316as the noise variance estimate318. The noise variance module414can also calculate the noise variance estimate318from at least the noise sample322ofFIG. 3of the signal region302. The noise variance module414can calculate the noise variance estimate318from both instances of the noise sample322and the noise region variance316.

It has been discovered that the mobile telecommunication system100with determining the noise variance estimate318from both the noise region304and the signal region302can allow for estimation of the signal to noise ratio118ofFIG. 1aimed at low SNR region. When the signal to noise ratio or the carrier to interference ratio is low, the noise variance can be more accurately estimated by sampling both the signal region302and the noise region304of the symbol duration116.

The mobile telecommunication system100can include a delay spread module416. The delay spread module416can be coupled to the Fourier transform module406to receive the Fourier transform324of the received reference signal110. The delay spread module416is for calculating a delay spread estimate418of the received reference signal110. The received reference signal110transmitted through the communication channel108ofFIG. 1can have the delay spread estimate418. The delay spread estimate418can be caused by channel characteristics, such as multi-path richness of the received reference signal110. The delay spread estimate418is defined as a measure of the multipath richness of the communication channel108. For example, the delay spread estimate418can represent the difference between the time of arrival of the earliest significant multipath component and the time of arrival of the latest multipath component. The delay spread estimate418can be quantified through different metrics, including the root mean square delay spread.

The noise variance module414can use side information on the delay spread estimate418to enhance estimation quality of the noise region variance316. The delay spread module416can calculate the delay spread estimate418, such as a root-mean square (RMS) delay spread.

The noise variance module414can size the noise region304relative to the signal region302and vice versa based on the delay spread estimate418. With the sample sizes of the noise region304adjusted, the receiver device104can add more samples for estimation of the noise region variance316or the noise variance estimate318. Further, if the position of the signal multipath can be measured precisely, the receiver device104can filter with a noise threshold420to determine the noise sample322in the signal region302that is not from the multipath including the sidelobes.

The mobile telecommunication system100can include a threshold calculation module421. The threshold calculation module421can couple with the noise variance module414. The threshold calculation module421is for determining the noise threshold420. The threshold calculation module421can determine the noise threshold420for collecting more noise samples from the signal region302received through the noise variance module414. The noise threshold420can be for calculating the noise variance estimate318. The threshold calculation module421can select the noise threshold420based on Equation 1:
Pth=α*σN0Eq. 1

Here, Pthrepresents the noise threshold420. σN0represents square root of the noise region variance316. α represents a channel dependent scaling factor423. The channel dependent scaling factor423can be determined through measurement of the delay spread of the communication channel108. The channel dependent scaling factor423can be user-defined or can be a stored variable on the receiver device104. The channel dependent scaling factor423can be received from the transmitter device106.

The channel dependent scaling factor423can be estimated based on the delay profile of the communication channel108. Different instances of the noise threshold420can be calculated for each channel delay profile depending on the communication channel108used. The channel dependent scaling factor423can be calculated based on the delay spread estimate418from the delay spread module416.

The threshold calculation module421can select the noise threshold420to satisfy Equation 2, as follows:
|rm(tTs)|<PthEq. 2

Here, rm(tTs) represents each potential instance of the noise sample322in the signal region302, where “Ts” represents a sampling interval of the inverse Fourier transform326and “t” represents a count of the multiples of the sampling interval. The symbols in the signal region302follow a normal distribution, and hence the absolute value of each symbol is a random variable that follows a Rayleigh distribution. In Rayleigh distribution, the probability density functions (“pdfs”) with different variances are distinguishable from each other based on their magnitude. Hence, if the variance of the received signal power120ofFIG. 1is not negligible compared to the noise variance estimate318, the noise threshold420selected by the threshold calculation module421can distinguish the noise sample322from the shifted samples310.

