JPH11331069A - Base band processor for digital cordless telephone set - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve quality of digital communication between a remote digital handset and a base unit without increasing noises and interferences in a given communication channel especially in an environment including interferences. SOLUTION: A transmitter base band processor 100 has a coder 300 with a 1st compression rate, a high compression rate coder 110 with a 2nd compression rate higher than the 1st compression rate, and an error correction coder 120 that provides error correction information to data passing through the high compression rate coder 110. A communication quality analysis module 140 selects a path of the coder 300 or a path of the high compression rate coder 110. A path is selected based on the characteristic of a received RF signal, a frame error rate, a received signal strength indicator signal, information included in the received RF signal or the characteristic of a communication channel between the base band processor 100 and the base unit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a digital cordless telephone, and more particularly to a digital cordless telephone which performs error correction and advanced data compression as required to improve the quality of communication between a remote digital handset and a base station. About.

[0002]

BACKGROUND OF THE INVENTION Remote telephones are well-known consumer devices that give home and office users the freedom to move about hundreds of feet (tens of meters) from a base unit. Initially, a cordless telephone remote handset communicated with a base unit using analog signals. In recent years, advances in cordless telephones have enabled digital communication between remote handsets and base units. The digital communication of cordless telephones has generally improved voice quality and improved the range slightly to improve noise rejection. However, as the distance between the remote handset and the base unit increases, communication between the remote handset and the base unit may degrade due to interference or other channel anomalies.

FIG. 3 shows a related structure of a conventional digital remote handset of a digital cordless telephone. In FIG. 3, the remote handset of the digital cordless telephone includes a transmitter baseband processor section 500 and a receiver baseband processor section 6.
A processor 550 (e.g., a digital signal processor (DSP), a microprocessor, or a microcontroller) that includes the H.00.

In the transmission direction, a microphone 590
Converts an analog signal into an analog-to-digital converter (A /
D) output to the 580 and the analog-digital converter 58
0 converts the microphone input signal to a digital microphone signal. The digital microphone signal is input to the transmitter baseband processor section 500 and is encoded into a compressed digital signal. The compressed digital signal is transmitted by a radio frequency (RF) transmitter 570 and an antenna to a mating base unit. FIG. 4 shows a transmitter baseband processor 500 having an encoder 300 in more detail.

Returning to FIG. 3, in the receiving direction, the antenna and the RF receiver 572 receive a digital signal from the base unit on the other side. The RF receiver 572 is
The digital signal is sent to a receiver baseband processor section 600 for decoding. The decoded digital signal is supplied to a digital-to-analog converter (D / A) 5
82 is input. Digital-to-analog converter 582
Converts a digital signal into an analog signal output by the speaker 592. FIG. 5 shows a receiver baseband processor 600 having a decoder 400 in detail.

The encoding and decoding schemes used by encoder 300 and decoder 400 are generally commercial (public network) telephone quality. For example, 8-bit linear pulse code modulation (PCM), μ-law, A-law, or adaptive differential pulse code modulation (ADPCM) is commonly used.

[0007] The base unit is a circuit corresponding to that contained in the remote digital handset, ie
Includes a corresponding transmitter baseband processor and receiver baseband processor. In the remote digital handset and / or base unit, the baseband processor portions of the transmitter and receiver can be included in the same processor (eg, the same DSP).

[0008] Although digital cordless telephones work well within the specified distance range, the environment in which digital cordless telephones operate is susceptible to significant interference from other sources and other channel anomalies, resulting in poor voice quality. May be. One technique commonly used to overcome interference in the communication channel between the remote handset and the base unit is to reserve or make available a plurality of communication channels, with each channel at a different frequency. is there. As the number of communication channels increases, the likelihood of finding at least one communication channel without significant interference for use during a call increases. Generally restricted by government regulations (eg, 9
02 to 928 MHz), as the channel bandwidth increases,
Generally, the possibility of receiving noise or interference also increases.

In general, the user of the remote digital handset selects one of the communication channels to use based on his own interpretation of the acoustic quality of the communication between the remote digital handset and the base unit. Therefore, the RF transmitter 57 shown in FIG.
Zero and RF receiver 572 generally have the ability to transmit over a communication channel selected from a plurality of communication channels. This ability is useful to avoid channels containing interference and other anomalies. However, the selection is generally made manually by the user based on empirical information, ie, the sound or performance of the selected communication channel.

[0010] Some cellular telephone systems (eg, GSM) use forward error correction to improve the quality of digital communications. However, such error correction techniques have been used to improve quality in many communication systems, but due to the high cost, high power requirements, and to provide commercial telephone quality, both voice and error correction information have been used. It is not used in cordless phones because transmission requires a large bandwidth.

[0011]

SUMMARY OF THE INVENTION Improving the quality of digital communication between a remote digital handset and a base unit without increasing noise and interference in a given communication channel, especially in environments containing interference. Is needed.

[0012]

According to the principles of the present invention,
The transmitter baseband processor portion has a first encoder having a first compression ratio. The transmitter baseband processor portion also includes a second encoder having a second compression ratio that is greater than the first compression ratio, and an error correction encoder that provides error correction information to data passing through the second encoder.

[0013] The receiver baseband processor section includes a first decoder having a first compression ratio (decompression ratio), a second decoder having a second compression ratio larger than the first compression ratio, and a second decoder. It has an error correction decoder for decoding error correction information included in passing data.

In accordance with the principles of the present invention, there is also provided a method for encoding data for transmission between a remote handset and a base unit of a digital cordless telephone. In this method, one of a plurality of encoding paths is selected to provide compressed data to an RF transmitter. Each encoding path includes an encoder having a different compression ratio. Data is transferred from the selected encoding path to RF
Sent to the transmitter. Correspondingly, in a receiving method for decoding data received between a remote handset and a base unit of a digital cordless telephone, one of a plurality of decoding paths is used to provide decompressed data to a digital-to-analog converter. Selected. In this method, each decoding path includes a decoder having a different compression ratio. Data is sent to the digital-to-analog converter from the selected decoding path.

[0015]

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a selective use of forward error correction (FEC) in cordless telephones and a high compression rate commercial telephone quality coding without increasing noise and interference. By providing reliable digital communication, the disadvantages of the prior art are overcome. This improves the coverage and sound quality of the digital cordless telephone. The present invention relates to digital cordless telephones used at any frequency in any country, but is particularly useful for digital cordless telephones operating in the 902-928 megahertz (MHz) band reserved for use in the United States. .

The frame structure and encoding method between the digital cordless telephone and the base unit is on-the-fly based on intelligent monitoring of certain characteristics of the currently used communication channel.
Can be changed selectively. Digital error correction is selectively performed on the channel between the remote digital handset and the base unit when the channel is degraded by factors such as interference. In this way, a balance is maintained between the coding scheme with the lowest compression ratio and the reliability of the communication channel, depending on the degradation experienced by the communication channel.

FIG. 1 shows a transmitter baseband processor portion 100 used in a digital cordless telephone according to the present invention. Elements not shown in FIG. 1 are similar to those in the related art (for example, the one shown in FIG. 4).

In FIG. 1, the transmitter baseband processor portion 100 includes a normal coding path represented by an encoder 300 and a high compression rate represented by a high compression rate encoder 110 and a forward error correction encoder 120. And at least one alternative encoding path having a forward error correction encoder. One of the outputs of the two encoding paths is selected by a multiplexer (MUX) 130 and output to a conventional RF transmitter.

The encoder 300 is a commercial telephone quality voice (eg, 32 kilobits per second (32 Kb / s) ADPCM).
It is widely accepted as a commercial telephone quality standard for telephone products such as digital cordless telephones. )
Is used. The high compression rate encoder 110 uses an encoding scheme with a higher compression rate than the encoder 300. The same or a completely different speech coding scheme can be used in the high compression rate encoder 110 and the (low compression rate) encoder 300 to maintain the same bandwidth. For example, the high-compression-rate encoder 110 is 16 Kb / s
ADPCM or 8 Kb / s CELP can be implemented.

The high-compression-rate encoder 110 has a capacity of 16 Kb.
It is also possible to use a low-computation / low-delay CELP coding scheme of / s. The difference between the coding rate of the high compression rate encoder 110 and the coding rate of the encoding at the encoder 300 enables commercial telephone quality speech in any case.
However, a high compression rate encoding path allows for increased data processing without having to increase the original bandwidth. Increasing the bandwidth of a channel will generally reduce the number of achievable channels and increase both the amount of noise and interference introduced into the channel and the amount of power consumed by the device. In contrast, according to the principles of the present invention, a channel supports a significant amount of forward error correction (or even redundant transmission of a transmitted data signal) without increasing the bandwidth of the channel. be able to.