The noise variance module414can include the noise sample322from the signal region302for calculating the noise variance estimate318when an absolute value of the noise sample322is smaller than the noise threshold420. The addition of the noise sample322can be included for calculation of the noise variance estimate318. In the signal region302, which can include time interval of the cyclic prefix308and time interval of the shifted samples310, the received reference signal110can be distributed as a normal distribution with the variance equal to the noise variance estimate318plus the signal power variance. The noise threshold420can add all instances of the noise sample322from the signal region302together with all sample points in the noise region304to calculate the noise variance estimate318.

When more instances of the noise sample322are detected in the signal region302, the noise variance estimate318can be updated based on all instances of the noise sample322in the noise region304and instances of the noise sample322in the signal region302below the noise threshold420. The total noise variance122can be calculated by the noise variance estimate318multiplied by a scaling factor of number of samples in the symbol duration116over the noise sample size320ofFIG. 3. For example, here the noise sample size320can be equal to the size of the Fourier transform324minus both the shift size312ofFIG. 3and the prefix sample size314, and plus the number of the noise sample322in the signal region302detected via thresholding with the noise threshold420. The noise sample size320can also be the number of the noise sample322in the noise region304plus the number of the noise sample322in the signal region302.

As new instances of the noise sample322are detected in the signal region302, the noise variance estimate318can be updated recursively. As the noise variance estimate318is updated recursively, the noise threshold420can also be updated recursively such that the noise threshold420is updated as the channel dependent scaling factor multiplied by the noise variance estimate318that is updated.

It has been discovered that selecting the noise threshold420based on the noise region variance316can accurately increase the quality of the noise variance estimate318. For example, the variance of the estimation can improve as high as 1 dB in low SNR regions. Noise symbols converge in distribution, and hence more noise symbols need to be computed to increase the quality of the noise variance estimate318. Selecting the noise threshold420based on the noise region variance316allow the noise variance module414to segregate out the noise sample322in the signal region302because the samples in the signal region302can follow Rayleigh distributions. Rayleigh distributions can be separated by its difference in variances by a magnitude threshold. Accordingly, selecting the noise threshold420based on the noise region variance316can accurately increase the quality of the noise variance estimate318.

It has been discovered that by adding the noise sample322in the signal region302based on the noise threshold420for calculation of the noise variance estimate318can improve the audio quality and data link speed of the receiver device102. Increased noise variance estimation quality increases the accuracy of the signal to noise ratio118, and hence improves radio link management, and allows users to have faster and higher quality voice and Internet communication.

The mobile telecommunication system100can include a signal power estimation module422. The signal power estimation module422can be coupled to the noise variance module414. The signal power estimation module422is for calculating the received signal power120in the signal region302of the received reference signal110. The signal power estimation module422can calculate the received signal power120in the signal region302based on the noise variance estimate318or the noise region variance316calculated by the noise variance module414. The signal power estimation module422can calculate the received signal power120in the signal region302based on Equation 3, as follows:

In Equation 3, NCPrepresents the prefix sample size314. NSSrepresents the shift size312. rk[n] represents discrete measures of the received signal power120based on the inverse Fourier transform326. {circumflex over (P)}signalrepresents the received signal power120. {circumflex over (σ)}NVT2represents the noise variance estimate318divided by the noise sample size320. In Equation 3, the noise variance estimate318can be equal to the noise region variance316.

The mobile telecommunication system100can include a leakage estimation module424. The leakage estimation module424can be coupled to the noise variance module414, the signal power estimation module422(not shown), and the sample shift module412(not shown). The leakage estimation module424can receive the received signal power120from the noise variance module414or directly from the signal power estimation module422.

The leakage estimation module424is for estimating a dispersion power426of the received signal power120. The leakage estimation module424can estimate the dispersion power426based on the received signal power120from the signal power estimation module422. The dispersion power426can be based on a leakage ratio428multiplied by the received signal power120, as shown in Equation 4, as follows:
{circumflex over (P)}leakage=PLSR·{circumflex over (P)}signalEq. 4

In Equation 4, PLSRrepresents the leakage ratio428. {circumflex over (P)}signalrepresents the received signal power120. {circumflex over (P)}leakagerepresents the dispersion power426.

The leakage ratio428is defined as the signal power leakage to signal ratio, a ratio of the signal dispersion power to the non-dispersed signal power. The leakage ratio428can be calculated from the non-dispersed signal power. The leakage ratio428can be represented as Equation 5:

Equation 5 can be simplified to Equation 6, as follows:

In Equations 5 and 6, PLSRrepresents the leakage ratio428. NCPrepresents the prefix sample size314. NSSrepresents the shift size312. Nfftrepresents the size of the Fourier transform324. NCRS-RErepresents the number of the reference element count112ofFIG. 1. rsignal represents discrete measures of the received signal power120based on the inverse Fourier transform326.

The leakage ratio428can also be computed offline based on the prefix sample size314and the shift size312with a pre-defined NCRS-REFor example, the leakage ratio428can be looked up in a table. Table 1 exemplifies a lookup table for the leakage ratio428based on the reference element count112, the shift size312, and the prefix sample size314. The reference element count112is proportional to the system bandwidth as exemplified in Table 1. For example, Table 1 can be computed at 10 MHz bandwidth.

The total noise variance122can be updated by subtracting the dispersion power426from the total noise variance122ofFIG. 1. For example, the total noise variance122can be updated as Equation 7:

In Equation 7, Nfftrepresents the size of the Fourier transform324. {circumflex over (P)}leakagerepresents the dispersion power426. {circumflex over (σ)}NVT2represents the noise variance estimate318divided by the noise sample size320before signal dispersion compensation. {circumflex over (σ)}SDC2represents the total noise variance112after signal dispersion compensation divided by the size of the Fourier transform324.

It has been unexpectedly discovered that compensating for signal dispersion through estimating the dispersion power426can increase the accuracy of the estimation of the signal to noise ratio118. Signal dispersion term is the dominant factor that makes estimation of the signal to noise ratio118inaccurate in high carrier to noise region. In regions with high values of the signal to noise ratio118, the noise variance estimate318can be asymptotically greater than the true noise variance due to signal dispersion. When the signal dispersion is compensated by subtracting the dispersion power426from the noise variance estimate318, accuracy of estimating the total noise variance122is improved.

It has been unexpectedly discovered compensating the dispersion power426before calculating the signal to noise ratio118can eliminate the long-tailed signal power leakage over an entire OFDM symbol duration, which can be an artifact associated with zero-padding the Fourier transform324of the received reference signal110.

The mobile telecommunication system100can include a total power calculation module432. The total power calculation module432can be coupled to the symbol isolation module404to receive the inverse Fourier transform326of the received reference signal110. The total power calculation module432is for calculating the total power124ofFIG. 1of the received reference signal110. The total power calculation module432can calculate the total power124of the received reference signal110from the inverse Fourier transform326of the received reference signal110. The total power124can be described as a weighted sum of the received signal power120and the total noise variance122. For example, the total power calculation module432can calculate the total power124with Equation 8:

Here, Pkrepresents the total power124. Nfftrepresents the total number of samples used to generate the Fourier transform324by the symbol isolation module404. rk[n] represents the sample power for each sample in time domain of the inverse Fourier transform326.

The mobile telecommunication system100can include a noise ratio module434. The noise ratio module434can be coupled to the noise variance module414to receive the noise variance estimate318. The noise ratio module434can be coupled to the total power calculation module432to receive the total power124.

The noise ratio module434is for determining the signal to noise ratio118from the noise variance estimate318. The noise ratio module434can calculate the signal to noise ratio118from the noise variance estimate318received from the noise variance module414and the total power124received from the total power calculation module432. The noise ratio module434can calculate the signal to noise ratio118from the noise variance estimate318for adjusting the receiver device104.