The encoding scheme used by both the (default) encoder 300 and the high compression encoder 110 is well known. However, the present invention uses at least two coding paths, each using a coding scheme having a different data output rate, which may result in lower audio quality but a fraction of the original bandwidth. Are used for forward error correction. Ideally, speech quality would generally be sacrificed as the compression ratio increases beyond a certain point, but the high reliability of the digital communication provided by the forward error correction encoder 120 in the high compression rate coding path would increase the reliability. Outweigh the quality loss due to compression ratio.

The data stream output to RF transmitter 570 is selected by MUX 130. MUX130
Is controlled by the communication quality analysis module 140. The communication quality analysis module 140 analyzes the characteristics of the communication channel in use and selects the most efficient coding path that provides sufficiently adequate communication.

It is possible to monitor or measure various characteristics of the communication channel between the digital remote handset and the base unit, so that the communication quality analysis module 140 allows the transmitter (and the receiver) to
A selection is made from among the possible coding paths in the baseband processor part. For example, a receive strength signal indicator (RSSI)
Parameters such as r)) and the frame error rate (FER) can be monitored to determine if error correction is beneficial.

In particular, weak signal strength (ie, low RS
If SI) is indicated with a high frame error rate, switching to a coding path that includes a forward error correction encoder 120 and a high compression rate encoder 110 is recommended. That is, R
If the SSI signal falls below a certain set threshold, or if the FER exceeds a certain set threshold, the communication quality analysis module 140 switches to an encoding path including forward error correction, It is desirable to improve the reliability of digital communication between the handset and the base unit.

Preferably, both RSSI and FER are used to determine a switch to a coding path that includes forward error correction (FEC). For example, if FER is above the set threshold but RSSI is not below the set threshold, it may be preferable to simply change the channel and not necessarily switch to an encoding path that includes forward error correction. This switching is preferably performed using both RSSI and FER information. It is possible to make this determination based on only one of RSSI or FER, but in this case, the FE is higher than using only RSSI.
It is preferable to use R. For example, even when the RSSI is low, if there is little or no error indicated by the FER, it is considered that there is no need to switch to an encoding path including forward error correction.

To perform the coding path change, communication quality analysis module 140 activates enable lines 104 and 106 to high compression rate encoder 110 and forward error correction encoder 120, respectively, and MUX.
130 is selected to output the signal b. If, for example, the RSSI signal falls below the set threshold and F
If the ER exceeds the set threshold, the communication quality analysis module 140 activates the enable line 102 and controls the MUX 130 appropriately to select the first encoding path a, thereby setting the default. That is, the low compression rate encoder 300 is selected.

In order to save power, especially with respect to a remote digital handset, the default mode of a digital cordless telephone can be an encoding path that includes the encoder 300. To select this encoding path, the communication quality analysis module 140 deactivates the enable line 106 to the forward error correction encoder 120 and the enable line 104 to the high compression rate encoder 110. Especially for remote digital handsets,
To maximize efficiency, it is preferable (but not required) to disable unused coding paths to reduce power requirements and extend the operating life of the remote digital handset battery. Therefore, as long as the interference of the selected or assigned communication channel is sufficiently low, the high compression rate coding path (ie, high compression rate encoder 110 and forward error correction encoder 120) is disabled to reduce the power demand. Can be minimized.

Either the remote digital handset or the base unit can make an initial determination that it is beneficial to include forward error correction;
In that case, switching to the encoding path including the forward error correction encoder 120 and the high compression rate encoder 110 is subsequently performed.

After switching to a coding path that includes forward error correction, this coding path can be used for the rest of the current call. Thereafter, for the next call, the digital cordless telephone can automatically return to the default state using the low compression rate encoder 300 until there is a new determination that forward error correction is again recommended. is there. Alternatively, the last coded path may be retained for future calls until the monitored channel characteristics indicate that a change is recommended. When either the handset or the base unit decides to change the coding path, a control message is sent to the other party and a switch to a new coding path (including, for example, the operation of the forward error correction encoder 110) is made. Done.