For example, the noise ratio module434can determine the signal to noise ratio118according to Equation 9:

Here, Pkrepresents the total power124. Nfftrepresents the total number of samples used to generate the Fourier transform324by the symbol isolation module404. {circumflex over (σ)}k2represents the total noise variance122divided by Nfft. For example, Nfftmultiplied by {circumflex over (σ)}k2would yield the total noise variance122. {circumflex over (γ)}krepresents the signal to noise ratio118.

The physical transformation of adjusting the receiver device104based on estimation of the signal to noise ratio118results in activations of displays, signal decoding hardware, or audio components in the receiver device104in the physical world. Further, as a result of the adjustment based on the signal to noise ratio118, the mobile telecommunication system100will physically change the operation of its symbol decoding module, radio link management module, and the downlink quality reporting module. Based on the change of symbol decoding, radio link management, and downlink reporting, the voice and data quality heard and displayed on the receiver device104is changed. Thus, the quality and delay of the receiver device104, such as a mobile device output, can change and improve based on those adjustments due to accurate estimation of the signal to noise ratio118by the mobile telecommunication system100.

The first software216ofFIG. 2of the receiver device104can include the modules of the mobile telecommunication system100. For example, the first software216can include the radio frequency module402, the symbol isolation module404, the sample shift module412, the noise variance module414, the leakage estimation module424, and the noise ratio module434.

The first control unit206ofFIG. 2can execute the first software216for the radio frequency module402to process received reference signal110at the receiver device104. The first control unit206can execute the first software216for the symbol isolation module404to remove the guard portion306from the received reference signal110. The first control unit206can execute the first software216for the sample shift module412to circular-shift the received reference signal110by the shift size312.

The first control unit206can execute the first software216for the leakage estimation module424for calculating the dispersion power426of the noise region304of the received reference signal110. The first control unit206can execute the first software216for the noise variance module414to determine the noise variance estimate318from both the noise region304and the signal region302of the received reference signal110or to determine the noise variance estimate318based on at least the dispersion power426. The first control unit206can execute the first software216for the noise ratio module434to calculate the signal to noise ratio118from the noise variance estimate318for adjusting the receiver device104.

The second software232ofFIG. 2of the transmitter device106ofFIG. 1can include the modules of the mobile telecommunication system100. For example, the second software232can include the radio frequency module402, the symbol isolation module404, the sample shift module412, the noise variance module414, the leakage estimation module424, and the noise ratio module434.

The second control unit224ofFIG. 2can execute the second software232for the radio frequency module402to process the received reference signal110at the receiver device104. The second control unit224can execute the second software232for the symbol isolation module404to remove the guard portion306from the received reference signal110. The second control unit224can execute the second software232for the sample shift module412to circular-shift the received reference signal110by the shift size312.

The second control unit224can execute the second software232for the leakage estimation module424for calculating the dispersion power426of the noise region304of the received reference signal110. The second control unit224can execute the second software232for the noise variance module414to determine the noise variance estimate318from both the noise region304and the signal region302of the received reference signal110or to determine the noise variance estimate318based on at least the dispersion power426. The second control unit224can execute the second software232for the noise ratio module434to calculate the signal to noise ratio118from the noise variance estimate318for adjusting the receiver device104.

The mobile telecommunication system100can be partitioned between the first software216and the second software232. For example, the second software232can include the symbol isolation module404, the sample shift module412, the noise variance module414, and the noise ratio module434. The second control unit224can execute modules partitioned on the second software232as previously described.

The first software216can include the radio frequency module402. Based on the size of the first storage unit208, the first software216can include additional modules of the mobile telecommunication system100. The first control unit206can execute the modules partitioned on the first software216as previously described.

The second control unit224can operate the second communication unit226ofFIG. 2to send the leakage ratio428to the receiver device104. The first control unit206can operate the first communication unit210ofFIG. 2to do the same. The second communication unit226can send the leakage ratio428to the receiver device104through the communication channel108ofFIG. 1.

The mobile telecommunication system100describes the module functions or order as an example. The modules can be partitioned differently. For example, the symbol isolation module404and the sample shift module412can be combined. Each of the modules can operate individually and independently of the other modules. Furthermore, data generated in one module can be used by another module without being directly coupled to each other.

Moreover, the modules described above can be implemented in hardware and should be considered as hardware functional units in addition to those described inFIG. 2, embedded into the functional units described inFIG. 2, or a combination thereof. For the purposes of this application, the modules are hardware implementation when claimed in apparatus claims.

The radio frequency module402, the symbol isolation module404, the Fourier transform module406, the smooth module408, the inverse Fourier module410, the sample shift module412, the noise variance module414, the delay spread module416, the signal power estimation module422, the leakage estimation module424, the threshold calculation module421the total power calculation module432, and the noise ratio module434can be implement in as hardware (not shown) within the first control unit206, the second control unit224, or special hardware (not shown) in the receiver device104or the transmitter device106.

Referring now toFIG. 5, therein is shown an example of a flow chart of the operation of the noise variance module414. The noise variance module414can receive the inverse Fourier transform326ofFIG. 3from the sample shift module412ofFIG. 4after circular shifting the inverse Fourier transform326. In a decision block502, the noise variance module414can determine whether to apply an estimation of the delay spread estimate418ofFIG. 4received from the delay spread module416ofFIG. 4. When the delay spread module416is applied, the noise variance module414can adjust temporal size of the noise region304ofFIG. 3or the signal region302ofFIG. 3based on the delay spread estimate418in a block504. After the adjustment in the block504or when the delay spread module416is determined not to applied, the noise variance module414can estimate the noise variance estimate318ofFIG. 3in a block506.

Once the noise variance estimate318has been estimated, the noise variance module414can receive the noise threshold420ofFIG. 4from the threshold calculation module421ofFIG. 4in a block508. The noise variance module414can determine if any samples in the signal region302is less than the noise threshold420received from the threshold calculation module421in a block510. Instances of the noise sample322ofFIG. 3in the signal region302are pooled together with samples in the noise region304in a block512. The noise variance module414can estimate the noise variance estimate318once again in the block506with the combined samples from the block512. If there are no more samples in the signal region302that is less than the noise threshold420, the noise variance module414can output the noise variance estimate318for other modules of the mobile telecommunication system100to use. The block510and the block512can be implemented by locating instances of the noise sample322that is below the noise threshold420one by one, or all together at once.

Referring now toFIG. 6, therein is shown a further example of a flow chart of the operation of the noise variance module414. The noise variance module414can calculate the noise region variance316with the noise region304ofFIG. 3in a block602. The noise variance module414can receive the noise threshold420ofFIG. 4from the threshold calculation module421ofFIG. 4based on the noise region variance316in a block604.

The noise variance module414can receive the received signal power120ofFIG. 1from the signal power estimation module422ofFIG. 4in a block606. For example, the signal power estimation module422can estimate the received signal power120by calculating the signal power in the signal region302ofFIG. 3minus any of the noise sample322ofFIG. 3in the signal region302below the noise threshold420.

The noise variance module414can receive the dispersion power426ofFIG. 4calculated based on the received signal power120from the leakage estimation module424ofFIG. 4in a block608. The noise variance module414can locate multiple instances of the noise sample322in the signal region302based on the noise threshold420in a block610. The noise variance module414can estimate the noise variance estimate318based on the noise region304and the multiple instances of the noise sample322in a block612.

Based on the dispersion power426and the noise variance estimate318, the noise variance module414can update the noise variance estimate318or calculate a second variance615, in a block616. For example, the second variance615can be calculated based on Equation 7. When the absolute difference between the noise variance estimate318and the second variance615is less than an error tolerance617, the noise variance module414can set the noise variance estimate318equal to the second variance615and output the second variance615in a block618. When the absolute difference between the noise variance estimate318and the second variance615is not less than the error tolerance617, than the noise variance module414can execute the block602, and thus recursively calculates the noise variance estimate318.