[0030] In addition, a high compression rate encoder having a different compression rate and a forward error correction scheme having a corresponding strength are provided.
It is also possible to make a multi-branch selection between several coding paths. In this case, it is possible to select a high bit rate high compression rate encoder using a stronger error correction code according to the conditions of the communication channel. But,
Empirically, for a given coding scheme, the higher the audio compression ratio, the lower the audio quality generally. Therefore,
For a given bandwidth, there is a trade-off as to the degree of speech compression that can be performed by the high compression encoder 110 to obtain the coding gain. That is, for a given bandwidth, as the quality of the communication channel between the remote digital handset and the base unit degrades, the compression rate of the data encoding is increased,
A larger portion of the bandwidth can be provided to select a stronger forward error correction encoder 120.

A certain degree of hysteresis is implemented in the communication quality analysis module 140 to prevent rapid switching between the encoding paths when the characteristics of the communication channel are floating near a set threshold. It is possible to That is, in addition to monitoring and comparing the characteristics of the communication channel to a particular value, it is possible to implement hysteresis by requiring that the monitored characteristic exceed a predetermined threshold for a predetermined time. It is possible. For example, if a hysteresis period is set, and after this period the error correction syndrome bits or cyclic redundancy check (CRC) checksum in the forward error correction encoder 120 indicates that error correction is no longer needed, the digital The processor, either the remote handset or the base unit, requests to return to using the coding path without forward error correction (ie, the path including the low compression rate encoder 300). Before it is possible to switch between encoding paths, it is possible to request an acknowledgment signal from the other party. Alternatively, hysteresis can be implemented by setting two predetermined thresholds.

Further, the communication quality analysis module 140
It is also possible to control the multiplexing and other enable signals used in the receiver baseband processor portion 200 of FIG.

FIG. 2 illustrates a receiver baseband processor 200 in accordance with the principles of the present invention. The receiver baseband processor portion 200 of FIG. 2 is complementary to the transmitter baseband processor portion 100 of FIG.

In FIG. 2, a signal is received from an RF receiver and input to a decoder 400. The decoder 400
1. Decode the encoding performed by encoder 300 of transmitter baseband processor portion 100 of FIG. The received RF signal is also input to a high compression rate decoding path represented by the high compression rate decoder 210 and the forward error correction decoder 220. High compression ratio decoder 210 and forward error correction decoder 220 of receiver baseband processor portion 200
Are complementary to the high compression rate encoder 110 and the forward error correction encoder 120 of FIG. 1, respectively.

In the default mode, receiver baseband processor portion 200 decodes the received RF signal at decoder 400 and the decoded signal is
/ A converter. However, the receiver baseband processor can enter a high compression mode as needed to improve the quality of the communication channel between the remote digital handset and the base unit. In this mode, the received RF signal is encoded at a higher compression ratio than the decoder 400 supports, and the forward error correction encoder performs forward error correction included in the received RF signal. Decrypt. Of course, the high compression mode presupposes that the transmitter baseband processor part 100 according to the invention, as shown for example in FIG. 1, is present in the base unit. Transmitter baseband processor portion 100 can be implemented on the same processor as receiver baseband processor portion 200 or on a different processor.

There are several ways to make the choice between the default low compression rate decoding path and the high compression rate decoding path including the high compression rate decoder 210 and the forward error correction decoder 220. . For example, in one embodiment, the communication quality analysis module 140 of the transmitter baseband processor portion 100 (FIG. 1) can also control the selection of the decoding path of the receiver baseband processor portion 200. In this embodiment, entering high compression mode in transmitter baseband processor portion 100 also enables high compression decoder 210 and forward error correction decoder 220 in receiver baseband processor portion 200. For high compression mode, MUX 230 is controlled to pass signal b; otherwise, MUX 230 passes default signal a. Transmitter baseband processor part 10
The operation of MUX 130 of zero can be combined with the corresponding operation of MUX 230 of receiver baseband processor portion 200.

In another embodiment of the present invention, communication quality analysis module 140 is capable of detecting a manual selection made by a digital cordless telephone user and selecting a forward error correction mode. Manual selection can be made by keypad input to a processor, including the baseband processor portion of the transmitter or receiver, on either the digital remote handset or the base unit.

[0038] To save power, the decoder 400 can be deactivated while the receiver baseband processor portion is in a high compression mode. Alternatively, when switching to a data path including forward error correction, it is also possible not to increase the bandwidth of the device or to limit the expansion.

Alternatively, in another embodiment of the present invention, the selection of a high compression mode in the receiver baseband processor portion 200 can be performed by the forward error correction detector module 240 of FIG. .
In this embodiment, the input RF signal is monitored to detect whether forward error correction information is included. If forward error correction information is present in the incoming RF signal, receiver baseband processor portion 200 automatically enters a high compression mode. Otherwise, the receiver baseband processor portion 200 enters a default decoding mode utilizing a decoding path that includes the decoder 400.