Referring now toFIG. 7, therein is shown an example of a first mean performance chart702of the mobile telecommunication system100ofFIG. 1. In the first mean performance chart702, simulation results of a single-tap channel are presented. The first mean performance chart702illustrates the bias associated with each examples of the mobile telecommunication system100. The x-axis of the first mean performance chart702is an actual signal to ratio704. The y-axis of the first mean performance chart702is the signal to noise ratio118as estimated by the mobile telecommunication system100.

A line706illustrates the example of the mobile telecommunication system100as shown inFIG. 5. A line708illustrates an example of the mobile telecommunication system100where the total noise variance122ofFIG. 3is calculated with compensation of the dispersion power426ofFIG. 4and where the total noise variance122is calculated without samples from the signal region302. A line710illustrates the example of the mobile telecommunication system100as shown inFIG. 6.

A line712illustrates a fixed window estimation of the signal to noise ratio118where the signal to noise ratio118is calculated based on the noise sample322from only the noise region304. A line714illustrates a Genie Signal Compensation estimation of the signal to noise ratio118where the signal to noise ratio118ofFIG. 1is calculated based on the noise sample322from only the noise region304.

Referring now toFIG. 8, therein is shown an example of a first performance error chart802of the mobile telecommunication system100ofFIG. 1. In the first performance error chart802, simulation results of a single-tap channel are presented. The line706, the line708, the line710, the line712, and the line714are compared. The x-axis of the first performance error chart802illustrates the actual signal to noise ratio704. The y-axis of the first performance error chart802illustrates the mean square error performance of the mobile telecommunication system100as compared to the actual signal to noise ratio704.

Referring now toFIG. 9, therein is shown an example of a second mean performance chart902of the mobile telecommunication system100ofFIG. 1. In the second mean performance chart902, simulation results of a two-tap channel are presented. The line706, the line708, the line710, the line712, and the line714are again compared. The x-axis of the second mean performance chart902is the actual signal to ratio704. The y-axis of the second mean performance chart902is the signal to noise ratio118ofFIG. 1as estimated by the mobile telecommunication system100.

Referring now toFIG. 10, therein is shown an example of a second performance error chart1002of the mobile telecommunication system100ofFIG. 1. In the second performance error chart1002, simulation results of a two-tap channel are presented. The line706, the line708, the line710, the line712, and the line714are again compared. The x-axis of the second performance error chart1002is the actual signal to ratio704. The y-axis of the second performance error chart1002illustrates the mean square error performance of the mobile telecommunication system100as compared to the actual signal to noise ratio704.

Referring now toFIG. 11, therein is shown a flow chart of a method1100of operation of a mobile telecommunication system in a further embodiment of the present invention. The method1100includes: measuring a received reference signal in a block1102; removing a guard portion from the received reference signal in a block1104; determining a noise variance estimate from both a noise region of the received reference signal and a noise sample in a signal region of the received reference signal in a block1106; and calculating a signal to noise ratio from the noise variance estimate for adjusting the receiver device in a block1108.

Referring now toFIG. 12, therein is shown a flow chart of a method1200of operation of a mobile telecommunication system in a yet further embodiment of the present invention. The method1200includes: measuring a received reference signal in a block1202; removing a guard portion from the received reference signal in a block1204; calculating a dispersion power of a noise region of the received reference signal in a block1206; determining a noise variance estimate based on at least the dispersion power in a block1208; and calculating a signal to noise ratio from the noise variance estimate for adjusting a receiver device in a block1210.

The resulting method, process, apparatus, device, product, and/or system is straightforward, cost-effective, uncomplicated, highly versatile, accurate, sensitive, and effective, and can be implemented by adapting known components for ready, efficient, and economical manufacturing, application, and utilization. Another important aspect of the present invention is that it valuably supports and services the historical trend of reducing costs, simplifying systems, and increasing performance. These and other valuable aspects of the present invention consequently further the state of the technology to at least the next level.