Although not excluding the ability to select one of a plurality of communication channels, the present invention minimizes or eliminates the need for a digital cordless telephone to access multiple communication channels and reduces interference. Avoid interference instead of dealing with However, the present invention can enhance the normal channel selection scheme to provide a more stable and effective digital cordless telephone system.

Implementing forward error correction as software in the DSP (which is already present on many conventional digital cordless telephones) minimizes the costly impact on the overall system for error correction functions. Is possible. In addition, the MIPS (million instructions per second) of the processor (such as a digital signal processor, microprocessor or microcontroller)
By manipulating the rate, it is possible to increase or decrease the power consumption of the device. That is, to save power in a battery powered device, the processor MI
It is possible to reduce the PS rate.

A cordless telephone that implements forward error correction according to the principles of the present invention has an increased range for a given amount of transmit power or transmission bandwidth. further,
The digital cordless telephone according to the invention has an increased immunity to interference in the same range as a comparable digital cordless telephone not according to the invention.

[0043]

As described above, according to the present invention, the quality of digital communication between a remote digital handset and a base unit can be reduced by noise and interference in a given communication channel, especially in an environment containing interference. It is possible to improve without increasing.

[Brief description of the drawings]

FIG. 1 is a diagram of a transmitter baseband processor portion of a digital cordless telephone according to the principles of the present invention.

FIG. 2 is a diagram of a receiver baseband processor portion of a digital cordless telephone according to the principles of the present invention.

FIG. 3 is a diagram of related functions of a conventional digital remote handset of a digital cordless telephone.

FIG. 4 is a diagram of the relevant functions of a conventional transmitter baseband processor in a conventional digital remote handset of the digital cordless telephone of FIG. 3;

FIG. 5 is a diagram of related functions of a conventional receiver baseband processor in a conventional digital remote handset of the digital cordless telephone of FIG. 3;

[Explanation of symbols]

 REFERENCE SIGNS LIST 100 Transmitter baseband processor part 110 High compression rate encoder 120 Forward error correction encoder 130 Multiplexer (MUX) 140 Communication quality analysis module 200 Receiver baseband processor part 210 High compression rate decoder 220 Forward error correction decoder 230 MUX 240 forward error correction detector module 300 encoder 400 decoder 500 transmitter baseband processor part 550 processor 570 radio frequency (RF) transmitter 572 RF receiver 580 analog-to-digital converter (A / D) 582 digital-to-analog conversion (D / A) 590 Microphone 592 Speaker 600 Receiver baseband processor

──────────────────────────────────────────────────の Continuation of front page (51) Int.Cl. ⁶ Identification symbol FI H04B 14/04 H04B 14/04 D H04M 1/72 H04M 1/72 Z (71) Applicant 596077259 600 Mountain Avenue, Murray Hill, New Jersey 07974-0636U. S. A. (72) Inventor Carl Earl. Stevenson United States, 18062 Pennsylvania, Macungi, West Chestnut Street 270

Claims (35)

[Claims] A first encoder having a first compression ratio; a second encoder having a second compression ratio greater than the first compression ratio; and providing error correction information to data passing through the second encoder. A transmitter baseband processor. 2. The transmitter baseband processor according to claim 1, further comprising a communication quality analysis module for selecting between the first encoder and the second encoder. 3. The communication quality analysis module according to claim 1, wherein
The transmitter baseband processor according to claim 2, wherein the selection is made based on characteristics of the F signal. 4. The transmitter baseband processor according to claim 2, wherein said communication quality analysis module makes a selection based on a frame error rate. 5. The transmitter baseband processor according to claim 4, wherein said communication quality analysis module further makes a selection based on a received signal strength indicator signal. 6. The communication quality analysis module according to claim 1, wherein
The transmitter baseband processor according to claim 2, wherein the selection is made based on information contained in the F signal. 7. The transmitter baseband processor of claim 2, wherein the communication quality analysis module makes a selection based on characteristics of a communication channel between the transmitter baseband processor and a base unit. . 8. The transmitter baseband processor of claim 1, wherein the transmitter baseband processor is configured to receive a user input indicating a selection between the first encoder and the second encoder. 9. A first decoder having a first expansion rate, a second decoder having a second expansion rate larger than the first expansion rate, and error correction information included in data passing through the second decoder. And an error correction decoder for decoding the baseband processor. 10. The receiver baseband processor according to claim 9, further comprising an error correction detector for selecting between the first decoder and the second decoder. 11. The apparatus according to claim 1, wherein the error correction detector makes a selection based on the content of a received RF signal.
0 Receiver baseband processor. 12. The receiver baseband processor according to claim 10, wherein the error correction detector makes a selection based on information included in a received RF signal. 13. The information included in the received RF signal,
13. The presence or absence of forward error correction.
A receiver baseband processor according to claim 1. 14. The receiver baseband processor of claim 9, wherein the receiver baseband processor is configured to receive user input indicating a selection between the first decoder and the second decoder. 15. The receiver baseband processor of claim 10, wherein said error correction detector makes a selection based on both a received signal strength indicator and a frame error rate. 16. A baseband processor for a digital cordless telephone having a transmitter baseband processor portion and a receiver baseband processor portion, the transmitter baseband processor portion comprising: a first encoder having a first compression ratio; A second encoder having a second compression ratio greater than the first compression ratio, and an error correction encoder for providing error correction information to data passing through the second encoder; the receiver baseband processor The part includes: a first decoder having a first expansion rate; a second decoder having a second expansion rate larger than the first expansion rate; and decoding error correction information included in data passing through the second decoder. A baseband processor, comprising: 17. A method for encoding data for transmission between a remote handset and a base unit of a digital cordless telephone, the encoder having different compression ratios for providing compressed data to an RF transmitter. Selecting one of a plurality of encoding paths including: transmitting data from the selected encoding path to an RF transmitter. 18. The method of claim 17, further comprising disabling a non-selected one of the plurality of coding paths. 19. The method of claim 17, further comprising reducing a MIPS rate of a selected coding path to save power. 20. The method of claim 17, further comprising the step of including forward error correction information in data passing through at least one of the plurality of encoding paths. 21. A method of decoding data received between a remote handset and a base unit of a digital cordless telephone, the decoder having different decompression rates for supplying decompressed data to a digital-to-analog converter. Selecting one of a plurality of decoding paths including: and sending data from the selected decoding path to a digital-to-analog converter. 22. The method of claim 21, further comprising disabling a non-selected one of the plurality of decoding paths. 23. The method of claim 21, further comprising reducing a MIPS rate of a selected decoding path to save power. 24. The method according to claim 2, further comprising the step of decoding forward error correction information included in data passing through at least one of the plurality of decoding paths.
2. The method according to 1. 25. A first encoding unit having a first compression ratio, a second encoding unit having a second compression ratio larger than the first compression ratio, and an error correction for data passing through the second encoding unit. Error correction coding means for providing information. 26. The transmitter baseband according to claim 25, further comprising MIPS adjustment means for adjusting a MIPS rate of at least one of the first encoding means and the second encoding means. Processor. 27. A first decoding means having a first expansion rate, a second decoding means having a second expansion rate larger than the first expansion rate, and error correction information included in data passing through the second decoding means. And an error correction detecting means for detecting the presence of the baseband processor. 28. The receiver baseband processor according to claim 27, further comprising MIPS adjusting means for adjusting a MIPS rate of at least one of said first decoding means and said second decoding means. 29. A first encoder, a second encoder including forward error correction, and a communication quality analysis module for selecting between the first encoder and the second encoder based on the quality of a received signal. And a transmitter baseband processor for the digital cordless telephone. 30. The transmitter baseband processor of claim 29, wherein the quality of the received signal is based on a received signal strength indicator. 31. The transmitter baseband processor of claim 30, wherein the quality of the received signal is further based on a frame error rate. 32. The transmitter baseband processor of claim 29, wherein the quality of the received signal is based on a frame error rate. 33. A method of encoding data for transmission between a remote handset and a base unit of a digital cordless telephone, the method including an encoder for supplying compressed data to an RF transmitter. Selecting one of a plurality of encoding paths; and sending data from the selected encoding path to an RF transmitter, wherein at least one of the plurality of encoding paths is A data encoding method comprising forward error correction. 34. The method of claim 33, wherein said selecting is based on at least one of a received signal strength indicator and a frame error rate. 35. The method of claim 33, wherein said selecting is based on both a received signal strength indicator and a frame error rate.